Abstract
Tuberculosis (TB), a disease caused by the bacterium Mycobacterium tuberculosis, has affected mankind for over 5000 years and the disease continues to be a major cause of morbidity and mortality. Vitamin A and zinc deficiency has been commonly observed in patients with tuberculosis. The deficiency of vitamin A observed in patients with TB might have contributed to the development of TB disease in them. Alternatively, deficiency could be due to loss of appetite, poor intestinal absorption, increased urinary loss of vitamin A or acute phase reaction in TB. Vitamin A deficiency lowers immunity while vitamin A supplementation reduces morbidity and mortality, particularly from measles and diarrhea. Zinc is known to be essential for all highly proliferating cells in the human body, especially the immune system. A variety of in vivo and in vitro effects of zinc on immune cells mainly depend on the zinc concentration. All kinds of immune cells show decreased function after zinc depletion. In monocytes, all functions are impaired, whereas in natural killer cells, cytotoxicity is decreased, and in neutrophil granulocytes, phagocytosis is reduced. B cells undergo apoptosis. Impaired immune functions due to zinc deficiency are shown to be reversed by adequate zinc supplementation, which must be adapted to the actual requirements of the patient. We conclude that vitamin A and Zinc have an important role in cell-mediated immune functions and they also function as anti-inflammatory and antioxidant agents in tuberculosis.