Julicristie M Oliveira, Roman Allert, Christine E East

In areas where vitamin A deficiency (VAD) is a public health concern, the maternal dietary intake of vitamin A may be not sufficient to meet either the maternal nutritional requirements, or those of the breastfed infant, due the low retinol concentrations in breast milk. To evaluate the effects of vitamin A supplementation for postpartum women on maternal and infant health. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (8 February 2016), LILACS (1982 to December 2015), Web of Science (1945 to December 2015), and the reference lists of retrieved studies. Randomised controlled trials (RCTs) or cluster-randomised trials that assessed the effects of vitamin A supplementation for postpartum women on maternal and infant health (morbidity, mortality and vitamin A nutritional status). Two review authors independently assessed trials for inclusion, conducted data extraction, assessed risk of bias and checked for accuracy. We assessed the quality of the evidence using the GRADE approach. Fourteen trials of mainly low or unclear risk of bias, enrolling 25,758 women and infant pairs were included. The supplementation schemes included high, single or double doses of vitamin A (200,000 to 400,000 internation units (IU)), or 7.8 mg daily beta-carotene compared with placebo, no treatment, other (iron); or higher (400,000 IU) versus lower dose (200,000 IU). In all trials, a considerable proportion of infants were at least partially breastfed until six months. Supplement (vitamin A as retinyl, water-miscible or beta-carotene) 200,000 to 400,000 IU versus control (placebo or no treatment) Maternal: We did not find evidence that vitamin A supplementation reduced maternal mortality at 12 months (hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.44 to 2.21; 8577 participants; 1 RCT, moderate-quality evidence). Effects were less certain at six months (risk ratio (RR) 0.50, 95% CI 0.09 to 2.71; 564 participants; 1 RCT; low-quality evidence). The effect on maternal morbidity (diarrhoea, respiratory infections, fever) was uncertain because the quality of evidence was very low (50 participants, 1 RCT). We found insufficient evidence that vitamin A increases abdominal pain (RR 1.28, 95% CI 0.95 to 1.73; 786 participants; 1 RCT; low-quality evidence). We found low-quality evidence that vitamin A supplementation increased breast milk retinol concentrations by 0.20 µmol/L at three to three and a half months (mean difference (MD) 0.20 µmol/L, 95% CI 0.08 to 0.31; 837 participants; 6 RCTs). Infant: We did not find evidence that vitamin A supplementation reduced infant mortality at two to 12 months (RR 1.08, 95% CI 0.77 to 1.52; 6090 participants; 5 RCTs; low-quality evidence). Effects on morbidity (gastroenteritis at three months) was uncertain (RR 6.03, 95% CI 0.30 to 121.82; 84 participants; 1 RCT; very low-quality evidence). There was low-quality evidence for the effect on infant adverse outcomes (bulging fontanelle at 24 to 48 hours) (RR 2.00, 95% CI 0.61 to 6.55; 444 participants; 1 RCT). Supplement (vitamin A as retinyl) 400,000 IU versus 200,000 IUThree studies (1312 participants) were included in this comparison. None of the studies assessed maternal mortality, maternal morbidity or infant mortality. Findings from one study showed that there may be little or no difference in infant morbidity between the doses (diarrhoea, respiratory illnesses, and febrile illnesses) (312 participants, data not pooled). No firm conclusion could be drawn on the impact on maternal and infant adverse outcomes (limited data available).The effect on breast milk retinol was also uncertain due to the small amount of information available. There was no evidence of benefit from different doses of vitamin A supplementation for postpartum women on maternal and infant mortality and morbidity, compared with other doses or placebo. Although maternal breast milk retinol concentrations improved with supplementation, this did not translate to health benefits for either women or infants. Few studies reported on maternal and infant mortality and morbidity. Future studies should include these important outcomes.