Comparison of Vitamin D plasma level in women with or without endometriosis: a case-control study

Comparison of Vitamin D plasma level in women with or without endometriosis: 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 Comparison of Vitamin D plasma level in women with or without endometriosis: a case-control study Shima Alizadeh, Dorna Nasiri, Fatemeh Keikha, Farnaz Khatami, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3095590/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: Endometriosis is a debilitating gynecologic disease affecting millions of women worldwide. The potential role of vitamin D is of increasing interest. Previous studies have provoked controversy over the role of vitamin D and have shown a correlation between endometriosis and low vitamin D serum levels. This study aimed to assess and compare vitamin D serum levels between women with and without endometriosis. Materials & Methods: We studied 47 patients with endometriosis who visited the Infertility and Reproductive Clinic at our tertiary hospital and compared their vitamin D levels with healthy control subjects (47 women). The analysis was performed using Mann-Whitney and chi-square tests. Results: The median age of the women was 32/49, and SD was 5.42. The Mann-Whitney test showed no significant relationship between the mean levels of vitamin D and endometriosis diagnosis ( P = 0.223). However, most of the patients with low level of vitamin D have endometriosis. This was confirmed by the chi-square test (odds ratio [OR] = 3.410; P = 0.008). Conclusion: In conclusion, these results indicate that women with a low level of vitamin D are statistically at higher risk of endometriosis and maybe there is a relationship between vitamin D and endometriosis so more studies are needed to determine the role of vitamin d in endometriosis Endometriosis Deficiency Vitamin D Background Endometriosis is a debilitating gynecologic disease affecting millions of women worldwide, with symptoms of dysmenorrhea, chronic pelvic pain, and infertility [ 1 ]. Women with endometriosis are also at increased risk of developing several cancers and autoimmune disorders [ 2 ]. It takes 7 years on average before a correct diagnosis is obtained from a laparoscopic procedure. Therefore, it is of great importance to patients and clinicians to have a less-invasive method that would allow an earlier diagnosis of endometriosis. Despite decades of research, there are no sufficiently sensitive and specific signs and symptoms nor blood tests for the clinical confirmation of endometriosis, which hampers prompt diagnosis and treatment [ 3 ]. The potential role of vitamin D is of increasing interest. Previous studies have demonstrated the role of vitamin D as a modulator of the immune system. Some authors have suggested a correlation between endometriosis and low vitamin D serum levels [ 4 , 5 , 6 ], while others have reported higher vitamin D serum levels in women with endometriosis [ 7 , 8 ]. This study aimed to assess and compare vitamin D serum levels between women with and without endometriosis. Materials and Methods In this observational case-control study, we studied 47 women who visited the Infertility and Reproductive Clinic at our tertiary hospital from 2020 to 2022. We had 2 groups: 1) patients with endometriosis and 2) control subjects without endometriosis ( n = 47 per group). Endometriosis was suspected by ultrasound scan and then confirmed by laparoscopy and pathology. Whole blood and serum samples were collected. Each serum sample was divided into 2 tubes and analyzed for total 25-hydroxyvitamin D. Serum total 25(OH)D concentrations were analyzed using Elecsys Vitamin D Total Kits with the Cobas e602 module (Roche Diagnostics, Mannheim, Germany). The analysis was performed using Mann-Whitney and chi-square tests. The patients’ ages were recorded, and their vitamin D levels were measured. P values less than 0.05 were considered statistically significant. This study was conducted in accordance with the Helsinki Declaration and was approved by the ethics committee. Results We studied patients who visited the Infertility and Reproductive Clinic at our tertiary hospital. All patients underwent laparoscopy to confirm endometriosis. All patients were diagnosed based on the pathological review of surgical specimens. Participants in this study were divided into 2 groups: patients with endometriosis and healthy controls. Healthy controls were recruited from women who were at the clinic for health screening and did not report any symptoms of endometriosis. Whole blood and serum samples were collected. The median age of the women was 32/49, and SD was 5.42 (Table 1 ). There was no significant difference in age and clinical characteristics between the 2 groups (Table 1 ). A correlation analysis was performed to compare vitamin D levels between the study groups. Although the results showed that 25(OH)D levels are significantly higher in healthy controls than in endometriosis patients, the mean level of vitamin D (in ng/mL) was not statistically correlated with endometriosis. The Mann-Whitney test showed no significant relationship between vitamin D levels and endometriosis diagnosis ( P = 0.223; Table 1 ). Table 1 characteristic of Participants characteristic Control group( n: 47) Endometriosis group( n:47) p-value Age ( year) (mean) 31.68 33.29 P = 0. 109 Marital status (% (n)) Unmarried married 21% (10) 79% ( 37) 26% (12) 74% ( 35) P = 0. 626 Gravidity (% (n)) NG > 1 49% (23) 51% ( 24) 55% (26) 45% ( 21) P = 0.536 Vitamin D level ( mean) ng/mL 23.27 26.35 P = 0.223 To confirm the relationships between low levels of vitamin D in patients and the incidence of endometriosis in them, patients were divided into 2 groups of with and without low level of vitamin D based on their vitamin D levels. Abnormal levels of vitamin D were defined as serum 25(OH)D levels lower than 30 ng/mL. Further analysis of patients with vitamin D < 30 ng/mL showed that most of the patients with these levels of vitamin D were diagnosed with endometriosis. This was confirmed by the chi-square test (odds ratio [OR] = 3.410; P = 0.008; Table 2 ). Table 2 Cross Tabulation show’s incidence rate of endometriosis and vitamin D level. Endometriosis Group ( % (n)) Healthy Group ( % (n)) OR p-value Normal Vitamin D 30% (9) 70% (21) OR = 3.410 pvalue = 0.008 Low Vitamin D(< 30 ng/mL) 59.4% (38) 40.6% (26) Considering patients in 3 categories of normal, insufficiency, and deficiency, were defined as serum 25(OH)D levels upper than 30 ng/mL, between 10 to 30 ng/mL, and less than 30 ng/mL respectively. patients with normal vitamin D levels were significantly less affected by endometriosis, and those with insufficient levels were significantly affected by endometriosis ( P = 0.016); however, in the deficiency group, this difference was not significant between subjects with and without endometriosis ( P > 0.05; Table 3 ). Table 3 Cross Tabulation show’s incidence rate of endometriosis and insufficiency/deficiency vitamin D level. Endometriosis Group (% (n)) Healthy Group(% (n)) p-value Normal Vitamin D 30% (9) 70% (21) 0.008 Vitamin D insufficiency 68% (17) 32% (8) 0.036 Vitamin D deficiency 53.8% (21) 46.2% (18) 0.530 Discussion Endometriosis is one of the most common gynecological diseases of reproductive age, with a prevalence of 5%-10%, decreasing quality of life and fertility. Vitamin D, a classic regulator of plasma calcium concentration and skeleton mineralization, is also an effective modulator of the immune system [ 9 ]. Vitamin D, as an immunomodulatory, has been hypothesized to play a critical role in the pathogenesis of endometriosis [ 10 ]. Although promising, several studies have not shown a cause-effect relationship between vitamin D status and endometriosis; therefore, further studies are needed to better understand the association between vitamin D and endometriosis [ 11 ]. However, Qiu et al recently published a meta-analysis and concluded that women with endometriosis had lower vitamin D status compared with controls, and a negative relationship between vitamin D levels and severity of endometriosis was observed [ 4 ]. Baek et al indicated no association between vitamin D and the severity of endometriosis [ 12 ]. In an observational study of 49 women, Ciavattini found a relatively high rate of women with ovarian endometriosis and hypovitaminosis D [ 13 ]. Recently, Dehbandi et al studied the serum levels of 25(OH)D in 56 healthy women and 54 patients with endometriosis and showed that subjects with vitamin D deficiency were at higher risk of endometriosis [ 14 ]. However, in a case-control study, Buggio et al assessed 434 women and concluded no association between vitamin D levels and endometriosis [ 9 , 15 ]. Regarding vitamin D levels in subjects with and without endometriosis, some previous studies have reported inconsistent findings. Our study shows free 25(OH)D concentrations between women with endometriosis and healthy controls. Women with endometriosis ( n = 47) and healthy controls ( n = 47) were enrolled in this observational case-control study. Our analysis showed no significant relationship between the 2 groups regarding the mean vitamin D levels, which is consistent with some previous studies [ 9 , 15 ]. To confirm the relationships between vitamin D deficiency and the occurrence of endometriosis, further analysis of patients with vitamin D < 30 ng/mL showed that most of the patients with vitamin D deficiency were diagnosed with endometriosis. A limitation of our study is that we did not determine body mass index (BMI), PTH (parathyroid hormone) and smoking. Our study also did not account for sunlight exposure. Given the heterogeneity and diversity of the different studies, more research is required to elucidate the association between vitamin D and endometriosis. Further, the small sample size of the study reduced its power; therefore, further studies with large sample sizes are needed. Conclusion in conclusion, these results indicate that women with a low level of vitamin D are statistically at higher risk of endometriosis and maybe there is a relationship between vitamin D and endometriosis so more studies are needed to determine the role of vitamin d in endometriosis. Abbreviations Vit D: vitamin D BMI: body mass index PTH: parathyroid hormone Declarations Ethics approval and consent to participate: This study was conducted in accordance with the Helsinki Declaration and was approved by the Tehran University of Medical Sciences ethics committee ( IR.TUMS.IKHC.REC.1397.34 .) Consent for publication: All the patients signed the informed consent form. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request Availability of data and materials: All data generated or analysed during this study are available for review by the Editor-in-Chief of this journal on request. Competing interests: The authors declare that they have no conflicts of interests. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Conflicts of Interest: The authors declare that they have no conflicts of interests. Authors' contributions: SH.A.: writing the article D.N.: collecting data F.K.: collecting data F.KH.: data analysis Z.P.: collecting data N.Z.: Editing the final manuscript, corresponding All authors have read and approved the manuscript. Acknowledgements: Not applicable References Ahn SH, Singh V, Tayade C. Biomarkers in endometriosis: challenges and opportunities. Fertil Steril. 2017 Mar;107(3):523-532. doi: 10.1016/j.fertnstert.2017.01.009. Epub 2017 Feb 8. PMID: 28189296. Giudice LC, Kao LC. Endometriosis. Lancet. 2004 Nov 13-19;364(9447):1789-99. doi: 10.1016/S0140-6736(04)17403-5. PMID: 15541453. Coutinho LM, Ferreira MC, Rocha ALL, Carneiro MM, Reis FM. New biomarkers in endometriosis. Adv Clin Chem. 2019;89:59-77. doi: 10.1016/bs.acc.2018.12.002. PMID: 30797471. Anastasi E, Fuggetta E, De Vito C, Migliara G, Viggiani V, Manganaro L, Granato T, Benedetti Panici P, Angeloni A, Porpora MG. Low levels of 25-OH vitamin D in women with endometriosis and associated pelvic pain. Clin Chem Lab Med. 2017 Oct 26;55(12):e282-e284. doi: 10.1515/cclm-2017-0016. PMID: 28453438. Harris HR, Chavarro JE, Malspeis S, Willett WC, Missmer SA. Dairy-food, calcium, magnesium, and vitamin D intake and endometriosis: a prospective cohort study. Am J Epidemiol. 2013 Mar 1;177(5):420-30. doi: 10.1093/aje/kws247. Epub 2013 Feb 3. PMID: 23380045; PMCID: PMC3626048. Cho MC, Kim JH, Jung MH, Cho IA, Jo HC, Shin JK, Lee SA, Choi WJ, Lee JH. Analysis of vitamin D-binding protein (VDBP) gene polymorphisms in Korean women with and without endometriosis. Clin Exp Reprod Med. 2019 Sep;46(3):132-139. doi: 10.5653/cerm.2019.00122. Epub 2019 Aug 13. PMID: 31405270; PMCID: PMC6736509. Somigliana E, Panina-Bordignon P, Murone S, Di Lucia P, Vercellini P, Vigano P. Vitamin D reserve is higher in women with endometriosis. Hum Reprod. 2007 Aug;22(8):2273-8. doi: 10.1093/humrep/dem142. Epub 2007 Jun 4. PMID: 17548365. Kalaitzopoulos DR, Lempesis IG, Athanasaki F, Schizas D, Samartzis EP, Kolibianakis EM, Goulis DG. Association between vitamin D and endometriosis: a systematic review. Hormones (Athens). 2020 Jun;19(2):109-121. doi: 10.1007/s42000-019-00166-w. Epub 2019 Dec 21. PMID: 31863346. Delbandi AA, Torab M, Abdollahi E, Khodaverdi S, Rokhgireh S, Moradi Z, Heidari S, Mohammadi T. Vitamin D deficiency as a risk factor for endometriosis in Iranian women. J Reprod Immunol. 2021 Feb;143:103266. doi: 10.1016/j.jri.2020.103266. Epub 2020 Dec 17. PMID: 33385732. Giampaolino P, Della Corte L, Foreste V, Bifulco G. Is there a Relationship Between Vitamin D and Endometriosis? An Overview of the Literature. Curr Pharm Des. 2019;25(22):2421-2427. doi: 10.2174/1381612825666190722095401. PMID: 31333100. Qiu Y, Yuan S, Wang H. Vitamin D status in endometriosis: a systematic review and meta-analysis. Arch Gynecol Obstet. 2020 Jul;302(1):141-152. doi: 10.1007/s00404-020-05576-5. Epub 2020 May 19. PMID: 32430755. Baek JC, Jo JY, Lee SM, Cho IA, Shin JK, Lee SA, Lee JH, Cho MC, Choi WJ. Differences in 25-hydroxy vitamin D and vitamin D-binding protein concentrations according to the severity of endometriosis. Clin Exp Reprod Med. 2019 Sep;46(3):125-131. doi: 10.5653/cerm.2018.00416. Epub 2019 Aug 1. PMID: 31370113; PMCID: PMC6736508. Ciavattini A, Serri M, Delli Carpini G, Morini S, Clemente N. Ovarian endometriosis and vitamin D serum levels. Gynecol Endocrinol. 2017 Feb;33(2):164-167. doi: 10.1080/09513590.2016.1239254. Epub 2016 Nov 4. PMID: 27809683. Delbandi AA, Torab M, Abdollahi E, Khodaverdi S, Rokhgireh S, Moradi Z, Heidari S, Mohammadi T. Vitamin D deficiency as a risk factor for endometriosis in Iranian women. J Reprod Immunol. 2021 Feb;143:103266. doi: 10.1016/j.jri.2020.103266. Epub 2020 Dec 17. PMID: 33385732. Buggio L, Somigliana E, Pizzi MN, Dridi D, Roncella E, Vercellini P. 25-Hydroxyvitamin D Serum Levels and Endometriosis: Results of a Case-Control Study. Reprod Sci. 2019 Feb;26(2):172-177. doi: 10.1177/1933719118766259. Epub 2018 Mar 27. PMID: 29587615. Additional Declarations No competing interests reported. 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-3095590","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":212565722,"identity":"c7da41aa-6471-4290-869b-d0c66b4eba93","order_by":0,"name":"Shima Alizadeh","email":"","orcid":"","institution":"Department of Oncologic gynecology, Vali-Asr Hospital, Tehran University of Medical Science","correspondingAuthor":false,"prefix":"","firstName":"Shima","middleName":"","lastName":"Alizadeh","suffix":""},{"id":212565723,"identity":"0f4d59ec-3741-4efb-8ec3-d8ce5d74293d","order_by":1,"name":"Dorna Nasiri","email":"","orcid":"","institution":"Department of Obstetrics \u0026 Gynecology, Vali-e-Asr Hospital, Tehran University of Medical Science","correspondingAuthor":false,"prefix":"","firstName":"Dorna","middleName":"","lastName":"Nasiri","suffix":""},{"id":212565724,"identity":"39b58998-39fd-405c-9768-9bc33051f5e3","order_by":2,"name":"Fatemeh Keikha","email":"","orcid":"","institution":"Department of Obstetrics \u0026 Gynecology, Vali-e-Asr Hospital, Tehran University of Medical Science","correspondingAuthor":false,"prefix":"","firstName":"Fatemeh","middleName":"","lastName":"Keikha","suffix":""},{"id":212565725,"identity":"cfd3f3ff-4628-4a5e-bcbf-f58c151c2e13","order_by":3,"name":"Farnaz Khatami","email":"","orcid":"","institution":"; Department of Community Medicine, School of Medicine, Tehran University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Farnaz","middleName":"","lastName":"Khatami","suffix":""},{"id":212565726,"identity":"13cdbe97-8f1d-4014-aeef-5ab8fbb6bc94","order_by":4,"name":"Zahra Panahi","email":"","orcid":"","institution":"Department of Obstetrics \u0026 Gynecology, Vali-e-Asr Hospital, Tehran University of Medical Science","correspondingAuthor":false,"prefix":"","firstName":"Zahra","middleName":"","lastName":"Panahi","suffix":""},{"id":212565727,"identity":"1b40587f-f2cd-4cfa-87de-c8b1f7d1e710","order_by":5,"name":"Narges Zamani","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFElEQVRIiWNgGAWjYDCCA2h8Hn4QmVBAihbJBpAWAxK0MBiARfBo4bt9gO3Bzz21cvIN7A8/3ai5I2N8fnXihwcGDPL8YhjGgYHkuQR2w55nx42BhidL5xx7xmN24+1mCaDDDGfOTsCqxeAMA5sEz4FjiRuAbpTOYTsM1HJ2A0hLgsFt3Fok/xw4Vj+/gbH5d86/wzzGM85u/kFIizTPgZoEhgPMbNK5bYd5DPh7t+G1RfIMY5u0zIEDhhsOs7FZ5/Yd5pG4wbvNIsFAAqdf+M4wH5N8c6BOXr69/fHtnG+H7fn7z26++aPCRp5fGrsWBgbGBiBxmIGBGSYgAVYpgUM5HNQhsfkPEFI9CkbBKBgFIwwAANAeYIvqs2AwAAAAAElFTkSuQmCC","orcid":"","institution":"Department of Oncologic gynecology, Vali-Asr Hospital, Tehran University of Medical Science","correspondingAuthor":true,"prefix":"","firstName":"Narges","middleName":"","lastName":"Zamani","suffix":""}],"badges":[],"createdAt":"2023-06-22 09:44:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3095590/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3095590/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":41830302,"identity":"b9894277-94da-45bd-b216-9ba9ddc545bc","added_by":"auto","created_at":"2023-08-20 14:37:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":217938,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3095590/v1/e552661d-7fba-4af7-b4a5-816486d2b81d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of Vitamin D plasma level in women with or without endometriosis: a case-control study","fulltext":[{"header":"Background","content":"\u003cp\u003eEndometriosis is a debilitating gynecologic disease affecting millions of women worldwide, with symptoms of dysmenorrhea, chronic pelvic pain, and infertility [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Women with endometriosis are also at increased risk of developing several cancers and autoimmune disorders [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. It takes 7 years on average before a correct diagnosis is obtained from a laparoscopic procedure. Therefore, it is of great importance to patients and clinicians to have a less-invasive method that would allow an earlier diagnosis of endometriosis. Despite decades of research, there are no sufficiently sensitive and specific signs and symptoms nor blood tests for the clinical confirmation of endometriosis, which hampers prompt diagnosis and treatment [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe potential role of vitamin D is of increasing interest. Previous studies have demonstrated the role of vitamin D as a modulator of the immune system. Some authors have suggested a correlation between endometriosis and low vitamin D serum levels [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], while others have reported higher vitamin D serum levels in women with endometriosis [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. This study aimed to assess and compare vitamin D serum levels between women with and without endometriosis.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eIn this observational case-control study, we studied 47 women who visited the Infertility and Reproductive Clinic at our tertiary hospital from 2020 to 2022. We had 2 groups: 1) patients with endometriosis and 2) control subjects without endometriosis (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;47 per group).\u003c/p\u003e \u003cp\u003eEndometriosis was suspected by ultrasound scan and then confirmed by laparoscopy and pathology. Whole blood and serum samples were collected. Each serum sample was divided into 2 tubes and analyzed for total 25-hydroxyvitamin D. Serum total 25(OH)D concentrations were analyzed using Elecsys Vitamin D Total Kits with the Cobas e602 module (Roche Diagnostics, Mannheim, Germany). The analysis was performed using Mann-Whitney and chi-square tests. The patients\u0026rsquo; ages were recorded, and their vitamin D levels were measured. \u003cem\u003eP\u003c/em\u003e values less than 0.05 were considered statistically significant.\u003c/p\u003e \u003cp\u003e This study was conducted in accordance with the Helsinki Declaration and was approved by the ethics committee.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eWe studied patients who visited the Infertility and Reproductive Clinic at our tertiary hospital. All patients underwent laparoscopy to confirm endometriosis. All patients were diagnosed based on the pathological review of surgical specimens.\u003c/p\u003e \u003cp\u003eParticipants in this study were divided into 2 groups: patients with endometriosis and healthy controls. Healthy controls were recruited from women who were at the clinic for health screening and did not report any symptoms of endometriosis. Whole blood and serum samples were collected.\u003c/p\u003e \u003cp\u003eThe median age of the women was 32/49, and SD was 5.42 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). There was no significant difference in age and clinical characteristics between the 2 groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A correlation analysis was performed to compare vitamin D levels between the study groups. Although the results showed that 25(OH)D levels are significantly higher in healthy controls than in endometriosis patients, the mean level of vitamin D (in ng/mL) was not statistically correlated with endometriosis. The Mann-Whitney test showed no significant relationship between vitamin D levels and endometriosis diagnosis (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.223; Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\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\u003echaracteristic of Participants\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003echaracteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003cp\u003egroup( n: 47)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEndometriosis group( n:47)\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 ( year) (mean)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0. 109\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarital status (% (n))\u003c/p\u003e \u003cp\u003eUnmarried\u003c/p\u003e \u003cp\u003emarried\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21% (10)\u003c/p\u003e \u003cp\u003e79% ( 37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26% (12)\u003c/p\u003e \u003cp\u003e74% ( 35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0. 626\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGravidity (% (n))\u003c/p\u003e \u003cp\u003eNG\u003c/p\u003e \u003cp\u003e\u0026gt;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49% (23)\u003c/p\u003e \u003cp\u003e51% ( 24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55% (26)\u003c/p\u003e \u003cp\u003e45% ( 21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0.536\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin D level ( mean) ng/mL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.223\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\u003eTo confirm the relationships between low levels of vitamin D in patients and the incidence of endometriosis in them, patients were divided into 2 groups of with and without low level of vitamin D based on their vitamin D levels. Abnormal levels of vitamin D were defined as serum 25(OH)D levels lower than 30 ng/mL.\u003c/p\u003e \u003cp\u003eFurther analysis of patients with vitamin D\u0026thinsp;\u0026lt;\u0026thinsp;30 ng/mL showed that most of the patients with these levels of vitamin D were diagnosed with endometriosis. This was confirmed by the chi-square test (odds ratio [OR]\u0026thinsp;=\u0026thinsp;3.410; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.008; Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\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\u003eCross Tabulation show\u0026rsquo;s incidence rate of endometriosis and vitamin D level.\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=\"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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\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\u003eEndometriosis Group ( % (n))\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHealthy Group ( % (n))\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\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\u003eNormal Vitamin D\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70% (21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eOR\u0026thinsp;=\u0026thinsp;3.410\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003epvalue\u0026thinsp;=\u0026thinsp;0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow Vitamin D(\u0026lt;\u0026thinsp;30 ng/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e59.4% (38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.6% (26)\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\u003eConsidering patients in 3 categories of normal, insufficiency, and deficiency, were defined as serum 25(OH)D levels upper than 30 ng/mL, between 10 to 30 ng/mL, and less than 30 ng/mL respectively. patients with normal vitamin D levels were significantly less affected by endometriosis, and those with insufficient levels were significantly affected by endometriosis (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.016); however, in the deficiency group, this difference was not significant between subjects with and without endometriosis (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\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\u003eCross Tabulation show\u0026rsquo;s incidence rate of endometriosis and insufficiency/deficiency vitamin D level.\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\u003eEndometriosis Group (% (n))\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHealthy Group(% (n))\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\u003eNormal Vitamin D\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70% (21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin D insufficiency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68% (17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32% (8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin D deficiency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53.8% (21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e46.2% (18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.530\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eEndometriosis is one of the most common gynecological diseases of reproductive age, with a prevalence of 5%-10%, decreasing quality of life and fertility. Vitamin D, a classic regulator of plasma calcium concentration and skeleton mineralization, is also an effective modulator of the immune system [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Vitamin D, as an immunomodulatory, has been hypothesized to play a critical role in the pathogenesis of endometriosis [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough promising, several studies have not shown a cause-effect relationship between vitamin D status and endometriosis; therefore, further studies are needed to better understand the association between vitamin D and endometriosis [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, Qiu et al recently published a meta-analysis and concluded that women with endometriosis had lower vitamin D status compared with controls, and a negative relationship between vitamin D levels and severity of endometriosis was observed [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Baek et al indicated no association between vitamin D and the severity of endometriosis [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn an observational study of 49 women, Ciavattini found a relatively high rate of women with ovarian endometriosis and hypovitaminosis D [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Recently, Dehbandi et al studied the serum levels of 25(OH)D in 56 healthy women and 54 patients with endometriosis and showed that subjects with vitamin D deficiency were at higher risk of endometriosis [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, in a case-control study, Buggio et al assessed 434 women and concluded no association between vitamin D levels and endometriosis [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRegarding vitamin D levels in subjects with and without endometriosis, some previous studies have reported inconsistent findings. Our study shows free 25(OH)D concentrations between women with endometriosis and healthy controls.\u003c/p\u003e \u003cp\u003eWomen with endometriosis (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;47) and healthy controls (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;47) were enrolled in this observational case-control study. Our analysis showed no significant relationship between the 2 groups regarding the mean vitamin D levels, which is consistent with some previous studies [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo confirm the relationships between vitamin D deficiency and the occurrence of endometriosis, further analysis of patients with vitamin D\u0026thinsp;\u0026lt;\u0026thinsp;30 ng/mL showed that most of the patients with vitamin D deficiency were diagnosed with endometriosis.\u003c/p\u003e \u003cp\u003eA limitation of our study is that we did not determine body mass index (BMI), PTH (parathyroid hormone) and smoking. Our study also did not account for sunlight exposure. Given the heterogeneity and diversity of the different studies, more research is required to elucidate the association between vitamin D and endometriosis. Further, the small sample size of the study reduced its power; therefore, further studies with large sample sizes are needed.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003e in conclusion, these results indicate that women with a low level of vitamin D are statistically at higher risk of endometriosis and maybe there is a relationship between vitamin D and endometriosis so more studies are needed to determine the role of vitamin d in endometriosis.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eVit D: vitamin D\u003c/p\u003e\n\u003cp\u003eBMI:\u0026nbsp;body mass index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePTH: parathyroid hormone\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate:\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the Helsinki Declaration and was approved by the Tehran University of Medical Sciences ethics committee (\u003cstrong\u003eIR.TUMS.IKHC.REC.1397.34\u003c/strong\u003e.)\u003c/p\u003e\n\u003cp\u003eConsent for publication:\u003c/p\u003e\n\u003cp\u003eAll the patients signed the informed consent form.\u0026nbsp;A copy of the written consent is available for review by the Editor-in-Chief of this journal on request\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials:\u003c/p\u003e\n\u003cp\u003eAll data generated or analysed during this study are\u0026nbsp;available for review by the Editor-in-Chief of this journal on request.\u003c/p\u003e\n\u003cp\u003eCompeting interests:\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflicts of interests.\u003c/p\u003e\n\u003cp\u003eFunding:\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003eConflicts of Interest:\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflicts of interests.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026apos; contributions:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eSH.A.: writing the article\u003c/li\u003e\n \u003cli\u003eD.N.: collecting data\u003c/li\u003e\n \u003cli\u003eF.K.: collecting data\u003c/li\u003e\n \u003cli\u003eF.KH.: data analysis\u003c/li\u003e\n \u003cli\u003eZ.P.: collecting data\u003c/li\u003e\n \u003cli\u003eN.Z.: Editing the final manuscript, corresponding\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eAll authors have read and approved the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Acknowledgements:\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Not applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAhn SH, Singh V, Tayade C. Biomarkers in endometriosis: challenges and opportunities. Fertil Steril. 2017 Mar;107(3):523-532. doi: 10.1016/j.fertnstert.2017.01.009. Epub 2017 Feb 8. PMID: 28189296.\u003c/li\u003e\n \u003cli\u003eGiudice LC, Kao LC. Endometriosis. Lancet. 2004 Nov 13-19;364(9447):1789-99. doi: 10.1016/S0140-6736(04)17403-5. PMID: 15541453.\u003c/li\u003e\n \u003cli\u003eCoutinho LM, Ferreira MC, Rocha ALL, Carneiro MM, Reis FM. New biomarkers in endometriosis. Adv Clin Chem. 2019;89:59-77. doi: 10.1016/bs.acc.2018.12.002. PMID: 30797471.\u003c/li\u003e\n \u003cli\u003eAnastasi E, Fuggetta E, De Vito C, Migliara G, Viggiani V, Manganaro L, Granato T, Benedetti Panici P, Angeloni A, Porpora MG. Low levels of 25-OH vitamin D in women with endometriosis and associated pelvic pain. Clin Chem Lab Med. 2017 Oct 26;55(12):e282-e284. doi: 10.1515/cclm-2017-0016. PMID: 28453438.\u003c/li\u003e\n \u003cli\u003eHarris HR, Chavarro JE, Malspeis S, Willett WC, Missmer SA. Dairy-food, calcium, magnesium, and vitamin D intake and endometriosis: a prospective cohort study. Am J Epidemiol. 2013 Mar 1;177(5):420-30. doi: 10.1093/aje/kws247. Epub 2013 Feb 3. PMID: 23380045; PMCID: PMC3626048.\u003c/li\u003e\n \u003cli\u003eCho MC, Kim JH, Jung MH, Cho IA, Jo HC, Shin JK, Lee SA, Choi WJ, Lee JH. Analysis of vitamin D-binding protein (VDBP) gene polymorphisms in Korean women with and without endometriosis. Clin Exp Reprod Med. 2019 Sep;46(3):132-139. doi: 10.5653/cerm.2019.00122. Epub 2019 Aug 13. PMID: 31405270; PMCID: PMC6736509.\u003c/li\u003e\n \u003cli\u003eSomigliana E, Panina-Bordignon P, Murone S, Di Lucia P, Vercellini P, Vigano P. Vitamin D reserve is higher in women with endometriosis. Hum Reprod. 2007 Aug;22(8):2273-8. doi: 10.1093/humrep/dem142. Epub 2007 Jun 4. PMID: 17548365.\u003c/li\u003e\n \u003cli\u003eKalaitzopoulos DR, Lempesis IG, Athanasaki F, Schizas D, Samartzis EP, Kolibianakis EM, Goulis DG. Association between vitamin D and endometriosis: a systematic review. Hormones (Athens). 2020 Jun;19(2):109-121. doi: 10.1007/s42000-019-00166-w. Epub 2019 Dec 21. PMID: 31863346.\u003c/li\u003e\n \u003cli\u003eDelbandi AA, Torab M, Abdollahi E, Khodaverdi S, Rokhgireh S, Moradi Z, Heidari S, Mohammadi T. Vitamin D deficiency as a risk factor for endometriosis in Iranian women. J Reprod Immunol. 2021 Feb;143:103266. doi: 10.1016/j.jri.2020.103266. Epub 2020 Dec 17. PMID: 33385732.\u003c/li\u003e\n \u003cli\u003eGiampaolino P, Della Corte L, Foreste V, Bifulco G. Is there a Relationship Between Vitamin D and Endometriosis? An Overview of the Literature. Curr Pharm Des. 2019;25(22):2421-2427. doi: 10.2174/1381612825666190722095401. PMID: 31333100.\u003c/li\u003e\n \u003cli\u003eQiu Y, Yuan S, Wang H. Vitamin D status in endometriosis: a systematic review and meta-analysis. Arch Gynecol Obstet. 2020 Jul;302(1):141-152. doi: 10.1007/s00404-020-05576-5. Epub 2020 May 19. PMID: 32430755.\u003c/li\u003e\n \u003cli\u003eBaek JC, Jo JY, Lee SM, Cho IA, Shin JK, Lee SA, Lee JH, Cho MC, Choi WJ. Differences in 25-hydroxy vitamin D and vitamin D-binding protein concentrations according to the severity of endometriosis. Clin Exp Reprod Med. 2019 Sep;46(3):125-131. doi: 10.5653/cerm.2018.00416. Epub 2019 Aug 1. PMID: 31370113; PMCID: PMC6736508.\u003c/li\u003e\n \u003cli\u003eCiavattini A, Serri M, Delli Carpini G, Morini S, Clemente N. Ovarian endometriosis and vitamin D serum levels. Gynecol Endocrinol. 2017 Feb;33(2):164-167. doi: 10.1080/09513590.2016.1239254. Epub 2016 Nov 4. PMID: 27809683.\u003c/li\u003e\n \u003cli\u003eDelbandi AA, Torab M, Abdollahi E, Khodaverdi S, Rokhgireh S, Moradi Z, Heidari S, Mohammadi T. Vitamin D deficiency as a risk factor for endometriosis in Iranian women. J Reprod Immunol. 2021 Feb;143:103266. doi: 10.1016/j.jri.2020.103266. Epub 2020 Dec 17. PMID: 33385732.\u003c/li\u003e\n \u003cli\u003eBuggio L, Somigliana E, Pizzi MN, Dridi D, Roncella E, Vercellini P. 25-Hydroxyvitamin D Serum Levels and Endometriosis: Results of a Case-Control Study. Reprod Sci. 2019 Feb;26(2):172-177. doi: 10.1177/1933719118766259. Epub 2018 Mar 27. PMID: 29587615.\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":"Endometriosis, Deficiency, Vitamin D","lastPublishedDoi":"10.21203/rs.3.rs-3095590/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3095590/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground:\u003c/h2\u003e \u003cp\u003eEndometriosis is a debilitating gynecologic disease affecting millions of women worldwide. The potential role of vitamin D is of increasing interest. Previous studies have provoked controversy over the role of vitamin D and have shown a correlation between endometriosis and low vitamin D serum levels. This study aimed to assess and compare vitamin D serum levels between women with and without endometriosis.\u003c/p\u003e\u003ch2\u003eMaterials \u0026amp; Methods:\u003c/h2\u003e \u003cp\u003eWe studied 47 patients with endometriosis who visited the Infertility and Reproductive Clinic at our tertiary hospital and compared their vitamin D levels with healthy control subjects (47 women). The analysis was performed using Mann-Whitney and chi-square tests.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eThe median age of the women was 32/49, and SD was 5.42. The Mann-Whitney test showed no significant relationship between the mean levels of vitamin D and endometriosis diagnosis (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.223). However, most of the patients with low level of vitamin D have endometriosis. This was confirmed by the chi-square test (odds ratio [OR]\u0026thinsp;=\u0026thinsp;3.410; \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.008).\u003c/p\u003e\u003ch2\u003eConclusion:\u003c/h2\u003e \u003cp\u003eIn conclusion, these results indicate that women with a low level of vitamin D are statistically at higher risk of endometriosis and maybe there is a relationship between vitamin D and endometriosis so more studies are needed to determine the role of vitamin d in endometriosis\u003c/p\u003e","manuscriptTitle":"Comparison of Vitamin D plasma level in women with or without endometriosis: a case-control study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-06-27 04:35:29","doi":"10.21203/rs.3.rs-3095590/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":"6f4bbe8a-5a6e-4f13-a8fb-696b379f1141","owner":[],"postedDate":"June 27th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-09-01T00:59:14+00:00","versionOfRecord":[],"versionCreatedAt":"2023-06-27 04:35:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3095590","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3095590","identity":"rs-3095590","version":["v1"]},"buildId":"WvIrzKhiLBfengagbw6Ux","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}