Background: Special attention has been given to the effect of vitamin D supplementation on fertility outcomes in both sexes.
Aims: The purpose of this narrative review was to elucidate the role of vitamin D in male and female reproduction, providing current evidence from both animal and human studies.
Materials and methods: Using PubMed and Medline, we searched for publications during the last 30 years regarding the role of vitamin D in human reproduction.
Results: Accumulating evidence from animal and human studies suggests that vitamin D is involved in many functions of the reproductive system in both genders. In women, vitamin D status has been associated with in vitro fertilization (IVF) outcome, features of polycystic ovarian syndrome (PCOS) and endometriosis. Although several data converge towards a beneficial effect of vitamin D supplementation in metabolic disturbances in women with PCOS, a significant knowledge gap precludes the establishment of a clear cause-effect relationship. In men, vitamin D status has been associated with semen quality and sperm count, motility and morphology. There is evidence for a favourable effect of vitamin D supplementation on semen quality, testosterone concentrations and fertility outcomes.
Discussion: Studies with superior methodological characteristics are needed in order to establish a role for vitamin D on the treatment of female and male infertility.
Conclusions: Recent data on vitamin D provide new insights in the complex pathogenesis and treatment of infertility.
© 2013 Blackwell Publishing Ltd.