Increased iron intake may reduce behavior problems in infants with low birth weight

December 21, 2012

According to a new Swedish study giving iron supplements to infants with low birth weight can reduce the risk of behavior problems like ADHD later in life.

In the randomized controlled trial, 285 marginally low birth weight (LBW) infants were given iron supple-ments in doses of either 0, 1 or 2 mg/kg per day from six weeks to six months of age (1). At age three-and-a-half, these infants and 95 who had a normal birth weight were assessed for intelligence and behavior. The study results showed that there were no significant differences in IQ between the LBW groups and the normal-weight control group. However, for behavioral problems like attention deficit hyperactivity disorder (ADHD), there was a significant effect from the iron supplements: of LBW infants who received no iron supplements, 12.7 percent showed signs of behavior problems, compared to 2.9 percent of infants in the 1-mg group and 2.7 percent of the 2-mg group. In the control group, 3.2 percent of children showed signs of behavioral problems.

The researchers concluded that early iron supplementation of marginally LBW infants does not affect cogni-tive function at 3.5 years of age but significantly reduces the prevalence of behavioral problems. They suggest a causal relation between infant iron deficiency and later behavioral problems. However, more research would be needed to evaluate the effectiveness.

Children suffering from ADHD can experience symptoms of poor impulse control, hyperactivity and problems paying attention. These symptoms can interfere in school and work performance. It is known that deficiency in iron can cause symptoms similar to those caused by ADHD such as attention deficits. Earlier studies have shown that children with ADHD who had the lowest levels of iron had worse symptoms of hyperactivity, impulsiveness and inattention (2). It has been suggested that treating children who are iron deficient with supplements may protect from damage caused by lead, an environmental factor whose exposure can cause problems with dopamine, a neurotransmitter linked to ADHD.