{"paper_id":"bd472382-5a97-4e3d-bdef-a86e977d9639","body_text":"Association Between Serum 25-Hydroxyvitamin D Levels and Clinical Characteristics of Adenomyosis: A Case-Control Study | 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 Association Between Serum 25-Hydroxyvitamin D Levels and Clinical Characteristics of Adenomyosis: A Case-Control Study Lingling Gao, Qingxing Yang, Yuxin Ju, Jianbo Xu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6656392/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Background Adenomyosis is a chronic gynecological condition characterized by the presence of endometrial glands and stroma within the myometrium, resulting in dysmenorrhea, menorrhagia, and infertility. Objectives This study was designed to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and adenomyosis and explore whether vitamin D deficiency is associated with the clinical characteristics of clinical symptoms. Methods This case-control study included 177 women with adenomyosis and 178 age-matched healthy controls. Demographic and clinical data were collected, including age, BMI, parity, VAS pain scores, serum CA125 levels, and uterine volume. Serum 25(OH)D levels were measured and analyzed. Univariate and multivariate regression models were used to assess associations between vitamin D levels and disease parameters. Results Women with adenomyosis had significantly lower serum 25(OH)D levels compared to controls (12.14 ± 4.65 ng/mL vs. 14.13 ± 5.02 ng/mL, p = 0.0001). They also had significantly higher VAS pain scores (7.17 ± 2.13 vs. 3.07 ± 1.98, p < 0.0001), larger uterine volumes (261.98 ± 81.99 cm³ vs. 110.98 ± 15.67 cm³, p < 0.0001), and elevated CA125 levels (70.32 ± 27.02 U/mL vs. 23.18 ± 6.09 U/mL, p < 0.0001). Multivariate linear regression showed that lower 25(OH)D levels were significantly associated with greater uterine volume and higher VAS pain scores. No significant association was observed between vitamin D and CA125 levels. Conclusion lower serum 25(OH)D levels were observed in adenomyosis patients and lower vitamin D levels is associated with increased pain severity and larger uterine volume in adenomyosis patients. Serum 25-Hydroxyvitamin D adenomyosis VAS uterine volume Introduction Adenomyosis is a chronic gynecological disorder characterized by the ectopic growth of endometrial glands and stroma within the myometrium, leading to dysmenorrhea, abnormal uterine bleeding, pelvic pain, and infertility. The prevalence of adenomyosis varies widely, ranging from 5–70%, largely depending on the diagnostic methods used 1 . Advances in imaging, particularly transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI), have improved the non-invasive diagnosis of adenomyosis, but the disease remains underdiagnosed and misinterpreted due to symptom overlap with conditions such as endometriosis and uterine fibroids. Until now the exact etiology and pathophysiology of adenomyosis remain poorly understood. Emerging evidence suggests that hormonal imbalance, chronic inflammation, immune dysregulation, and fibrosis play key roles in disease progression. Studies have demonstrated that adenomyosis is associated with increased expression of inflammatory mediators and cytokines, indicating the involvement of inflammatory pathways in its pathogenesis 2 . Additionally, alterations in sex steroid hormone receptors and inflammatory molecules have been implicated in the disease's development 3 . Furthermore, immunological changes, including the activation of immune cells and the release of immune soluble factors, have been observed in adenomyosis, highlighting the role of immune system dysregulation 4 . Finally, mechanisms underlying adenomyosis-related fibrogenesis involve transforming growth factor beta (TGF-β)-dependent and independent pathways, contributing to fibrosis in the uterine tissue 5 . ​Among potential contributing factors, vitamin D deficiency has gained increasing attention in gynecological disorders, including polycystic ovary syndrome (PCOS), endometriosis, and uterine fibroids 6 . However, its role in adenomyosis is not well established, necessitating further investigation. Vitamin D is a steroid hormone primarily known for its role in calcium homeostasis and bone metabolism. However, recent research has highlighted its pleiotropic effects, particularly in immune modulation, inflammation control, and hormone regulation 7 , 8 . The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)₂D₃), exerts its biological functions by binding to the vitamin D receptor (VDR), which is expressed in endometrial, myometrial, and immune cells 6 . The circulating form of vitamin D, 25-hydroxyvitamin D (25(OH)D), is widely used as a biomarker for vitamin D status. Deficiency in 25(OH)D has been linked to various gynecological diseases, but its relationship with adenomyosis is not well explored. Given that adenomyosis shares pathophysiological similarities with endometriosis—where vitamin D deficiency is implicated 9 —there is growing interest in the potential role of vitamin D on adenomyosis pathogenesis. Therefore, this study aims to investigate the correlation between serum 25-hydroxyvitamin D levels and adenomyosis and assess whether low vitamin D levels correlate with the severity of symptoms, uterine volume, or lesion characteristics in adenomyosis, with the goal of providing new insights for the early diagnosis, treatment, and prevention of adenomyosis. Materials and methods Study design This study is designed as a retrospective case-control study following the Helsinki Declaration. The study received approval from the Ethics Committee of Northern Jiangsu People’s Hospital Affiliated to Yangzhou University and informed consent was collected from all participants. A total of 177 women who underwent hysterectomy were histopathologically diagnosed with adenomyosis between January 2022 and March 2025 and 178 women without adenomyosis were retrospectively evaluated. The study group only recruited premenopausal females between the ages of 35 and 50 years with pathologically confirmed adenomyosis. The control group contained 178 females who came to hospital for physical examination, and no adenomyosis was detected by transvaginal ultrasound. Patients with vitamin D use during the last 6 months, the presence of any systemic disease, known malignancy, hormone replacement therapy, oral contraceptive use, uterine fibroid, and ovarian cyst were excluded from the study. Demographic, clinical and laboratory characteristics (e.g., age, body mass index (BMI), obstetric history, employed status, smoking and alcohol consumption) were recorded at the time of admission. Visual analogue scale (VAS, 0–10 points) scores were calculated for each patient to evaluate the severity of dysmenorrhea. A VAS value of “0” denoted the absence of pain, whereas a VAS value of “10” represented the maximum level of discomfort. CA125, uterine volume and VAS score were recorded for adenomyosis patients. The volume of the uterus is calculated using the prolate ellipsoid formula: Uterine Volume (cm³) = Length (cm)×Width (cm)×Height (cm)×0.523. Statistical analysis Continuous variables (e.g., serum 25(OH)D levels) were analyzed using independent t-tests or Mann-Whitney U tests for non-normally distributed data between adenomyosis and control groups. Pearson or Spearman correlation coefficients were used to determine the relationship between vitamin D levels and clinical parameters, such as CA125, pain severity, and uterine volume. Multiple linear regression was performed to assess whether serum 25(OH)D is an independent risk factor for adenomyosis severity. Results Demographic characteristics of study participants A total of 355 women were included in the study, with 177 patients diagnosed with adenomyosis and 178 women serving as healthy controls. The demographic characteristics of the participants are summarized in Table 1 . The mean age was 44.68 ± 3.71 years in the adenomyosis group and 44.52 ± 3.73 years in the control group, with no significant difference between the two groups (p = 0.7047). The BMI was also comparable between these two groups (25.90 ± 4.19 vs. 26.34 ± 3.85, p = 0.3117). However, the number of pregnancies (gravida) was significantly higher in the adenomyosis group (2.672 ± 0.926) compared to the control group (2.382 ± 0.950, p = 0.0038). The number of parities did not show significant differences between the two groups (1.102 ± 0.400 vs. 1.084 ± 0.423). The proportion of employment status was not significantly different in the adenomyosis group and control group (80.79% vs. 83.15%). The smoking, and alcohol consumption rate was similar between the two groups. Table 1 The demographic characteristics of women with and without adenomyosis. adenomyosis group (n = 177) Conrol group (n = 178) p-value Age 44.68 ± 3.71 44.52 ± 3.73 0.7047 BMI 25.90 ± 4.19 26.34 ± 3.85 0.3117 Gravida 2.672 ± 0.926 2.382 ± 0.950 0.0038 ** Parity 1.102 ± 0.400 1.084 ± 0.423 0.6905 Employed (n) 143(80.79%) 148(83.15%) 0.3331 Smoking (n) 10(5.65%) 12(6.74%) 0.1820 Alcohol (n) 13(7.34%) 15(8.43%) 0.7050 Serum 25(OH)D levels and clinical parameters of women with and without adenomyosis The comparison of serum 25(OH)D levels and clinical parameters between adenomyosis group and control group are presented in Table 2 . Serum 25-hydroxyvitamin D levels were significantly lower in the adenomyosis group (12.14 ± 4.65 ng/mL) compared to the control group (14.13 ± 5.02 ng/mL, p = 0.0001). CA125 levels were substantially elevated in the adenomyosis group (70.32 ± 27.02 U/mL) compared to controls (23.18 ± 6.09 U/mL, p < 0.0001). Additionally, pain severity, measured by the VAS, was significantly higher in the adenomyosis group (7.17 ± 2.13) compared to the control group (3.07 ± 1.98, p < 0.0001). The uterine volume was significantly larger in women with adenomyosis (261.98 ± 81.99 cm³) compared to the control group (110.98 ± 15.67 cm³, p < 0.0001). Table 2 Serum 25(OH)D levels and clinical parameters of women with and without adenomyosis. adenomyosis group (n = 177) Conrol group (n = 178) p-value 25-OH vitamin D(ng/ml) 12.14 ± 4.65 14.13 ± 5.02 0.0001 ** CA125(U/ml) 70.32 ± 27.02 23.18 ± 6.09 0.0000 ** VAS 7.17 ± 2.13 3.07 ± 1.98 0.0000 ** Uterine volume 261.98 ± 81.99 110.98 ± 15.67 0.0000 ** Association between 25(OH)D and adenomyosis-related parameters Table 3 presents the results of univariate and multivariate analyses evaluating the association between 25(OH)D levels and adenomyosis-related parameters. No significant correlation was found between serum 25(OH)D levels and CA125 levels in adenomyosis patients (p = 0.913). In univariate analysis, serum 25(OH)D levels were negatively correlated with pain severity (β = -0.106, 95% CI: -0.172 to -0.039, p = 0.002). This association remained significant in multivariate analysis after adjusting for confounders (β = -0.422, 95% CI: -0.710 to -0.133, p = 0.004), suggesting that lower 25(OH)D levels were associated with higher pain severity. Table 3 Association between 25(OH)D and adenomyosis-related parameters Variables Univariate analysis Multivariate analysis (95%CI) p OR (95%CI) p CA125 0.001( -0.024, 0.027) 0.913 VAS -0.106(-0.172, -0.039) 0.002 ** -0.422(-0.710, -0.133) 0.004 ** Uterine volume -7.692(-10.058, -5.326) 0.000 ** -0.023(-0.031, -0.016) 0.000 ** A strong negative correlation was observed between serum 25(OH)D levels and uterine volume in both univariate (β = -7.692, 95% CI: -10.058 to -5.326, p < 0.0001) and multivariate analyses (β = -0.023, 95% CI: -0.031 to -0.016, p < 0.0001). These results indicate that lower vitamin D levels were significantly associated with increased uterine volume in adenomyosis patients. Discussion Our results suggest that serum 25-hydroxyvitamin D levels were significantly lower in women with adenomyosis compared to healthy controls. Furthermore, lower vitamin D levels were associated with increased pain severity and larger uterine volume in adenomyosis patients. However, no significant correlation was observed between 25(OH)D levels and CA125 levels. These findings highlight the potential role of vitamin D in adenomyosis pathophysiology and warrant further investigation into its therapeutic implications. Vitamin D is a secosteroid hormone with well-established roles in calcium homeostasis and bone metabolism. However, accumulating evidence suggests that vitamin D also exerts immunomodulatory and anti-inflammatory effects 10 , which may be relevant to adenomyosis, a chronic inflammatory condition characterized by the ectopic presence of endometrial glands and stroma within the myometrium. Several studies have demonstrated that vitamin D deficiency is associated with various gynecological disorders, including endometriosis and uterine fibroids 11 , 12 . Given that adenomyosis shares common pathological mechanisms with endometriosis, such as inflammation, immune dysregulation, and hormonal imbalances, vitamin D may also play a role in the development and progression of adenomyosis. Several biological mechanisms have been proposed to explain how vitamin D deficiency may contribute to adenomyosis development. Adenomyosis is associated with chronic inflammation, as evidenced by elevated levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) in affected tissues 13 . Vitamin D is a potent anti-inflammatory agent, capable of suppressing the expression of pro-inflammatory cytokines and enhancing the production of anti-inflammatory mediators such as interleukin-10 (IL-10) 14 . Vitamin D deficiency may exacerbate the inflammatory microenvironment of the uterus, promoting adenomyosis progression. Estrogen dominance is a well-established factor in adenomyosis, driving myometrial hyperplasia, chronic inflammation, and increased endometrial invasiveness 15 . Vitamin D has been shown to modulate estrogen metabolism by inhibiting aromatase activity 16 and downregulating estrogen receptor (ER) expression, thereby reducing estrogenic stimulation of the endometrium. Furthermore, vitamin D enhances progesterone receptor (PR) expression, potentially restoring progesterone sensitivity and counteracting estrogen-driven hyperplasia 17 . One of the key findings of our study is the significant negative correlation between serum 25(OH)D levels and pain severity, measured by the VAS. This aligns with previous research suggesting that vitamin D plays a crucial role in pain modulation by regulating neuroinflammatory responses and reducing prostaglandin synthesis 18 , 19 . Vitamin D has been shown to downregulate the expression of inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) 20 , which are known to contribute to dysmenorrhea and chronic pelvic pain. Moreover, vitamin D enhances the production of anti-inflammatory cytokines, such as interleukin-10 (IL-10) 14 , thereby relieving pain-related inflammation. The finding validates that vitamin D deficiency may contribute to the exacerbation of pain symptoms in adenomyosis patients. Fibrosis and extracellular matrix (ECM) remodeling are key features of adenomyosis, contributing to uterine enlargement and increased stiffness. Another important observation in our study was the inverse relationship between serum 25(OH)D levels and uterine volume. This suggests that vitamin D may play a role in regulating myometrial remodeling and fibrosis, which are key pathological features of adenomyosis. Vitamin D has anti-fibrotic properties, primarily mediated through inhibition of the TGF-β/SMAD signaling pathway, which is upregulated in adenomyotic lesions 21 . In a study on uterine fibroids, vitamin D was shown to reduce fibrotic markers and inhibit cell proliferation in myometrial tissue 22 . Given the overlapping fibrotic mechanisms between fibroids and adenomyosis, it is plausible that vitamin D deficiency contributes to increased uterine volume in adenomyosis patients through increasing fibroblast activation and excessive collagen deposition. Interestingly, our study did not find a significant correlation between serum 25(OH)D levels and CA125, a biomarker that has been widely used in the diagnosis and monitoring of adenomyosis and endometriosis. Our findings indicate that vitamin D deficiency in adenomyosis patients may not directly impact CA125 expression. This suggests that the effect of vitamin D on adenomyosis pathophysiology may be mediated through mechanisms independent of CA125-related pathways. Our findings suggest that vitamin D deficiency may contribute to the pathogenesis of adenomyosis, particularly in terms of pain severity and uterine volume. These results raise the possibility of vitamin D supplementation as a potential therapeutic approach for adenomyosis patients. Previous studies have demonstrated the beneficial effects of vitamin D supplementation in reducing pain and inflammatory markers in conditions such as endometriosis and primary dysmenorrhea 18 , 23 , 24 . However, clinical trials specifically investigating the role of vitamin D supplementation in adenomyosis are currently lacking. There are some limitations in this study. First, the cross-sectional design of the study precludes the establishment of a causal relationship between vitamin D deficiency and adenomyosis. Second, the study did not account for seasonal variations in vitamin D levels, which may influence the findings. Lastly, while we identified significant associations, the precise molecular mechanisms through which vitamin D influences adenomyosis remain unclear and warrant further investigation. Future studies should aim to elucidate the underlying molecular mechanisms linking vitamin D to adenomyosis and assess whether vitamin D supplementation can improve clinical outcomes in affected patients. Additionally, larger prospective cohort studies are needed to confirm the causal relationship between vitamin D deficiency and adenomyosis. In conclusion, this study found that lower serum 25(OH)D levels were observed in adenomyosis patients and lower vitamin D levels is associated with increased pain severity and larger uterine volume in adenomyosis patients. These findings suggest that vitamin D may play a role in adenomyosis pathophysiology, and further research is needed to determine whether vitamin D supplementation could serve as a potential therapeutic strategy for this condition. Declarations Acknowledgements The authors sincerely thank all the participants who voluntarily participated in this study. We also express our gratitude to the research assistants who helped with data collection. Declaration of interest statement The authors report there are no competing interests to declare. Ethics approval and informed consent Ethical approval and permission to conduct the study were obtained from Northern Jiangsu People's Hospital Affiliated to Yangzhou University (clinical trial number: not applicable). All the data collection procedures were performed in accordance with the principles of the Declaration of Helsinki. The participants provided written informed consent, which contained detailed information about the study before they consented to participate. Data availability The datasets used in this study are available from the corresponding author on reasonable request. Authors' contributions G.L.L and Y.Q.X drafted the manuscript, recruited patients, and completed the survey. J.Y.X. performed statistical analyses. X.J.B. designed the study, and revised the manuscript. All authors have read and approved the final version of the manuscript. Funding Declaration There was no Funding. References A. Pontis； L. Nappi； F. Sorrentino SA. Differential diagnosis of adenomyosis: the role of hysteroscopy and laparoscopy. Clinical and Experimental Obstetrics and Gynecology . 2019;46(4):6. Zhai J, Vannuccini S, Petraglia F, Giudice LC. Adenomyosis: Mechanisms and Pathogenesis. Semin Reprod Med . May 2020;38(2-03):129-143. doi:10.1055/s-0040-1716687 Vannuccini S, Tosti C, Carmona F, et al. Pathogenesis of adenomyosis: an update on molecular mechanisms. Reprod Biomed Online . Nov 2017;35(5):592-601. doi:10.1016/j.rbmo.2017.06.016 Bourdon M, Santulli P, Jeljeli M, et al. Immunological changes associated with adenomyosis: a systematic review. Hum Reprod Update . Jan 4 2021;27(1):108-129. doi:10.1093/humupd/dmaa038 Kobayashi H, Kishi Y, Matsubara S. Mechanisms Underlying Adenomyosis-Related Fibrogenesis. Gynecol Obstet Invest . 2020;85(1):1-12. doi:10.1159/000502822 Buggio L, Roncella E, Somigliana E, Vercellini P. Vitamin D and benign gynaecological diseases: a critical analysis of the current evidence. Gynecol Endocrinol . 2016;32(4):259-63. doi:10.3109/09513590.2015.1111329 Skrobot A, Demkow U, Wachowska M. Immunomodulatory Role of Vitamin D: A Review. Adv Exp Med Biol . 2018;1108:13-23. doi:10.1007/5584_2018_246 Farhana A, Khan YS, Alsrhani A. Vitamin D at the intersection of health and disease: The immunomodulatory perspective. Int J Health Sci (Qassim) . Jul-Aug 2024;18(4):1-4. Qiu Y, Yuan S, Wang H. Vitamin D status in endometriosis: a systematic review and meta-analysis. Arch Gynecol Obstet . Jul 2020;302(1):141-152. doi:10.1007/s00404-020-05576-5 Krishnan AV, Feldman D. Mechanisms of the anti-cancer and anti-inflammatory actions of vitamin D. Annu Rev Pharmacol Toxicol . 2011;51:311-36. doi:10.1146/annurev-pharmtox-010510-100611 Yarmolinskaya M, Denisova A, Tkachenko N, et al. Vitamin D significance in pathogenesis of endometriosis. Gynecol Endocrinol . 2021;37(sup1):40-43. doi:10.1080/09513590.2021.2006516 Oskovi Kaplan ZA, Tasci Y, Topcu HO, Erkaya S. 25-Hydroxy vitamin D levels in premenopausal Turkish women with uterine leiomyoma. Gynecol Endocrinol . Mar 2018;34(3):261-264. doi:10.1080/09513590.2017.1391774 Maclean A, Barzilova V, Patel S, Bates F, Hapangama DK. Characterising the immune cell phenotype of ectopic adenomyosis lesions compared with eutopic endometrium: A systematic review. J Reprod Immunol . Jun 2023;157:103925. doi:10.1016/j.jri.2023.103925 Di Liberto D, Scazzone C, La Rocca G, et al. Vitamin D increases the production of IL-10 by regulatory T cells in patients with systemic sclerosis. Clin Exp Rheumatol . Dec 3 2020;38(6):1276. Donnez J, Stratopoulou CA, Dolmans MM. Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists. Int J Environ Res Public Health . Sep 22 2021;18(19)doi:10.3390/ijerph18199941 Tanaka S, Haji M, Takayanagi R, Tanaka S, Sugioka Y, Nawata H. 1,25-Dihydroxyvitamin D3 enhances the enzymatic activity and expression of the messenger ribonucleic acid for aromatase cytochrome P450 synergistically with dexamethasone depending on the vitamin D receptor level in cultured human osteoblasts. Endocrinology . May 1996;137(5):1860-9. doi:10.1210/endo.137.5.8612525 Hosseinirad H, Novin MG, Hosseini S, et al. Effect of 1,25(OH)2-vitamin D3 on expression and phosphorylation of progesterone receptor in cultured endometrial stromal cells of patients with repeated implantation failure. Acta Histochem . Feb 2020;122(2):151489. doi:10.1016/j.acthis.2019.151489 Abdi F, Amjadi MA, Zaheri F, Rahnemaei FA. Role of vitamin D and calcium in the relief of primary dysmenorrhea: a systematic review. Obstet Gynecol Sci . Jan 2021;64(1):13-26. doi:10.5468/ogs.20205 Lin KC, Huang KJ, Lin MN, Wang CY, Tsai TY. Vitamin D Supplementation for Patients with Dysmenorrhoea: A Meta-Analysis with Trial Sequential Analysis of Randomised Controlled Trials. Nutrients . Apr 8 2024;16(7)doi:10.3390/nu16071089 Delbandi AA, Mahmoudi M, Shervin A, Zarnani AH. 1,25-Dihydroxy Vitamin D3 Modulates Endometriosis-Related Features of Human Endometriotic Stromal Cells. Am J Reprod Immunol . Apr 2016;75(4):461-73. doi:10.1111/aji.12463 Li X, Xu S, Liu J, et al. Treatment with 1,25-Dihydroxyvitamin D3 Delays Choroid Plexus Infiltration and BCSFB Injury in MRL/lpr Mice Coinciding with Activation of the PPARgamma/NF-kappaB/TNF-alpha Pathway and Suppression of TGF-beta/Smad Signaling. Inflammation . Apr 2023;46(2):556-572. doi:10.1007/s10753-022-01755-5 Halder SK, Goodwin JS, Al-Hendy A. 1,25-Dihydroxyvitamin D3 reduces TGF-beta3-induced fibrosis-related gene expression in human uterine leiomyoma cells. J Clin Endocrinol Metab . Apr 2011;96(4):E754-62. doi:10.1210/jc.2010-2131 Kalaitzopoulos DR, Samartzis N, Daniilidis A, et al. Effects of vitamin D supplementation in endometriosis: a systematic review. Reprod Biol Endocrinol . Dec 28 2022;20(1):176. doi:10.1186/s12958-022-01051-9 Mehdizadehkashi A, Rokhgireh S, Tahermanesh K, Eslahi N, Minaeian S, Samimi M. The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis. Gynecol Endocrinol . Jul 2021;37(7):640-645. doi:10.1080/09513590.2021.1878138 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 05 Jun, 2025 Reviewers agreed at journal 05 Jun, 2025 Reviewers invited by journal 05 Jun, 2025 Editor invited by journal 15 May, 2025 Editor assigned by journal 15 May, 2025 Submission checks completed at journal 15 May, 2025 First submitted to journal 13 May, 2025 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-6656392\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":466961480,\"identity\":\"8da5c23d-dde6-4dec-8a29-af650c7ea4c1\",\"order_by\":0,\"name\":\"Lingling Gao\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Northern Jiangsu People's Hospital Affiliated to Yangzhou University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Lingling\",\"middleName\":\"\",\"lastName\":\"Gao\",\"suffix\":\"\"},{\"id\":466961483,\"identity\":\"02f4a7bf-e220-49d3-a7bc-786a1fe9a0df\",\"order_by\":1,\"name\":\"Qingxing Yang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Northern Jiangsu People's Hospital Affiliated to Yangzhou University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Qingxing\",\"middleName\":\"\",\"lastName\":\"Yang\",\"suffix\":\"\"},{\"id\":466961484,\"identity\":\"5de3f0b1-4b4d-49ec-a25a-acf23cdf40c8\",\"order_by\":2,\"name\":\"Yuxin Ju\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Northern Jiangsu People's Hospital Affiliated to Yangzhou University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Yuxin\",\"middleName\":\"\",\"lastName\":\"Ju\",\"suffix\":\"\"},{\"id\":466961485,\"identity\":\"f2f9d520-f9ac-4e9f-b061-d5ab4af84e03\",\"order_by\":3,\"name\":\"Jianbo Xu\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIie3PMWsCMRTA8XccxCXUNYKcX+GBoBSEfpUEIVMFxwyCHpRk8Mp9ldvqeBq4Ke43dIiLs26OtnOluW4d8pvfn/ceQBT9Q6SXmwvHWfZiyqvnahVOnqhtwCs5RlqP0bsmnGRMysS7g6gYnwxOb2mHw6ibeKHr5IPWUokNgb7Z8sAvxRSF/kyfzaZpxW4IzB2r0BZkQp8JuL1uhSOAbBFI2Ot3Yim0c7IUOu2SSMm4swxbSaBbQq1FriQOCpd+tQ0N/jIyeX664Wxd9orkelOrrG/ef09+oH8bj6Ioih66A+mdUHlYmCyGAAAAAElFTkSuQmCC\",\"orcid\":\"\",\"institution\":\"Northern Jiangsu People's Hospital Affiliated to Yangzhou University\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Jianbo\",\"middleName\":\"\",\"lastName\":\"Xu\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-05-13 14:23:09\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-6656392/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-6656392/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":84208961,\"identity\":\"f8e7ae5d-c4d8-4c76-bc6b-ac8965b59950\",\"added_by\":\"auto\",\"created_at\":\"2025-06-09 09:41:05\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":513897,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6656392/v1/e9b8cc08-e81a-4207-af91-0457b48cc765.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Association Between Serum 25-Hydroxyvitamin D Levels and Clinical Characteristics of Adenomyosis: A Case-Control Study\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eAdenomyosis is a chronic gynecological disorder characterized by the ectopic growth of endometrial glands and stroma within the myometrium, leading to dysmenorrhea, abnormal uterine bleeding, pelvic pain, and infertility. The prevalence of adenomyosis varies widely, ranging from 5\\u0026ndash;70%, largely depending on the diagnostic methods used\\u003csup\\u003e\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e\\u003c/sup\\u003e. Advances in imaging, particularly transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI), have improved the non-invasive diagnosis of adenomyosis, but the disease remains underdiagnosed and misinterpreted due to symptom overlap with conditions such as endometriosis and uterine fibroids.\\u003c/p\\u003e \\u003cp\\u003eUntil now the exact etiology and pathophysiology of adenomyosis remain poorly understood. Emerging evidence suggests that hormonal imbalance, chronic inflammation, immune dysregulation, and fibrosis play key roles in disease progression. Studies have demonstrated that adenomyosis is associated with increased expression of inflammatory mediators and cytokines, indicating the involvement of inflammatory pathways in its pathogenesis\\u003csup\\u003e\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e\\u003c/sup\\u003e. Additionally, alterations in sex steroid hormone receptors and inflammatory molecules have been implicated in the disease's development\\u003csup\\u003e\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u003c/sup\\u003e. Furthermore, immunological changes, including the activation of immune cells and the release of immune soluble factors, have been observed in adenomyosis, highlighting the role of immune system dysregulation\\u003csup\\u003e\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e\\u003c/sup\\u003e. Finally, mechanisms underlying adenomyosis-related fibrogenesis involve transforming growth factor beta (TGF-β)-dependent and independent pathways, contributing to fibrosis in the uterine tissue\\u003csup\\u003e\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e\\u003c/sup\\u003e. ​Among potential contributing factors, vitamin D deficiency has gained increasing attention in gynecological disorders, including polycystic ovary syndrome (PCOS), endometriosis, and uterine fibroids\\u003csup\\u003e\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e\\u003c/sup\\u003e. However, its role in adenomyosis is not well established, necessitating further investigation.\\u003c/p\\u003e \\u003cp\\u003eVitamin D is a steroid hormone primarily known for its role in calcium homeostasis and bone metabolism. However, recent research has highlighted its pleiotropic effects, particularly in immune modulation, inflammation control, and hormone regulation\\u003csup\\u003e\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e,\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e\\u003c/sup\\u003e. The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)₂D₃), exerts its biological functions by binding to the vitamin D receptor (VDR), which is expressed in endometrial, myometrial, and immune cells\\u003csup\\u003e\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e\\u003c/sup\\u003e. The circulating form of vitamin D, 25-hydroxyvitamin D (25(OH)D), is widely used as a biomarker for vitamin D status. Deficiency in 25(OH)D has been linked to various gynecological diseases, but its relationship with adenomyosis is not well explored. Given that adenomyosis shares pathophysiological similarities with endometriosis\\u0026mdash;where vitamin D deficiency is implicated\\u003csup\\u003e\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e\\u003c/sup\\u003e\\u0026mdash;there is growing interest in the potential role of vitamin D on adenomyosis pathogenesis. Therefore, this study aims to investigate the correlation between serum 25-hydroxyvitamin D levels and adenomyosis and assess whether low vitamin D levels correlate with the severity of symptoms, uterine volume, or lesion characteristics in adenomyosis, with the goal of providing new insights for the early diagnosis, treatment, and prevention of adenomyosis.\\u003c/p\\u003e\"},{\"header\":\"Materials and methods\",\"content\":\"\\u003cp\\u003eStudy design\\u003c/p\\u003e \\u003cp\\u003eThis study is designed as a retrospective case-control study following the Helsinki Declaration. The study received approval from the Ethics Committee of Northern Jiangsu People\\u0026rsquo;s Hospital Affiliated to Yangzhou University and informed consent was collected from all participants. A total of 177 women who underwent hysterectomy were histopathologically diagnosed with adenomyosis between January 2022 and March 2025 and 178 women without adenomyosis were retrospectively evaluated. The study group only recruited premenopausal females between the ages of 35 and 50 years with pathologically confirmed adenomyosis. The control group contained 178 females who came to hospital for physical examination, and no adenomyosis was detected by transvaginal ultrasound. Patients with vitamin D use during the last 6 months, the presence of any systemic disease, known malignancy, hormone replacement therapy, oral contraceptive use, uterine fibroid, and ovarian cyst were excluded from the study. Demographic, clinical and laboratory characteristics (e.g., age, body mass index (BMI), obstetric history, employed status, smoking and alcohol consumption) were recorded at the time of admission. Visual analogue scale (VAS, 0\\u0026ndash;10 points) scores were calculated for each patient to evaluate the severity of dysmenorrhea. A VAS value of \\u0026ldquo;0\\u0026rdquo; denoted the absence of pain, whereas a VAS value of \\u0026ldquo;10\\u0026rdquo; represented the maximum level of discomfort. CA125, uterine volume and VAS score were recorded for adenomyosis patients. The volume of the uterus is calculated using the prolate ellipsoid formula: Uterine Volume (cm\\u0026sup3;)\\u0026thinsp;=\\u0026thinsp;Length (cm)\\u0026times;Width (cm)\\u0026times;Height (cm)\\u0026times;0.523.\\u003c/p\\u003e \\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003eStatistical analysis\\u003c/h2\\u003e \\u003cp\\u003eContinuous variables (e.g., serum 25(OH)D levels) were analyzed using independent t-tests or Mann-Whitney U tests for non-normally distributed data between adenomyosis and control groups. Pearson or Spearman correlation coefficients were used to determine the relationship between vitamin D levels and clinical parameters, such as CA125, pain severity, and uterine volume. Multiple linear regression was performed to assess whether serum 25(OH)D is an independent risk factor for adenomyosis severity.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cp\\u003eDemographic characteristics of study participants\\u003c/p\\u003e \\u003cp\\u003eA total of 355 women were included in the study, with 177 patients diagnosed with adenomyosis and 178 women serving as healthy controls. The demographic characteristics of the participants are summarized in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. The mean age was 44.68\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.71 years in the adenomyosis group and 44.52\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.73 years in the control group, with no significant difference between the two groups (p\\u0026thinsp;=\\u0026thinsp;0.7047). The BMI was also comparable between these two groups (25.90\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.19 vs. 26.34\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.85, p\\u0026thinsp;=\\u0026thinsp;0.3117). However, the number of pregnancies (gravida) was significantly higher in the adenomyosis group (2.672\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.926) compared to the control group (2.382\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.950, p\\u0026thinsp;=\\u0026thinsp;0.0038). The number of parities did not show significant differences between the two groups (1.102\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.400 vs. 1.084\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.423). The proportion of employment status was not significantly different in the adenomyosis group and control group (80.79% vs. 83.15%). The smoking, and alcohol consumption rate was similar between the two groups.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eThe demographic characteristics of women with and without adenomyosis.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eadenomyosis group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;177)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eConrol group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;178)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003ep-value\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAge\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e44.68\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.71\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e44.52\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.73\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.7047\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBMI\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e25.90\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.19\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e26.34\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.85\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.3117\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eGravida\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2.672\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.926\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.382\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.950\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.0038\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eParity\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1.102\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.400\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.084\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.423\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.6905\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eEmployed (n)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e143(80.79%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e148(83.15%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.3331\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eSmoking (n)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e10(5.65%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e12(6.74%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.1820\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAlcohol (n)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e13(7.34%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e15(8.43%)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.7050\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eSerum 25(OH)D levels and clinical parameters of women with and without adenomyosis\\u003c/p\\u003e \\u003cp\\u003eThe comparison of serum 25(OH)D levels and clinical parameters between adenomyosis group and control group are presented in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e. Serum 25-hydroxyvitamin D levels were significantly lower in the adenomyosis group (12.14\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.65 ng/mL) compared to the control group (14.13\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.02 ng/mL, p\\u0026thinsp;=\\u0026thinsp;0.0001). CA125 levels were substantially elevated in the adenomyosis group (70.32\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;27.02 U/mL) compared to controls (23.18\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.09 U/mL, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001). Additionally, pain severity, measured by the VAS, was significantly higher in the adenomyosis group (7.17\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.13) compared to the control group (3.07\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.98, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001). The uterine volume was significantly larger in women with adenomyosis (261.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;81.99 cm\\u0026sup3;) compared to the control group (110.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;15.67 cm\\u0026sup3;, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eSerum 25(OH)D levels and clinical parameters of women with and without adenomyosis.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eadenomyosis group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;177)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eConrol group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;178)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003ep-value\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e25-OH vitamin D(ng/ml)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e12.14\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.65\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e14.13\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.0001\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCA125(U/ml)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e70.32\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;27.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e23.18\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.09\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.0000\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVAS\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e7.17\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.13\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3.07\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.98\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.0000\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eUterine volume\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e261.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;81.99\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026plusmn;\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e110.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;15.67\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.0000\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eAssociation between 25(OH)D and adenomyosis-related parameters\\u003c/p\\u003e \\u003cp\\u003eTable\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e presents the results of univariate and multivariate analyses evaluating the association between 25(OH)D levels and adenomyosis-related parameters. No significant correlation was found between serum 25(OH)D levels and CA125 levels in adenomyosis patients (p\\u0026thinsp;=\\u0026thinsp;0.913). In univariate analysis, serum 25(OH)D levels were negatively correlated with pain severity (β = -0.106, 95% CI: -0.172 to -0.039, p\\u0026thinsp;=\\u0026thinsp;0.002). This association remained significant in multivariate analysis after adjusting for confounders (β = -0.422, 95% CI: -0.710 to -0.133, p\\u0026thinsp;=\\u0026thinsp;0.004), suggesting that lower 25(OH)D levels were associated with higher pain severity.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eAssociation between 25(OH)D and adenomyosis-related parameters\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"5\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\"\\u0026minus;\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\"\\u0026minus;\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"1\\\" rowspan=\\\"2\\\"\\u003e \\u003cp\\u003eVariables\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eUnivariate analysis\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c5\\\" namest=\\\"c4\\\"\\u003e \\u003cp\\u003eMultivariate analysis\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e(95%CI)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003ep\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eOR (95%CI)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003ep\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCA125\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026minus;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.001( -0.024, 0.027)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.913\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVAS\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026minus;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-0.106(-0.172, -0.039)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.002\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026minus;\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-0.422(-0.710, -0.133)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.004\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eUterine volume\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026minus;\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-7.692(-10.058, -5.326)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.000\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\"\\u0026minus;\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-0.023(-0.031, -0.016)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.000\\u003csup\\u003e**\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eA strong negative correlation was observed between serum 25(OH)D levels and uterine volume in both univariate (β = -7.692, 95% CI: -10.058 to -5.326, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001) and multivariate analyses (β = -0.023, 95% CI: -0.031 to -0.016, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001). These results indicate that lower vitamin D levels were significantly associated with increased uterine volume in adenomyosis patients.\\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eOur results suggest that serum 25-hydroxyvitamin D levels were significantly lower in women with adenomyosis compared to healthy controls. Furthermore, lower vitamin D levels were associated with increased pain severity and larger uterine volume in adenomyosis patients. However, no significant correlation was observed between 25(OH)D levels and CA125 levels. These findings highlight the potential role of vitamin D in adenomyosis pathophysiology and warrant further investigation into its therapeutic implications.\\u003c/p\\u003e \\u003cp\\u003eVitamin D is a secosteroid hormone with well-established roles in calcium homeostasis and bone metabolism. However, accumulating evidence suggests that vitamin D also exerts immunomodulatory and anti-inflammatory effects\\u003csup\\u003e\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e\\u003c/sup\\u003e, which may be relevant to adenomyosis, a chronic inflammatory condition characterized by the ectopic presence of endometrial glands and stroma within the myometrium. Several studies have demonstrated that vitamin D deficiency is associated with various gynecological disorders, including endometriosis and uterine fibroids\\u003csup\\u003e\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e,\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e\\u003c/sup\\u003e. Given that adenomyosis shares common pathological mechanisms with endometriosis, such as inflammation, immune dysregulation, and hormonal imbalances, vitamin D may also play a role in the development and progression of adenomyosis.\\u003c/p\\u003e \\u003cp\\u003eSeveral biological mechanisms have been proposed to explain how vitamin D deficiency may contribute to adenomyosis development. Adenomyosis is associated with chronic inflammation, as evidenced by elevated levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) in affected tissues\\u003csup\\u003e\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e\\u003c/sup\\u003e. Vitamin D is a potent anti-inflammatory agent, capable of suppressing the expression of pro-inflammatory cytokines and enhancing the production of anti-inflammatory mediators such as interleukin-10 (IL-10)\\u003csup\\u003e\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e\\u003c/sup\\u003e. Vitamin D deficiency may exacerbate the inflammatory microenvironment of the uterus, promoting adenomyosis progression.\\u003c/p\\u003e \\u003cp\\u003eEstrogen dominance is a well-established factor in adenomyosis, driving myometrial hyperplasia, chronic inflammation, and increased endometrial invasiveness\\u003csup\\u003e\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e\\u003c/sup\\u003e. Vitamin D has been shown to modulate estrogen metabolism by inhibiting aromatase activity\\u003csup\\u003e\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e\\u003c/sup\\u003e and downregulating estrogen receptor (ER) expression, thereby reducing estrogenic stimulation of the endometrium. Furthermore, vitamin D enhances progesterone receptor (PR) expression, potentially restoring progesterone sensitivity and counteracting estrogen-driven hyperplasia\\u003csup\\u003e\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003cp\\u003eOne of the key findings of our study is the significant negative correlation between serum 25(OH)D levels and pain severity, measured by the VAS. This aligns with previous research suggesting that vitamin D plays a crucial role in pain modulation by regulating neuroinflammatory responses and reducing prostaglandin synthesis\\u003csup\\u003e\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e,\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e\\u003c/sup\\u003e. Vitamin D has been shown to downregulate the expression of inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)\\u003csup\\u003e\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e\\u003c/sup\\u003e, which are known to contribute to dysmenorrhea and chronic pelvic pain. Moreover, vitamin D enhances the production of anti-inflammatory cytokines, such as interleukin-10 (IL-10)\\u003csup\\u003e\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e\\u003c/sup\\u003e, thereby relieving pain-related inflammation. The finding validates that vitamin D deficiency may contribute to the exacerbation of pain symptoms in adenomyosis patients.\\u003c/p\\u003e \\u003cp\\u003eFibrosis and extracellular matrix (ECM) remodeling are key features of adenomyosis, contributing to uterine enlargement and increased stiffness. Another important observation in our study was the inverse relationship between serum 25(OH)D levels and uterine volume. This suggests that vitamin D may play a role in regulating myometrial remodeling and fibrosis, which are key pathological features of adenomyosis. Vitamin D has anti-fibrotic properties, primarily mediated through inhibition of the TGF-β/SMAD signaling pathway, which is upregulated in adenomyotic lesions\\u003csup\\u003e\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e\\u003c/sup\\u003e. In a study on uterine fibroids, vitamin D was shown to reduce fibrotic markers and inhibit cell proliferation in myometrial tissue\\u003csup\\u003e\\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e\\u003c/sup\\u003e. Given the overlapping fibrotic mechanisms between fibroids and adenomyosis, it is plausible that vitamin D deficiency contributes to increased uterine volume in adenomyosis patients through increasing fibroblast activation and excessive collagen deposition.\\u003c/p\\u003e \\u003cp\\u003eInterestingly, our study did not find a significant correlation between serum 25(OH)D levels and CA125, a biomarker that has been widely used in the diagnosis and monitoring of adenomyosis and endometriosis. Our findings indicate that vitamin D deficiency in adenomyosis patients may not directly impact CA125 expression. This suggests that the effect of vitamin D on adenomyosis pathophysiology may be mediated through mechanisms independent of CA125-related pathways.\\u003c/p\\u003e \\u003cp\\u003eOur findings suggest that vitamin D deficiency may contribute to the pathogenesis of adenomyosis, particularly in terms of pain severity and uterine volume. These results raise the possibility of vitamin D supplementation as a potential therapeutic approach for adenomyosis patients. Previous studies have demonstrated the beneficial effects of vitamin D supplementation in reducing pain and inflammatory markers in conditions such as endometriosis and primary dysmenorrhea\\u003csup\\u003e\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e,\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e,\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e\\u003c/sup\\u003e. However, clinical trials specifically investigating the role of vitamin D supplementation in adenomyosis are currently lacking.\\u003c/p\\u003e \\u003cp\\u003eThere are some limitations in this study. First, the cross-sectional design of the study precludes the establishment of a causal relationship between vitamin D deficiency and adenomyosis. Second, the study did not account for seasonal variations in vitamin D levels, which may influence the findings. Lastly, while we identified significant associations, the precise molecular mechanisms through which vitamin D influences adenomyosis remain unclear and warrant further investigation. Future studies should aim to elucidate the underlying molecular mechanisms linking vitamin D to adenomyosis and assess whether vitamin D supplementation can improve clinical outcomes in affected patients. Additionally, larger prospective cohort studies are needed to confirm the causal relationship between vitamin D deficiency and adenomyosis.\\u003c/p\\u003e \\u003cp\\u003eIn conclusion, this study found that lower serum 25(OH)D levels were observed in adenomyosis patients and lower vitamin D levels is associated with increased pain severity and larger uterine volume in adenomyosis patients. These findings suggest that vitamin D may play a role in adenomyosis pathophysiology, and further research is needed to determine whether vitamin D supplementation could serve as a potential therapeutic strategy for this condition.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgements\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors sincerely thank all the participants who voluntarily participated in this study. We also express our gratitude to the research assistants who helped with data collection.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eDeclaration of interest statement\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors report there are no competing interests to declare.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eEthics approval and informed consent\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eEthical approval and permission to conduct the study were obtained from Northern Jiangsu People\\u0026apos;s Hospital Affiliated to Yangzhou University (clinical trial number: not applicable). All the data collection procedures were performed in accordance with the principles of the Declaration of Helsinki. The participants provided written informed consent, which contained detailed information about the study before they consented to participate.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eData availability\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe datasets used in this study are available from the corresponding author on reasonable request.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthors\\u0026apos; contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eG.L.L and Y.Q.X drafted the manuscript, recruited patients, and completed the survey. J.Y.X. performed statistical analyses. X.J.B. designed the study, and revised the manuscript. All authors have read and approved the final version of the manuscript.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFunding Declaration\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThere was no Funding.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eA. Pontis； L. Nappi； F. Sorrentino SA. Differential diagnosis of adenomyosis: the role of hysteroscopy and laparoscopy. \\u003cem\\u003eClinical and Experimental Obstetrics and Gynecology\\u003c/em\\u003e. 2019;46(4):6. \\u003c/li\\u003e\\n\\u003cli\\u003eZhai J, Vannuccini S, Petraglia F, Giudice LC. Adenomyosis: Mechanisms and Pathogenesis. \\u003cem\\u003eSemin Reprod Med\\u003c/em\\u003e. May 2020;38(2-03):129-143. doi:10.1055/s-0040-1716687\\u003c/li\\u003e\\n\\u003cli\\u003eVannuccini S, Tosti C, Carmona F, et al. Pathogenesis of adenomyosis: an update on molecular mechanisms. \\u003cem\\u003eReprod Biomed Online\\u003c/em\\u003e. Nov 2017;35(5):592-601. doi:10.1016/j.rbmo.2017.06.016\\u003c/li\\u003e\\n\\u003cli\\u003eBourdon M, Santulli P, Jeljeli M, et al. Immunological changes associated with adenomyosis: a systematic review. \\u003cem\\u003eHum Reprod Update\\u003c/em\\u003e. Jan 4 2021;27(1):108-129. doi:10.1093/humupd/dmaa038\\u003c/li\\u003e\\n\\u003cli\\u003eKobayashi H, Kishi Y, Matsubara S. Mechanisms Underlying Adenomyosis-Related Fibrogenesis. \\u003cem\\u003eGynecol Obstet Invest\\u003c/em\\u003e. 2020;85(1):1-12. doi:10.1159/000502822\\u003c/li\\u003e\\n\\u003cli\\u003eBuggio L, Roncella E, Somigliana E, Vercellini P. Vitamin D and benign gynaecological diseases: a critical analysis of the current evidence. \\u003cem\\u003eGynecol Endocrinol\\u003c/em\\u003e. 2016;32(4):259-63. doi:10.3109/09513590.2015.1111329\\u003c/li\\u003e\\n\\u003cli\\u003eSkrobot A, Demkow U, Wachowska M. Immunomodulatory Role of Vitamin D: A Review. \\u003cem\\u003eAdv Exp Med Biol\\u003c/em\\u003e. 2018;1108:13-23. doi:10.1007/5584_2018_246\\u003c/li\\u003e\\n\\u003cli\\u003eFarhana A, Khan YS, Alsrhani A. Vitamin D at the intersection of health and disease: The immunomodulatory perspective. \\u003cem\\u003eInt J Health Sci (Qassim)\\u003c/em\\u003e. Jul-Aug 2024;18(4):1-4. \\u003c/li\\u003e\\n\\u003cli\\u003eQiu Y, Yuan S, Wang H. Vitamin D status in endometriosis: a systematic review and meta-analysis. \\u003cem\\u003eArch Gynecol Obstet\\u003c/em\\u003e. Jul 2020;302(1):141-152. doi:10.1007/s00404-020-05576-5\\u003c/li\\u003e\\n\\u003cli\\u003eKrishnan AV, Feldman D. Mechanisms of the anti-cancer and anti-inflammatory actions of vitamin D. \\u003cem\\u003eAnnu Rev Pharmacol Toxicol\\u003c/em\\u003e. 2011;51:311-36. doi:10.1146/annurev-pharmtox-010510-100611\\u003c/li\\u003e\\n\\u003cli\\u003eYarmolinskaya M, Denisova A, Tkachenko N, et al. Vitamin D significance in pathogenesis of endometriosis. \\u003cem\\u003eGynecol Endocrinol\\u003c/em\\u003e. 2021;37(sup1):40-43. doi:10.1080/09513590.2021.2006516\\u003c/li\\u003e\\n\\u003cli\\u003eOskovi Kaplan ZA, Tasci Y, Topcu HO, Erkaya S. 25-Hydroxy vitamin D levels in premenopausal Turkish women with uterine leiomyoma. \\u003cem\\u003eGynecol Endocrinol\\u003c/em\\u003e. Mar 2018;34(3):261-264. doi:10.1080/09513590.2017.1391774\\u003c/li\\u003e\\n\\u003cli\\u003eMaclean A, Barzilova V, Patel S, Bates F, Hapangama DK. Characterising the immune cell phenotype of ectopic adenomyosis lesions compared with eutopic endometrium: A systematic review. \\u003cem\\u003eJ Reprod Immunol\\u003c/em\\u003e. Jun 2023;157:103925. doi:10.1016/j.jri.2023.103925\\u003c/li\\u003e\\n\\u003cli\\u003eDi Liberto D, Scazzone C, La Rocca G, et al. Vitamin D increases the production of IL-10 by regulatory T cells in patients with systemic sclerosis. \\u003cem\\u003eClin Exp Rheumatol\\u003c/em\\u003e. Dec 3 2020;38(6):1276. \\u003c/li\\u003e\\n\\u003cli\\u003eDonnez J, Stratopoulou CA, Dolmans MM. Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists. \\u003cem\\u003eInt J Environ Res Public Health\\u003c/em\\u003e. Sep 22 2021;18(19)doi:10.3390/ijerph18199941\\u003c/li\\u003e\\n\\u003cli\\u003eTanaka S, Haji M, Takayanagi R, Tanaka S, Sugioka Y, Nawata H. 1,25-Dihydroxyvitamin D3 enhances the enzymatic activity and expression of the messenger ribonucleic acid for aromatase cytochrome P450 synergistically with dexamethasone depending on the vitamin D receptor level in cultured human osteoblasts. \\u003cem\\u003eEndocrinology\\u003c/em\\u003e. May 1996;137(5):1860-9. doi:10.1210/endo.137.5.8612525\\u003c/li\\u003e\\n\\u003cli\\u003eHosseinirad H, Novin MG, Hosseini S, et al. Effect of 1,25(OH)2-vitamin D3 on expression and phosphorylation of progesterone receptor in cultured endometrial stromal cells of patients with repeated implantation failure. \\u003cem\\u003eActa Histochem\\u003c/em\\u003e. Feb 2020;122(2):151489. doi:10.1016/j.acthis.2019.151489\\u003c/li\\u003e\\n\\u003cli\\u003eAbdi F, Amjadi MA, Zaheri F, Rahnemaei FA. Role of vitamin D and calcium in the relief of primary dysmenorrhea: a systematic review. \\u003cem\\u003eObstet Gynecol Sci\\u003c/em\\u003e. Jan 2021;64(1):13-26. doi:10.5468/ogs.20205\\u003c/li\\u003e\\n\\u003cli\\u003eLin KC, Huang KJ, Lin MN, Wang CY, Tsai TY. Vitamin D Supplementation for Patients with Dysmenorrhoea: A Meta-Analysis with Trial Sequential Analysis of Randomised Controlled Trials. \\u003cem\\u003eNutrients\\u003c/em\\u003e. Apr 8 2024;16(7)doi:10.3390/nu16071089\\u003c/li\\u003e\\n\\u003cli\\u003eDelbandi AA, Mahmoudi M, Shervin A, Zarnani AH. 1,25-Dihydroxy Vitamin D3 Modulates Endometriosis-Related Features of Human Endometriotic Stromal Cells. \\u003cem\\u003eAm J Reprod Immunol\\u003c/em\\u003e. Apr 2016;75(4):461-73. doi:10.1111/aji.12463\\u003c/li\\u003e\\n\\u003cli\\u003eLi X, Xu S, Liu J, et al. Treatment with 1,25-Dihydroxyvitamin D3 Delays Choroid Plexus Infiltration and BCSFB Injury in MRL/lpr Mice Coinciding with Activation of the PPARgamma/NF-kappaB/TNF-alpha Pathway and Suppression of TGF-beta/Smad Signaling. \\u003cem\\u003eInflammation\\u003c/em\\u003e. Apr 2023;46(2):556-572. doi:10.1007/s10753-022-01755-5\\u003c/li\\u003e\\n\\u003cli\\u003eHalder SK, Goodwin JS, Al-Hendy A. 1,25-Dihydroxyvitamin D3 reduces TGF-beta3-induced fibrosis-related gene expression in human uterine leiomyoma cells. \\u003cem\\u003eJ Clin Endocrinol Metab\\u003c/em\\u003e. Apr 2011;96(4):E754-62. doi:10.1210/jc.2010-2131\\u003c/li\\u003e\\n\\u003cli\\u003eKalaitzopoulos DR, Samartzis N, Daniilidis A, et al. Effects of vitamin D supplementation in endometriosis: a systematic review. \\u003cem\\u003eReprod Biol Endocrinol\\u003c/em\\u003e. Dec 28 2022;20(1):176. doi:10.1186/s12958-022-01051-9\\u003c/li\\u003e\\n\\u003cli\\u003eMehdizadehkashi A, Rokhgireh S, Tahermanesh K, Eslahi N, Minaeian S, Samimi M. The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis. \\u003cem\\u003eGynecol Endocrinol\\u003c/em\\u003e. Jul 2021;37(7):640-645. doi:10.1080/09513590.2021.1878138\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"bmc-womens-health\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"bmwh\",\"sideBox\":\"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)\",\"snPcode\":\"\",\"submissionUrl\":\"https://www.editorialmanager.com/bmwh/default.aspx\",\"title\":\"BMC Women's Health\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"BMC Series\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Serum 25-Hydroxyvitamin D, adenomyosis, VAS, uterine volume\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-6656392/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-6656392/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eBackground\\u003c/h2\\u003e \\u003cp\\u003eAdenomyosis is a chronic gynecological condition characterized by the presence of endometrial glands and stroma within the myometrium, resulting in dysmenorrhea, menorrhagia, and infertility.\\u003c/p\\u003e\\u003ch2\\u003eObjectives\\u003c/h2\\u003e \\u003cp\\u003eThis study was designed to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and adenomyosis and explore whether vitamin D deficiency is associated with the clinical characteristics of clinical symptoms.\\u003c/p\\u003e\\u003ch2\\u003eMethods\\u003c/h2\\u003e \\u003cp\\u003eThis case-control study included 177 women with adenomyosis and 178 age-matched healthy controls. Demographic and clinical data were collected, including age, BMI, parity, VAS pain scores, serum CA125 levels, and uterine volume. Serum 25(OH)D levels were measured and analyzed. Univariate and multivariate regression models were used to assess associations between vitamin D levels and disease parameters.\\u003c/p\\u003e\\u003ch2\\u003eResults\\u003c/h2\\u003e \\u003cp\\u003eWomen with adenomyosis had significantly lower serum 25(OH)D levels compared to controls (12.14\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.65 ng/mL vs. 14.13\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.02 ng/mL, p\\u0026thinsp;=\\u0026thinsp;0.0001). They also had significantly higher VAS pain scores (7.17\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.13 vs. 3.07\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.98, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001), larger uterine volumes (261.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;81.99 cm\\u0026sup3; vs. 110.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;15.67 cm\\u0026sup3;, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001), and elevated CA125 levels (70.32\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;27.02 U/mL vs. 23.18\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.09 U/mL, p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.0001). Multivariate linear regression showed that lower 25(OH)D levels were significantly associated with greater uterine volume and higher VAS pain scores. No significant association was observed between vitamin D and CA125 levels.\\u003c/p\\u003e\\u003ch2\\u003eConclusion\\u003c/h2\\u003e \\u003cp\\u003elower serum 25(OH)D levels were observed in adenomyosis patients and lower vitamin D levels is associated with increased pain severity and larger uterine volume in adenomyosis patients.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Association Between Serum 25-Hydroxyvitamin D Levels and Clinical Characteristics of Adenomyosis: A Case-Control Study\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-06-09 09:32:56\",\"doi\":\"10.21203/rs.3.rs-6656392/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"reviewerAgreed\",\"content\":\"109912557979630041114986945667011393067\",\"date\":\"2025-06-05T10:44:28+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"299374237895424701836967103433171342227\",\"date\":\"2025-06-05T05:30:13+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-06-05T05:23:36+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvited\",\"content\":\"\",\"date\":\"2025-05-15T07:53:28+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-05-15T05:55:05+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2025-05-15T05:51:45+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"BMC Women's Health\",\"date\":\"2025-05-13T14:09:01+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"bmc-womens-health\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"bmwh\",\"sideBox\":\"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)\",\"snPcode\":\"\",\"submissionUrl\":\"https://www.editorialmanager.com/bmwh/default.aspx\",\"title\":\"BMC Women's Health\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"BMC Series\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"a5b84d05-22a0-47a0-9caa-71c592bfc2d5\",\"owner\":[],\"postedDate\":\"June 9th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-06-09T09:32:56+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-06-09 09:32:56\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-6656392\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-6656392\",\"identity\":\"rs-6656392\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC0","license_restricted":false}