A 210-μmol dose of vitamin A provides more prolonged impact on vitamin A status than 105 μmol among preschool children
Journal of Nutrition
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 μmol or 210 μmol of vitamin A. At 3 and 6 mo, mean serum retinol concentration was significantly higher in the 210-μmol group than in the 105-μmol 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-μmol group. Most of the observed difference was confined to children with xerophthalmia at baseline. The relative benefit of the 210-μmol dose was related to baseline vitamin A status. The current World Health Organization recommended prophylactic dose of 210 μmol seems appropriate.
Humphrey, J., Natadisastra, G., Muhilal, Friedman, D., Tielsch, J., West, K., & Sommer, A. (1994). A 210-μmol dose of vitamin A provides more prolonged impact on vitamin A status than 105 μmol among preschool children. Journal of Nutrition, 124 (8). http://dx.doi.org/10.1093/jn/124.8.1172