Increasing serum 25OHD level via vitamin D supplement is a potentially effective way to treat or prevent male factor infertility.

A mendelian randomization study was conducted to examine the link between male factor infertility and serum levels of 25-hydroxyvitamin D (25OHD).

Four-step two samples Mendelian randomization analysis were carried out. Overall, 417,580 Europeans from the UK Biobank were used to gather single-nucleotide polymorphisms (SNPs) for vitamin D, while the FinnGen was used to get summary-level information on male factor infertility (825 cases and 85,722 controls).

A total of 99 SNPs that were strongly linked with the 25OHD were incorporated. All 3 sensitivity analyses (weighted mode, weighted median, and MR-Egger methods) showed that a 1-unit rise in the genetically predicted natural-log transformed 25OHD levels was related to a lower probability of infertility (odds ratio [OR], 0.62).

Increased levels of serum 25OHD in the general population appear to be a causal protective factor for  male factor infertility. Even after excluding SNPs that were linked to confounders (coronary artery diseases, smoking, type 2 diabetes, and body mass index) of male factor infertility (OR, 0.58) and that explained more variance in male factor infertility contrasted with the 25OHD (OR, 0.61), the findings remained valid.

In the general population, the use of vitamin D supplementation to raise serum 25OHD levels might be clinically valuable for male factor infertility.