Serum Vitamin D Levels in Fertile and Infertile Women with Polycystic Ovary Syndrome.

In polycystic ovary syndrome, serum vitamin D levels are known to correlate with metabolic conditions such as diabetes mellitus, metabolic syndrome and cardiovascular disease. However, there are not enough studies showing such a relationship with female fertility. We aimed to compare serum vitamin D levels in fertile and infertile women with polycystic ovary syndrome to evaluate whether vitamin D may play a role in the pathogenesis of fertility problems in women with polycystic ovary syndrome. 274 infertile and 111 fertile women with polycystic ovary syndrome were included in this retrospective study. Infertile and fertile groups were matched by age, body mass index and homeostasis model assessment of insulin resistance. Anthropometric, clinical and laboratory characteristics of the women were recorded. Serum 25(OH)D levels were used to assess serum vitamin D levels. No significant differences were detected between groups in terms of anthropometric, clinical and laboratory features except for serum 25(OH)D levels and the incidence of vitamin D deficiency. Vitamin D levels were significantly lower and vitamin D deficiency was more common in the infertile group compared to the fertile group. When the groups were stratified into obese/non-obese or insulin resistance positive/negative, infertile obese and infertile insulin resistance-positive women had the lowest serum 25(OH)D levels. Serum vitamin D levels are lower in infertile women with polycystic ovary syndrome compared to fertile women. When insulin resistance or obesity was present, vitamin D levels were reduced further. Thus, in polycystic ovary syndrome, lower vitamin D levels may play a role in the pathogenesis of fertility problems.