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Randomised study of effect of different doses of vitamin A on childhood morbidity and mortality

BMJ 2005; 331 doi: (Published 15 December 2005) Cite this as: BMJ 2005;331:1428
  1. Christine Stabell Benn, research fellow (cb{at},
  2. Cesario Martins, research fellow2,
  3. Amabelia Rodrigues, research fellow2,
  4. Henrik Jensen, statistician1,
  5. Ida Maria Lisse, research fellow2,
  6. Peter Aaby, professor of international health1
  1. 1 Danish Epidemiology Science Centre, Statens Serum Institut, Copenhagen, Denmark
  2. 2 Projecto de Saúde de Bandim, Bissau, Guinea-Bissau
  1. Correspondence to: C Stabell Benn
  • Accepted 27 September 2005


Objectives To determine whether the dose of vitamin A currently recommended by the World Health Organization or half this dose gives better protection against childhood morbidity and mortality.

Design Randomised study.

Setting A combined oral polio vaccine and vitamin A supplementation campaign in Guinea-Bissau, Africa.

Participants 4983 children aged 6 months to 5 years.

Interventions One of two doses of vitamin A (recommended and half); oral polio vaccine.

Main outcome measures Mortality and morbidity at six and nine months.

Results Mortality was lower in the children who took half the recommended dose of vitamin A compared with the full dose at both six months (mortality rate ratio 0.69, 95% confidence interval 0.36 to 1.35) and nine months (0.62, 0.36 to 1.06) of follow-up. There was a significant interaction between sex and dose, the lower dose being associated with significantly reduced mortality in girls (0.19, 0.06 to 0.66) but not in boys (1.98, 0.74 to 5.29). The lower dose of vitamin A was consistently associated with lower hospital case fatality in girls (0.19, 0.02 to 1.45). Paradoxically, in children aged 6-18 months, the low dose was associated with slightly higher morbidity.

Conclusions Half the dose of vitamin A currently recommended by WHO may provide equally good or better protection against mortality but not against morbidity.


  • Contributors CSB, CM, AR, IML, and PA planned the study. CM was responsible for the data collection. CSB, PA, and HJ analysed the data. CSB wrote the first draft of the paper and all authors contributed to the final version. CSB and PA are guarantors.

  • Funding Danish Medical Research Council.

  • Competing interests None declared.

  • Ethical approval Ministry of Health's committee for research in Guinea-Bissau and the central ethical committee in Denmark.

  • Accepted 27 September 2005
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