Endocrine connections 2018 02 15() pii EC-18-0009
Accumulating evidence from animal and human studies suggests that vitamin D is involved in many functions of the reproductive system in both genders.
The aim of this review was to provide an overview on the effects of vitamin D on polycystic ovary syndrome (PCOS) in women and androgen metabolism in men.
We performed a systematic literature search in Pubmed for relevant English language publications published from January 2012 until July 2017.
RESULTS AND DISCUSSION
The vitamin D receptor and vitamin D metabolizing enzymes are found in reproductive tissues of women and men. In women, vitamin D status has been associated with several features of PCOS. In detail, cross-sectional data suggest a regulatory role of vitamin D in PCOS-related aspects such as ovulatory dysfunction, insulin resistance as well as hyperandrogenism. Moreover, results from randomized controlled trials (RCTs) suggest that vitamin D supplementation may be beneficial for metabolic, endocrine and fertility aspects in PCOS. In men, vitamin D status has been associated with androgen levels and hypogonadism. Further, there is some evidence for a favourable effect of vitamin D supplementation on testosterone concentrations, although others failed to show a significant effect on testosterone levels.
In summary, vitamin D deficiency is associated with adverse fertility outcomes including PCOS and hypogonadism, but the evidence is insufficient to establish causality. High quality RCTs are needed to further evaluate the effects of vitamin D supplementation in PCOS women as well as on androgen levels in men.