Vitamin A effects on immune system

Vitamin A is vital for the development of the body's barriers to infection and stimulates and enhances many immune functions, including antibody response and the activity of various white blood cells such as T helper cells and phagocytes. This immune-enhancing function promotes healing of infected tissues and increases resistance to infection. Episodes of acute infection may deplete body stores of vitamin A, possibly by increasing excretion, suggesting that vitamin A requirements may be higher during infection.

Death rates and susceptibility to infection and diarrhea are higher in children with vitamin A deficiency, particularly in developing countries. However, vitamin A deficiency may also contribute to susceptibility to infection in developed countries. A 1992 study involving 20 children with measles in Long Beach, California found that half of them were vitamin A-deficient. Measles may increase the body's utilization of vitamin A, possibly because of the rapid destruction of epithelial surfaces.

Vitamin A effects of deficiency is common in HIV-positive people and this may be due to metabolic changes associated with HTV infection. Vitamin A effects on immune system are very important. Vitamin A deficiency is often seen in HIV-positive pregnant women and severe deficiency increases infant mortality and the risk of mother-to-child transmission of HIV.

Vitamin A supplements have been used to enhance resistance to infection and to treat measles and respiratory infections, particularly in areas where vitamin A deficiency is widespread. A recent research review analyzing the results of several studies found that adequate vitamin A intake in children resulted in a 30 per cent decrease in deaths from all causes. Children in developing countries are often at high risk of vitamin A deficiency. In developed countries, ensuring adequate vitamin A intake is particularly important in those with life-threatening infections such as measles, and in those at risk of relative deficiency, such as premature infants.

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Vitamin a effects on immune system
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Vitamin E benefits for immune system
B vitamins for immune system
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