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. 1. Introduction Estimates show that each year approximately 20 million pregnant women living in areas at risk for vitamin A deficiency (VAD) have low concentrations of retinol (<0.70？μmol/L) in blood. In the Americas and Brazil VAD prevalence estimates are around 8% and 5%, respectively [1]. The Brazilian Northeast is one of the poorest regions of the country with a 46% Human Poverty Index. A study in a big city of the Northeast region observed a 25% prevalence of inadequate serum retinol concentration among breastfeeding women [2]. The World Health Organisation (WHO) recommends mass supplementation with a megadose of vitamin A in the immediate postpartum period in countries where VAD is endemic [3]. Several randomised controlled clinical trials have shown that vitamin A supplementation in areas at risk for VAD can significantly reduce child mortality [4–6]. However, there is still no consensus on whether the vitamin A supplementation during pregnancy produces the same benefits in reducing maternal morbidity and mortality [7]. Although a strategy for supplementation during the immediate postpartum period has been implemented in several countries (including Brazil), there are still doubts regarding the most effective regimen. Investigations have warned that a dose of 200,000, IU seems to be insufficient to correct subclinical
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