Vitamin D has a major play in bone and calcium metabolism. Vitamin D deficiency (below 20 ng/ml) has also been linked to adverse health outcomes such as malignancy, cardiovascular disease, immune functioning, and glucose metabolism. Recent data from retrospective and prospective trials have demonstrated contradictive results concerning the role of vitamin D in female reproduction and IVF outcome. Some studies have found that women deficient in vitamin D had lower ovarian reserve and significantly lower clinical pregnancy rates when compared to patients who were sufficient levels in vitamin D. Some studies also demonstrated that serum 25-OH-D3 levels correlates with antimullerian hormone (AMH) levels in women of advanced reproductive age. It may also have a role to play in endocrine dysfunction and abnormal folliculogenesis in polycystic ovaries .