What is the recommended dose of ferrous sulfate (iron supplement) for pediatric patients with iron deficiency anemia?

Ferrous Sulfate Pediatric Dosing

For treatment of iron deficiency anemia in pediatric patients, administer 3 mg/kg/day of elemental iron as ferrous sulfate, given between meals to maximize absorption. 1, 2

Age-Specific Dosing Recommendations

Preterm and Low Birthweight Infants

• Start 2-4 mg/kg/day of elemental iron drops (maximum 15 mg/day) at 1 month of age and continue until 12 months 1
• This higher dose accounts for increased iron requirements in this vulnerable population 1

Term Breastfed Infants (≥6 months)

• Administer 1 mg/kg/day of elemental iron drops if supplementary foods provide insufficient iron 1
• When exclusive breastfeeding stops, provide approximately 1 mg/kg/day from supplementary foods or drops 1

Children with Confirmed Iron Deficiency Anemia

• Standard therapeutic dose: 3 mg/kg/day of elemental iron given as ferrous sulfate 1, 2, 3
• This can be given as a single daily dose or divided into 2-3 doses throughout the day 4
• A recent high-quality RCT demonstrated that low-dose ferrous sulfate (3 mg/kg once daily) significantly increased hemoglobin by 4.0 g/dL over 12 weeks, superior to iron polysaccharide complex 3

Children with Chronic Kidney Disease

• Use 2-3 mg/kg/day of elemental iron in divided doses 1

Formulation and Elemental Iron Content

• Ferrous sulfate is the preferred formulation due to better clinical response, fewer side effects, and cost-effectiveness 1
• Each 325 mg tablet of ferrous sulfate contains 65 mg of elemental iron 1
• Liquid iron preparations are more appropriate for young children than tablets 4

Administration Guidelines for Optimal Absorption

• Administer iron between meals or at bedtime for optimal absorption 1, 2
• Food reduces iron absorption by up to 50% if consumed within 2 hours before or 1 hour after the iron supplement 1, 4
• Avoid cow's milk consumption exceeding 24 oz daily, as it interferes with iron absorption 1
• Include vitamin C-rich foods with meals to enhance iron absorption 1
• Separate aluminum-based phosphate binders from iron dosing, as they reduce absorption 1, 4

Monitoring Response to Therapy

• Recheck hemoglobin after 4 weeks of treatment 2
• Adequate response is defined as hemoglobin rise of ≥1.0 g/dL (or hematocrit ≥3%) 1, 2
• If this response is achieved, continue treatment for 2 additional months to replenish iron stores 2
• If no response occurs despite compliance and absence of acute illness, obtain further evaluation with MCV, RDW, and serum ferritin 4, 2
• After completing therapy, recheck hemoglobin and iron studies 2-4 weeks later 2

Common Pitfalls and Management Strategies

Gastrointestinal Side Effects

• Mild GI symptoms (nausea, vomiting, diarrhea) should not necessarily prompt discontinuation 4, 2
• If side effects occur, reduce to smaller, more frequent doses or consider alternate-day dosing rather than stopping therapy 4
• Starting with a lower dose and gradually increasing to target may improve tolerance 4
• Notably, ferrous sulfate caused less diarrhea than iron polysaccharide complex in a recent trial (35% vs 58%) 3

Dosing Frequency

• While traditional regimens use 3-times-daily dosing, research demonstrates that single daily dosing at the same total dose achieves similar efficacy (61% vs 56% treatment success) and may improve adherence 5

Risk of Iron Overload

• Never exceed recommended doses, as systemic iron toxicity with hepatocellular damage has been reported in pediatric patients 4, 2
• Regularly monitor iron status (ferritin and hemoglobin) in patients on long-term supplementation to prevent both deficiency and overload 2