• Mortality
  
• Hospitalisations
  

• Adverse effects
  
• Tuberculin reaction
  
• BCG scarring
  
• Growth
  
• Vitamin A status
  
• Cytokine responses
  
• Malaria
  
• Measles
  
• Rotavirus
  
• All primary and secondary outcomes will be analysed for interactions between vitamin A and sex and last vaccine received
  

Vitamin A deficiency is common in low-income countries. Vitamin A supplementation to children above 6 months of age reduces all-cause mortality with 23 % to 30 %. Studies on vitamin A supplementation in infants younger than 6 months of age have reported inconsistent effects on mortality. Studies providing supplementation between 1 and 5 months of age have found no effect or even a negative effect. However, the only two studies of supplementation at birth, both conducted in Asia, showed substantial significant reductions in infant all-cause mortality.

The beneficial effect of neonatal vitamin A supplementation may be a result of correcting the congenital vitamin A deficiency resulting from maternal vitamin A deficiency. On the other hand, it has been speculated that the beneficial effect of vitamin A supplementation given at birth may in part be explained by a synergistic effect of vitamin A supplementation and BCG vaccination given at the time of birth.

The protective effect on mortality of vitamin A supplementation given at birth needs to be confirmed in an African population. Furthermore, none of the two previous studies have reported data on vaccination status of the included infants.

In this study, the effect on mortality and morbidity of given vitamin A supplementation simultaneously with BCG vaccination at birth to normal birth weight infants will be investigated in an African population. Furthermore, the effects of vitamin A supplementation will be evaluated with respect to effect on growth, the response to BCG vaccination, infant vitamin A status and infant cytokine profile. Furthermore the effect on specific diseases such as malaria, measles and rotavirus infections. The mechanisms behind the effects of vitamin A will be evaluated.

We will include 4,800 normal birth weight infants (> 2500 g) infants randomized to 50,000 IU of vitamin A or placebo given simultaneously with BCG vaccine. The study take place in Guinea-Bissau, West Africa. The study area consists of five districts in the capital of Guinea-Bissau. The Bandim Health Project has been working in the study area for almost 25 years, and a demographic surveillance system has been established and functioned for many years.