Vitamin E supplementation enhances cell-mediated immunity in healthy elderly subjects

The effect of vitamin E supplementation on the immune response of healthy older adults was studied in a double-blind, placebo-controlled trial. Subjects (n = 32) resided in a metabolic research unit and received placebo or vitamin E (800 mg dl-α-tocopheryl acetate) for 30 d. Alpha-tocopherol content of plasma and peripheral blood mononuclear cells (PBMCs), delayed-type hypersensitivity skin test (DTH), mitogen-stimulated lymphocyte proliferation, as well as interleukin (IL)-1, IL-2, prostaglandin (PG) E₂, and serum lipid peroxides were evaluated before and after treatment. In the vitamin E-supplemented group 1) α-tocopherol content was significantly higher (p < 0.0001) in plasma and PBMCs, 2) cumulative diameter and number of positive antigen responses in DTH response were elevated (p < 0.05), 3) IL-2 production and mitogenic response to optimal doses of concanavalin A were increased (p < 0.05), and 4) PGE₂ synthesis by PBMCs (p < 0.005) and plasma lipid peroxides (p < 0.001) were reduced. Short-term vitamin E supplementation improves immune responsiveness in healthy elderly individuals; this effect appears to be mediated by a decrease in PGE₂ and/or other lipid-peroxidation products.