The impact of different doses of vitamin A supplementation on male and female mortality. A randomised trial from Guinea-Bissau
1 Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau
2 Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S Denmark
3 Department of Infectious Diseases, Skejby Sygehus, Aarhus, Denmark
BMC Pediatrics 2011, 11:77 doi:10.1186/1471-2431-11-77Published: 1 September 2011
Vitamin A supplementation (VAS) given to children between 6 months and 5 years of age is known to reduce mortality in low-income countries. We have previously observed that girls benefit more from a lower dose of VAS than the one recommended by WHO, the effect being strongest if diphtheria-tetanus-pertussis vaccine (DTP) was the most recent vaccination. We aimed to test these observations.
During national immunisations days in Guinea-Bissau, West Africa, combining oral polio vaccination and VAS, we randomised 8626 children between 6 months and 5 years of age to receive the dose of VAS recommended by WHO or half this dose. Mortality rate ratios (MRRs) were assessed after 6 and 12 month.
The overall mortality rate among participants was lower than expected. There was no significant difference in mortality at 6 months and 12 months of follow up between the low dose VAS group and the recommended dose VAS group. The MRRs were 1.23 (0.60-2.54) after 6 months and 1.17 (0.73-1.87) after 12 months. This tendency was similar in boys and girls. The low dose was not associated with lower mortality in girls if the most recent vaccine was DTP (MRR = 0.60 (0.14-2.50) after 6 months).
Our sample size does not permit firm conclusions since mortality was lower than expected. We could not confirm a beneficial effect of a lower dose of VAS on mortality in girls.
The study was registered under clinicaltrials.gov, number NCT00168636