Recommended Ferrous Sulfate Dose in Children
For treatment of iron-deficiency anemia in infants and children, administer 3 mg/kg/day of elemental iron as ferrous sulfate, given between meals to maximize absorption. 1
Treatment Dosing for Iron-Deficiency Anemia
Standard therapeutic dose: 3 mg/kg/day of elemental iron (given as ferrous sulfate drops or liquid formulation for infants and young children who cannot swallow tablets) 1
This dose should be administered between meals (on an empty stomach) because concurrent food reduces iron bioavailability by up to 50% 1, 2
Once-daily dosing is as effective as divided doses: A randomized controlled trial demonstrated that 40 mg elemental iron given once daily achieved the same treatment success rate (61%) as the same total dose divided three times daily (56%) over 2 months 3
If gastrointestinal side effects occur, the total daily dose may be divided into smaller administrations throughout the day, though this is not the primary recommendation 1
Formulation and Elemental Iron Content
Ferrous sulfate 200 mg tablets contain 65 mg elemental iron 4
Ferrous sulfate drops provide 25 mg/mL elemental iron 4
For a practical example: A 10 kg child requires 30 mg elemental iron daily, which equals approximately 1.2 mL of ferrous sulfate drops (25 mg/mL) 4, 1
Treatment Duration and Monitoring Algorithm
Initial 4-week period:
- Continue 3 mg/kg/day for 4 weeks, then recheck hemoglobin 1
- Response confirmation: An increase of ≥1 g/dL in hemoglobin (or ≥3% in hematocrit) confirms iron-deficiency anemia 1
If adequate response at 4 weeks:
- Continue treatment for an additional 2 months (total ~3 months) to replenish iron stores 1
- Recheck hemoglobin after completing the full course, with further reassessment approximately 6 months later 1
If inadequate response at 4 weeks:
- Obtain further laboratory evaluation including MCV, RDW, and serum ferritin to exclude alternative etiologies 1
- Consider malabsorption, non-compliance, continued blood loss, or concurrent vitamin B12/folate deficiency 4
- If oral therapy fails despite confirmed adherence, consider parenteral iron 1, 5
Prophylaxis Dosing (Not Treatment)
- The evidence provided focuses primarily on treatment doses; prophylactic dosing is typically lower (1-2 mg/kg/day) but was not the primary focus of the high-quality guidelines reviewed 6
Critical Administration Pitfalls to Avoid
- Do not give iron with meals, dairy, tea, or coffee: These reduce absorption by up to 50% 1, 2
- Timing matters: Administer at least 2 hours before or 1 hour after meals 2
- Avoid aluminum-based phosphate binders: These reduce iron absorption and should be separated from iron dosing 2
- Do not discontinue for mild GI symptoms: Nausea, vomiting, and diarrhea are common but should not necessarily prompt discontinuation 1
Comparison to Adult Dosing
- Adults with iron-deficiency anemia require 50-100 mg elemental iron once daily, which is substantially higher than the weight-based pediatric dose 4
- The British Society of Gastroenterology guidelines emphasize once-daily dosing in adults for improved tolerance and compliance 4
Dietary Counseling
- Concurrent dietary counseling is essential to address the underlying inadequate dietary iron intake that precipitated the deficiency 1
Safety Considerations
- Systemic iron toxicity with hepatocellular damage has been reported with excessive iron administration in pediatric patients, emphasizing the importance of proper weight-based dosing 1, 5
- Regular monitoring of iron status (ferritin and hemoglobin) is recommended in patients on long-term supplementation to prevent both deficiency and overload 1