Research project Behavioural problems (e.g. ADHD) affects up to 20% of all children and often remains in adhulthood. Causes are largely unknown but our hypothesis is that early iron deficiency is a contributing factor. Young children and especially low birth weight infants are at high risk of iron deficiency and iron is necessary for brain development while iron over load can have adverse effects. It is therefore important to determine iron needs in different populations. In this study, 267 marginally low birth weight infants were randomized to receive iron drops in two different doses or placebo (no iron) from 6 weeks of age until 6 months of age. Our first results showed that iron supplements at a dose of 2 mg/kg/d reduced the risk of severe iron deficiency (with anemia) at 6 months of age from 10% to 0% in these infants.
At 3 years, we found that the children who had received iron drops had significantly lower risk of behavioural problems (3% as compared to 13% among children who did not recieve iron drops). This suggests that it is important that low birth weight infants ( We are currently performing a follow-up study of these children at 7 years of age, when they undergo comprehensive neuropsychological testing in order to determine whether there are still remaining differences between the groups. Our project has significant importance for health in the risk group of marginally low birth weight infants, who comprise 3-5% of all newborns. Our results have already led to changed national guidelines in Sweden. The project will also lead to a better understanding of basic mechanisms of iron metabolism in young children.