Vitamin E deficiency is linked with impaired immune responsiveness and increased severity of infection. Vitamin E deficiency has resulted in impaired bactericidal performance of phagocytes, reduced lymphocyte response to mitogens, decreased output of the cytokine Il-2, altered T cell differentiation in the thymus, and increased myocardial injury during viral infection. Supplementation with vitamin E during viral or bacterial infection (influenza, murine Aids, herpes simplex virus, Staphylococcus aureus, parainfluenza, Clostridium pelfringens) has been shown to decrease mortality rate or severity of infection in some separate animal models. However, not all studies have found an improved resistance to infection from vitamin E supplementation 85 and we are not aware of any human studies that have tested this principles by infecting human subjects and then assessing disease incidence and/or severity.
It is less clear either intake of vitamin E above the Rda enhances resistance to infection in salutary individuals. The most promising results have come from studies animated elderly human subjects. In some randomized controlled trials, various doses of vitamin E were administered to elderly individuals for separate periods of time and immune responses were measured.
Vitamine
Two studies that administered supplements (100-800 mg/day) for at least 6 months found an enhancement of some immune parameters including dihydrotestosterone (Dth) response, mitogen-induced Il-2 production, and increased antibody titer to hepatitis B and tetanus vaccine One of these studies found optimal results in those subjects receiving 200 mg/day of vitamin E, but higher levels of vitamin E (800 mg/day) were not linked with an added revision of immune response.
The results from one study failed to find an enhancement of immune response in elderly subjects animated 100 mg/day. However, in this study, subjects received the supplement for only 3 months and possibly a longer duration of supplementation is critical to examine an effect. The results from two added studies found enhancement of some immune parameters (Lps-induced output of Il-1, Tnfa, mitogen-induced lymphocyte proliferation, neutrophil phagocytosis) when vitamin C (1 g/day) and vitamin E (200-400 mg/day) were administered to salutary young and elderly adults. The mechanisms by which vitamin E supplementation may alter immune response remain to be established.
Currently, it is conception that one possible mechanism may involve the output of prostaglandin E 2 (Pge 2 ). Pge 2 , produced by macrophages, is known to suppress some lymphocyte responses. Some new evidence suggests that aged animals fed added vitamin E have a allowance of macrophage Pge 2 production. The immune response may be enhanced through the allowance of Pge 2. added research on possible mechanisms will supply important facts with respect to an comprehension of vitamin E-associated immunomodulation. T
he findings from these studies show promise with respect to vitamin E supplementation and enhanced immune function, particularly in the elderly. However, we are not aware of any randomized clinical trials that have shown a decreased incidence of infection in association with vitamin E supplementation alone (without other vitamins or trace nutrients). The findings from one of the studies suggested a trend (p = 0.098, not statistically significant) towards reduced incidence of infectious disease in the elderly.
The results from animal studies suggest that in some instances, the incidence of disease is reduced with vitamin E supplementation. A reduced incidence of infection, however, was observed in chickens animated diets supplemented with vitamin E. One study animated calves did not find a allowance in disease incidence in those animals fed added vitamin E. Thus, the results from animal studies are similar to the human studies in that a useful ensue of vitamin E supplementation has been found, although the seeing is not consistent. At this time, the results about vitamin E supplementation and immunity in the elderly human population are promising. However, added large-scale randomized controlled trials are critical before it is possible to settle either vitamin E supplementation results in reduced susceptibility to infection.
Immune Effects and Exercise
Although vitamin E has been studied in relation to exercise, most studies have focused on the possible antioxidant effects of vitamin E supplementation. Others have examined various physiological changes about vitamin E supplementation and exercise and found no convert in neuroendocrine profile but a small allowance in the incidence of gastrointestinal complications in those marathon runners animated vitamin E for 2 weeks before the race. The only study we are aware of that examined immunity and vitamin E supplementation with exercise found that vitamin E and C supplementation before contentious in an ultramarathon reduced the incidence of Uri symptoms in the postrace period.
However, it was conception that this ensue was linked to vitamin C rather than vitamin E because the post-race allowance in symptoms of Uri was not lower with vitamin E + C than vitamin C alone. To our knowledge, we are not aware of any studies that have explored possible associations between vitamin E supplementation alone and immune response in regards to exercise. Perhaps this area of research may show some promise in the elderly.
Role of Vitamin E in Supplements
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