ASSESSMENT OF MILD ZINC-DEFICIENCY IN CHILDREN

Gross zinc deficiency is not common in India. However, the extent of subclinical zinc deficiency in the undernourished population is not so far established. Plasma and leukocyte zinc levels were determined in 103 preschool children belonging to different nutritional grades. In addition, serum thymulin activity was determined to detect mild zinc deficiency. All three parameters showed gross impairment in severely malnourished children compared to normal and undernourished groups (P<0.001). However, normal and undernourished children were comparable with respect to plasma and leukocyte zinc and basal thymulin activity (2-9 and 2-6). The undernourished children showed a significant increase (P<0.025) in thymulin activity after in vitro zinc supplementation reflecting mild zinc deficiency. Estimation of rise in thymulin activity following zinc supplementation appears to be a sensitive indicator to detect mild zinc deficiency. However, the functional significance of such a mild zinc deficient status in populations in whom invariably other nutritional deficiencies are coexistent, is not clear. Until the functional significance of mild zinc deficiency is established, leukocyte and plasma zinc levels estimated under controlled conditions might be useful parameters to detect gross changes in zinc status.