Early neonatal vitamin A supplementation and infant mortality: two alternative hypotheses

摘要

In 2008, WHO hosted a technical consultation on neonatal vitamin A supplementation (NVAS).1 The investigators of the existing NVAS trials participated. At that time, six NVAS trials had been conducted, yielding conflicting results. Some investigators supported the prevailing ‘NVAS prevents vitamin A deficiency’ hypothesis; they proposed that the variability of effects was seen because there were differences in the prevalence of vitamin A deficiency (VAD) in different settings. Based on our NVAS trials in Guinea-Bissau, we put forward an alternative hypothesis; that NVAS interacted negatively with subsequent diphtheria–tetanus–pertussis (DTP) vaccine in females, the ‘Negative interaction between NVAS and DTP in females’ hypothesis.2–5 If true, this would lead to negative effects of NVAS in females in areas with high DTP coverage. We proposed to test the hypothesis in the other NVAS trials.