Vitamin E and immune response in the aged: molecular mechanisms and clinical implications

Abstract

Nutritional status has been indicated as a contributing factor to age-related dysregulation of the immune response. Vitamin E, a lipid-soluble antioxidant vitamin, is important for normal function of the immune cells. The elderly are at a greater risk for vitamin E intake that is lower than recommended levels. Vitamin E supplementation above currently recommended levels has been shown to improve immune functions in the aged including delayed-type hypersensitivity skin response and antibody production in response to vaccination, which was shown to be mediated through increased production of interleukin (IL)-2, leading to enhanced proliferation of T cells, and through reduced production of prostaglandin E(2), a T-cell suppressive factor, as a result of a decreased peroxynitrite formation. Vitamin E increased both cell-dividing and IL-producing capacities of naive T cells, but not memory T cells. The vitamin E-induced enhancement of immune functions in the aged was associated with significant improvement in resistance to influenza infection in aged mice and a reduced risk of acquiring upper respiratory infections in nursing home residents. Further studies are needed to determine the signaling mechanisms involved in the upregulation of naive T-cell function by vitamin E as well as the specific mechanisms involved in reduction of risk for upper respiratory infections.

Prediagnostic circulating carotenoid levels and the risk of non-Hodgkin lymphoma: the Multiethnic Cohort

“…41 Carotenoids also may influence the risk of NHL through immune-mediated pathways. 31,42 For example, elderly subjects who received supplementation with carotenoid-containing vitamins and trace elements showed a higher production of the cytokine IL-2 and a lower rate of infections, 43 and a carotenoid-rich vegetable intervention suppressed the secretion of IL-2 and IL-4. 44,45 This study had several strengths, including the prospective design that allowed for the prediagnostic assessment of serum carotenoid levels, the ethnic diversity of the study sample, and the population-based sampling frame allowing for generalizability of results.…”

Nutrition, diet and immunosenescence

“…Vitamin E includes tocopherols and tocotrienols that exhibit the biological activity of α-tocopherol with both synthetic and natural forms of tocopherols being used experimentally. Results from animal studies have established that vitamin E can enhance T cell functions by directly influencing membrane integrity and signal transduction or, indirectly by reducing production of suppressive factors such as PGE 2 by macrophages (Meydani et al, 2005;Wu and Meydani, 2008). Many studies have reported beneficial effects of vitamin E supplementation in healthy elderly people (Belisle et al, 2008;De la Fuente et al, 2008;Meydani et al, 1990;Meydani et al, 1997;Pallast et al, 1999) with the majority finding improvements in immune function.…”

Effect of Multivitamin Supplementation on Measles Vaccine Response among HIV-Exposed Uninfected Tanzanian Infants

“…Micronutrients are known to have a wide range of effects on immune responses (8,9). The effect of vitamin A on measles vaccine responses has been studied in multiple clinical trials, but the results are unclear (10).…”

“…Vitamin A may improve measles vaccine responses among boys when administered with the vaccine at 9 months of age but may worsen responses when administered at 6 months of age (10)(11)(12). Randomized controlled trials of vitamin E supplementation have found an improved innate immune activity, lymphocyte proliferation, and tetanus vaccine response among adults and elderly populations (9). Only one randomized trial of vitamin E supplementation and vaccine responses has been conducted in infants, and it reported no effect of supplementation on IgG titers following tetanus vaccination (13).…”