Effect of zinc supplementation on plasma levels of vitamin A and retinol-binding protein in malnourished children.

The relationship between plasma levels of vitamin A and zinc was studied in 45 children suffering from vitamin A deficiency and 20 children with protein-energy malnutrition. Thirty apparently normal children of the same age group were also studied for comparison. The mean levels of plasma vitamin A, retinol-binding protein and zinc were significantly lower in vitamin A-deficient children and in children with PEM, as compared to controls. Supplementation with 40 mg zinc daily for 5--10 days resulted in a significant increase in plasma vitamin A and RBP levels in children with PEM but not in the vitamin A-deficient group. There was, however, no correlation between plasma levels of vitamin A and zinc. The data suggest that in children with PEM, apart from deficiencies of protein and vitamin A, zinc deficiency may also contribute to the lowering of plasma vitamin A levels. They also suggest that in vitamin A-deficient children, without protein-energy malnutrition, zinc deficiency does not seem to have a role.