The Relationship Between Female Reproductive Functions and Vitamin D.

Nonclassical target organs recently defined for vitamin D, a major regulator of calcium phosphorus homeostasis and bone health, include reproductive ones. This compilation study focuses on the potential effects of vitamin D on female reproductive functions. Vitamin D receptor enzymes that metabolize vitamin D are expressed in both central and peripheral reproductive organs. Most studies suggest that vitamin D may be directly or indirectly related to gonadal functions. Vitamin D's effects on reproductive functions may be indirectly related to diseases such as polycystic ovary syndrome (PCOS), uterine leiomyomas, and endometriosis. In case of vitamin D deficiency during infertility treatment, vitamin D supplementation can be recommended especially for women who have PCOS, insulin resistance, or low anti-Mullerian hormone levels. Supplementation, however, should take into account possible toxic effects of high-dose vitamin D. To be able to recommend measuring vitamin D as a routine screening test and to better understand the effects of vitamin D and its supplementation on female reproductive functions, larger randomized controlled prospective studies are needed.