A wealth of zinc and folic acid supplements claim to increase male fertility, spurring use among couples trying to conceive. However, a new trial published in JAMA casts doubt on the supplements’ abilities to help.
The trial, conducted at four centers across the United States, found no difference in live birth or semen quality measures between men who received supplementation versus men who received a placebo.
“Many of us believed that antioxidant treatment of males would improve sperm parameters and pregnancy outcomes,” said Dr. Jared Robins, associate professor of obstetrics and gynecology, at Northwestern Feinberg School of Medicine, who was a co-author of the study. “We did not expect this result.”
As many as 45 percent of adult men in the United States reported using some type of dietary supplement from 1999 to 2012, according to previously published findings.
Many of these formulations claim benefits for fertility, ranging from increased sperm count to other, less quantitative measures like enhanced “libido” or “vitality.” These purported fertility boosters often contain folic acid and zinc, both of which are involved in spermatogenesis, but exact details of these compounds’ role in sperm creation is still uncertain.
The Food and Drug Administration is not permitted to evaluate dietary supplements until after they hit the market, creating a largely unregulated morass of dubious claims and uncertain effectiveness, according to Dr. Robins. Past trials have been small and, consequently, results have widely varied, so a large randomized trial was needed to determine the effectiveness, if any, of zinc and folic acid.Friday Letter Submission, Publish on February 21