What is the first-line treatment for iron deficiency?

First-Line Treatment for Iron Deficiency

Oral iron supplementation should be considered as first-line treatment for iron deficiency in patients with mild anemia, whose disease is clinically inactive, and who have not been previously intolerant to oral iron. 1

Treatment Algorithm for Iron Deficiency

Initial Assessment

• Determine severity of anemia (hemoglobin level)
• Assess clinical disease activity (particularly in IBD patients)
• Check for previous intolerance to oral iron
• Evaluate inflammatory markers (C-reactive protein)

First-Line Treatment

1. For most patients with iron deficiency or mild anemia:

   • Oral iron supplementation (ferrous sulfate 324 mg daily, providing 65 mg of elemental iron) 2
   • Alternative dosing: every other day dosing may improve absorption and reduce gastrointestinal side effects 3
   • Duration: 2 months to normalize hemoglobin, then 2-3 additional months to replenish iron stores 4

2. For patients with specific conditions, intravenous iron should be first-line:

   • Clinically active inflammatory bowel disease
   • Previous intolerance to oral iron
   • Hemoglobin below 100 g/L (severe anemia)
   • Patients requiring erythropoiesis-stimulating agents
   • Ongoing blood loss
   • Malabsorption conditions (celiac disease, post-bariatric surgery)
   • Chronic inflammatory conditions (CKD, heart failure, cancer) 1, 5

Monitoring and Follow-up

• For patients with mild disease or in remission: check hemoglobin, serum ferritin, and C-reactive protein every 6-12 months
• For patients with active disease: check these parameters at least every 3 months 1
• Target values: normalize hemoglobin and replenish iron stores (serum ferritin >100 μg/L) 1
• After successful IV iron treatment, re-treatment should be initiated when serum ferritin drops below 100 μg/L or hemoglobin falls below gender-specific thresholds (12 g/dL for women, 13 g/dL for men) 1

Common Pitfalls and Caveats

• Diagnostic challenges: In patients without inflammation, serum ferritin <30 μg/L confirms iron deficiency. However, in the presence of inflammation, serum ferritin up to 100 μg/L may still be consistent with iron deficiency 1
• Compliance issues: Poor adherence to oral iron is common due to gastrointestinal side effects (constipation, nausea, abdominal pain). Patient education about the importance of completing the full treatment course is essential 6, 4
• Absorption limitations: The hepcidin-ferroportin regulatory pathway limits gastrointestinal iron uptake, especially with high doses. This can lead to unabsorbed iron causing gastrointestinal side effects 3
• Underlying causes: Always identify and address the underlying cause of iron deficiency (menstrual bleeding, gastrointestinal blood loss, malabsorption, inadequate dietary intake, pregnancy) 5, 7
• Iron overload risk: Excessive iron supplementation should be avoided, particularly in patients with hereditary hemochromatosis 7

By following this algorithm and addressing common pitfalls, clinicians can effectively manage iron deficiency, improve patient outcomes, and reduce complications associated with untreated iron deficiency.