Nutritional status and immune responses.

The immune system is dependent on good nutritional status for its optimal functioning. Immune function itself can provide a broad measure of nutritional deficiency. For example, lymphocyte count and skin reactivity most often are used for this purpose. Of course, such tests are of little value in monitoring nutritional therapy. Several nutrients that are likely to be deficient in hospitalized patients and are especially important in the maintenance of immune function include protein, ascorbic acid, and zinc.