摘要:Objective. To test whether the serum retinol level in mothers supplemented with 400,000 IU of vitamin A is higher than in those supplemented with 200,000 IU and to estimate duration of the protective effect of vitamin A supplementation in the serum retinol level. Methods. Double-blind, randomised controlled trial performed in two hospitals in the state of Pernambuco in northeast Brazil. Three hundred twelve mothers were recruited immediately postpartum. All women received a capsule containing 200,000 IU of vitamin A, and 10 days after delivery, they were randomly assigned to one of two treatment groups. One group received a second capsule containing vitamin A and the other group received a placebo. Each group was invited back after 2, 4, and 6 months for serum retinol analyses. Results. No difference was found between the two groups in serum maternal retinol concentration at 2 months (2.13 versus 2.03 μmol/L), 4 months (2.20 versus 2.24 μmol/L) or 6 months (2.29 versus 2.31 μmol/L). Because there was no further effect and because this population has a level of vitamin A deficiency considered mild, our results do not support a proposal to increase the dosing schedule for vitamin A in postpartum women as recommended by the IVACG.