Individuals deficient in vitamin A are more susceptible to infectious disease in general but especially viral infections.
Vitamin A deficiency is associated with increased mortality in children and pregnant women. An estimated 253 million children are at risk of immunodeficiency due to vitamin A deficiency (WHO) and millions of pregnant and lactating women are also at high risk in developing countries.
Vitamin A plays an important function in host defense mechanism, including both cell-mediated immunity and humoral immune mechanisms.
This vitamin involves in the maintenance of mucosal surfaces, in the generation of antibody responses, in hematopoiesis and in the function of T and B lymphocytes, natural killer cells and neutrophils.
Vitamin A also acts to eliminate free radicals before they can do severe cell damage, thus strengthening the immune system.
Researchers have found that children with low vitamin A had abnormally low levels of T-cells in their blood. Vitamin A makes T-cells more active and stronger.
Vitamin A and resistance to disease