The role of vitamin D in PCOs

Background: Vitamin D is essential for the proper functioning of human body and has association with fertility problems. PCOS is the most common endocrine disorder causing infertility that the causes are unknown but insulin resistance and obesity are related factors.Methods: This review of the literature was conducted in PubMed, EMBASE and Cochrane Library for relevant english language publications until 2017.Result: Studies show an association between low level of 25(OH)D3 and insulin resistance, but the mechanisms remain unknown. One theory relies on regulatory effect of vitamin D on intracellular and extracellular calcium level that is essential for insulin-mediated intracellular processes and may have impact on insulin secretion. Another hypothesis involves the stimulatory effect of vitamin D on insulin receptors leading to increase of insulin sensitivity.Finally,vitamin D influences the immune system and can cause a higher inflammatory response associated with insulin resistance. The association between vitamin D and obesity is demonstrated in PCOS women that can be a consequence of association between obesity and insulin resistance, correlated with decreased levels of vitamin D.Vitamin D deficiency is also related to an imbalance in hyperandrogenism markers.Conclusion: Vitamin D is involved in the regulation of steroidogenesis of sex hormones and may have a regulatory role in several PCOS-associated symptoms,including ovulatory dysfunction,hyperandrogenism and insulin resistance.Studies in PCOS women showed that vitamin D did not improve metabolic parameters of insulin resistance and markers of hyperandrogenism. However, a causal link between vitamin D levels and the pathogenesis of PCOS is still missing and high quality large randomized clinical trials are needed to evaluate the effect of vitamin D supplementation on female fertility.

کلیدواژه ها:

Fertility ، Polycystic ovary ، Vitamin D