Supplementing the diet with folic acid and zinc can have a significant effect on improving semen quality in sub-fertile men, according to recent research from the Netherlands.
The Dutch team published their findings in the March issue of the journal Fertility and Sterility. They focused on folic acid and zinc because both are known to be essential to the creation of both DNA and sperm.
Fertile men, whose wives had conceived within one year of regular, unprotected intercourse, were recruited from midwifery practices. Sub-fertile men, whose wives had failed to conceive under the same conditions, and who had an initial semen analysis showing a sperm concentration between 5 and 20 million per millilitre, were recruited from fertility clinics.
Before treatment, each participant provided a blood sample to gauge baseline levels of the nutrients and a semen sample to be evaluated for sperm concentration, motility and morphology (form). Both groups, fertile and sub-fertile, were divided into four subgroups, and instructed to take two pills a day for 26 weeks.
The sub-groups were randomly allocated either zinc sulfate and folic acid supplements, two placebos, zinc and a placebo or folic acid and a placebo. None of the participants knew which set of pills he had received and all were asked to refrain from taking additional nutritional supplements during the study, the authors said.
At the conclusion of treatment, the participants again provided semen and blood samples. These were evaluated and the researchers found that the set of sub-fertile men receiving both zinc sulfate and folic acid exhibited a 74 per cent increase in the number of normally formed sperm in their semen samples. The number of abnormally formed sperm in their samples increased by 4 per cent. A less dramatic increase in sperm concentration was observed in fertile men receiving zinc only or zinc and folic acid.
While the results of the research are encouraging, the researchers said that further research was needed to understand how the two micronutrients worked together to affect male fertility before widespread use of the supplements could be recommended as a fertility treatment.