Nutrient

Dose

Reason

Calcium

1,000 mg/day

Supports healthy defenses by transmitting messages through nerves and cells and by activating enzyme reactions.

Magnesium

400 mg/day

Enhances innate and acquired immune responses.

Vitamin C

1,000 mg/day (during cold and flu season)

In clinical research, people who took 1,000 mg of vitamin C daily experienced fewer colds than those taking a placebo. However, the increased virus-fighting action ceased after two weeks.

Vitamin E

200 IU/day

Protects white blood cells, the body’s critical immune defenders, from free radical damage.

Zinc

12 mg/day

Contributes an essential cofactor to more than 100 enzymatic reactions in the body, including many protective functions.

—A.L.

Source: Understanding Normal and Clinical Nutrition by Eleanor Noss Whitney, et al. (West Publishing Company, 1998).