Vitamin A status of children with a history of respiratory syncytial virus infection in infancy.

In order to extend our earlier observation that children who experience frequent respiratory episodes may benefit from Vitamin A supplementation, 206 children aged 2-7 years who had been hospitalized for bronchiolitis during infancy were randomized into a controlled trial of Vitamin A supplementation. Of these, 149 met the criteria of protocol compliance after 12 months of follow-up. Mean plasma retinol at baseline was 39.2 micrograms/100 ml (s.e.m. = 1.0) and did not increase after 12 months (mean = 36.0 micrograms/100 ml, s.e.m. = 0.7) despite the older age of the cohort. The range observed (11.7-73.9 micrograms/100 ml) included some children at risk of marginal Vitamin A deficiency. Mean plasma retinol levels were 20% lower than those of children experiencing frequent respiratory episodes recorded earlier. Oral supplementation did not change plasma retinol levels, nor did it affect respiratory morbidity.