Nutritional factors can modulate immune responses. The concentration of iron, amongst other nutrients, influences host defence mechanisms. In experimentally induced iron deficiency in animals, morbidity and mortality on bacterial challenge are increased several-fold. Cell-mediated immunity and intra-cellular bacterial killing by polymorphonuclear leucocytes are impaired in iron-deficient individuals. This impairment is likely to be mediated by the effect of iron lack on cell proliferation, DNA synthesis and activity of iron-containing and iron-dependent enzymes involved in killing and elimination of microbes. Conversely, the availability of the free iron is a critical determinant for bacterial multiplication. It is not surprising then that epidemiological and clinical data on the frequency of infections--bacterial, fungal and others--in iron-deficient, iron-overloaded and healthy groups differ so widely. Vulnerability to infection based on the individual's iron status must be the net result of the effect of iron, or the lack of it, on microbial growth on the one hand and on immunocompetence of the host on the other. The key to keeping these interactions within physiological bounds is 'optimal iron nutrition'.

Anemia, Hypochromic↗

PubMedDate not supplied

Nutritional regulation of immunity and risk of illness.

Nutrition is a critical determinant of immunocompetence and risk of illness. Young children with protein-energy malnutrition exhibit increased mortality and morbidity, largely due to infectious disease. Recent work has demonstrated that, undernourished individuals have impaired immune responses. The most consistent abnormalities are seen in cell-mediated immunity, complement system, phagocytes, mucosal secretory antibody response, and antibody affinity. These changes, together with other handicapping factors observed in underprivileged societies, lead to more infections, which in turn produce physiological changes that worsen nutritional status. It is now established that deficiencies of single nutrients also impair immune responses. The best studied are zinc, iron vitamin B6, vitamin A, copper and selenium. If malnutrition occurs during fetal life, as epitomized by small-for-gestational age infants, the effects on cell-mediated immunity are very significant and long lasting. These interactions on nutrition and immunity have several practical applications.

Child↗

PubMedDate not supplied

Indian childhood cirrhosis: a critique of recent observations.

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Child↗