Appropriate Dosing of Ferrous Sulfate Oral Drops for a 3-Year-Old with Iron Deficiency
For this 3-year-old child weighing 14.4 kg with iron deficiency (ferritin 10), administer 3 mg/kg/day of elemental iron, which equals 43.2 mg of elemental iron daily, translating to approximately 2.9 mL of the ferrous sulfate drops (15 mg iron/mL) given once daily between meals. 1, 2
Dosing Calculation and Rationale
- The CDC recommends 3 mg/kg/day of elemental iron for treating presumptive iron-deficiency anemia in children 1, 2
- For a 14.4 kg child: 14.4 kg × 3 mg/kg = 43.2 mg elemental iron per day 1
- With your formulation (15 mg elemental iron per mL): 43.2 mg ÷ 15 mg/mL = 2.9 mL daily 1
- Round to 3 mL daily for practical administration 1
Administration Guidelines
- Administer iron drops between meals or at bedtime for optimal absorption, as food can reduce iron absorption by up to 50% if consumed within 2 hours before or 1 hour after the supplement 2
- Provide vitamin C-rich foods or juice with the iron dose to enhance absorption 1
- Limit cow's milk intake to no more than 24 oz daily, as excessive milk consumption interferes with iron absorption and contributes to iron deficiency 1, 2
Monitoring and Follow-Up Protocol
- Recheck hemoglobin or hematocrit in 4 weeks to confirm response to therapy 1
- An increase in hemoglobin ≥1 g/dL or hematocrit ≥3% confirms iron-deficiency anemia and indicates adequate response 1, 2
- If the diagnosis is confirmed, continue iron treatment for 2 additional months (total 3 months), then recheck hemoglobin/hematocrit 1
- Reassess approximately 6 months after successful treatment completion 1
Important Caveats
- If anemia does not respond after 4 weeks despite compliance, further evaluate with additional laboratory tests including MCV, RDW, and repeat ferritin 1
- Ferrous sulfate is the preferred oral iron formulation due to better clinical response, fewer side effects, and cost-effectiveness 2
- Common side effects include gastrointestinal upset, which may affect adherence; counsel parents about this possibility 3
- Concurrent dietary counseling is essential to address the underlying cause of low iron intake and prevent recurrence 1