High-dose vitamin E has been tested as a treatment for subfertility in men. By mopping up superoxide free radicals, doses as high as 600 mg vitamin E per day have shown a significant benefit on sperm numbers. This leaves vitamin E in an inactive form which is rapidly reactivated by vitamin C. It is therefore important for men to obtain adequate dietary supplies of both vitamins.
Vitamin E is a component of the non-specific sperm agglutinin (NSSA) and, together with vitamin C, plays a role in preventing sperm clumping and promoting motility. It also has a beneficial effect on the flexibility of sperm cell walls.
Supplements containing up to 100 mg of vitamin E are useful for general sperm health. In subfertility, doses up to 600 mg may be suggested by an andrologist. Vitamin E is non-toxic and seems safe at doses of 1,000 mg per day or more.