Chronic Iron Deficiency and Cognitive Function in Early Childhood

A landmark longitudinal study conducted in Costa Rica in the 1980s showed that children with chronic iron deficiency, compared with good iron status in infancy, have 8 to 9 points lower cognitive scores up to 19 years of age. 

Hence Gingoyon A et al. examined this association in a contemporary, high-resource setting.

Their study included children aged 12 to 40 months screened with hemoglobin and serum ferritin. They rendered all parents diet advice, while children received oral iron according to iron status. After four months, they grouped children as chronic iron deficiency (iron deficiency anemia at baseline or persistent nonanemic iron deficiency) or iron sufficiency (IS) (IS at baseline or resolved nonanemic iron deficiency); and measured the Early Learning Composite (from the Mullen Scales of Early Learning) and serum ferritin, at 4 and 12 months.

After screening 1478 children and including 116 (41 chronic, 75 sufficient), they found the mean between-group differences in the Early Learning Composite at four months was −6.4 points and at 12 months was −7.4 points; while the mean between-group differences in serum ferritin at four months was 14.3 μg/L and was not significantly different at 12 months.

Through this study, the researchers show that children with chronic iron deficiency, compared with children with IS, show improved iron status. Still, cognitive scores are 6 to 7 points lower 4 and 12 months after the intervention. Future research must examine the outcomes of a screening strategy based on early detection of iron deficiency using serum ferritin.

Gingoyon A, et al. Chronic Iron Deficiency and Cognitive Function in Early Childhood. Pediatrics. 2022;150 (6): e2021055926. https://doi.org/10.1542/peds.2021-055926