The dietary supplement market has largely unregulated products with unproven safety and efficacy. Most supplements for male fertility contain folic acid and zinc, therefore a study aimed to determine the effect of these supplements on semen quality and live birth.
Couples planning infertility treatment were enrolled in the Folic Acid and Zinc Supplementation Trial (ClinicalTrials.gov Identifier: NCT01857310). Men were block randomised to receive either 5mg of folic acid and 30mg elemental zinc (n=1185) or placebo (n=1185) daily for six months.
Primary outcomes were live births resulting from pregnancies occurring within nine months of randomisation, and semen quality parameters at six months post-randomisation.
Live birth outcomes were available for all couples, with no significant difference between the two groups (risk difference -0.9%; 95% CI -4.7% to 2.8%).
Most semen quality parameters were not significantly different between the groups. A statistically significant increase in mean percentage DNA fragmentation was observed with folic acid and zinc supplementation (29.7%) compared to controls (27.2%), with a mean difference of 2.4% (95% CI 0.5%-4.4%].
The study concluded that the use of folic acid and zinc does not significantly improve semen quality or couples’ live birth rates.