Iron Deficiency Begins Before Anemia

Why Pediatricians Should Recognize and Treat Iron Deficiency Before Anemia Develops

For generations, pediatricians have been taught to think about iron deficiency in the context of anemia. We routinely screen infants for anemia and, when hemoglobin is low, diagnose and treat iron deficiency. If hemoglobin is normal, we generally assume iron status is adequate.

Today, it is clear that this approach misses many children with clinically significant iron deficiency.

Recent studies show that children experience the effects of iron deficiency before their iron stores reach the traditional laboratory definition of deficiency. This evidence helped shape new recommendations from the American Academy of Pediatrics (AAP) and coming soon from the American Society of Hematology (ASH). Together, they represent an important shift in how we understand, diagnose and manage pediatric iron deficiency.

Recognizing the Signs Earlier

During Miriam Rule’s freshman year of high school, her race times suddenly slowed. She struggled to finish workouts, needed daily naps and developed brain fog and muscle soreness. For a normally energetic teenager who loved to run, the change was alarming. Yet routine blood work showed she was not anemic.

A family friend, who is an elite running coach, encouraged her family to request ferritin testing, which revealed significant iron deficiency. Oral iron provided modest improvement, but her symptoms returned the following season. After a referral to Nationwide Children’s, she began receiving intravenous iron, which restored her iron stores, energy level and athletic performance. By her senior year, she qualified for the state cross-country championships. She also made it to the Nike Cross Country Regionals and earned a chance to compete in college.

“Having my ferritin treated allowed me to compete at the level I knew I was capable of,” says Miriam, who is now 18 years old. “More importantly, I finally felt like myself again.”

Miriam’s experience is not unusual. Iron deficiency without anemia may present as restless sleep, chronic headaches, poor concentration, exercise intolerance, declining athletic performance or behavioral changes. Many children simply adapt to these symptoms. Families may not recognize that anything is wrong.

Using these physiologically based definitions more than doubles the estimated prevalence of iron deficiency among young children, from 16% to 34%. The prevalence of iron deficiency anemia changes very little. This reinforces what many pediatric hematologists have observed in practice: iron deficiency is far more common than iron deficiency anemia. We will now identify children previously considered healthy because their hemoglobin was normal as having iron deficiency, and they will receive appropriate evaluation and treatment.

Why More Screening Is Worth the Effort

I recognize what these recommendations mean for busy primary care pediatricians. They expand routine screening, increase laboratory testing and require more conversations with families, as well as additional treatment and follow-up.

That is a significant commitment. But I believe it is one worth making. When iron deficiency goes unrecognized, children may struggle in school, athletes experience unexplained declines in performance and families spend months searching for answers. Earlier screening gives us the opportunity to identify these children before those problems become more significant.

Treatment Must Evolve

Most children with iron deficiency require therapeutic-dose oral iron. Dietary changes or a standard multivitamin are generally insufficient to replenish depleted iron stores.

For children who cannot tolerate oral iron, have malabsorption, follow highly restricted diets or require more rapid iron repletion, intravenous iron should be considered. Modern formulations have an excellent safety profile. At Nationwide Children’s, my colleagues and I administer thousands of pediatric intravenous iron infusions each year with an outstanding safety record.

Blood transfusion is rarely recommended for iron deficiency. Unless a child is hemodynamically unstable or actively bleeding, transfusion exposes them to unnecessary risks and will not adequately correct the underlying iron deficit.

A New Definition of Iron Deficiency

Most importantly, a normal hemoglobin level should no longer reassure us that iron status is normal. We have learned that iron deficiency can exist long before anemia develops. Our screening and treatment strategies should reflect what we now know about iron deficiency so we can recognize it earlier and treat it sooner.

This article appeared in the 2026 Fall/Winter issue. Download the issue here.

References:

1. Powers JM, Heeney MM, Hord J, Lehmann CU, Abrams SA, Buchanan GR; AAP Section on Hematology-Oncology, AAP Committee on Nutrition: American Society of Pediatric Hematology-Oncology. Prevention, screening, diagnosis and treatment of iron deficiency and iron deficiency anemia in infants, children and adolescents: Clinical Report. Pediatrics. 2026;158(1):e202677414.
2. Addo OY, Mei Z, Jefferds M, Jenkins M, ED Flores-Ayala R, Williams AM, Young MF, Luo H, Ko Y-A, Papassotiriou I, Palmieri M, Mesarina K, Bhutta Z, Suchdev PS, Brittenham GM. Physiologically based serum ferritin thresholds for iron deficiency among women and children from Africa, Asia, Europe, and Central America: A multinational comparative study. The Lancet Global Health. 2025;13(5):e831-e842.

Image Credits: Nationwide Children’s