The role of vitamin D deficiency in the etiology of polycystic ovary syndrome disorders

Vitamin D deficiency, connected with insufficient production in the skin and limited alimentation delivery, disrupts the function of all systems of the body and increases the risk of chronic diseases. Many studies have reported associations between low serum 25-hydroxyvitamin D [25(OH) D] level and symptoms of the polycystic ovary syndrome (PCOS) - insulin resistance, hirsutism, and infertility associated with both, ovulatory disorders and abnormal endometrial receptivity. The beneficial effects of vitamin D supplementation on insulin resistance, ovarian follicles maturation, ovulation and menstrual regularity were confirmed. Due to limited evidence, the additional randomized trials are required to establish the correct dose of vitamin D and confirm the effectiveness of vitamin D treatment in PCOS disorders. However, it seems evident that correct supplementation of vitamin D is beneficial in the management of women with PCOS and low 25(OH) D serum levels, and that it could be helpful in improving the effects of PCOS treatment.