The study looked at 5,398 children who participated in a health survey from 1988 to 1994. Severe iron loss, or anemia, is diagnosed with a simple blood test. But youngsters are not routinely screened for less severe iron deficiencies. Average math scores for iron-deficient adolescents were about six points lower than those with normal iron levels. Among adolescent girls, the difference in scores was more than eight points.
Girls have a higher chance of iron loss due to blood loss through menses and rapid growth.
Boys mostly experience iron loss during pubescent rapid growth but don't have the added iron loss from menses. The findings appear to suggest that giving girls more iron may improve their math performance, but Halterman stressed the findings are preliminary. Halterman suggests parents make sure children, especially girls, get an iron-rich diet. Animal studies have shown that iron deficiency affects the brain's neurotransmitters. A comparable loss in humans may impact math comprehension.