The study, published in the New England Journal of Medicine on Thursday, measured the impact of iron supplements on child cognitive function, behavior and development.
The researchers from Walter and Eliza Hall Institute of Medical Research (WEHI) in Australia and International Center for Diarrheal Diseases Research Bangladesh provided iron to 3,300 eight-month-old children, as both iron drops and home fortification packets.
Neither intervention improved child development, although both improved anemia, they found.
The researchers analyzed children’s cognitive, language and motor development, as well as behaviour, and growth, including height and weight.
They found iron supplements had no impact on any of these areas of development.
According to WEHI Associate Professor Sant-Rayn Pasricha, the research could lead to major changes in global nutrition policy.
“We have been administering iron supplements to young children worldwide for decades in the belief that it had a positive impact on their development, without proper evidence it was actually beneficial,” Pasricha said.
“What we have demonstrated, is that while iron supplements improved anemia in children, these interventions had no impact on growth, cognitive function, behavior or development,” he added.
The researchers said this finding has implications worldwide for how iron deficiency and anemia is treated in babies and young children.
The study also evaluated adverse side effects in children who took the iron supplements preventatively.
Jena Hamadani from the International Center for Diarrheal Diseases Research said for some of these children the supplements may do more harm than good.
“In children taking iron supplements who did not have anemia, they may actually have had increased presentations to clinics due to episodes of diarrhea, possibly indicating iron interventions were doing more harm than good,” she said.
The World Health Organization (WHO) recommends iron supplements are given to all young children in low and middle income countries where anemia is common.
“We need to carefully reconsider the use of these interventions based on this study,” Pasricha said.