Vitamins & Nutritional Supplements for Immune System Support

Most, but not all, double-blind studies have shown that elderly people have better immune function and reduced infection rates when taking amultiple vitamin-mineral formula. In one double-blind trial, supplements of 100 mcg per day of selenium and 20 mg per day of zinc, with or without additional vitamin C, vitamin E, and beta-carotene, reduced infections in elderly people, though vitamins without minerals had no effect. Burn victims have also experienced fewer infections after receiving trace mineral supplements in double-blind research. These studies suggest that trace minerals may be the most important micronutrients for enhancing immunity and preventing infections in the elderly.

Vitamin E enhances some measures of immune-cell activity in the elderly. This effect is more pronounced with 200 IU per day compared with either lower (60 IU per day) or higher (800 IU per day) amounts, according to double-blind research. Intakes under 200 IU per day have not boosted immune function in some reports.

Beta-carotene and other carotenoids have increased immune cell numbers and activity in animal and human research, an effect that appears to be separate from their role as precursors to vitamin A. Placebo-controlled research has shown positive benefits of beta-carotene supplements in increasing numbers of some white blood cells and enhancing cancer-fighting immune functions in healthy people at 25,000–100,000 IU per day.

In double-blind trials in the elderly, supplementation with 40,000–150,000 IU per day of beta-carotene has increased natural killer (NK) cell activity, but not several other measures of immunity...