A 210-MU-MOL DOSE OF VITAMIN-A PROVIDES MORE PROLONGED IMPACT ON VITAMIN-A STATUS THAN 105-MU-MOL AMONG PRESCHOOL-CHILDREN

A randomized controlled clinical trial was conducted to determine the relative protection afforded by two large doses of vitamin A against subclinical vitamin A deficiency among 345 preschool children. At baseline, children either had or were at high risk of developing non-corneal xerophthalmia. Vitamin A status was assessed by the relative dose response (RDR) test, serum retinol concentration, and ocular examination before and 3 and 6 mo following one oral dose of 105 mu mol or 210 mu mol of vitamin A. At 3 and 6 mo, mean serum retinol concentration was significantly higher in the 210-mu mol group than in the 105-mu mol group. The proportion of children with a positive RDR did not differ between groups at 3 mo, but by 6 mo there were three times more children positive in the 105-mu mol group. Most of the observed difference was confined to children with xerophthalmia at baseline. The relative benefit of the 210-mu mol dose was related to baseline vitamin A status. The current World Health Organization recommended prophylactic dose of 210 mu mol seems appropriate.