Vitamin D in Reproductive Health Disorders: A Comprehensive Review focusing on Infertility, Endometriosis and Polycystic Ovarian Syndrome

Vitamin D (VD) is a fat-soluble steroid hormone with crucial physiological functions beyond calcium and bone metabolism. In recent years, the role of VD in women’s reproductive health has garnered significant attention. It has been implicated in ovarian function, follicular development, endometrial receptivity, and the regulation of steroid hormone production. VD deficiency has been associated with a range of reproductive health disorders, including Polycystic Ovarian Syndrome (PCOS), endometriosis, and infertility. Studies indicate that up to 40-50% of healthy pregnant women exhibit deficient serum VD levels, which may be linked to adverse pregnancy outcomes and impaired fertility. VD plays a key role in regulating ovarian function, promoting proper follicular development, and modulating the immune response in reproductive tissues. Its deficiency has been linked to insulin resistance, hormonal imbalances, and inflammatory processes, all of which contribute to the pathophysiology of reproductive disorders. This review synthesizes current research on VD's therapeutic potential in managing these disorders and enhancing fertility outcomes, emphasizing the importance of maintaining adequate VD levels for optimal reproductive health. Understanding the reference values for VD in reproductive medicine is essential for optimizing fertility treatments and improving clinical outcomes in women with reproductive health disorders.