A to Z: vitamin A and zinc, the miracle duo.
Molina EL; Patel JA
Indian Journal of Pediatrics 1996 Jul-Aug;63(4):427-31
micronutrients such as vitamins and trace minerals are known modulators
of host immune responses against common pathogens. In this respect, vitamin
A and zinc have recently received increased attention. Several in vivo
and in vitro studies suggest that vitamin A may be a critical player in
the mucosal immune responses in the respiratory and gastrointestinal tracts,
particularly in undernourished children. The effect may be mediated primarily
by stabilization of the membrane of mucosal epithelial cells, as well
as enhanced leukocyte functions. The beneficial effect of vitamin A therapy
in reducing measles-associated morbidity and mortality suggests its crucial
role in defenses against viral pathogens. Zinc is also known affect leukocyte
functions such as phagocytosis and T-lymphocyte-mediated immune responses.
However, unlike vitamin A, zinc has been investigated primarily for its
effects on bacterial infections. Dietary supplementation or therapeutic
treatment with vitamin A and zinc may be a cheap yet effective means of
preventing or treating infections in highly susceptible populations. Additional
studies, however, are required to better define the types of pathogens
and the specific human populations that may benefit from such therapy.