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

1. Serum levels of retinol-binding protein (RBP), total vitamin A and retinyl ester were measured in twenty-four malnourished children with corneal lesions and nine normal children. 2. Initially, the RBP and vitamin A levels were significantly lower in malnourished children than in normal children. 3. After intramuscular injection of 30000 microgram of aqueous vitamin A, serum levels of total vitamin A were increased significantly at 24 h and tended to fall within 5 d of treatment in both groups. 4. Before treatment, retinyl ester accounted for less than 10% of the vitamin in circulation. After vitamin A injection, it increased to 30%, a level much lower than that reported in patients with hypervitaminosis A. 5. There was no significant difference between the two groups of children and none of them showed clinical signs of toxicity. These observations indicate that administration of massive doses of vitamin A over a short period will not produce toxic effects even in malnourished children.