June 20, 2001 -- Even if it's not severe, iron deficiency could affect your child's performance in school, a new study shows. Researchers found that kids -- especially teenage girls -- with lower-than-normal iron counts performed worse than their well-nourished peers on standardized tests.
"There's lots of data showing that [anemia] leads to problems with behavior and learning. We wanted to see if iron deficiency at a lower level was also a problem," researcher Andrew Aligne, MD, assistant professor of pediatrics at New York's University of Rochester School of Medicine, tells WebMD.
The researchers compared standardized test scores of children with normal iron levels, those with iron deficiency, and those with iron deficiency severe enough to cause anemia. Of the nearly 5,500 kids aged 6-16 examined, 3% were iron deficient. Teenage girls were at highest risk. Those with iron deficiency, with or without anemia, were more than twice as likely to have below average math scores than those with normal iron levels.
"It's a good [study] looking at a large number of children, and the findings are in line with previous studies in animals and smaller children," says Ian Griffin, MD, assistant professor of pediatrics at Baylor College of Medicine in Houston. He reviewed the paper for WebMD.
Griffin cautions against drawing faulty conclusions. "The study shows an association, but not cause and effect. If you're iron deficient, you do worse in math scores," he says, but "something could be causing both." It could be that "children with poor social networks, poor encouragement, and poor support, might also have poor diets, and so do poorly at school," he tells WebMD.
The findings do, however, emphasize the importance of a healthy diet for growing children. Teenage girls, in particular, must replace the iron lost through monthly periods. "The most common cause of iron deficiency is not getting enough iron in your diet," says Aligne. "And you can be below normal without being anemic."
It's too early to recommend routine screening tests for this age group, the doctors agree. The findings need to be confirmed, and there's no evidence yet that treating the iron deficiency would raise test scores.
In the meantime, parents should watch what their kids eat and read the package labels.
"In our culture, the easiest way to get enough iron is to eat fortified [breakfast] cereals," says Aligne. A daily multivitamin with iron is also a possibility, he adds, but getting nutrients from whole foods is always preferable to taking a supplement.
Even kids who eat their veggies can have low iron, says Griffin, as vegetables with lots of it -- such as spinach and kale -- also contain chemicals that block its absorption. "The iron in meat is much better absorbed," he says. For vegetarian kids, and their parents for that matter, the best source of easily absorbed dietary iron is "anything with flour, as all flour in the U.S. is fortified."