A Multistage, Multiarmed, Double-Blind Placebo-Controlled Human Transdermal Vitamin D Supplement Study (TransVitD)

A Multistage, Multiarmed, Double-Blind Placebo-Controlled Human Transdermal Vitamin D Supplement Study (TransVitD) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article A Multistage, Multiarmed, Double-Blind Placebo-Controlled Human Transdermal Vitamin D Supplement Study (TransVitD) Thomas Hibbard, Paolo Andriollo, Chui Hua Lim, Qing Guo, Karl Lawrence, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3499598/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Life-style changes have meant that it is problematic to maintain adequate vitamin D concentrations in many people across the globe. Given that it's mainly generated by UV-catalysed production in the skin where it uses vitamin D binding protein to facilitate systemic absorption., it is questionable if oral administration of this vitamin is the optimal means to replace it. However, supplementing this oil-soluble vitamin is problematic as it gets stuck in the stratum corneum after topical application. This clinical study will test the ability of a new vitamin D ester, vitamin D phosphate, which is more water-soluble compared to vitamin D, can be administered via a transdermal patch to improve vitamin D status. Method: This is a two-part study comprising a dose-escalation with the vitamin D phosphate transdermal patch followed by a randomised, double-blind, placebo-controlled, multi-armed, multi-stage clinical trial. It is a single-centred, 12-week study that will enrol a maximum of 100 participants. The blinded, randomised trial will test different dose frequencies for four weeks compared to a placebo, then after an interim analysis, the best dosing frequency will be assessed against a placebo. The dose escalation study will monitor safety and tolerability using serum calcium levels. The primary outcome for the multi-stage clinical study will be the concentration of 25(OH)D3 in the serum (ng/mL) at weeks 4 and 8 compared to baseline. The secondary outcome measures include serum vitamin D binding protein levels, skin interstitial fluid biomarker concentrations, and nail appearance after 4 and 8 weeks compared to baseline. Discussion: This study will determine if a vitamin D phosphate transdermal patch can improve vitamin D status. In addition, it could provide a better understanding of how vitamin D is absorbed after application directly to the skin by measuring the serum vitamin D binding protein and skin biomarker responses to transdermal supplementation. Trial Registration: Clinical Trials .gov NCT06098846, registered on 23 rd October 2023 Vitamin D phosphate Vitamin D Vitamin D binding protein transdermal clinical trial interstitial fluid 25(OH)D3 Figures Figure 1 Figure 2 Introduction Background and rationale Vitamin D deficiency is common worldwide; predicating and exacerbating a wide variety of health conditions ( 1 , 2 ). Vitamin D supplementation is recommended to prevent vitamin D deficiency from having an impact on health ( 3 ). For example, the UK government advises individuals to take daily vitamin D supplements (400 IU, 10 µg) to ensure adequate vitamin D blood levels and protect musculoskeletal health ( 4 ). Despite the state-level advice, the health benefits of vitamin D supplementation, especially the non-skeletal benefits are not currently strongly supported robust clinical trial data, therefore there remains a need to better understand the contribution of vitamin to health ( 2 ). Vitamin D is available in two forms, vitamin D 2 (ergocalciferol) and vitamin D 3 (cholecalciferol), which differ from each other via slight differences in chemical structure. Both forms of vitamin D are active and are extensively metabolised in the liver to form 25(OH)VD 2 and 25(OH)VD 3 as well as subsequent active metabolites, 1α,25(OH) 2 D 3 and 1α,25(OH) 2 D 2 ( 5 ). Vitamin D 3 is formed endogenously by UV-B light-mediated cutaneous synthesis whereas vitamin D 2 is obtained in very small amounts through dietary sources ( 6 ). Individuals with low vitamin D levels, due to insufficient dietary intake or limited exposure to direct sunlight, often a result of geographical location or lifestyle, can improve vitamin D status through supplementation ( 7 ). Vitamin D 3 is currently the most effective means of supplementing vitamin D levels and, as such, is provided in most supplement formulations on the market ( 8 , 9 ). Although their use is widespread, these oral formulations are subject to limited oral bioavailability, which is influenced by factors such as genetics and the presence of food in the gastrointestinal tract during supplement ingestion ( 10 ). Even under controlled conditions, such as those in nutritional clinical trials, the 25(OH)D3 plasma levels can vary by > 50% in individual participants after each dose ( 11 ). In this work, it was hypothesised that delivering vitamin D through the skin may overcome the disadvantages of oral administration and lead to an efficacious and tolerable means of supplementation. This is in part due to the presence of vitamin D binding protein (VDBP) in the skin which increases the potency and duration of action of skin-generated vitamin D ( 12 ). However, as vitamin D does not readily pass through the lipidic barrier in the skin, the stratum corneum, it is problematic to deliver adequate quantities of Vitamin D3 to act as a supplement ( 13 ). Prior research at King’s College London has developed a functionalised form of vitamin D (vitamin D phosphate, VDP, WO2022084669A1), which does effectively passes through the stratum corneum of skin, where it is metabolised back into vitamin D that can then bind to the VDBP and be absorbed into the blood ( 14 , 15 ). This compound has been developed into a drug-in-adhesive transdermal patch formulation which delivers vitamin D in sufficient quantities across the skin to theoretically be used as a supplement and this new approach will be the intervention tested in this trial. Hypothesis Vitamin D phosphate administered as a transdermal patch will enhance vitamin D status in humans. Objectives The objectives of the study are: To investigate the extent of systemic exposure of vitamin D following administration of a vitamin D phosphate transdermal patch, in healthy individuals using 25(OH)D3 as a biomarker. To determine how transdermal administration of vitamin D phosphate influences vitamin D binding protein (VDBP) levels in the serum. To investigate how interstitial skin biomarkers in the local tissue are changed after the transdermal administration of vitamin D phosphate. To understand if the visual appearance of the human nail plate changes as a consequence of transdermal vitamin D supplementation. Trial Design This study is a two-part study that comprises a dose-finding and a randomised, placebo-controlled, double-blind clinical trial using an adaptive design (Figs. 1 and 2). Randomisation will be performed using block randomisation with an equal allocation ratio. This study aims to evaluate the efficacy of a VDP transdermal supplement patch compared to a placebo. Methods: Participants, Interventions and Outcomes Study setting The study will take place in the Institute of Pharmaceutical Science, King’s College London, London, UK. Planned recruitment will be primarily from participants from London and the surrounding areas thus the trial participants will be drawn from a multicultural and multiethnic setting. Eligibility criteria Interested participants will be provided with a participant information sheet and the study will be explained by a member of the trial staff. Initial screening and subsequent recruitment will be based on participant suitability as per the inclusion and exclusion criteria ( Table 1 ) and a successful patch adhesive sensitivity test using a placebo patch. Table 1 Participant inclusion and exclusion criteria Inclusion Criteria 1. Healthy adults between 18 and 65 years of age. 2. Suspected low vitamin D levels (defined as moderate or high risk using the Deschasaux questionnaire (( 16 ))). 3. Written informed consent for study participation. 4. Willingness to comply with the study requirements. 5. Competent use of English language. Exclusion Criteria 1. Patients unable to give informed consent. 2. The use of vitamin D supplements 4 weeks prior to the commencement of the study (and unwilling to washout). 3. Pregnancy. 4. Those with parathyroid, thyroid, or calcium disorders, sarcoidosis, taking calcium channel blocking medication, Type I diabetes, and concurrent active malignancies. 5. Those who have been diagnosed with vitamin D deficiency by a GP in the last 3 months using a blood test. 6. Those who have been diagnosed with vitamin D deficiency by a GP in the last 6 months using a blood test and have not taken any vitamin D supplements. Screening will occur at least 24 before the baseline visit to allow time for the participant to understand the information provided. Study staff will request the participants sign a statement of informed consent and they will be invited to participate in three study visits. A maximum of 100 participants will be enrolled in the trial. A set of patch application instructions will be provided to the participants to aid the daily application of the patches and to re-enforce the instructions after the participants have left the clinical site. Explanation for the Choice of Comparators Although other patches containing vitamin D are available on the market, no clinical studies have demonstrated their efficacy in improving vitamin D status, presumably due to the limited transdermal bioavailability of vitamin D ( 15 , 16 ). As a consequence, we will compare the innovative transdermal vitamin D supplementation approach using vitamin D phosphate with a placebo patch. Intervention The intervention will be the application of daily transdermal patches. They will be active in adhesive patches manufactured at King’s College London comprising food-grade vitamin D phosphate and cosmetic/food-grade excipients. The patches underwent ISO standard toxicology testing for medical devices before clinical use (cytotoxicity, irritation, and sensitization). Patches will be packaged in aluminium sealable pouches (primary packaging) and then a cardboard box (secondary packaging). Criteria for discontinuing or modifying allocated intervention A mechanism will be in place to report any adverse events to the study team through a dedicated study email address. If any of the adverse events are classified as serious the study team will advise the participant to exit the study and be directed to receive appropriate medical attention. Participants can exit the study at any time. Participant Timeline Baseline Assessment Volunteers will provide demographic data, relevant medical history, allergy status, Fitzpatrick skin type, and lifestyle data including diet specifically to measure vitamin D intake, and level of regular sun exposure. We will use the participant location to calculate UV exposure during the trials. Baseline measurements will be taken including, trans-epidermal water loss (TEWL), a blood sample to measure plasma vitamin D (25(OH)VD 3 and calcium levels, skin interstitial fluid (ISF) sample, and fingernail photographs. Part 1 After receiving informed consent and completing the baseline assessment, two cohorts of 8 participants will take part in a non-blinded dosing escalation pilot study. These cohorts will be supplemented via a transdermal patch application, with one cohort completing the 4-week study, the data being analysed, and the choice of second dose made, before dosing the second cohort. The primary outcome measure will be safety and tolerability assessed by report of local or systemic side effects, calcium and 25(OH)VD 3 levels at 2 weeks and 4 weeks of dosing. If analysis at either time point show blood plasma levels with a serum calcium measure of more than 12 mg/dL or a 25(OH)VD 3 level > 150 nmol/L this will indicate a risk of toxicity. In this eventuality, the dosing will be terminated, and a serious adverse event would be recorded. If there are serious adverse events in 2 or more participants, the dose will be classified as not safe . The secondary outcome will be efficacy by further analysis of the 25(OH)VD 3 blood level. A blood concentration change of 25% of participants will indicate that the dose is ineffective after 4 weeks of treatment. The primary and secondary outcome measures for the “lowest dose” cohort will direct the dosing of the second cohort in Part 1. Participants partaking in Part 1 of the study will not be eligible for inclusion in Part 2. Part 2 This part of the trial will be multi-staged. In the first stage, four cohorts of 14 participants will be enrolled in a double-blinded randomised placebo-controlled study. The randomisation sequence will be designed by a statistician independent to the trial team. Participants will be assigned according to the randomisation schedule by a local researcher independent of the study team into one of three treatment arms or one placebo arm. The treatment arms will measure different dosing frequencies of the same strength vitamin D patch. The participants in Part 2 will have their parathyroid hormone levels monitored and be subject to genetic analysis to help understand any changes in vitamin D binding protein, these are additional tests compared to Part 1. The first stage of the study will last 4 weeks, after which there will be an interim data analysis to select the treatment arm for the second stage. In the second stage, two cohorts of 14 participants will be blinded and randomised into the final two study arms consisting of one treatment arm and one placebo arm. The second stage will run for 8 weeks with measurements at week 4 and a final measurement at week 8. The aim of Part 2 is to establish whether vitamin D supplementation via the skin increases the concentration of vitamin D in the blood and which dosing interval is best suited to achieve this. Strategies to improve adherence to interventions To aid participant adherence to the trial regimen, a specific set of written instructions regarding the patch application will be used to reinforce the verbal directions provided by the study team. Dosing reminders will be sent to participants to their mobile phones each day. At each visit, the participants will be asked to bring any unused transdermal batches back for inspection by the study team, who will count any unused patches to determine % compliance over the study duration. Relevant concomitant care permitted or prohibited during the trial The trial will monitor the participant's UV exposure, vitamin D intake, medical history and medication intake during the trial. However, the trial will not change diet, sun exposure or medical treatment. Ancillary and Post-Trial Care Participants will be instructed to contact the study research team via the designated study email address if symptoms relating to the application of study patches are experienced following the completion of the trial. In such an event participants will be assessed and referred for further medical attention if required. Outcomes Primary Outcomes Concentration of 25(OH)D 3 in the serum (ng/mL) compared to baseline. Secondary Outcome The concentration of VDBP levels in the serum (µg/mL) compared to baseline. The concentration of chemical biomarker levels in the skin interstitial fluid (ng/mL) compared to baseline. Quantification of image feature change in nail photographs (unit pixels). Sample Size Calculation For Part 1 the sample size is based on clinical considerations. With 6 patients per cohort there is greater than 80% probability of detecting an adverse event with a population frequency of 25% using the simple probabilistic calculations below: Table 2 Part 1 probability of detecting adverse event calculations. \(\varvec{p}\) \(\varvec{n}\) \(\varvec{n}\left(1-\varvec{p}\right)\) \(\varvec{n}\varvec{p}\) 0.01 6 0.94148 0.05852 0.2 6 0.262144 0.737856 0.25 6 0.177979 0.822021 Definitions Sample Size \(n\) Pr of observing an event \(p\) Pr not observing event in a patient \(1-p\) Pr not observing an event in n patients \(n\left(1-p\right)\) Pr of observing an event in n patients \(np\) Considering a 20% dropout rate, 8 patients is required for each cohort in Part 1 of the study. For Part 2 the sample size calculation is based on a 4-arm 2-stage design. The minimum clinically important change in 25-(OH)VD 3 from baseline to week 8 is 10 nmol/L based on previous studies. The typical value of 25-(OH)VD 3 in placebo arm was estimated at 37.7 nmol/L with standard deviation (SD) of 9.1 nmol/L. With 1000 simulation runs, considering 5% significance level 2-sided and Dunnet test for multiple comparisons to select the best treatment, 12 participants are need for stage 1 in each arm. Assuming a 15% dropout rate, 56 participants in total will be recruited in stage 1. For stage 2, 12 participants will be enrolled in each of the selected and placebo arms. Considering the same 15% dropout rate, 28 participants are required for stage 2. The overall sample size for Part 2 of the study is 84. The overall sample size for two parts of the study is 84 + 16 = 100. Recruitment Strategy Participants will be primarily recruited from King’s College London staff and students and members of the public from the local area who voluntarily respond to trial advertising. Participants expressing interest in the trial will receive a patient information leaflet and consent form and will be invited to screening and baseline assessments. All study participants will be offered financial compensation of £50 on completion of the study to reimburse the inconvenience of clinical visits. Despite this, participation in the trial is voluntary and participants may withdraw at any time for any reason. Assignment of interventions Allocation, Concealment, Implementation Part 2 of the trial will be randomised. A code generated by an independent statistician will ensure equal participant recruitment into each of the trail cohorts by a block randomisation process. Group allocation will be performed by an independent researcher using the randomisation code. The blinding will remain in place until completion of the trial and the final data analysis has been finished. In stage one of Part 2, a total of 56 participants will be randomised and allocated into 4 groups. Following the interim data analysis, 28 additional participants will be randomised and allocated into the two final groups for Part 2 stage two. Blinding Participants, researchers, and the study statistician will be blinded to the treatment allocation. Treatment and placebo patches will be visually identical and labelled by a pharmacist independent of the trial, who will package them in the same way and assign each box with a code according to the independent statistician's list of codes. The independent researcher responsible for participant allocations will check the codes against the statistician's randomisation list to ensure accuracy. Where the frequency of treatment patch application is assessed, daily patch application will still be used with a mixture of treatment and placebo patches to maintain participant and researcher blinding. Any interim analysis that needs to be completed will be performed by an independent statistician and data review committee so as not to break the blinding code. In the event of a major adverse event, the team will contact the independent researcher responsible for the group allocation and ask them to unblind the participant affected by the event to ensure they receive the appropriate medical attention. Data collection, Management, Analysis Data Collection Methods Screening Questionnaire Participants will be identified as having moderate or high risk of vitamin D deficiency via the validated Deschasaux questionnaire ( 16 ). Scores are assigned based on the patient age, sex, body type, Fitzpatrick skin type, location, and level of physical activity. Demographic, diet and exercise questionnaire The participants will be asked a series of questions to gather demographic information. This will generate data for potential covariates. The most important information will include participant BMI, sex, age, body fat, dietary vitamin D intake, UV exposure levels (monitored through location information), skin type, ethnicity, and exercise habits. Blood Sampling Venous blood (max. 3 x 10 mL) will be collected from a peripheral vein by a trained phlebotomist. Serum vitamin D levels. 25(OH)VD 3 and relevant vitamin D metabolite concentrations in blood serum will be determined using ELISA and/or gas/liquid mass spectrometry analysis. Plasma calcium concentration will be determined in triplicate based using colourmetric methods. Parathyroid hormone and vitamin D binding protein levels will also be determined using ELISA assays. Skin Interstitial Fluid (ISF) Extraction ISF samples (max. 3 x 150 µL) will be collected from the outer side of the forearm for the determination of vitamin D bind protein (VDBP) levels at the skin sites where the patches have been applied. ISF samples will be collected under hypobaric pressure (510 mBar) using an in-house designed extraction chamber and hand pump fitted with manometer. VDBP level will be determined using a commercial ELISA testing kit. Transepidermal Water Loss (TEWL) TEWL will be measured in triplicate at each study visit using a AquaFlux AF200 condensing chamber probe (Biox Systems Ltd., UK) as a means of measuring skin barrier dysfunction and skin irritation. Fingernail Imaging Images of one fingernail from each hand will be taken using a digital camera as a means of monitoring visual changes. Genetic variation profiling We will collect biological samples to generate profiles of genetic variation in participants to investigate the relationship between genetic variation and specific measured traits. Participants will be asked to use an Oragene saliva sample tube. If this fails for any reason a similar analysis will be performed on blood samples already collected for the other analytical measurement. DNA extraction from these samples will be performed using standard protocols appropriate to the source of the sample. Following DNA extraction, genotyping will be conducted using microarrays, a reliable and widely accepted technique for identifying genetic variants across the genome simultaneously. Once the genotypic data is obtained, association testing will be carried out. This process will evaluate the correlation between the genetic variants identified and the traits measured in the study, allowing us to ascertain potential genetic contributions to these traits. Data management All study participants will be allocated a unique study identification number so that researchers will not have access to subject-identifiable information. Study data, patient contact details, and patient medical information will be entered onto a secure password-protected research database (provided by: REDCap®). Copies of protocols, case report forms, physiological test results, participant correspondence, informed consent documents, and other files relevant to the study will be kept securely by the Principal Investigator for at least 15 years following the completion or discontinuation of the research study. All data recording and retention will comply with King’s College London policies for sensitive data. Confidentiality All study staff will endeavour to protect the privacy and consent rights of the participants and will adhere to the Data Protection act, 2018. Access to study information will be limited to study staff, investigators, and trial conduct auditors. Statistical methods for primary and secondary outcomes Descriptive statistics on participants’ demographics and baseline clinical characteristics will be provided using frequency and percentage or median and range in both parts of the study. The first part of the study focuses on safety endpoint. Frequency and percentage of occurrence of adverse events and calcium > 12 mg/dL or 25(OH)VD 3 > 150 nmol/L will be reported in the first cohort of 6. If there are serious adverse events in 2 or more of participants, the dose will not be safe. The secondary outcome is efficacy, the change in 25(OH)VD 3 . Participants with a 25(OH)VD 3 change less than 5 nmol/L will be reported as frequency percentage. If the 25(OH)VD 3 change in more than 75% of participants is observed, the dose will be considered ineffective after 4 weeks. The decision for second cohort dosing will be made according to these results. The safety and efficacy of second cohort will be reported similar to the first cohort. For the second part of the MAMS study, an interim analysis is planned at 4 weeks for the end of the first stage. The mean change in 25(OH)VD 3 in each treatment arm will be tested against the placebo arm using a z-test. Two treatment arms will be dropped and the treatment arm with the highest observed response as compared to placebo will be selected for testing at the second stage. As multiple doses are compared to the shared control, multiplicity adjustment will be considered in the first stage, and familywise error rate (FWER) will be controlled at 2.5%. Therefore, the probability of incorrectly rejecting the null hypothesis for at least one experimental arm is 0.025. If the z-value of the test is greater than 2.797 in stage 1, the treatment arm will be considered efficacious. At the final stage, the efficacy of treatment arm against placebo will be tested using a z-test. The error rate is 5% and the efficacy z-value for final stage is 1.977. For secondary outcomes such as VDBP levels in the blood and ISF, similar analysis will be performed. Descriptive statistics will be reported for the number of vitamin D patches used in each arm at weeks 2, 4, and 8. All statistical analysis will be conducted using RStudio. Data monitoring Data monitoring: formal committee and interim analysis A data monitoring committee consisting of a chair, clinician, and statistician who are independent to the researchers will manage the regulatory and supervisory running of the trial. The committee will ensure consent, data collection, and recording of results are accurate to promote the reliability of the trial. The monitoring committee will undertake the interim data analysis of Part 2 and make decisions on the dosing of different treatment arms. In addition, the committee have the power to terminate the trial in the event of participant safety incidents as detailed below. Adverse event reporting and harms Safety and tolerability of the vitamin D patch will be monitored throughout the study. Patients will be asked to report any adverse events or changes to their health status during the study visits and encouraged to contact the research team via the designated study email address outside of these times if required. Possible adverse events occurring due to this study are expected to be the same as those reported following the administration of vitamin D by other routes. According to Vitamin D “Summary of Product Characteristics” possible adverse events of vitamin D supplementation include: Metabolic: hypercalemia, hypercalciuria (uncommon, 0.1% − 1%) Dermatologic: pruritis, rash, urticaria (rare, < 0.1%) Gastrointestinal: nausea, vomiting (frequency not reported) Hypersensitivity: angioedema, laryngeal oedema (frequency not reported) This information will be included in the patient information leaflet to aid participant identification of adverse events. Adverse events will be recorded using the standardised MEDDRA ( https://www.meddra.org/how-to-use/basics/hierarchy ) protocol (an Excel sheet is provided by the study lead) to detail the time and date of the event, duration, symptoms, and severity. The MEDDRA classification guides the team as to how to assess the action required, from no medical attention being required, non-urgent medical attention is required, or urgent medical attention is required. All MDDRA Class 2 adverse drug reactions (ADRs) and above will be reported to the principal investigator of the study. The team will use the MDDRA classification to aid referral to medical services. In cases of doubt participants with ADRs will be referred for medical attention. Auditing The independent data monitoring committee will perform auditing and review of the study activity through the inbuilt auditing and monitoring feature in the research database. In particular, the committee will be responding to queries raised by the study facilitators and managing any discrepancies study records or data. Reports detailing the presentation of adverse events, participant drop out will be sent to the data monitoring committee via traceable means. Full access to electronic and written study records will be afforded to external auditors if required. Discussion TransVitD aims to assess the ability of a vitamin D phosphate transdermal patch to improve vitamin D status in healthy volunteers. It is anticipated that supplementation via the skin can use the transport machinery, i.e., the vitamin D binding protein, present in the tissue to facilitate effective absorption ( 11 ). The study adds to the limited amount of pilot clinical work that suggests that transdermal vitamin D could be a useful means to deliver this important vitamin ( 17 ). As far as we are aware, no other vitamin D phosphate based transdermal patch formulation has been tested in a double blinded, placebo-controlled human clinical trial. This study will, through pilot dose escalation, be followed by a double-blind, placebo-controlled supplementation trial, investigate the blood serum 25(OH)VD 3 levels after the application of a vitamin D phosphate transdermal patch. This is a standard means to determine the effectiveness of vitamin D dosing during an interventional trail. However, in addition the study will also measure both local and systemic VDBP concentrations. Recent work on vitamin D generation by UV-irradiation in VDBP knock out animals has shown that the VDBP is essential to carry vitamin D synthesised in the skin out of the tissue and into the systemic circulation ( 18 ). Therefore, it was hypothesised in this work that the VDBP could be important in the absorption and transport of the vitamin D administered into the skin using a transdermal patch. In the second part of the study, we added genetic analysis to search for associations between various biochemical processes that could improve or dimmish an individual’s response to vitamin D in order to try and understand the positive or negative impact the potential for the VDBP facilitating the absorption after penetration into the skin. The trial faces some challenges, such as anticipating the initial vitamin D status of the trial participants, monitoring the vitamin D intake from food and sunlight. However, we have put in place validated questionnaires and monitoring strategies to evaluate these. Other potential covariates such as ethnicity, sex, age, weight and % body fat of the participants will also be monitored to enable post-trial data processes to account for these factors. The long half-life and distribution of vitamin D in body fat complicates the blood sampling regimen. Therefore, we have scheduled a participant sampling window of two weeks to allow sufficient time for vitamin D, relevant metabolites, and vitamin D binding protein to reach steady state levels. Initial dosing was calculated considering a relative 15% transdermal bioavailability measured in rats, with the caveat that this could be reduced to 1.5% in humans given the reduction in skin permeability compared to rats. There is no literature to provide accurate allometric scaling from humans to animals for vitamin D absorption. As a consequence, in the trial care the main focus was to optimise the vitamin D transdermal dosing. The design allows up to five different opportunities to get an appropriate dose and dosing interval in humans. Relevant clinical data detailing the extent of transdermal delivery of vitamin D phosphate is required to confirm the extensive preclinical evidence which shows the efficacy of transdermal vitamin D supplementation. The results of this study may promote further investigation into transdermal delivery of current active pharmaceutical ingredients through appropriate chemical modification within nutraceutical and other medical categories. Declarations Ethics and Dissemination Research Ethics Approval This clinical trial has been approved by the King’s College, London Research Ethics Committee (KCL-REC) [Reference Number: HR/DP-22/23-34078, Study Title: TransVitD]. Any protocol amendments will be submitted to King’s College REC for approval. The trial will comply with good clinical practice guidelines over the reporting of adverse events (AEs), serious adverse events (SAE’s) and suspected serious adverse reactions (SUSAR’s) as well as providing the REC with progress reports and final study report. Protocol Amendments If amendments to this protocol are required, approval will be sought from the KCL-REC and updated protocol will be made available on request. This protocol version is 1.4, 19 th October. Consent / Assent for Publication All participants have agreed to the publication of these results. Declarations of Interests SAJ is the inventor of the vitamin D phosphate patent WO2022084669A1. MAA and SAJ have received funding to develop and test in pre-clinical studies the vitamin D patch from Vitamax Patch Wholesaler LLC. Access to Data The principal investigator SAJ has access to the full trial data and materials and they can be made available upon request Dissemination Policy It is intended that the results of this study will be reported and disseminated at international conferences and in peer-reviewed scientific journals. Following trial competition and the publication of results, data requests may be submitted to the researchers at the Institute of Pharmaceutical Science, King’s College London. In addition, we will send a summary of the study results to study participants at their request. Plans for collection, laboratory evaluation, and storage of biological specimens for genetic or molecular analysis in this trial/future use Samples will be taken by delegated researchers with the appropriate training in sample collection techniques. All samples will be labelled in such a way that the participant and date of collection can be identified beyond the unique study participant number, if required. All biological samples will be stored at -80°C in accordance with the human tissue act where appropriate. If samples are to be used in future studies outside of the scope of this trial, Research Ethics Committee approval will be sought. Author Details and Contributions Thomas Hibbard 1 , Paolo Andriolo 1 , Charlie Lim 1 , Qing Guo 1 , Karl Lawrence 1 , Bolaji Coker, Rayka Malek 2 , Abdel Douiri 2 , Mohamed A Alhnan 1 and Stuart Jones 1 * 1 Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, Franklin-Wilkins Building, King's College London, London, UK. 2 School of Population Health and Environmental Sciences, King’s College London, London, UK. TH: writing draft, editing; PA TH: writing draft, editing; CL: writing draft, editing; QG: writing draft, editing; KL: conceptualisation, BC: editing; AD: writing draft, editing, supervision; RM: writing draft, editing; MAA writing draft, editing, supervision; SAJ: Conceptualisation, writing draft, editing, supervision; Funding We acknowledge and thank Vitamax Patch Wholesaler LLC for supplying the grant required to finance this study. Vitamax Patch Wholesaler LLC is not involved in the design, data collection, analysis or interpretation of data in this study. Name and Contact Information for Trial Sponsor Keith Brennan, Director of Research, King’s College London, Guy's Campus, King's College London. LONDON, SE1 4UL. Telephone: 020 7848 6960 Email: [email protected] Trial Status This protocol version is 1.4, 19th October. Study recruitment started on 23 rd Oct 2023.Recruitment is expected to complete by the end of March 2024. Abbreviations ISF Interstitial Fluid KCL King’s College London SPIRIT Standard Protocol Items:Recommendations for Interventional Trials TEWL Transepidermal Water Loss VDBP vitamin D binding protein VDP vitamin D phosphate. References Holick MF. Vitamin D Deficiency. New England Journal of Medicine. 2007;357(3):266-81. Rejnmark L, Bislev LS, Cashman KD, Eiríksdottir G, Gaksch M, Grübler M, et al. Non-skeletal health effects of vitamin D supplementation: A systematic review on findings from meta-analyses summarizing trial data. PLOS ONE. 2017;12(7):e0180512. Autier P, Boniol M, Pizot C, Mullie P. Vitamin D status and ill health: a systematic review. The Lancet Diabetes & Endocrinology. 2014;2(1):76-89. Vitamin D. health report. The Scientific Advisory Committee on Nutrition (SACN) recommendations on vitamin D. Public Health England. 2016;289. Bikle Daniel D. Vitamin D Metabolism, Mechanism of Action, and Clinical Applications. Chemistry & Biology. 2014;21(3):319-29. Carlberg C. The physiology of vitamin D—far more than calcium and bone. Frontiers in Physiology. 2014;5. Bendik I, Friedel A, Roos FF, Weber P, Eggersdorfer M. Vitamin D: a critical and essential micronutrient for human health. Frontiers in Physiology. 2014;5. Lehmann U, Hirche F, Stangl GI, Hinz K, Westphal S, Dierkes J. Bioavailability of Vitamin D2 and D3 in Healthy Volunteers, a Randomized Placebo-Controlled Trial. The Journal of Clinical Endocrinology & Metabolism. 2013;98(11):4339-45. Wan M, Patel A, Patel JP, Rait G, Jones SA, Shroff R. Quality and use of unlicensed vitamin D preparations in primary care in England: Retrospective review of national prescription data and laboratory analysis. British Journal of Clinical Pharmacology. 2021;87(3):1338-46. Boucher BJ. Why do so many trials of vitamin D supplementation fail? Endocrine Connections. 2020;9(9):R195-R206. Desmarchelier C, Borel P, Goncalves A, Kopec R, Nowicki M, Morange S, et al. A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Cholecalciferol Bioavailability in Healthy Men1234. The Journal of Nutrition. 2016;146(12):2421-8. Duchow EG, Duchow MW, Plum LA, DeLuca HF. Vitamin D binding protein greatly improves bioactivity but is not essential for orally administered vitamin D. Physiological Reports. 2021;9(23):e15138. Sawarkar S, Ashtekar A. Transdermal vitamin D supplementation—A potential vitamin D deficiency treatment. Journal of Cosmetic Dermatology. 2020;19(1):28-32. Fraser DR, Kodicek E. Investigations on vitamin D esters synthesized in rats. Detection and identification. Biochemical Journal. 1968;106(2):485-90. Duchow EG, Sibilska-Kaminski IK, Plum LA, DeLuca HF. Vitamin D esters are the major form of vitamin D produced by UV irradiation in mice. Photochemical & Photobiological Sciences. 2022;21(8):1399-404. Deschasaux M, Souberbielle J-C, Andreeva VA, Sutton A, Charnaux N, Kesse-Guyot E, et al. Quick and Easy Screening for Vitamin D Insufficiency in Adults: A Scoring System to Be Implemented in Daily Clinical Practice. Medicine. 2016;95(7). Angie J, Clarice B. Evaluation of the safety, tolerability and plasma vitamin D response to long-term use of patented transdermal vitamin D patches in healthy adults: a randomised parallel pilot study. BMJ Nutrition, Prevention &amp; Health. 2022:e000471. Duchow EG, Cooke NE, Seeman J, Plum LA, DeLuca HF. Vitamin D binding protein is required to utilize skin-generated vitamin D. Proceedings of the National Academy of Sciences. 2019;116(49):24527-32. Supplementary Files Appendices.docx SPIRIT2013Checklist.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3499598","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":281580845,"identity":"19861bf3-a44e-4dfe-978a-b1a7de0c104f","order_by":0,"name":"Thomas Hibbard","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Thomas","middleName":"","lastName":"Hibbard","suffix":""},{"id":281580846,"identity":"db291d30-dcb5-4599-a71c-a5d7a815c8dc","order_by":1,"name":"Paolo Andriollo","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Paolo","middleName":"","lastName":"Andriollo","suffix":""},{"id":281580847,"identity":"4f595e8e-ccb9-4579-a5c7-1d97932607ea","order_by":2,"name":"Chui Hua Lim","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Chui","middleName":"Hua","lastName":"Lim","suffix":""},{"id":281580848,"identity":"7d13aa00-ff12-4539-a3cf-0b950c019efb","order_by":3,"name":"Qing Guo","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Qing","middleName":"","lastName":"Guo","suffix":""},{"id":281580849,"identity":"d6a3fe5a-e631-4367-a297-9c93f1f41ab4","order_by":4,"name":"Karl Lawrence","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Karl","middleName":"","lastName":"Lawrence","suffix":""},{"id":281580850,"identity":"264b5325-b952-4558-9295-1610f556978c","order_by":5,"name":"Bolaji Coker","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Bolaji","middleName":"","lastName":"Coker","suffix":""},{"id":281580851,"identity":"357f4f29-d886-42a3-bf87-41b34b8f4374","order_by":6,"name":"Rayka Malek","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Rayka","middleName":"","lastName":"Malek","suffix":""},{"id":281580852,"identity":"c2ca153f-99a0-4f4c-8ff8-e4c054071c7b","order_by":7,"name":"Abdel Douiri","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Abdel","middleName":"","lastName":"Douiri","suffix":""},{"id":281580853,"identity":"b683bd10-013d-442b-b300-b8b20dbf5ac6","order_by":8,"name":"Mohamed A Alhnan","email":"","orcid":"","institution":"King's College London","correspondingAuthor":false,"prefix":"","firstName":"Mohamed","middleName":"A","lastName":"Alhnan","suffix":""},{"id":281580854,"identity":"491fe167-f0b1-4ca2-939c-48c5f39105df","order_by":9,"name":"Stuart Jones","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYBADZjD54QCDDIR/AI9aNhCRANHCOOMAAw/RWiBW8RCjRX5+j+Hnyh8M7PzSzYc/25yx42FgP/yAmecMbi0Gx3iMJc8AHSY551iadM6NZB4GnjQDZp4beLSw8RhINgC1GNzIMWPO+XAA6LAcoAs/4HFYG4/xT4iW/M+fLUBa+N/g18JwjMcMZguDNMMNoBYJkC34HHYsrcyyIU2CWXJGmplkz5lkHjaJZwYH5+Dxvnzz4c03G2xskvklkh9/+HHMTo6fP/nhgzfH8DgMAiSS4UxQRB0gqAEI7IhRNApGwSgYBSMUAADpwUgbZtVUxQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0001-5078-0250","institution":"King's College London","correspondingAuthor":true,"prefix":"","firstName":"Stuart","middleName":"","lastName":"Jones","suffix":""}],"badges":[],"createdAt":"2023-10-27 14:51:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3499598/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3499598/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53254066,"identity":"1ffb68c1-7eb4-49cf-8b59-f2d04078af0e","added_by":"auto","created_at":"2024-03-22 13:21:25","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":281161,"visible":true,"origin":"","legend":"\u003cp\u003ePatient flow diagram\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3499598/v1/1ce453f477e7209c6125f89f.png"},{"id":53254065,"identity":"ab033ced-90df-41ec-ad13-64b073f9f25f","added_by":"auto","created_at":"2024-03-22 13:21:25","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":36937,"visible":true,"origin":"","legend":"\u003cp\u003eSPIRIT diagram detailing enrollment, interventions, and assessments. *Note: Part 2, 8 Week time point only for one frequency and placebo following Part 2, week 4 interim analysis. \u003csup\u003e$\u003c/sup\u003eOnly tested in Part 2. ISF = interstitial fluid, VDBP = vitamin D binding protein, TEWL = transepidermal water loss.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3499598/v1/1e5fc69360574995e277159f.png"},{"id":60975959,"identity":"7ae55a91-56f1-4f86-bdbf-51b0eeba54ce","added_by":"auto","created_at":"2024-07-24 08:14:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1079704,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3499598/v1/7da42828-589a-404a-8695-8cca4392e070.pdf"},{"id":53254067,"identity":"ce7a124a-2983-4e74-9c31-5af96e55286c","added_by":"auto","created_at":"2024-03-22 13:21:25","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":36399,"visible":true,"origin":"","legend":"","description":"","filename":"Appendices.docx","url":"https://assets-eu.researchsquare.com/files/rs-3499598/v1/8ed38aa7b2b8509994ef3101.docx"},{"id":53255692,"identity":"a0a42ce4-1838-40f5-b434-983c3f54e9f2","added_by":"auto","created_at":"2024-03-22 13:29:25","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":41523,"visible":true,"origin":"","legend":"","description":"","filename":"SPIRIT2013Checklist.docx","url":"https://assets-eu.researchsquare.com/files/rs-3499598/v1/512384c541f7707c1b7bfc69.docx"}],"financialInterests":"","formattedTitle":"A Multistage, Multiarmed, Double-Blind Placebo-Controlled Human Transdermal Vitamin D Supplement Study (TransVitD)","fulltext":[{"header":"Introduction","content":"\u003ch3\u003eBackground and rationale\u003c/h3\u003e\n\u003cp\u003eVitamin D deficiency is common worldwide; predicating and exacerbating a wide variety of health conditions (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e). Vitamin D supplementation is recommended to prevent vitamin D deficiency from having an impact on health (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e). For example, the UK government advises individuals to take daily vitamin D supplements (400 IU, 10 \u0026micro;g) to ensure adequate vitamin D blood levels and protect musculoskeletal health (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e). Despite the state-level advice, the health benefits of vitamin D supplementation, especially the non-skeletal benefits are not currently strongly supported robust clinical trial data, therefore there remains a need to better understand the contribution of vitamin to health (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eVitamin D is available in two forms, vitamin D\u003csub\u003e2\u003c/sub\u003e (ergocalciferol) and vitamin D\u003csub\u003e3\u003c/sub\u003e (cholecalciferol), which differ from each other via slight differences in chemical structure. Both forms of vitamin D are active and are extensively metabolised in the liver to form 25(OH)VD\u003csub\u003e2\u003c/sub\u003e and 25(OH)VD\u003csub\u003e3\u003c/sub\u003e as well as subsequent active metabolites, 1\u0026alpha;,25(OH)\u003csub\u003e2\u003c/sub\u003eD\u003csub\u003e3\u003c/sub\u003e and 1\u0026alpha;,25(OH)\u003csub\u003e2\u003c/sub\u003eD\u003csub\u003e2\u003c/sub\u003e (\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e). Vitamin D\u003csub\u003e3\u003c/sub\u003e is formed endogenously by UV-B light-mediated cutaneous synthesis whereas vitamin D\u003csub\u003e2\u003c/sub\u003e is obtained in very small amounts through dietary sources (\u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e). Individuals with low vitamin D levels, due to insufficient dietary intake or limited exposure to direct sunlight, often a result of geographical location or lifestyle, can improve vitamin D status through supplementation (\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eVitamin D\u003csub\u003e3\u003c/sub\u003e is currently the most effective means of supplementing vitamin D levels and, as such, is provided in most supplement formulations on the market (\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e). Although their use is widespread, these oral formulations are subject to limited oral bioavailability, which is influenced by factors such as genetics and the presence of food in the gastrointestinal tract during supplement ingestion (\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e). Even under controlled conditions, such as those in nutritional clinical trials, the 25(OH)D3 plasma levels can vary by \u0026gt;\u0026thinsp;50% in individual participants after each dose (\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eIn this work, it was hypothesised that delivering vitamin D through the skin may overcome the disadvantages of oral administration and lead to an efficacious and tolerable means of supplementation. This is in part due to the presence of vitamin D binding protein (VDBP) in the skin which increases the potency and duration of action of skin-generated vitamin D (\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e). However, as vitamin D does not readily pass through the lipidic barrier in the skin, the stratum corneum, it is problematic to deliver adequate quantities of Vitamin D3 to act as a supplement (\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003ePrior research at King\u0026rsquo;s College London has developed a functionalised form of vitamin D (vitamin D phosphate, VDP, WO2022084669A1), which does effectively passes through the stratum corneum of skin, where it is metabolised back into vitamin D that can then bind to the VDBP and be absorbed into the blood (\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e). This compound has been developed into a drug-in-adhesive transdermal patch formulation which delivers vitamin D in sufficient quantities across the skin to theoretically be used as a supplement and this new approach will be the intervention tested in this trial.\u003c/p\u003e\n\u003ch3\u003eHypothesis\u003c/h3\u003e\n\u003cp\u003eVitamin D phosphate administered as a transdermal patch will enhance vitamin D status in humans.\u003c/p\u003e\n\u003ch3\u003eObjectives\u003c/h3\u003e\n\u003cp\u003eThe objectives of the study are:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eTo investigate the extent of systemic exposure of vitamin D following administration of a vitamin D phosphate transdermal patch, in healthy individuals using 25(OH)D3 as a biomarker.\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eTo determine how transdermal administration of vitamin D phosphate influences vitamin D binding protein (VDBP) levels in the serum.\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eTo investigate how interstitial skin biomarkers in the local tissue are changed after the transdermal administration of vitamin D phosphate.\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eTo understand if the visual appearance of the human nail plate changes as a consequence of transdermal vitamin D supplementation.\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ul\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n\u003ch2\u003eTrial Design\u003c/h2\u003e\n\u003cp\u003eThis study is a two-part study that comprises a dose-finding and a randomised, placebo-controlled, double-blind clinical trial using an adaptive design (Figs.\u0026nbsp;1 and 2). Randomisation will be performed using block randomisation with an equal allocation ratio. This study aims to evaluate the efficacy of a VDP transdermal supplement patch compared to a placebo.\u003c/p\u003e"},{"header":"Methods: Participants, Interventions and Outcomes ","content":"\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n\u003ch2\u003eStudy setting\u003c/h2\u003e\n\u003cp\u003eThe study will take place in the Institute of Pharmaceutical Science, King\u0026rsquo;s College London, London, UK. Planned recruitment will be primarily from participants from London and the surrounding areas thus the trial participants will be drawn from a multicultural and multiethnic setting.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003ch2\u003eEligibility criteria\u003c/h2\u003e\n\u003cp\u003eInterested participants will be provided with a participant information sheet and the study will be explained by a member of the trial staff. Initial screening and subsequent recruitment will be based on participant suitability as per the inclusion and exclusion criteria (\u003cstrong\u003eTable\u0026nbsp;1\u003c/strong\u003e) and a successful patch adhesive sensitivity test using a placebo patch.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eParticipant inclusion and exclusion criteria\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eInclusion Criteria\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1. Healthy adults between 18 and 65 years of age.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2. Suspected low vitamin D levels (defined as moderate or high risk using the Deschasaux questionnaire ((\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e))).\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3. Written informed consent for study participation.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4. Willingness to comply with the study requirements.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5. Competent use of English language.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1. Patients unable to give informed consent.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2. The use of vitamin D supplements 4 weeks prior to the commencement of the study (and unwilling to washout).\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3. Pregnancy.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4. Those with parathyroid, thyroid, or calcium disorders, sarcoidosis, taking calcium channel blocking medication, Type I diabetes, and concurrent active malignancies.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5. Those who have been diagnosed with vitamin D deficiency by a GP in the last 3 months using a blood test.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6. Those who have been diagnosed with vitamin D deficiency by a GP in the last 6 months using a blood test and have not taken any vitamin D supplements.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eScreening will occur at least 24 before the baseline visit to allow time for the participant to understand the information provided. Study staff will request the participants sign a statement of informed consent and they will be invited to participate in three study visits. A maximum of 100 participants will be enrolled in the trial. A set of patch application instructions will be provided to the participants to aid the daily application of the patches and to re-enforce the instructions after the participants have left the clinical site.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n\u003ch2\u003eExplanation for the Choice of Comparators\u003c/h2\u003e\n\u003cp\u003eAlthough other patches containing vitamin D are available on the market, no clinical studies have demonstrated their efficacy in improving vitamin D status, presumably due to the limited transdermal bioavailability of vitamin D (\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e). As a consequence, we will compare the innovative transdermal vitamin D supplementation approach using vitamin D phosphate with a placebo patch.\u003c/p\u003e\n\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n\u003ch2\u003eIntervention\u003c/h2\u003e\n\u003cp\u003eThe intervention will be the application of daily transdermal patches. They will be active in adhesive patches manufactured at King\u0026rsquo;s College London comprising food-grade vitamin D phosphate and cosmetic/food-grade excipients. The patches underwent ISO standard toxicology testing for medical devices before clinical use (cytotoxicity, irritation, and sensitization). Patches will be packaged in aluminium sealable pouches (primary packaging) and then a cardboard box (secondary packaging).\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n\u003ch2\u003eCriteria for discontinuing or modifying allocated intervention\u003c/h2\u003e\n\u003cp\u003eA mechanism will be in place to report any adverse events to the study team through a dedicated study email address. If any of the adverse events are classified as serious the study team will advise the participant to exit the study and be directed to receive appropriate medical attention. Participants can exit the study at any time.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003ch2\u003eParticipant Timeline\u003c/h2\u003e\n\u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n\u003ch2\u003eBaseline Assessment\u003c/h2\u003e\n\u003cp\u003eVolunteers will provide demographic data, relevant medical history, allergy status, Fitzpatrick skin type, and lifestyle data including diet specifically to measure vitamin D intake, and level of regular sun exposure. We will use the participant location to calculate UV exposure during the trials. Baseline measurements will be taken including, trans-epidermal water loss (TEWL), a blood sample to measure plasma vitamin D (25(OH)VD\u003csub\u003e3\u003c/sub\u003e and calcium levels, skin interstitial fluid (ISF) sample, and fingernail photographs.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003ch2\u003ePart 1\u003c/h2\u003e\n\u003cp\u003eAfter receiving informed consent and completing the baseline assessment, two cohorts of 8 participants will take part in a non-blinded dosing escalation pilot study. These cohorts will be supplemented via a transdermal patch application, with one cohort completing the 4-week study, the data being analysed, and the choice of second dose made, before dosing the second cohort. The primary outcome measure will be safety and tolerability assessed by report of local or systemic side effects, calcium and 25(OH)VD\u003csub\u003e3\u003c/sub\u003e levels at 2 weeks and 4 weeks of dosing. If analysis at either time point show blood plasma levels with a serum calcium measure of more than 12 mg/dL or a 25(OH)VD\u003csub\u003e3\u003c/sub\u003e level\u0026thinsp;\u0026gt;\u0026thinsp;150 nmol/L this will indicate a risk of toxicity. In this eventuality, the dosing will be terminated, and a serious adverse event would be recorded. If there are serious adverse events in 2 or more participants, the dose will be classified as \u003cem\u003enot safe\u003c/em\u003e. The secondary outcome will be efficacy by further analysis of the 25(OH)VD\u003csub\u003e3\u003c/sub\u003e blood level. A blood concentration change of \u0026lt;\u0026thinsp;5 nmol/L in \u0026gt;\u0026thinsp;25% of participants will indicate that the dose is ineffective after 4 weeks of treatment. The primary and secondary outcome measures for the \u0026ldquo;lowest dose\u0026rdquo; cohort will direct the dosing of the second cohort in Part 1. Participants partaking in Part 1 of the study will not be eligible for inclusion in Part 2.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n\u003ch2\u003ePart 2\u003c/h2\u003e\n\u003cp\u003eThis part of the trial will be multi-staged. In the first stage, four cohorts of 14 participants will be enrolled in a double-blinded randomised placebo-controlled study. The randomisation sequence will be designed by a statistician independent to the trial team. Participants will be assigned according to the randomisation schedule by a local researcher independent of the study team into one of three treatment arms or one placebo arm. The treatment arms will measure different dosing frequencies of the same strength vitamin D patch. The participants in Part 2 will have their parathyroid hormone levels monitored and be subject to genetic analysis to help understand any changes in vitamin D binding protein, these are additional tests compared to Part 1. The first stage of the study will last 4 weeks, after which there will be an interim data analysis to select the treatment arm for the second stage. In the second stage, two cohorts of 14 participants will be blinded and randomised into the final two study arms consisting of one treatment arm and one placebo arm. The second stage will run for 8 weeks with measurements at week 4 and a final measurement at week 8. The aim of Part 2 is to establish whether vitamin D supplementation via the skin increases the concentration of vitamin D in the blood and which dosing interval is best suited to achieve this.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\n\u003ch2\u003eStrategies to improve adherence to interventions\u003c/h2\u003e\n\u003cp\u003eTo aid participant adherence to the trial regimen, a specific set of written instructions regarding the patch application will be used to reinforce the verbal directions provided by the study team. Dosing reminders will be sent to participants to their mobile phones each day. At each visit, the participants will be asked to bring any unused transdermal batches back for inspection by the study team, who will count any unused patches to determine % compliance over the study duration.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\n\u003ch2\u003eRelevant concomitant care permitted or prohibited during the trial\u003c/h2\u003e\n\u003cp\u003eThe trial will monitor the participant's UV exposure, vitamin D intake, medical history and medication intake during the trial. However, the trial will not change diet, sun exposure or medical treatment.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\n\u003ch2\u003eAncillary and Post-Trial Care\u003c/h2\u003e\n\u003cp\u003eParticipants will be instructed to contact the study research team via the designated study email address if symptoms relating to the application of study patches are experienced following the completion of the trial. In such an event participants will be assessed and referred for further medical attention if required.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\n\u003ch2\u003eOutcomes\u003c/h2\u003e\n\u003cp\u003e\u003cspan class=\"Underline\"\u003ePrimary Outcomes\u003c/span\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cp\u003eConcentration of 25(OH)D\u003csub\u003e3\u003c/sub\u003e in the serum (ng/mL) compared to baseline.\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cspan class=\"Underline\"\u003eSecondary Outcome\u003c/span\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cp\u003eThe concentration of VDBP levels in the serum (\u0026micro;g/mL) compared to baseline.\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eThe concentration of chemical biomarker levels in the skin interstitial fluid (ng/mL) compared to baseline.\u003c/p\u003e\n\u003c/li\u003e\n\u003cli\u003e\n\u003cp\u003eQuantification of image feature change in nail photographs (unit pixels).\u003c/p\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\n\u003ch2\u003eSample Size Calculation\u003c/h2\u003e\n\u003cp\u003eFor Part 1 the sample size is based on clinical considerations. With 6 patients per cohort there is greater than 80% probability of detecting an adverse event with a population frequency of 25% using the simple probabilistic calculations below:\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003ePart 1 probability of detecting adverse event calculations.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\varvec{p}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\varvec{n}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\varvec{n}\\left(1-\\varvec{p}\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\varvec{n}\\varvec{p}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.94148\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.05852\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.262144\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.737856\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.177979\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.822021\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"4\" align=\"left\"\u003e\n\u003cp\u003e\u003cstrong\u003eDefinitions\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSample Size\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(n\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003ePr of observing an event\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(p\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003ePr not observing event in a patient\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(1-p\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003ePr not observing an event in n patients\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(n\\left(1-p\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003ePr of observing an event in n patients\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(np\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eConsidering a 20% dropout rate, 8 patients is required for each cohort in Part 1 of the study.\u003c/p\u003e\n\u003cp\u003eFor Part 2 the sample size calculation is based on a 4-arm 2-stage design. The minimum clinically important change in 25-(OH)VD\u003csub\u003e3\u003c/sub\u003e from baseline to week 8 is 10 nmol/L based on previous studies. The typical value of 25-(OH)VD\u003csub\u003e3\u003c/sub\u003e in placebo arm was estimated at 37.7 nmol/L with standard deviation (SD) of 9.1 nmol/L. With 1000 simulation runs, considering 5% significance level 2-sided and Dunnet test for multiple comparisons to select the best treatment, 12 participants are need for stage 1 in each arm. Assuming a 15% dropout rate, 56 participants in total will be recruited in stage 1. For stage 2, 12 participants will be enrolled in each of the selected and placebo arms. Considering the same 15% dropout rate, 28 participants are required for stage 2. The overall sample size for Part 2 of the study is 84. The overall sample size for two parts of the study is 84\u0026thinsp;+\u0026thinsp;16\u0026thinsp;=\u0026thinsp;100.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\n\u003ch2\u003eRecruitment Strategy\u003c/h2\u003e\n\u003cp\u003eParticipants will be primarily recruited from King\u0026rsquo;s College London staff and students and members of the public from the local area who voluntarily respond to trial advertising. Participants expressing interest in the trial will receive a patient information leaflet and consent form and will be invited to screening and baseline assessments. All study participants will be offered financial compensation of \u0026pound;50 on completion of the study to reimburse the inconvenience of clinical visits. Despite this, participation in the trial is voluntary and participants may withdraw at any time for any reason.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e\n\u003ch2\u003eAssignment of interventions\u003c/h2\u003e\n\u003cdiv id=\"Sec22\" class=\"Section3\"\u003e\n\u003ch2\u003eAllocation, Concealment, Implementation\u003c/h2\u003e\n\u003cp\u003ePart 2 of the trial will be randomised. A code generated by an independent statistician will ensure equal participant recruitment into each of the trail cohorts by a block randomisation process. Group allocation will be performed by an independent researcher using the randomisation code. The blinding will remain in place until completion of the trial and the final data analysis has been finished. In stage one of Part 2, a total of 56 participants will be randomised and allocated into 4 groups. Following the interim data analysis, 28 additional participants will be randomised and allocated into the two final groups for Part 2 stage two.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec23\" class=\"Section3\"\u003e\n\u003ch2\u003eBlinding\u003c/h2\u003e\n\u003cp\u003eParticipants, researchers, and the study statistician will be blinded to the treatment allocation. Treatment and placebo patches will be visually identical and labelled by a pharmacist independent of the trial, who will package them in the same way and assign each box with a code according to the independent statistician's list of codes. The independent researcher responsible for participant allocations will check the codes against the statistician's randomisation list to ensure accuracy. Where the frequency of treatment patch application is assessed, daily patch application will still be used with a mixture of treatment and placebo patches to maintain participant and researcher blinding. Any interim analysis that needs to be completed will be performed by an independent statistician and data review committee so as not to break the blinding code. In the event of a major adverse event, the team will contact the independent researcher responsible for the group allocation and ask them to unblind the participant affected by the event to ensure they receive the appropriate medical attention.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec24\" class=\"Section2\"\u003e\n\u003ch2\u003eData collection, Management, Analysis\u003c/h2\u003e\n\u003cdiv id=\"Sec25\" class=\"Section3\"\u003e\n\u003ch2\u003eData Collection Methods\u003c/h2\u003e\n\u003cdiv id=\"Sec26\" class=\"Section4\"\u003e\n\u003ch2\u003eScreening Questionnaire\u003c/h2\u003e\n\u003cp\u003eParticipants will be identified as having moderate or high risk of vitamin D deficiency via the validated Deschasaux questionnaire (\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e). Scores are assigned based on the patient age, sex, body type, Fitzpatrick skin type, location, and level of physical activity.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec27\" class=\"Section3\"\u003e\n\u003ch2\u003eDemographic, diet and exercise questionnaire\u003c/h2\u003e\n\u003cp\u003eThe participants will be asked a series of questions to gather demographic information. This will generate data for potential covariates. The most important information will include participant BMI, sex, age, body fat, dietary vitamin D intake, UV exposure levels (monitored through location information), skin type, ethnicity, and exercise habits.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec28\" class=\"Section2\"\u003e\n\u003ch2\u003eBlood Sampling\u003c/h2\u003e\n\u003cp\u003eVenous blood (max. 3 x 10 mL) will be collected from a peripheral vein by a trained phlebotomist. Serum vitamin D levels. 25(OH)VD\u003csub\u003e3\u003c/sub\u003e and relevant vitamin D metabolite concentrations in blood serum will be determined using ELISA and/or gas/liquid mass spectrometry analysis. Plasma calcium concentration will be determined in triplicate based using colourmetric methods. Parathyroid hormone and vitamin D binding protein levels will also be determined using ELISA assays.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec29\" class=\"Section2\"\u003e\n\u003ch2\u003eSkin Interstitial Fluid (ISF) Extraction\u003c/h2\u003e\n\u003cp\u003eISF samples (max. 3 x 150 \u0026micro;L) will be collected from the outer side of the forearm for the determination of vitamin D bind protein (VDBP) levels at the skin sites where the patches have been applied. ISF samples will be collected under hypobaric pressure (510 mBar) using an in-house designed extraction chamber and hand pump fitted with manometer. VDBP level will be determined using a commercial ELISA testing kit.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eTransepidermal Water Loss (TEWL)\u003c/h3\u003e\n\u003cp\u003eTEWL will be measured in triplicate at each study visit using a AquaFlux AF200 condensing chamber probe (Biox Systems Ltd., UK) as a means of measuring skin barrier dysfunction and skin irritation.\u003c/p\u003e \u003cdiv id=\"Sec31\" class=\"Section2\"\u003e \u003ch2\u003eFingernail Imaging\u003c/h2\u003e \u003cp\u003eImages of one fingernail from each hand will be taken using a digital camera as a means of monitoring visual changes.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec32\" class=\"Section2\"\u003e \u003ch2\u003eGenetic variation profiling\u003c/h2\u003e \u003cp\u003eWe will collect biological samples to generate profiles of genetic variation in participants to investigate the relationship between genetic variation and specific measured traits. Participants will be asked to use an Oragene saliva sample tube. If this fails for any reason a similar analysis will be performed on blood samples already collected for the other analytical measurement. DNA extraction from these samples will be performed using standard protocols appropriate to the source of the sample. Following DNA extraction, genotyping will be conducted using microarrays, a reliable and widely accepted technique for identifying genetic variants across the genome simultaneously. Once the genotypic data is obtained, association testing will be carried out. This process will evaluate the correlation between the genetic variants identified and the traits measured in the study, allowing us to ascertain potential genetic contributions to these traits.\u003c/p\u003e \u003cdiv id=\"Sec33\" class=\"Section3\"\u003e \u003ch2\u003eData management\u003c/h2\u003e \u003cp\u003eAll study participants will be allocated a unique study identification number so that researchers will not have access to subject-identifiable information. Study data, patient contact details, and patient medical information will be entered onto a secure password-protected research database (provided by: REDCap\u0026reg;). Copies of protocols, case report forms, physiological test results, participant correspondence, informed consent documents, and other files relevant to the study will be kept securely by the Principal Investigator for at least 15 years following the completion or discontinuation of the research study. All data recording and retention will comply with King\u0026rsquo;s College London policies for sensitive data.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec34\" class=\"Section3\"\u003e \u003ch2\u003eConfidentiality\u003c/h2\u003e \u003cp\u003eAll study staff will endeavour to protect the privacy and consent rights of the participants and will adhere to the Data Protection act, 2018. Access to study information will be limited to study staff, investigators, and trial conduct auditors.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eStatistical methods for primary and secondary outcomes\u003c/h3\u003e\n\u003cp\u003eDescriptive statistics on participants\u0026rsquo; demographics and baseline clinical characteristics will be provided using frequency and percentage or median and range in both parts of the study. The first part of the study focuses on safety endpoint. Frequency and percentage of occurrence of adverse events and calcium\u0026thinsp;\u0026gt;\u0026thinsp;12 mg/dL or 25(OH)VD\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;\u0026gt;\u0026thinsp;150 nmol/L will be reported in the first cohort of 6. If there are serious adverse events in 2 or more of participants, the dose will not be safe. The secondary outcome is efficacy, the change in 25(OH)VD\u003csub\u003e3\u003c/sub\u003e. Participants with a 25(OH)VD\u003csub\u003e3\u003c/sub\u003e change less than 5 nmol/L will be reported as frequency percentage. If the 25(OH)VD\u003csub\u003e3\u003c/sub\u003e change in more than 75% of participants is observed, the dose will be considered ineffective after 4 weeks. The decision for second cohort dosing will be made according to these results. The safety and efficacy of second cohort will be reported similar to the first cohort.\u003c/p\u003e \u003cp\u003eFor the second part of the MAMS study, an interim analysis is planned at 4 weeks for the end of the first stage. The mean change in 25(OH)VD\u003csub\u003e3\u003c/sub\u003e in each treatment arm will be tested against the placebo arm using a z-test. Two treatment arms will be dropped and the treatment arm with the highest observed response as compared to placebo will be selected for testing at the second stage. As multiple doses are compared to the shared control, multiplicity adjustment will be considered in the first stage, and familywise error rate (FWER) will be controlled at 2.5%. Therefore, the probability of incorrectly rejecting the null hypothesis for at least one experimental arm is 0.025. If the z-value of the test is greater than 2.797 in stage 1, the treatment arm will be considered efficacious. At the final stage, the efficacy of treatment arm against placebo will be tested using a z-test. The error rate is 5% and the efficacy z-value for final stage is 1.977. For secondary outcomes such as VDBP levels in the blood and ISF, similar analysis will be performed. Descriptive statistics will be reported for the number of vitamin D patches used in each arm at weeks 2, 4, and 8. All statistical analysis will be conducted using RStudio.\u003c/p\u003e\n\u003ch3\u003eData monitoring\u003c/h3\u003e\n\u003cdiv id=\"Sec37\" class=\"Section2\"\u003e \u003ch2\u003eData monitoring: formal committee and interim analysis\u003c/h2\u003e \u003cp\u003eA data monitoring committee consisting of a chair, clinician, and statistician who are independent to the researchers will manage the regulatory and supervisory running of the trial. The committee will ensure consent, data collection, and recording of results are accurate to promote the reliability of the trial. The monitoring committee will undertake the interim data analysis of Part 2 and make decisions on the dosing of different treatment arms. In addition, the committee have the power to terminate the trial in the event of participant safety incidents as detailed below.\u003c/p\u003e \u003cdiv id=\"Sec38\" class=\"Section3\"\u003e \u003ch2\u003eAdverse event reporting and harms\u003c/h2\u003e \u003cp\u003eSafety and tolerability of the vitamin D patch will be monitored throughout the study. Patients will be asked to report any adverse events or changes to their health status during the study visits and encouraged to contact the research team via the designated study email address outside of these times if required.\u003c/p\u003e \u003cp\u003ePossible adverse events occurring due to this study are expected to be the same as those reported following the administration of vitamin D by other routes. According to Vitamin D \u0026ldquo;Summary of Product Characteristics\u0026rdquo; possible adverse events of vitamin D supplementation include:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eMetabolic: hypercalemia, hypercalciuria (uncommon, 0.1% \u0026minus;\u0026thinsp;1%)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eDermatologic: pruritis, rash, urticaria (rare, \u0026lt; 0.1%)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eGastrointestinal: nausea, vomiting (frequency not reported)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHypersensitivity: angioedema, laryngeal oedema (frequency not reported)\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003e This information will be included in the patient information leaflet to aid participant identification of adverse events.\u003c/p\u003e \u003cp\u003eAdverse events will be recorded using the standardised MEDDRA (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.meddra.org/how-to-use/basics/hierarchy\u003c/span\u003e\u003cspan address=\"https://www.meddra.org/how-to-use/basics/hierarchy\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) protocol (an Excel sheet is provided by the study lead) to detail the time and date of the event, duration, symptoms, and severity. The MEDDRA classification guides the team as to how to assess the action required, from no medical attention being required, non-urgent medical attention is required, or urgent medical attention is required. All MDDRA Class 2 adverse drug reactions (ADRs) and above will be reported to the principal investigator of the study. The team will use the MDDRA classification to aid referral to medical services. In cases of doubt participants with ADRs will be referred for medical attention.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec39\" class=\"Section2\"\u003e \u003ch2\u003eAuditing\u003c/h2\u003e \u003cp\u003eThe independent data monitoring committee will perform auditing and review of the study activity through the inbuilt auditing and monitoring feature in the research database. In particular, the committee will be responding to queries raised by the study facilitators and managing any discrepancies study records or data. Reports detailing the presentation of adverse events, participant drop out will be sent to the data monitoring committee via traceable means. Full access to electronic and written study records will be afforded to external auditors if required.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eTransVitD aims to assess the ability of a vitamin D phosphate transdermal patch to improve vitamin D status in healthy volunteers. It is anticipated that supplementation via the skin can use the transport machinery, i.e., the vitamin D binding protein, present in the tissue to facilitate effective absorption (\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e). The study adds to the limited amount of pilot clinical work that suggests that transdermal vitamin D could be a useful means to deliver this important vitamin (\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e). As far as we are aware, no other vitamin D phosphate based transdermal patch formulation has been tested in a double blinded, placebo-controlled human clinical trial.\u003c/p\u003e\n\u003cp\u003eThis study will, through pilot dose escalation, be followed by a double-blind, placebo-controlled supplementation trial, investigate the blood serum 25(OH)VD\u003csub\u003e3\u003c/sub\u003e levels after the application of a vitamin D phosphate transdermal patch. This is a standard means to determine the effectiveness of vitamin D dosing during an interventional trail. However, in addition the study will also measure both local and systemic VDBP concentrations. Recent work on vitamin D generation by UV-irradiation in VDBP knock out animals has shown that the VDBP is essential to carry vitamin D synthesised in the skin out of the tissue and into the systemic circulation (\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e). Therefore, it was hypothesised in this work that the VDBP could be important in the absorption and transport of the vitamin D administered into the skin using a transdermal patch. In the second part of the study, we added genetic analysis to search for associations between various biochemical processes that could improve or dimmish an individual\u0026rsquo;s response to vitamin D in order to try and understand the positive or negative impact the potential for the VDBP facilitating the absorption after penetration into the skin.\u003c/p\u003e\n\u003cp\u003eThe trial faces some challenges, such as anticipating the initial vitamin D status of the trial participants, monitoring the vitamin D intake from food and sunlight. However, we have put in place validated questionnaires and monitoring strategies to evaluate these. Other potential covariates such as ethnicity, sex, age, weight and % body fat of the participants will also be monitored to enable post-trial data processes to account for these factors. The long half-life and distribution of vitamin D in body fat complicates the blood sampling regimen. Therefore, we have scheduled a participant sampling window of two weeks to allow sufficient time for vitamin D, relevant metabolites, and vitamin D binding protein to reach steady state levels. Initial dosing was calculated considering a relative 15% transdermal bioavailability measured in rats, with the caveat that this could be reduced to 1.5% in humans given the reduction in skin permeability compared to rats. There is no literature to provide accurate allometric scaling from humans to animals for vitamin D absorption. As a consequence, in the trial care the main focus was to optimise the vitamin D transdermal dosing. The design allows up to five different opportunities to get an appropriate dose and dosing interval in humans.\u003c/p\u003e\n\u003cp\u003eRelevant clinical data detailing the extent of transdermal delivery of vitamin D phosphate is required to confirm the extensive preclinical evidence which shows the efficacy of transdermal vitamin D supplementation. The results of this study may promote further investigation into transdermal delivery of current active pharmaceutical ingredients through appropriate chemical modification within nutraceutical and other medical categories.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics and Dissemination\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResearch Ethics Approval\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis clinical trial has been approved by the King\u0026rsquo;s College, London Research Ethics Committee (KCL-REC) [Reference Number: HR/DP-22/23-34078, Study Title: TransVitD]. Any protocol amendments will be submitted to King\u0026rsquo;s College REC for approval. The trial will comply with good clinical practice guidelines over the reporting of adverse events (AEs), serious adverse events (SAE\u0026rsquo;s) and suspected serious adverse reactions (SUSAR\u0026rsquo;s) as well as providing the REC with progress reports and final study report. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProtocol Amendments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIf amendments to this protocol are required, approval will be sought from the KCL-REC and updated protocol will be made available on request. This protocol version is 1.4, 19\u003csup\u003eth\u003c/sup\u003e October.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent / Assent for Publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants have agreed to the publication of these results.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations of Interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSAJ is the inventor of the vitamin D phosphate patent WO2022084669A1. MAA and SAJ have received funding to develop and test in pre-clinical studies the vitamin D patch from Vitamax Patch Wholesaler LLC.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAccess to Data \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe principal investigator SAJ has access to the full trial data and materials and they can be made available upon request\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDissemination Policy\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIt is intended that the results of this study will be reported and disseminated at international conferences and in peer-reviewed scientific journals. Following trial competition and the publication of results, data requests may be submitted to the researchers at the Institute of Pharmaceutical Science, King\u0026rsquo;s College London. In addition, we will send a summary of the study results to study participants at their request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlans for collection, laboratory evaluation, and storage of biological specimens for genetic or molecular analysis in this trial/future use\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSamples will be taken by delegated researchers with the appropriate training in sample collection techniques. All samples will be labelled in such a way that the participant and date of collection can be identified beyond the unique study participant number, if required. All biological samples will be stored at -80\u0026deg;C in accordance with the human tissue act where appropriate. If samples are to be used in future studies outside of the scope of this trial, Research Ethics Committee approval will be sought. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Details and Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThomas Hibbard \u003csup\u003e1\u003c/sup\u003e, Paolo Andriolo \u003csup\u003e1\u003c/sup\u003e, Charlie Lim \u003csup\u003e1\u003c/sup\u003e, Qing Guo \u003csup\u003e1\u003c/sup\u003e, Karl Lawrence \u003csup\u003e1\u003c/sup\u003e, Bolaji Coker, Rayka Malek \u003csup\u003e2\u003c/sup\u003e, Abdel Douiri \u003csup\u003e2\u003c/sup\u003e, Mohamed A Alhnan \u003csup\u003e1\u003c/sup\u003e and Stuart Jones \u003csup\u003e1\u003c/sup\u003e* \u003csup\u003e1\u003c/sup\u003e Institute of Pharmaceutical Science, Faculty of Life Sciences \u0026amp; Medicine, Franklin-Wilkins Building, King\u0026apos;s College London, London, UK. \u003csup\u003e2\u003c/sup\u003e School of Population Health and Environmental Sciences, King\u0026rsquo;s College London, London, UK.\u003c/p\u003e\n\u003cp\u003eTH: writing draft, editing; PA TH: writing draft, editing; CL: \u0026nbsp;writing draft, editing; QG: writing draft, editing; KL: conceptualisation, BC: editing; AD: writing draft, editing, supervision; RM: writing draft, editing; MAA writing draft, editing, supervision; SAJ: Conceptualisation,\u0026nbsp;writing draft, editing, supervision; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge and thank Vitamax Patch Wholesaler LLC for supplying the grant required to finance this study. Vitamax Patch Wholesaler LLC is not involved in the design, data collection, analysis or interpretation of data in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eName and Contact Information for Trial Sponsor\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKeith Brennan, Director of Research, King\u0026rsquo;s College London, Guy\u0026apos;s Campus, King\u0026apos;s College London. LONDON, SE1 4UL. Telephone: 020 7848 6960 Email:\u0026nbsp;\u003ca href=\"mailto:[email protected]\"\[email protected]\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial Status\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;This protocol version is 1.4, 19th October. Study recruitment started on 23\u003csup\u003erd\u003c/sup\u003e Oct 2023.Recruitment is expected to complete by the end of March 2024.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eISF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInterstitial Fluid\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eKCL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eKing\u0026rsquo;s College London\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSPIRIT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandard Protocol Items:Recommendations for Interventional Trials\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTEWL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTransepidermal Water Loss\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVDBP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003evitamin D binding protein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVDP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003evitamin D phosphate.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHolick MF. Vitamin D Deficiency. New England Journal of Medicine. 2007;357(3):266-81.\u003c/li\u003e\n\u003cli\u003eRejnmark L, Bislev LS, Cashman KD, Eir\u0026iacute;ksdottir G, Gaksch M, Gr\u0026uuml;bler M, et al. Non-skeletal health effects of vitamin D supplementation: A systematic review on findings from meta-analyses summarizing trial data. PLOS ONE. 2017;12(7):e0180512.\u003c/li\u003e\n\u003cli\u003eAutier P, Boniol M, Pizot C, Mullie P. Vitamin D status and ill health: a systematic review. The Lancet Diabetes \u0026amp; Endocrinology. 2014;2(1):76-89.\u003c/li\u003e\n\u003cli\u003eVitamin D. health report. The Scientific Advisory Committee on Nutrition (SACN) recommendations on vitamin D. Public Health England. 2016;289.\u003c/li\u003e\n\u003cli\u003eBikle Daniel\u0026nbsp;D. Vitamin D Metabolism, Mechanism of Action, and Clinical Applications. Chemistry \u0026amp; Biology. 2014;21(3):319-29.\u003c/li\u003e\n\u003cli\u003eCarlberg C. The physiology of vitamin D\u0026mdash;far more than calcium and bone. Frontiers in Physiology. 2014;5.\u003c/li\u003e\n\u003cli\u003eBendik I, Friedel A, Roos FF, Weber P, Eggersdorfer M. Vitamin D: a critical and essential micronutrient for human health. Frontiers in Physiology. 2014;5.\u003c/li\u003e\n\u003cli\u003eLehmann U, Hirche F, Stangl GI, Hinz K, Westphal S, Dierkes J. Bioavailability of Vitamin D2 and D3 in Healthy Volunteers, a Randomized Placebo-Controlled Trial. The Journal of Clinical Endocrinology \u0026amp; Metabolism. 2013;98(11):4339-45.\u003c/li\u003e\n\u003cli\u003eWan M, Patel A, Patel JP, Rait G, Jones SA, Shroff R. Quality and use of unlicensed vitamin D preparations in primary care in England: Retrospective review of national prescription data and laboratory analysis. British Journal of Clinical Pharmacology. 2021;87(3):1338-46.\u003c/li\u003e\n\u003cli\u003eBoucher BJ. Why do so many trials of vitamin D supplementation fail? Endocrine Connections. 2020;9(9):R195-R206.\u003c/li\u003e\n\u003cli\u003eDesmarchelier C, Borel P, Goncalves A, Kopec R, Nowicki M, Morange S, et al. A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Cholecalciferol Bioavailability in Healthy Men1234. The Journal of Nutrition. 2016;146(12):2421-8.\u003c/li\u003e\n\u003cli\u003eDuchow EG, Duchow MW, Plum LA, DeLuca HF. Vitamin D binding protein greatly improves bioactivity but is not essential for orally administered vitamin D. Physiological Reports. 2021;9(23):e15138.\u003c/li\u003e\n\u003cli\u003eSawarkar S, Ashtekar A. Transdermal vitamin D supplementation\u0026mdash;A potential vitamin D deficiency treatment. Journal of Cosmetic Dermatology. 2020;19(1):28-32.\u003c/li\u003e\n\u003cli\u003eFraser DR, Kodicek E. Investigations on vitamin D esters synthesized in rats. Detection and identification. Biochemical Journal. 1968;106(2):485-90.\u003c/li\u003e\n\u003cli\u003eDuchow EG, Sibilska-Kaminski IK, Plum LA, DeLuca HF. Vitamin D esters are the major form of vitamin D produced by UV irradiation in mice. Photochemical \u0026amp; Photobiological Sciences. 2022;21(8):1399-404.\u003c/li\u003e\n\u003cli\u003eDeschasaux M, Souberbielle J-C, Andreeva VA, Sutton A, Charnaux N, Kesse-Guyot E, et al. Quick and Easy Screening for Vitamin D Insufficiency in Adults: A Scoring System to Be Implemented in Daily Clinical Practice. Medicine. 2016;95(7).\u003c/li\u003e\n\u003cli\u003eAngie J, Clarice B. Evaluation of the safety, tolerability and plasma vitamin D response to long-term use of patented transdermal vitamin D patches in healthy adults: a randomised parallel pilot study. BMJ Nutrition, Prevention \u0026amp;amp;amp; Health. 2022:e000471.\u003c/li\u003e\n\u003cli\u003eDuchow EG, Cooke NE, Seeman J, Plum LA, DeLuca HF. Vitamin D binding protein is required to utilize skin-generated vitamin D. Proceedings of the National Academy of Sciences. 2019;116(49):24527-32.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Vitamin D phosphate, Vitamin D, Vitamin D binding protein, transdermal, clinical trial, interstitial fluid, 25(OH)D3","lastPublishedDoi":"10.21203/rs.3.rs-3499598/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3499598/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eLife-style changes have meant that it is problematic to maintain adequate vitamin D concentrations in many people across the globe. Given that it's mainly generated by UV-catalysed production in the skin where it uses vitamin D binding protein to facilitate systemic absorption., it is questionable if oral administration of this vitamin is the optimal means to replace it. However, supplementing this oil-soluble vitamin is problematic as it gets stuck in the stratum corneum after topical application. This clinical study will test the ability of a new vitamin D ester, vitamin D phosphate, which is more water-soluble compared to vitamin D, can be administered via a transdermal patch to improve vitamin D status.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethod:\u003c/strong\u003e This is a two-part study comprising a dose-escalation with the vitamin D phosphate transdermal patch followed by a randomised, double-blind, placebo-controlled, multi-armed, multi-stage clinical trial. It is a single-centred, 12-week study that will enrol a maximum of 100 participants. The blinded, randomised trial will test different dose frequencies for four weeks compared to a placebo, then after an interim analysis, the best dosing frequency will be assessed against a placebo. The dose escalation study will monitor safety and tolerability using serum calcium levels. The primary outcome for the multi-stage clinical study will be the concentration of 25(OH)D3 in the serum (ng/mL) at weeks 4 and 8 compared to baseline. The secondary outcome measures include serum vitamin D binding protein levels, skin interstitial fluid biomarker concentrations, and nail appearance after \u0026nbsp;\u0026nbsp;4 and 8 weeks compared to baseline.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion:\u003c/strong\u003e This study will determine if a vitamin D phosphate transdermal patch can improve vitamin D status. In addition, it could provide a better understanding of how vitamin D is absorbed after application directly to the skin by measuring the serum vitamin D binding protein and skin biomarker responses to transdermal supplementation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial Registration: \u003c/strong\u003eClinical Trials .gov NCT06098846, registered on 23\u003csup\u003erd\u003c/sup\u003e October 2023\u003c/p\u003e","manuscriptTitle":"A Multistage, Multiarmed, Double-Blind Placebo-Controlled Human Transdermal Vitamin D Supplement Study (TransVitD)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-22 13:21:20","doi":"10.21203/rs.3.rs-3499598/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2713f20f-e587-4e82-9cf4-7c08b7e8c955","owner":[],"postedDate":"March 22nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-09-01T18:19:47+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-22 13:21:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3499598","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3499598","identity":"rs-3499598","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}