The Association Between Polycystic Ovary Syndrome and Vitamin D Deficiency in Infertile Women: A Case‐Control Study

Background and Aims Vitamin D deficiency is a common nutritional problem in women of childbearing age. Polycystic ovary syndrome (PCOS) is a frequent endocrine disorder associated with various metabolic complications. While meta‐analyses of interventional trials have explored the role of vitamin D in PCOS, there is a lack of local data from specific populations. This study aimed to provide updated provincial epidemiological data by comparing vitamin D levels in women with and without PCOS, with a specific focus on elucidating the association after adjustment for key confounders, particularly body mass index (BMI). Methods This retrospective cohort study included 66 women with PCOS and 66 healthy controls. compared vitamin D levels between infertile women with polycystic ovary syndrome (PCOS) and healthy controls. We employed both crude and multivariable logistic regression analyses, adjusting for body mass index (BMI), age, socioeconomic status, and season, to calculate odds ratios (ORs) for vitamin D deficiency. Results The groups were comparable in age, education, and employment status ( p > 0.05), but differed in BMI and socioeconomic status ( p < 0.05). In the crude analysis, the odds of vitamin D deficiency were 2.37 times higher in the PCOS group (Crude OR = 2.37, 95% CI 1.59–3.46). After adjusting for confounders, particularly BMI, the association was attenuated but remained significant (Adjusted OR = 1.89, 95% CI 1.15–3.11). Conclusions After controlling for major confounders, a significant association between PCOS and vitamin D deficiency persists in this population. This adjusted analysis strengthens the finding that PCOS is an independent correlate of vitamin D status, beyond the effect of BMI. These results support the need for screening and inform future interventional studies.