Rate of Ferritin Rise in Toddlers Treated with Oral Iron
In toddlers with iron-deficiency anemia receiving oral ferrous sulfate at standard doses (2–3 mg/kg/day elemental iron), serum ferritin typically normalizes within 8 weeks of therapy, with measurable increases evident as early as 2–4 weeks.
Expected Timeline of Hematologic Response
Reticulocyte response appears first, with a significant increase detectable within 3 days of starting oral iron supplementation in children. 1
Hemoglobin rise becomes evident at 2 weeks, with an expected increase of approximately 1–2 g/dL after 3–4 weeks of adequate therapy. 2, 1, 3
Ferritin normalization (≥12 ng/mL in young children) is achieved in 84–95% of toddlers by 3 months of treatment with standard-dose ferrous sulfate (2 mg/kg/day). 3
In one prospective study of children aged 6–17 months with iron-deficiency anemia, mean ferritin levels rose from baseline to 31.5 ± 19.4 ng/mL at 3 months on 2 mg/kg/day ferrous sulfate. 3
Dosing Considerations That Affect Response Rate
Standard pediatric dosing is 2–3 mg/kg/day of elemental iron in divided doses, though once-daily dosing at 2 mg/kg has been shown to be equally effective. 4, 3, 5
Higher doses (4 mg/kg/day) produce a faster median hemoglobin increase at 2 and 8 weeks compared to 2 mg/kg/day, though both regimens ultimately achieve normalization. 1
Once-daily dosing (40 mg elemental iron total) is as effective as three-times-daily dosing for the same total dose, with 61% achieving hemoglobin >10 g/dL after 2 months in both groups. 5
Monitoring Schedule
Reticulocyte count should be checked at 3 days to confirm early bone-marrow response. 1
Hemoglobin should be rechecked at 2–4 weeks, expecting a rise of 1–2 g/dL. 2, 1, 3
Ferritin and hemoglobin should be reassessed at 3 months to confirm normalization; if not achieved, treatment should be extended for an additional 3 months. 3
After correction, monitor hemoglobin and red-cell indices every 3 months for the first year, then again after another year. 2
Treatment Duration
Oral iron should be continued for 3 months after hemoglobin normalizes to fully replenish iron stores, resulting in a total treatment duration of approximately 6–7 months. 2
In toddlers with mild-to-moderate iron-deficiency anemia, 95% achieve hemoglobin normalization and 84% achieve ferritin normalization by 3 months on standard-dose ferrous sulfate. 3
Formulation Considerations
Ferrous sulfate (2 mg/kg/day) produces superior ferritin increases compared to ferric or liposomal iron preparations in infants and toddlers. 6
In a comparative study of iron prophylaxis in infants aged 6–12 months, mean ferritin levels were significantly higher with ferrous sulfate (30.1 ± 10.8 µg/L) compared to ferric iron (17.6 ± 14.5 µg/L) or liposomal iron (15.4 ± 12.1 µg/L). 6
Bis-glycinate iron (0.45 mg/kg) shows good efficacy with fewer gastrointestinal side effects (6% vs. 16% with ferrous sulfate), though ferrous preparations produce faster hemoglobin gains. 1
Common Pitfalls to Avoid
Do not discontinue iron therapy when hemoglobin normalizes; continue for an additional 3 months to restore ferritin stores. 2
Do not rely solely on hemoglobin improvement; ferritin must also be measured to confirm adequate iron repletion. 3
Do not use multiple daily doses unnecessarily; once-daily dosing improves adherence without compromising efficacy in toddlers. 5
Do not delay reassessment beyond 3 months if initial response is inadequate; consider switching to intravenous iron or investigating malabsorption. 2, 3
When to Switch to Intravenous Iron
Switch to IV iron if there is intolerance to at least two different oral iron preparations. 2
Switch to IV iron if ferritin fails to improve after 4 weeks of compliant oral therapy. 2
In toddlers with active inflammatory bowel disease and hemoglobin <10 g/dL, IV iron is first-line because inflammation-driven hepcidin blocks oral absorption. 2