According to new research published in the Canadian Medical Association Journal, about 25 percent of school-aged children around the world are anemic, with iron deficiency the cause of about half of the cases.
Iron deficiency, which has been associated with impaired cognitive and physical development, is caused by a lack of dietary iron and, in developing countries, by parasites such as hookworm and schistosomiasis.
The researchers note that concerns that iron supplementation may have negative health effects have limited efforts to address these deficiencies.
For the study, Australian researchers conducted an analysis of 32 studies including 7,089 children, mainly in low- and middle-income countries. The researchers found that anemic children who received iron supplements had higher cognitive scores than children in the control groups. They also showed substantial improvement in IQ scores and other cognitive tests.
Children who received iron supplements were also slightly taller for their age and had improved weight-for-age when compared with children who did not receive the supplements.
“We found evidence of a benefit of iron supplementation on cognitive performance among primary school-aged children, including on IQ among children with anemia,” said Dr. Sant-Rayn Pasricha of the Royal Melbourne Hospital and a member of the faculty at The University of Melbourne. “Iron may also improve growth.”
According to the researchers, daily iron supplementation decreased the prevalence of anemia by about 50 percent and reduced the prevalence of iron deficiency by 79 percent.
There appeared to be no adverse effects, with no differences in the prevalence of malaria or gastrointestinal issues between the groups that received iron and the control groups, the researchers noted. In addition, some studies reported fewer respiratory tract infections.
“Iron supplementation benefits global cognitive performance,” the researchers concluded in their study.
“Routine daily iron supplementation is likely to benefit cognitive performance in primary schoolchildren in developing settings where anemia is prevalent and testing hemoglobin before iron supplementation may not be feasible.”