Serum retinol-binding protein and vitamin A levels in malnourished children.

Serum levels of vitamin A and retinol-binding protein (RBP) were measured in children with vitamin A deficiency, in children with protein-energy malnutrition (PEM) and in normal children, before and after administration of 100 000 IU of water-miscible vitamin A. Serum vitamin A and RBP levels were significantly low in children with vitamin A deficiency and in children with severe PEM, whereas the values in milder grades of PEM were similar to those of normal subjects. In severely malnourished children with corneal lesions, serum vitamin A concentration was reduced to a much greater extent than the level of serum RBP. Administration of vitamin A resulted in a significant increase in serum levels of both the components within 4 hours in all the 3 groups of children. The increase in RBP concentration observed in children with PEM was similar to that in vitamin A deficient children. These results indicate that in malnourished children, particularly in those who are at risk of developing keratomalacia, vitamin A is the main limiting factor. It is, therefore, recommended that children with PEM should be treated with vitamin A in addition to dietary protein and calories.