Possible influence of vitamin D on male reproduction

J Steroid Biochem Mol Biol. 2017 Oct;173:215-222. doi: 10.1016/j.jsbmb.2016.09.023. Epub 2016 Sep 28.

Abstract

Vitamin D is a versatile signaling molecule with an established role in the regulation of calcium homeostasis and bone health. In recent years the spectrum of vitamin D target organs has expanded and a reproductive role is supported by the presence of the vitamin D receptor (VDR) and the vitamin D metabolizing enzymes in the gonads, reproductive tract, and human spermatozoa. Interestingly, expression levels of VDR and the vitamin D inactivating enzyme CYP24A1 in human spermatozoa serve as positive predictive markers of semen quality and are higher expressed in spermatozoa from normal than infertile men. VDR mediates a non-genomic increase in intracellular calcium concentration, sperm motility, and induces the acrosome reaction. Furthermore, functional animal model studies have shown that vitamin D is important for sex steroid production, estrogen signaling, and semen quality. Cross-sectional clinical studies have supported the notion of a positive association between serum 25-hydroxyvitamin D (25-OHD) level and semen quality in both fertile and infertile men. However, it remains to be determined whether this association reflects a causal effect. The VDR is ubiquitously expressed and activated vitamin D is a regulator of insulin, aromatase, and osteocalcin. Hence, it is plausible that the influence of vitamin D on gonadal function may be mediated indirectly through other vitamin D regulated endocrine factors. Recent studies have indicated that vitamin D supplementation may be beneficial for couples in need of assisted reproductive techniques as high serum vitamin D levels were found to be associated with a higher chance of achieving pregnancy. Randomized clinical trials are needed to determine whether systemic changes in vitamin D metabolites can influence semen quality, fertility, and sex steroid production in infertile men. In this review known and possible future implications of vitamin D in human male reproduction function will be discussed.

Keywords: Calcium; Fertility; Reproduction; Sex hormones; Vitamin D.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aromatase / metabolism
  • Estradiol / metabolism
  • Humans
  • Male
  • Receptors, Calcitriol / metabolism
  • Reproduction
  • Semen Analysis
  • Signal Transduction*
  • Spermatozoa / cytology*
  • Spermatozoa / metabolism
  • Testicular Neoplasms / metabolism
  • Testis / cytology
  • Testis / physiology*
  • Vitamin D / metabolism*

Substances

  • Receptors, Calcitriol
  • VDR protein, human
  • Vitamin D
  • Estradiol
  • Aromatase