Coenzyme Q10; 50-200 mg/day.

This antioxidant may help fight cancer and other diseases linked to damage by free radicals.

May take eight weeks or longer to have an effect, so experts recommend long-term use.

Folate; 400 mcg/day.

May protect against breast cancer in some women.

At least 600 mcg of folate daily may help decrease breast-cancer risk in women who drink more than 15 grams of alcohol a day.

Indole-3-carbinol; 150-300 mg/day.

Stimulates enzymes that may slow tumor growth.

Not recommended for pregnant or nursing women; food sources include broccoli, cabbage, kale, and turnips.

Vitamin B12; 500 mcg/day.

To aid in the proper absorption of nutrients and cell formation.

Found in brewer's yeast, eggs, milk and other dairy products, seafood, sea vegetables, and soy products.

Vitamin C; 75 mg/day.

May help prevent breast cancer.

To ensure efficient absorption, scatter supplementation throughout the day.

Vitamin E (mixed tocopherol/tocotrienol complex), containing 400 IU of d-alpha tocopherol; 270 mg/day.

May protect against cancer because of antioxidant properties.

Pregnant or nursing women should avoid high dosages; avoid synthetic vitamin E, which is less potent.

Zinc; 12 mg/day.

Boosts immune function.

Very high doses can cause adverse reactions and may even suppress the immune system.

Note: Larger doses may be necessary for disease management and prevention. Check with your health care practitioner for individualized recommendations.

Sources: Jaime S. Ruud, RD, research analyst in the department of nutritional science and dietetics at the University of Nebraska and author of Nutrition and the Female Athlete (CRC Press, 1996); PDR for Nutritional Supplements (Medical Economics Co., 2001); Breast Cancer Q&A by Charyn Pfeuffer (Penguin Putnam, 2003).