Teens who suffered iron deficiency as infants are likely to score lower on cognitive and motor tests, even if that iron deficiency was identified and treated in infancy, a new University of Michigan study shows. Researcher Betsy Lozoff, who has studied iron deficiency for nearly three decades, followed Costa Rican children who were diagnosed with severe, chronic iron deficiency when they were 12-23 months old and were treated with iron supplements. She and her collaborators examined 191 children at 5 years, 11-14 years and again at 15-17, and found the iron-deficient babies grew up to lag their peers in both motor and mental measures.

Children who had good iron status as babies showed better motor skills than those who had been iron deficient, said Lozoff. That gap remained throughout childhood and adolescence. But even worse were the cognitive measures: children who had previously suffered iron deficiency not only lagged behind their peers, but the difference actually increased over time. They scored about six points lower on cognitive tests at age 1-2 years, and 11 points lower at age 15-18 years.

Lozoff emphasized that these results are not a function of extreme poverty or general malnutrition. “This is a uniformly literate population,” she said. “The children are at the U.S. 50th percentile for growth.”

Iron-deficiency anemia affects about 25% of infants worldwide and twice as many have iron deficiency without anemia.

University of Michigan, May 4, 2004