What is the standard treatment for iron deficiency?

Standard Treatment for Iron Deficiency

Oral ferrous sulfate 200 mg once daily is the first-line treatment for iron deficiency, with intravenous iron reserved for specific clinical scenarios including intolerance to oral therapy, malabsorption conditions, active inflammatory bowel disease with hemoglobin <10 g/dL, or ongoing blood loss exceeding oral replacement capacity. 1

First-Line Oral Iron Therapy

Ferrous sulfate 200 mg once daily is the preferred formulation due to its effectiveness and low cost, with each 324 mg tablet containing 65 mg of elemental iron. 1, 2 This once-daily dosing strategy improves tolerability while maintaining effectiveness compared to multiple daily doses. 1

Key Implementation Details:

• Take on an empty stomach for optimal absorption, though taking with food is acceptable if gastrointestinal side effects occur 1
• Add vitamin C (ascorbic acid) 500 mg with the iron dose to enhance absorption, particularly when response is suboptimal 1, 3
• Continue therapy for 3 months after anemia correction to fully replenish iron stores 1, 3
• Alternative formulations (ferrous gluconate or ferrous fumarate) are equally effective if ferrous sulfate is not tolerated 1, 3

Expected Response:

• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 1, 3
• If no response occurs within 4 weeks, assess for non-adherence, malabsorption, or ongoing blood loss 1

Indications for Intravenous Iron

Switch to IV iron when oral therapy fails or specific contraindications exist:

Absolute Indications:

• Intolerance to at least two different oral iron preparations 1, 3
• Active inflammatory bowel disease with hemoglobin <10 g/dL 3, 1
• Post-bariatric surgery patients with disrupted duodenal iron absorption 1
• Celiac disease with inadequate response to oral iron despite gluten-free diet adherence 1
• Ongoing gastrointestinal blood loss exceeding oral replacement capacity 1
• Second and third trimesters of pregnancy when oral iron is insufficient 1

IV Iron Formulations:

• Prefer formulations allowing 1-2 infusions to replace total iron deficit 1
• Ferric carboxymaltose allows single doses of 500-1000 mg infused over 15 minutes 3
• Iron sucrose requires repeated dosing limited to 200-300 mg per treatment episode 3
• Avoid high molecular weight iron dextran due to higher anaphylaxis risk, though test doses are required for all iron dextran preparations 3

Monitoring and Follow-Up

• Monitor hemoglobin and red cell indices every 3 months for the first year after correction, then again after another year 1
• Do not recheck ferritin earlier than 8-10 weeks after IV iron infusion, as levels are falsely elevated 3
• Provide additional iron supplementation if hemoglobin or MCV falls below normal 1
• Further investigation is recommended if anemia doesn't resolve within 6 months despite appropriate therapy 1

Special Population Considerations

Inflammatory Bowel Disease:

• Treat active inflammation first to enhance iron absorption and reduce iron depletion 1
• IV iron is first-line in patients with clinically active IBD, previous intolerance to oral iron, or hemoglobin <10 g/dL 3

Pregnancy:

• Start low-dose oral iron (30 mg/day) at first prenatal visit for prevention 3
• Prescribe 60-120 mg/day for treatment of iron deficiency anemia 3
• Refer for further evaluation if hemoglobin <9.0 g/dL 1
• IV iron is indicated during second and third trimesters if oral therapy is insufficient 1

Celiac Disease:

• Ensure strict adherence to gluten-free diet to improve iron absorption 1
• Progress to IV iron if oral supplementation fails despite dietary compliance 1

Critical Pitfalls to Avoid

• Do not prescribe multiple daily doses of oral iron—this increases side effects without improving efficacy 1
• Do not stop iron therapy when hemoglobin normalizes—continue for 3 months to replenish stores 1
• Do not continue oral iron indefinitely without response—reassess after 4 weeks and switch to IV iron if hemoglobin fails to rise 1
• Do not overlook vitamin C supplementation when oral iron response is suboptimal 1
• Do not fail to identify and treat the underlying cause of iron deficiency while supplementing 1
• Do not use parenteral iron as first-line unless specific contraindications to oral therapy exist 1

Dosing for Specific Populations

Children and Adolescents:

• Infants and preschool children: 3 mg/kg per day of elemental iron administered between meals 3
• School-age children: One 60 mg iron tablet daily 3
• Adolescent boys: Two 60 mg iron tablets daily 3
• Adolescent girls: 60-120 mg/day 3

Adults:

• Standard dose: 100-200 mg/day elemental iron in divided doses, though once-daily dosing is preferred 3, 1
• Athletes and military personnel: 22 mg/day for prevention in high-risk groups 3