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

摘要

Objective To determine the effect of weekly low-dose vitamin A supplementation on cause-specific mortality in women of reproductive age in Ghana.Methods A cluster-randomized, triple-blind, placebo-controlled trial was conducted in seven districts of the Brong Ahafo region of Ghana. Women aged 15–45 years who were capable of giving informed consent and intended to live in the trial area for at least 3 months were enrolled and randomly assigned, according to their cluster of residence, to receive oral vitamin A (7500 μg) or placebo once a week. Randomization was blocked, with two clusters in each fieldwork area allocated to vitamin A and two to placebo. Every 4 weeks, fieldworkers distributed capsules and collected data during home visits. Verbal autopsies were conducted by field supervisors and reviewed by physicians, who assigned a cause of death. Cause-specific mortality rates in both arms were compared by means of random-effects Poisson regression models to allow for the cluster randomization. Analysis was by intention-to-treat, based on cluster of residence, with women eligible for inclusion once they had consistently received the supplement or placebo capsules for 6 months.Findings The analysis was based on 581 870 woman–years and 2624 deaths. Cause-specific mortality rates were found to be similar in the two study arms.Conclusion Low-dose vitamin A supplements administered weekly are of no benefit in programmes to reduce mortality in women of childbearing age.