Lessons Learned from the Testing of Neonatal Vitamin A Supplementation.

Christine Benn,Peter Aaby,Ane Fisker

doi:10.3390/nu11020449

Abstract

A total of 12 trials have tested the effect of neonatal vitamin A supplementation (NVAS) on mortality. Overall, NVAS had no effect on mortality, but results were heterogeneous. Two competing hypotheses have been put forward to explain the divergent effects: A) NVAS works by preventing vitamin A deficiency (VAD) and not all countries have VAD; B) NVAS interacts negatively with subsequent diphtheria-tetanus-pertussis (DTP) vaccine, increasing mortality in females; in countries with low DTP coverage NVAS may have a beneficial effect. Only hypothesis A was tested in a recent meta-analysis; there is no strong empirical support for hypothesis A and it would not explain observed negative effects in some settings. Hypothesis B accounts for most observations. However, so far it has only been tested properly in a few trials. If hypothesis B is correct, it has major consequences for the understanding of the effects of vitamin A, and for the VAS policy in older children. As a WHO priority, the DTP coverage is bound to increase, and therefore hypothesis B urgently needs to be tested.

Highlights

Vitamin A deficiency (VAD) is widespread in low-income settings
A total of 12 randomized trials assessing the effect of neonatal vitamin A supplementation (VAS) (NVAS) versus no NVAS/placebo on overall mortality have been carried out; one was reported separately for HIV
Many studies have suggested that it is harmful to combine VAS and DTP in older children [25,30,37,38,39,40,41]. This should be of immediate concern in relation to the VAS policy to older children

Summary

Introduction

Vitamin A deficiency (VAD) is widespread in low-income settings. In the late 1980s and early1990s, several randomized trials tested the effect on overall mortality of providing high-dose vitamin A supplementation (VAS) to children between 6 months and 5 years of age. Vitamin A deficiency (VAD) is widespread in low-income settings. 1990s, several randomized trials tested the effect on overall mortality of providing high-dose vitamin A supplementation (VAS) to children between 6 months and 5 years of age. VAS was associated with 23% reduced child mortality [1], and in 1993 WHO recommended biannual. VAS to all children between 6 months and 5 years of age [2]. As newborns are born with low vitamin A stores, it seemed obvious to attempt to extend the benefits to younger children. Studies in children aged 1–5 months of age showed no beneficial effects and even a tendency for negative effects of VAS [3].

Results

Discussion

Conclusion