Effect of antioxidative vitamins on immune function with clinical applications.

Infection and trauma cause inflammatory stress in patients. Tissue damage, enhanced inflammatory mediator production and suppressed lymphocyte function may occur as a consequence. The antioxidative vitamins, ascorbic acid and the tocopherols, are important not only for limiting tissue damage but also in preventing increased cytokine production which is a consequence of excessive activation of NF kappa B. Glutathione is a major endogenous antioxidant and is important for lymphocyte replication. Two vitamins, vitamin B6 and riboflavin participate in the maintainance of glutathione status.

The former vitamin acts as a cofactor in the synthesis of cysteine (the rate limiting precursor for glutathione biosynthesis) and the latter vitamin is a cofactor for glutathione reductase. Deficiencies in tocopherol, vitamin B6 and riboflavin reduce cell numbers in lymphoid tissues of experimental animals and produce functional abnormalities in the cell mediated immune response. Ascorbic acid and tocopherols exert anti-inflammatory effects in studies in man and animals. In humans, dietary supplementation with ascorbic acid, tocopherols and vitamin B6 enhances a number of aspects of lymphocyte function. The effect is most apparent in the elderly.