In a study involving 89 otherwise healthy men, results indicate that high folate intake may lower frequencies of several types of genetic defects in sperm that contribute to birth defects and miscarriages. The men who had the highest intake of folate—722 to 1,150 micrograms a day—had a 20-30% lower frequency of sperm abnormalities, compared to men who consumed less folate. The authors of this study conclude, "Men with high folate intake had lower overall frequencies of several types of aneuploid sperm."
A good multivitamin powder supplies 800 mcg of folic acid.
"The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men," Young SS, Eskenazi B, et al, Hum Reprod, 2008 Mar 19; [Epub ahead of print].