A seminal series of studies by Lozoff et al (references 1-4 in the corresponding commentary) evaluated a cohort of infants born in Costa Rica followed for nearly 20 years to assess the impact of chronic iron deficiency. A key finding was that cognitive performance scores were worse. Still, questions remain about iron deficiency not associated with anemia.
Gingoyon et al (10.1542/peds.2021-055926) share with us a 1-year prospective observational study of 116 children ages 12-40 months. Parents in the study were given advice about sources of iron for their young children and those who were iron deficient were given supplements. The authors found that even after resolving anemia, those who still had low ferritin levels had a significant 6.4 point difference in cognitive outcome composite scoring that included evaluation of fine motor, visual reception, and receptive and expressive language. While there were no differences in ferritin levels 12 months after a low level had initially been detected, a 7.4 point reduction in the cognitive composite score persisted.
The American Academy of Pediatrics (AAP) recommends screening for anemia at 12 months of age (reference 18 in Gingoyon et al)—but that will not identify those who only have iron deficiency. Should we screen all children with a ferritin? We asked nutritional deficiency specialists Dr. Frank Greer from University of Wisconsin and Dr. Robert Baker from State University of New York, Buffalo to share with us their thoughts on whether we should change our screening approach based on this study (10.1542/peds.2022-058591).
Drs. Greer and Baker note the strengths (e.g., the longitudinal follow-up) and limitations (e.g., small sample size) of the study by Gingoyon et al and consider the risks and benefits of whether to screen for non-anemic iron deficiency. They underscore that measuring ferritin is needed to identify iron deficiency in the absence of anemia and suggest that clinicians use their judgement about whether to routinely use this test. It is likely that the AAP will be revisiting their iron screening recommendations based on studies like this one, but until then, we’d be interested in learning what you do. Feel free to share your comments when you link to this study or share them with this blog on our social media pages.