Seventy boys, aged 6-13 years were subjected to periodic oral vitamin A program. Non-parasitized boys (n = 63) responded to the oral treatment with significant increase in plasma retinol level, even five weeks after the end of oral treatment. On the other hand, boys infested with parasites, none of whom had originally acceptable plasma-retinol level, did not respond significantly to the oral treatment. Vitamin A was found also to have an effect on growth, and there was highly significant correlation between retinol level and percentile weight for age.