Folic Acid, Zinc Supplementation May Help Infertile Men
Men with infertility due to an abnormally low sperm count may benefit from taking supplemental folic acid and zinc, according to a new study in Fertility and Sterility.1
Scientists conducted a 26-week trial that included 108 fertile and 103 infertile men. Both groups were assigned to receive one of four treatments: (1) zinc alone (15 mg per day), (2) folic acid alone (5 mg per day), (3) zinc plus folic acid, or (4) a placebo. Sperm counts, motility (ability of sperm to move), and the shape of sperm cells, as well as blood levels of zinc and folic acid, were measured in both groups at the beginning and conclusion of the study.
The concentration of normal sperm cells increased by 74% in infertile men who took the combination of zinc and folic acid supplements, compared with initial measurements, although many of these men failed to achieve normal sperm count values. The concentration of normal sperm cells also increased in infertile men receiving zinc alone or folic acid alone, but these increases were not statistically significant. In those receiving placebo, the normal-sperm count actually declined slightly. Fertile men had no significant change in sperm counts, regardless of treatment. Motility and sperm cell shape were not affected by zinc or folic acid in either group.
Levels of folic acid increased in both fertile and infertile men who received supplemental folic acid, whereas zinc supplementation did not increase the average blood zinc concentration. Both nutrients are involved in DNA production, an important step in the formation of sperm cells. However, it is not clear to what extent subtle deficiencies of these nutrients contribute to the common sperm abnormalities seen in infertile men.
Infertility affects 20% of all couples in the United States, with sperm abnormalities being the main culprit among 35% of infertile couples.2 Though supplementation with zinc and folic acid didn’t lead to normal sperm values, the findings still demonstrate a clear benefit in increasing sperm count in infertile men. Whether that translates into increased fertility remains to be seen; more studies are needed to verify this possibility.
Other nutritional supplements may also benefit men with low sperm counts. Several small studies have shown that L-arginine, an amino acid, increases sperm count and fertility.3 4 However, men with extremely low sperm counts (less than ten million per milliliter) do not seem to respond to supplementation with L-arginine. Some physicians recommend 4 grams of L-arginine a day. Other preliminary trials suggest vitamin B12, L-carnitine, coenzyme Q10, vitamin E, and S-adenosylmethionine (SAMe) may each improve sperm quality in infertile men, though a physician should be consulted to determine the appropriate intake amount.
1. Wong WY, Merkus HM, Thomas CM, et al. Effects of folic acid and zinc sulfate on male factor subfertility: a double-blind, randomized, placebo-controlled trial. Fertil Steril 2002;77:491–8.
2. The Merck Manual, 17th Edition. Whitehouse Station, NJ: Merck and Company, Inc., 1999.
3. De Aloysio D, Mantuano R, Mauloni M, Nicoletti G. The clinical use of arginine aspartate in male infertility. Acta Eur Fertil 1982;13:133–67.
4. Schachter A, Goldman JA, Zukerman Z. treatment of oligospermia with the amino acid arginine. J Urol 1973;110:311–3.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of Garlic and Cholesterol: Everything You Need to Know (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice in Westport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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