What types of iron supplementation are recommended for patients with iron deficiency?

Types of Iron Supplementation for Iron Deficiency

Oral iron supplementation should be the first-line treatment for most patients with iron deficiency, with ferrous sulfate 50-100 mg of elemental iron once daily being the standard recommendation, while intravenous iron should be reserved for specific indications such as oral iron intolerance, malabsorption, or inflammatory conditions. 1

Oral Iron Supplementation Options

Ferrous Salt Preparations (First-Line)

• Ferrous sulfate: Most commonly prescribed, provides 50-100 mg of elemental iron per dose 1
• Ferrous gluconate: Alternative ferrous salt option
• Ferrous fumarate: Alternative ferrous salt option

Optimal Dosing Strategy

• Standard dosing: 50-100 mg of elemental iron once daily, taken in the morning on an empty stomach 1
• Alternative dosing: Every-other-day dosing may improve absorption and reduce side effects 2
• Duration: Continue for 3 months after hemoglobin normalization to replenish iron stores 1

Newer Oral Formulations

• Ferric maltol: Better tolerated in some patients, especially those with inflammatory bowel disease 1, 3
• Sucrosomial iron: Nanoparticle encapsulated iron with potentially improved absorption and tolerability 3

Intravenous Iron Supplementation

Indications for IV Iron (Over Oral)

• Oral iron intolerance or poor absorption 1
• Chronic inflammatory conditions (e.g., inflammatory bowel disease) 4
• Ongoing blood loss exceeding oral iron absorption capacity 1
• Post-bariatric surgery 1
• Chronic kidney disease 5
• Chronic heart failure with iron deficiency 5

IV Iron Formulations

• Ferric carboxymaltose: Administered as 750 mg in two doses separated by at least 7 days (for patients ≥50 kg) 5
• Ferric gluconate: Alternative IV iron option 6
• Iron sucrose: Preferred in children due to safety profile 1

Patient-Specific Considerations

Diagnostic Criteria for Iron Supplementation

• Absolute iron deficiency: Serum ferritin <30 ng/mL 1
• Functional iron deficiency: Ferritin 30-100 ng/mL with transferrin saturation <20%, especially with inflammation 1
• Inflammatory conditions: Consider iron deficiency when ferritin <100 ng/mL 1

Special Populations

• Children: 3 mg/kg/day of elemental iron for infants with iron deficiency anemia 1
• Pregnant women: 30 mg daily for prevention, 60-120 mg for treatment of anemia 1
• Heart failure patients: Specific dosing regimen based on weight and hemoglobin levels 5

Monitoring and Follow-up

• Monitor hemoglobin response within 4 weeks of starting therapy 1
• An increase in hemoglobin of at least 2 g/dL within 4 weeks is considered an acceptable response 4
• Continue treatment for 3 months after hemoglobin normalization 1
• Target ferritin >100 μg/L to ensure adequate iron stores are replenished 1

Common Pitfalls to Avoid

• Excessive dosing: Higher doses don't improve absorption and increase side effects 2
• Multiple daily doses: May not improve absorption due to hepcidin elevation 1
• Modified-release preparations: Less effective due to reduced absorption in small intestine 1
• Delaying IV iron when indicated: Can prolong anemia and associated symptoms 1
• Overreliance on ferritin alone: May be falsely elevated in inflammatory conditions 1
• Taking iron with food: Decreases absorption (except when needed to improve tolerability) 4
• Enteric-coated formulations: May improve tolerability but decrease absorption 4

By following these evidence-based recommendations for iron supplementation, clinicians can effectively manage iron deficiency while minimizing side effects and optimizing patient outcomes.