Many cases of iron deficiency in school-age children could be diagnosed earlier, according to a new study published in red blood cells and ironJournal of the American Society of Hematology (ASH). By applying higher ferritin thresholds than those used in current guidelines, researchers found that iron deficiency in children aged 5 to 14 years in the United States may be more common than previously thought, and in many cases may be diagnosed earlier.
Low iron levels can lead to serious health problems such as difficulty concentrating and learning, fatigue, and decreased physical performance, so it’s important to determine the level of ferritin in your child’s blood that they need to support their physical growth and learning. ”
Dr. Yo Addo, lead author and epidemiologist, Division of Nutrition, Physical Activity, and Obesity, Centers for Disease Control and Prevention (CDC)
Researchers have developed a new method to identify ferritin cutoff levels for school-age children in the United States. This new method detects the early stages of iron deficiency by observing changes in red blood cells and how the body produces them. Using this updated approach, approximately one in three (30%) children aged 5 to 14 in the study’s sample were identified as having iron deficiency, a significant increase from the 9% identified in the same sample using the previous method.
Ferritin is a protein that stores iron within cells and releases it when needed. The iron is then used to produce hemoglobin, a protein in red blood cells that carries oxygen to organs and tissues. Low ferritin in children can lead to iron deficiency, which can impair brain development, learning, and growth. Iron deficiency may be present with anemia (such as low hemoglobin) or without anemia.
The study included data from 3,765 otherwise healthy children ages 5 to 14 years (mean 10.3 years) who participated in CDC’s 1988-1994 national survey, NHANES III, and underwent physical examinations and blood draws. Children were excluded from the analysis if there was evidence of infection, inflammation, liver-related problems (all of which can affect ferritin), or if data were missing on ferritin, hemoglobin, or zinc protoporphyrin (ZPP, a red blood cell compound that increases when tissue iron demand increases during iron deficiency).
Current guidelines from the CDC and the World Health Organization (WHO) identify iron deficiency at a ferritin threshold of approximately 15 μg/L. However, the researchers’ findings suggest that if a child’s ferritin level is less than 24 μg/L, iron levels may already be insufficient to maintain normal red blood cell production. This finding adds to the evidence that current CDC and WHO thresholds across the life cycle tend to detect iron deficiency at more advanced stages, when iron levels are already low and may be depleted. Iron deficiency begins with hemoglobin levels higher than those used to diagnose anemia. Screening often relies on anemia and may miss early treatable iron deficiencies.
“This study applied a new methodology to identify iron deficiency and found that if ferritin is less than 24 μg/L, iron is already deficient and can begin to affect a child’s health. Results of this study may help identify iron deficiency earlier than previously recommended cutoffs,” said co-author Maria Elena Jeffers, Ph.D., team leader in the CDC’s Division of Nutrition, Physical Activity, and Obesity. “CDC continues to consider how health care providers can use these thresholds to improve the detection of iron deficiency in children ages 5 to 14.”
The increased demand and need for iron nutrition during this life stage is similar between boys and girls, who are all actively growing and require iron for skeletal growth and development. However, iron deficiency was higher in older girls (12 to 14 years), likely due to menstrual blood loss. Still, ferritin thresholds were consistently higher than current cutoff values across age and gender.
Because this study was based on 30-year-old NHANES III data, the researchers performed a supplementary analysis using more recent NHANES data (2017-2023) that included soluble transferrin receptor instead of ZPP, and the identified ferritin thresholds were consistent with the NHANES III study, further validating the results. The researchers said one of the study’s limitations was that it could not account for puberty in boys and girls or the onset of menstruation in girls.
The researchers hope that these data will improve the detection of iron deficiency in children aged 5 to 14 years.
sauce:
American Society of Hematology
Reference magazines:
Addo, Y. Others. (2026) Physiologically-based ferritin thresholds for defining iron deficiency in children aged 5–14 years in the United States. red blood cells and iron. DOI: 10.1016/j.brci.2026.100093. https://www.sciencedirect.com/science/article/pii/S305059842600048X?via%3Dihub
