Fresh fruits and vegetables are the ultimate natural vitamin sources. If you eat a balanced diet you'll get these important nutrients and you won't need vitamin supplements to correct nutritional deficiencies. Unfortunately, most Americans eat fewer than the recommended 5 servings of fruits and vegetables per day. To date, no evidence suggests that extra vitamins will enhance athletic performance, increase strength or endurance, increase energy, or build muscles. Certainly, a vitamin deficiency can impair performance, but deficiencies are generally related to conditions such as anorexia, unhealthy weight loss, malabsorption, or poor eating habits.
Deficiencies are unlikely in active people with robust appetites.
Vitamin E is an antioxidant, which means it helps fight damage to body cells. It may help reduce the tissue damage associated with intense exercise. Researchers are still trying to determine if extra vitamin E offers benefits for athletes. Although outright vitamin deficiencies are rare, some people are at risk for marginal vitamin shortages. People who restrict their food intake to less than 1,200 calories per day may miss out on important nutrients.