SIDBI trial: No benefit of iron supplements for breastfed infants' development

Umeå UniversityMay 20 2024

The American Pediatric Association recommends iron supplements to all healthy infants who breastfeed longer than 4 months, while its European counterpart, Society of Gastroenterology, Hepataology and Nutrition, does not recommend it.

"These deviating guidelines stimulated us to design the study. Breastfeeding is strongly recommended, and the proportion of children are breastfed during the first half of life is high. We wanted to determine whether breastfeeding babies could benefit from extra iron."

The aim of the SIDBI trial was to compare the guidelines based on the effect of iron supplementation on the children's psychomotor development.

International cooperation

SIDBI stands for Supplementing Iron and Development in Breastfed Infants and is a randomized, placebo-controlled trial that was conducted between December 2015 and May 2020 with follow-up until May 2023. It was an international collaboration between the Medical University of Warsaw and Umeå University, and the children were recruited in both Poland and Sweden. In total, 221 infants were recruited. If exclusively breastfed at 4 months, they were randomly assigned to receive either iron, 1 mg/kg, or placebo once daily from 4 to 9 months of age. The participants were then assessed by a psychologist at 12, 24 and 36 months of age. Cognitive, motor and language abilities as well as behavioral problems were studied.

Results fill the knowledge gap

We did not see any significant differences in psychomotor development between children who received extra iron and children who received placebo. In other words, there was no benefit from iron supplements for development. More children in the placebo group had iron deficiency, but the difference was not significant. Our results provide high-quality evidence in the field where randomized trials were lacking. They reinforce the European guidelines not to recommend iron supplements to all healthy breastfed infants. We are proud to have published the results in JAMA Pediatrics, and we hope for a lot of attention for the study."

Ludwig Svensson, PhD student in the SIDBI trial

Continued work

Ludwig is looking forward to analyzing the remaining data within the SIDBI study.

"Among other things, we will look at behavioral problems at the age of 3. It will be very exciting to see if behavior that can be associated with ADHD or autism spectrum was affected by iron supplements."