Teasing out fact from fiction in global guidelines for iron supplements in children

Nearly half of the world's young children are anaemic, having low haemoglobin levels in their blood. This is often caused by a lack of iron in their diets. Anaemia may influence the burden of disease in children, particularly as it correlates with impaired cognitive development. But there have been questions about whether addressing anaemia through iron supplements improves child developmental outcomes.

Researchers from the University of Melbourne and WEHI have now determined that while iron supplements produce sustained improvements in blood levels of iron and iron stores, they do not improve developmental, behavioural or child growth outcomes in the immediate or medium term. This brings into the spotlight global recommendations for iron supplements and related aid programs to improve anaemia.

The team, led by Professor Sant-Rayn Pasricha and Professor Beverley-Ann Biggs, delivered the largest randomised controlled trial ever conducted into the effects of iron supplementation on child growth and development. Working with the International Center for Diarrheal Disease Research, Bangladesh, they studied 3,300 Bangladeshi children, visiting each child more than 20 times over the course of the research. This equated to more than 60,000 visits in villages across rural Bangladesh. 

“This study was so complex! And that's why I think it hasn't been done before. But it has given us a very high resolution understanding of the effects of iron interventions on child growth, child development and wellbeing,” explained Professor Pasricha. 

“We are so grateful to the 60 staff who helped with the study, including the trained psychologists who undertook almost 10,000 painstaking, hour long developmental tests,” he said.

Completing the large study in Bangladesh, the most densely populated country in the world, provided cost benefits for Australian research and aid decisions, collaboration opportunities, and provided results that are globally relevant, explained Professor Pasricha. 

“Australian children also experience iron deficiency and anaemia, and these results help Australian agencies make better decisions about investing in aid programs that have tangible health outcomes, leading to a happier, more secure Asia-Pacific region,” he said.

This pivotal work is the result of an almost 20-year collaboration between Professor Pasricha, a haematologist, and Professor Biggs, an infectious disease doctor. 

“As a junior doctor I was interested in haematology and global health. I approached Beverley and she took me under her wing and trained me in how to start thinking about anaemia, nutrition and hookworm,” said Professor Pasricha.

“While we knew that iron supplementation reduces anaemia, this research funded by NHMRC has filled critical knowledge gaps in global health. It’s been a career highlight to do this work,” he said.

Next steps

Using DNA samples from the children, the researchers aim to explore the interactions between genetics, nutrition, and environmental factors. The researchers will also follow up with the children from the study until they are 6 years old to assess any long-term impacts from the original trial. 

“We are also exploring if the long-standing association between anaemia and child development is causal or whether it's been observed because of confounding from other factors.”

Chief Investigators: Professor Sant-Rayn Pasricha and Professor Beverley-Ann Biggs

Team Members: Dr Jena Hamadani, Md Imrul Hasan, Associate Professor Sabine Braat and Dr Leila Larson

Institution: WEHI and University of Melbourne

Grant information: Project Grant (2016–2022), $2,893,139.37.