Vitamin A supplementation and childhood morbidity from diarrhea, fever, respiratory problems and anemia in sub-Saharan Africa

摘要

Background: Systematic reviews consistently indicated that vitamin A supplementation (VAS) (100,000–200,000 international unit [IU] semiannually) to children aged 6–59?months substantially reduces all-cause child mortality. Yet, its effect on morbidity is inconsistent and its contribution to the reduction of anemia has not been sufficiently explored. Objective: The objective of this study was to assess the association between routine VAS (100,000 IU for children aged 6–11?months and 200,000 IU for children aged 1–5?years) and the occurrence of common childhood illnesses (fever, diarrhea, acute respiratory infection [ARI] and anemia) in preschool children in sub-Saharan Africa (SSA). Methods: The analysis was made based on the data of 28 demographic and health surveys (DHSs) conducted in SSA since 2010. The data of 152,406 children were included. The VAS status in the preceding 6?months and the occurrence of the illnesses in the past 2?weeks were determined based on the information given by the caregivers. The hemoglobin level was determined using a portable photometer. Data were analyzed using mixed-effects logistic regression model. The outputs were provided using adjusted odds ratio (AOR) with the respective 95% confidence intervals (CIs). The practical significance of the association was measured via Cohen’s effect size ( d ). Results: The coverage of VAS was 56.3% (95% CI: 56.1–56.5). VAS was modestly associated with increased odds of fever (AOR=1.12 [95% CI: 1.09–1.15]), diarrhea (AOR=1.09 [95% CI: 1.05–1.13]) and ARI (AOR=1.18 [95%: 1.12–1.24]). Conversely, in the supplemented children, the odds of anemia were reduced by 10.1% (95% CI: 7.0–13.1). All the associations translated into trivial effect sizes ( d <0.2). Conclusion: VAS is associated with an inconsequential increase in the occurrence of common childhood ailments.