Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis

Abstract

Objective To determine if vitamin A supplementation is associated with reductions in mortality and morbidity in children aged 6 months to 5 years.Design Systematic review and meta-analysis. Two reviewers independently assessed studies for inclusion. Data were double extracted; discrepancies were resolved by discussion. Meta-analyses were performed for mortality, illness, vision, and side effects.Data sources Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline, Embase, Global Health, Latin American and Caribbean Health Sciences, metaRegister of Controlled Trials, and African Index Medicus. Databases were searched to April 2010 without restriction by language or publication status.Eligibility criteria for selecting studies Randomised trials of synthetic oral vitamin A supplements in children aged 6 months to 5 years. Studies of children with current illness (such as diarrhoea, measles, and HIV), studies of children in hospital, and studies of food fortification or β carotene were excluded.Results 43 trials with about 215 633 children were included. Seventeen trials including 194 483 participants reported a 24% reduction in all cause mortality (rate ratio=0.76, 95% confidence interval 0.69 to 0.83). Seven trials reported a 28% reduction in mortality associated with diarrhoea (0.72, 0.57 to 0.91). Vitamin A supplementation was associated with a reduced incidence of diarrhoea (0.85, 0.82 to 0.87) and measles (0.50, 0.37 to 0.67) and a reduced prevalence of vision problems, including night blindness (0.32, 0.21 to 0.50) and xerophthalmia (0.31, 0.22 to 0.45). Three trials reported an increased risk of vomiting within the first 48 hours of supplementation (2.75, 1.81 to 4.19).Conclusions Vitamin A supplementation is associated with large reductions in mortality, morbidity, and vision problems in a range of settings, and these results cannot be explained by bias. Further placebo controlled trials of vitamin A supplementation in children between 6 and 59 months of age are not required. However, there is a need for further studies comparing different doses and delivery mechanisms (for example, fortification). Until other sources are available, vitamin A supplements should be given to all children at risk of deficiency, particularly in low and middle income countries.

Vitamin A Deficiency Induces Congenital Spinal Deformities in Rats

“…VAD is still a major public health problem worldwide, which has contributed substantially to the health threat among young children and women of reproductive age in developing coutries. VAD in pregnant women is associated with night blindness, severe anaemia, wasting, malnutrition, and reproductive and infectious morbidity, and increased risk of mortality 1-2 years following delivery [31]. Several previous studies have demonstrated that VAD induces congenital heart, ocular tissues, respiratory, urogenital and circulatory systems, and skeletal deformities in experimental animals including monkeys, rabbits, rats, mice and hamsters [22].…”

Effect of vitamin A supplementation on cause-specific mortality in women of reproductive age in Ghana: a secondary analysis from the ObaapaVitA trial

“…Given that the study population is deficient in vitamin A 13 and has a high burden of infections, 21 this apparent lack of benefit was unexpected, especially as vitamin A supplementation in children between the ages of 6 months and 5 years in similar populations has reduced allcause mortality and mortality from diarrhoeal diseases. 2 The trial had adequate power to examine the effect of vitamin A supplementation on pregnanc yrelated deaths. It also had adequate power to examine the effect of such supplementation on rates of infection, as these were more common, among CI, confidence interval; RR, rate ratio.…”

“…1 Although in these countries allcause mortality among young children (i.e. children aged from 6 months to 5 years) can be reduced by administering vitamin A supplements, 2 there is little evidence that such supplements are beneficial among adults. In a meta-analysis of trials in which adults were given antioxidant supplementation, supplements of vitamin A (alone or combined with other antioxidants) were found to have either no effect on all-cause mortality or to increase such mortality.…”

Scientific Opinion on Dietary Reference Values for vitamin A

“…The Panel is aware of other studies which looked at possible associations between preformed vitamin A intake or blood retinol concentration and adverse health outcomes (Grotto et al, 2003;Bjelakovic et al, 2008;Chen et al, 2008;Mayo-Wilson et al, 2011;Beydoun et al, 2012;Bjelakovic et al, 2012;Bjelakovic et al, 2013;Field et al, 2013;Bjelakovic et al, 2014). Available data on individual outcomes are limited or relate to interventions that used large doses of retinol (≥ 6 000 µg) once or several times a year, which are difficult to relate to a potential effect of daily dietary intake of retinol.…”