A number of nutrients are essential for building a strong immune system. Vitamin A, for instance, strengthens the immune system by enhancing white-blood-cell function and antibody activity. Vitamin C, which stimulates and supports many components of the immune system, may help reduce the duration and intensity of cold symptoms. Studies also support the use of B complex, selenium, and zinc as immune boosters.
(Source: Body & Soul magazine, Nov/Dec 2003.)