Vitamin A supplementation for the prevention of morbidity and mortality in infants six months of age or less

Vitamin A deficiency is a significant public health problem in low and middle income countries. Vitamin A supplementation (VAS) provided to lactating postpartum mothers or to infants less than six months of age are two possible strategies to improve the nutrition of infants at high risk of vitamin A deficiency and thus potentially reduce their mortality and morbidity. To evaluate the effect of:1. VAS in postpartum breast feeding mothers in low and middle income countries, irrespective of antenatal VAS status, on mortality, morbidity and adverse effects in their infants up until the age of one year.2. VAS initiated in the first half of infancy (< 6 months of age) in low and middle income countries, irrespective of maternal antenatal or postnatal VAS status, on mortality, morbidity and adverse effects up until the age of one year. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), EMBASE, MEDLINE, clinical trials websites, conference proceedings, donor agencies, 'experts' and researchers (up to October 15, 2010). Randomized or quasi-randomised, individually or cluster randomised, placebo controlled trials involving synthetic VAS provided to the postpartum mothers or their infants up to the age of six months were eligible. Two review authors assessed the studies for their risk of bias and collected data on outcomes. Of the 18 included studies, eight provided information on maternal VAS and 15 on infant VAS.For maternal VAS, there was no evidence of a reduced risk of mortality of their babies during infancy (96,203 participants, seven studies, high quality evidence; random-effects model RR 1.00, 95% CI 0.94 to 1.06, P = 0.9; test of heterogeneity I(2) = 0%, P = 0.9) or in the neonatal period (moderate quality evidence); nor of morbidities (very low quality evidence). For infant VAS, there was no evidence of a reduced risk of mortality during infancy (59,402 participants, nine studies, moderate quality evidence; random-effects model RR 0.97, 0.83 to 1.12, P = 0.65; test of heterogeneity I(2) = 49%, P = 0.05) or in the neonatal period, nor morbidities (low quality evidence), but an increased risk of bulging fontanelle (32,978 participants, 10 studies, low quality evidence; random-effects model RR 1.55, 1.05 to 2.28, P = 0.03; test of heterogeneity I(2) = 68%, P = 0.0009). There is no convincing evidence that either maternal postpartum or infant vitamin A supplementation results in a reduction in infant mortality or morbidity in