Vitamin D and Male Reproduction: Updated Evidence Based on Literature Review.

Area of Science:

• Endocrinology
• Reproductive Medicine
• Nutritional Science

Background:

• Vitamin D (VD) is increasingly recognized for its potential role in male reproductive health.
• Existing research suggests a link between VD levels and semen quality, but findings are not always consistent.

Purpose of the Study:

• To systematically review and synthesize evidence on the effects of vitamin D on male infertility and reproductive function.
• To investigate the relationship between VD levels and semen parameters.
• To assess the impact of VD supplementation on male reproductive health.

Main Methods:

• A comprehensive literature search was conducted across major electronic databases (MEDLINE, Embase, Web of Science, Scopus, ClinicalTrials.gov, Cochrane Library).
• Inclusion criteria encompassed randomized controlled trials and non-randomized studies examining vitamin D and male reproductive function.
• Studies were categorized based on their focus: molecular mechanisms, VD levels and semen quality, or VD supplementation effects.

Main Results:

• A significant interrelation was found between male VD concentrations and semen parameters, particularly sperm motility.
• Evidence regarding the effect of VD on male sex steroid hormone levels was inconclusive.
• Most studies indicated a positive effect of VD on semen quality, benefiting both fertile and infertile men.

Conclusions:

• Vitamin D plays a role in male reproduction, with a notable positive influence on semen quality and sperm motility.
• Further dedicated research is necessary to clarify the controversial aspects and confirm the hormonal effects of vitamin D in men.
• The findings support the consideration of vitamin D status in the management of male infertility.