Anemia is an important public health and clinical problem throughout the world. Researchers from the University of Melbourne, Australia, claim that giving anemic primary school-aged children daily iron supplements provides both cognitive and physical benefits.

The World Health Organization (WHO) estimates that approximately 25% of the world’s school-aged children are anemic, with insufficient dietary iron accounting for half of all cases.

Iron deficiency is associated with impaired cognitive and physical development. In developing countries, lack of dietary iron is a contributing factor, along with parasites such as hookworm and schistosomiasis.

In developed countries, disadvantaged groups and some ethnic populations can be anemic. American Family Physician estimates that 20% of American children will be anemic at some point in their childhood.

However, concerns that iron supplements may have negative health effects may cause medical staff to shy away from it when tackling anemia. Iron supplements are known to cause gastrointestinal adverse effects, including diarrhea or constipation as well as feelings of nausea.

To understand the effects of iron supplementation, the researchers searched databases around the world for controlled trials involving daily iron supplementation.

Researchers analyzed the results of 32 studies involving 7,089 children mainly in low- and middle-income countries. The results showed that anemic children who received iron supplements had higher cognitive scores than children in the control groups (nine studies involving 2,355 children).

The children who received supplements also demonstrated significant improvement in IQ scores and other cognitive tests. Other differences included being slightly taller for their age, as well as improved weight for age.

Dr. Sant-Rayn Pasricha, from The Royal Melbourne Hospital Faculty of Medicine, Dentistry and Health Sciences, says:

We found evidence of a benefit of iron supplementation on cognitive performance among primary-school-aged children, including on IQ among children with anemia. Iron may also improve growth. Daily iron supplementation decreased the prevalence of anemia by about 50% and reduced the prevalence of iron deficiency by 79%.”

The research did not reveal any differences in the prevalence gastrointestinal issues between the groups that received iron and the control groups.

The authors conclude:

Routine daily iron supplementation is likely to benefit cognitive performance in primary school children in developing settings where anemia is prevalent and testing hemoglobin before iron supplementation may not be feasible.”

The research results are published in the Canadian Medical Association Journal. In a related commentary, Dr. Katherine Gray-Donald, from McGill University, Montréal, writes that meta-analysis:

“…is important in that it quantifies the robust effects of iron supplementation on cognitive performance among anemic children who are iron deficient. The next challenge is to determine how to safely, economically and sustainably provide better iron nutrition to children in many poor settings of the world. Clearly anemic children will benefit, but the risks of iron for all remain to be elucidated.”