Treatment with folic acid and zinc supplements may raise the sperm count of some men with fertility problems, new research suggests.
The study, which included about 100 subfertile men, did not look at whether this boost in sperm number translated to better odds of conceiving. But researchers say their findings open up that possibility.
Their results are published in the March issue of the journal Fertility and Sterility.
Investigators led by Dr. Wai Yee Wong of the University Medical Centre Nijmegen in the Netherlands studied men with fertility problems of unknown cause, as well as a comparison group of fertile men. Over 26 weeks, men in both groups followed one of four regimens: daily doses of folic acid and zinc, folic acid alone, zinc alone, or inactive treatment with a placebo.
After treatment, the subfertile men given both supplements showed a 74% increase in the number of normal sperm in their semen, along with a small increase in abnormal sperm. Men in the fertile group had small increases in sperm count when given folic acid plus zinc, or zinc alone, according to the report.
Male infertility involves multiple underlying factors, including genetics. According to Wong’s team, animal research has suggested that nutrition affects the production of sperm, although the key nutrients remain unclear.
Also unknown is whether deficiencies in folate–the naturally occurring form of folic acid–or zinc are risk factors for male infertility, the researchers note. The subfertile men in their study did not differ from fertile men in blood levels of folate or zinc.
Still, both nutrients are essential to proper genetic expression, which means they could play a role in the normal generation of sperm.
Folate occurs in foods such as green, leafy vegetables, legumes and oranges; many cereals and grain products are fortified with folic acid. Zinc is found foods like red meat, poultry, and fortified cereals.
While the current findings are encouraging, Wong’s team points out that it is unclear whether the boost in sperm count will lead to higher pregnancy rates. They call for larger trials to look further into the safety and effectiveness of giving the supplements to subfertile men.