Effect of Zinc and Folic Acid on Sperm

A study published in 2002 examined the effect of folic acid and zinc sulfate on male factor subfertility. This large, well-designed clinical trial found a 74% increase in total normal sperm when subfertile men took 66 mg of zinc sulfate and 5 mg of folic acid daily. Sperm count also increased in fertile men, but this was not statistically significant.

The doses used in this study are rather high, considering that the US RDA is 15 mg per day of zinc and 400 micrograms (400 mcg = 0.4 mg).

While these results appear very promising, the impact of increased sperm count on likelihood of conception was not evaluated in this study.