Role of low dose iron intake on acute respiratory tract infection in infants: A longitudinal study

Background: Anaemia and respiratory tract infections are common problems among infants and a complex relationship exists between iron status and infection. Studies on possible role of iron supplementation to prevent respiratory tract infection in healthy infants are needed so that strategies could be made at the community level to reduce its burden.
Objectives: To study the effect of iron intake on the incidence of acute respiratory infection (ARI) in healthy infants.  
Method: A longitudinal study was done in 106 infants at the paediatric department of a teaching hospital, in which infants coming for routine vaccination with haemoglobin levels ≥10g/dl were divided into two groups after computer generated randomization. Group A received 2mg/kg/day of iron for 3 months and Group B received no supplementation. Episodes of respiratory tract infection were recorded. Follow up was done at 4, 8 and 12 weeks and at 6 months for new episodes of ARI. Growth was monitored. Data were analysed using Mann-Whitney U test, Chi square test and Student ‘t’ test via SPSS version 20.0.
Results: After 6 months of follow up, mean haemoglobin in the iron supplemented group (12.76±0.63g/dl) was significantly higher than in the non-supplemental group (11.29±0.98g/dl) (p<0.001), when the baseline haemoglobin levels in both groups were comparable. The incidence of ARI was 66% lower in the iron supplemented group compared with the group with no supplementation (IRR=0.34, 95%CI=0.19-0.59, p=0.0001)  
Conclusions: Iron supplementation in infants improves their haemoglobin status and decreases episodes of ARI in them.