ASSOCIATION BETWEEN SERUM VITAMIN D LEVELS AND OVULATORY FUNCTION IN WOMEN OF REPRODUCTIVE AGE

Abstract

Background: Vitamin D deficiency is a global health concern and has been increasingly recognized as a modifiable risk factor for reproductive disorders. This study investigates the association between serum Vitamin D (25(OH)D) levels and ovulatory function, as measured by mid-luteal progesterone, in women of reproductive age.

Methods: A cross-sectional study was conducted with 40 women (aged 18–40 years) over a 12-month period (January 2025 – December 2025). Anthropometric data (BMI) and biochemical markers, including serum 25(OH)D and mid-luteal progesterone, were collected. Participants were categorized into Ovulatory (n=24) and Anovulatory (n=16) groups based on a progesterone threshold of 3.0 ng/ml. Statistical analyses included independent samples t-tests and Pearson correlation.

Results: The mean Vitamin D level for the cohort was 20.29 ±8.96 ng/ml, with 57.5% of participants being deficient (<20 ng/ml). Women in the ovulatory group had significantly higher Vitamin D levels compared to the anovulatory group (23.69 ±8.86 ng/ml  vs. 15.18 ±6.46 ng/ml; p = 0.0021). A moderate positive correlation was observed between Vitamin D levels and mid-luteal progesterone (r = 0.446). Within the anovulatory group, 81.25% of women were Vitamin D deficient. In the subgroup of women with Polycystic Ovary Syndrome (PCOS, n=6), all were anovulatory and 83.3% were deficient. No significant correlation was found between BMI and Vitamin D levels in this cohort (r = 0.018).

Conclusion: Our findings suggest that Vitamin D deficiency is strongly associated with ovulatory dysfunction. The significant disparity in Vitamin D levels between ovulatory and anovulatory women underscores its role as a critical modifiable factor in female reproductive health. Screening and correction of Vitamin D deficiency may serve as a valuable intervention for women experiencing ovulatory disorders.