Ascorbic acid levels are much higher in seminal fluid than in other body fluids, including the blood. The important role played by Vitamin C in male fertility had been proved in animal and human studies. In one study, when dietary vitamin C was reduced from 250 mg to 5 mg per day in healthy human subjects, the seminal fluid ascorbic acid level decreased by fifty percent and the number of sperm with damage to their DNA increased by ninety-one percent. Thus, dietary vitamin C plays a critical role in protecting against sperm damage. Low dietary vitamin C levels are likely to lead to infertility.
Cigarette smoking is known to greatly reduce the vitamin C levels in our bodies.
RDA of Vitamin C for smokers is twice as much as that for nonsmokers. After one month, sperm quality improved proportional to the level of vitamin C supplementation. Nonsmokers also benefit from vitamin C supplementation. For example, in one study, thirty infertile, but otherwise healthy, men received either 200 mg or 1,000 mg of vitamin C or a placebo daily. Their sperm was tested weekly for sperm count, viability, motility, agglutination, abnormalities, and immaturity.