Vitamin D supplementation fails to improve semen quality in men with infertility

Vitamin D supplementation did not improve the quality of semen in men with infertility and vitamin D deficiency, a randomized clinical trial found. However, supplementation was linked with an increased rate of live births in men with oligozoospermia.

Researchers from the University of Copenhagen in Denmark and Harvard University performed a triple-blind, randomized trial of 330 men with infertility and serum-25 hydroxyvitamin D levels 50 nmol/L or less. Patients were randomly assigned to placebo or to vitamin D supplementation with 300,000 IU cholecalciferol, followed by a daily dose of 1,400 IU cholecalciferol and 500 mg calcium for 150 days.

Men in the vitamin D group had higher serum 25-(OH)D and 1,25OH₂D₃ compared with those in the placebo group, Jensen and colleagues reported. There was no association between changes in semen parameters and vitamin D supplementation; however, spontaneous pregnancies were more frequent with vitamin D supplementation (7.3% vs. 2.4%).

In a subgroup of men with oligozoospermia, those assigned to vitamin D demonstrated an increased chance of live birth compared with placebo (35.6% vs. 18.3%), the researchers wrote. Participants assigned to vitamin D supplementation had higher serum inhibin B compared with placebo (193 pg/ml vs. 143 pg/ml), but did not demonstrate a significantly higher sperm concentration.

“This study shows that supplementation with vitamin D and calcium had no effect on semen quality or live birth rate in men with vitamin D insufficiency,” the researchers wrote. “However, vitamin D treatment increased serum inhibin B and resulted in an insignificant increase in sperm production in interfile men with vitamin D deficiency. … New clinical studies are required to investigate whether high-dose vitamin D supplementation daily to the man and/or woman is able to influence the function of the male gamete and thereby increase the chance of spontaneous pregnancies and live birth rates before vitamin D supplementation can be recommended routinely as part of the treatment for male infertility.” – by Andy Polhamus

Disclosures: The authors report no relevant financial disclosures.