Iron supplementation is unlikely to increase the incidence of infectious disease in children
- Kolsteren, Dr Patrick
- Roberfroid, Dominique
BACKGROUND
Anaemia is a major public health issue, affecting up to half of school age children in the world. Iron supplements can be administered using a range of methods, but the safety of supplementation remains uncertain. There are concerns that iron supplements may increase the risk of infectious disease, especially in developing countries.
OBJECTIVE
To assess the relationship between iron supplementation and the incidence of infectious disease in children.
METHOD
Systematic review with meta-analysis.
SEARCH STRATEGY
The authors searched MEDLINE, the Cochrane Controlled Trials Register, HealthSTAR, IBIS, EMBASE, reference lists of identified studies, bibliographies and reviews and the proceedings of conferences and meetings. Experts and donor agencies were contacted for additional studies.
INCLUSION/EXCLUSION CRITERIA
Randomised placebo-controlled trials were eligible if they assessed iron supplementation in children administered orally, through formula milk or fortified cereals or parenterally. Non-placebo-controlled trials of iron given parenterally were also eligible. Twenty-eight trials with 7892 children were included. Six were unpublished.
OUTCOMES
Total recorded infectious illnesses; incidence of individual illnesses including respiratory tract infection, diarrhoea and malaria; positive smear for malaria.
MAIN RESULTS
Iron supplementation did not increase the overall risk of infectious illness (incidence rate ratio 1.02, 95% CI 0.96 to 1.08) or the risk of developing specific diseases such as malaria. Iron supplementation was associated with an increased risk of diarrhoea, equivalent to about 0.05 episodes per child year (incidence rate ratio 1.11, 95% CI 1.01 to 1.23). Fortified foods may be the safest method of iron supplementation. There was significant unexplained heterogeneity between trials.
AUTHORS' CONCLUSIONS
Iron supplementation is unlikely to increase the overall incidence of infectious illness in children, though it may increase the risk of developing diarrhoea.