Mortality Benefits of Vitamin A Are Not Affected by Varying Frequency, Total Dose, or Duration of Supplementation

Food Nutr Bull. 2017 Jun;38(2):260-266. doi: 10.1177/0379572117696663. Epub 2017 Mar 10.

Abstract

Background: Although vitamin A supplementation reduces child mortality, it remains unclear whether dosing frequency, total dose, or duration modifies effectiveness.

Objective: Determine whether mortality effects of vitamin A vary by dosing frequency, total dose, or duration.

Methods: Meta-analysis of randomized controlled trials, identified by systematic review and expert opinion, utilizing relatively standard World Health Organization doses in children <5 years. Meta-regression evaluated whether mortality effects varied by dosing frequency, total dose, or supplementation duration.

Results: Identified 17 trials, including 1,180,718 children, mean (standard deviation [SD]) age 31.5 (15.4) months at baseline. Supplementation frequency ranged every 3 months-every 2 years, supplementation duration 4-60 months (mean = 15.4; SD = 12.8), and total dose 134,361-2,200,000 IU (mean = 667,132 IU; SD = 540,795). Compared with control, vitamin A reduced mortality 22% (95% confidence interval [CI] = 10-32; P = 0.002). This protective effect was not modified by increasing supplementation frequency (dose/year: relative risk [RR] = 1.02; 95% CI = 0.98-1.06; P = .22), total dose (per 200,000 IU: RR = 1.02; 95% CI = 0.97-1.06; P = .31), nor supplementation duration (per year: RR = 1.06; 95% CI = 0.97-1.15; P = 0.14). Multivariate meta-regression showed similar results. Sensitivity analyses excluding 1 controversial trial (Aswathi 2013) did not alter findings.

Conclusion: Results confirm benefits of vitamin A supplementation in children <5 years in nations with vitamin A deficiency, without influence of frequency, total dose, or dosing duration within ranges evaluated. These findings inform design and efficiency of vitamin A supplementation policies.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Child Mortality
  • Child Nutritional Physiological Phenomena*
  • Child, Preschool
  • Dietary Supplements*
  • Evidence-Based Medicine*
  • Global Health*
  • Humans
  • Randomized Controlled Trials as Topic
  • Time Factors
  • Vitamin A / administration & dosage
  • Vitamin A / therapeutic use*
  • Vitamin A Deficiency / diet therapy*
  • Vitamin A Deficiency / mortality
  • Vitamin A Deficiency / prevention & control

Substances

  • Vitamin A