What is the recommended treatment for iron deficiency?

Treatment of Iron Deficiency

The recommended treatment for iron deficiency is oral iron supplementation with ferrous sulfate 65mg elemental iron daily, administered between meals to maximize absorption, with continuation for 3 months after normalization of hemoglobin to replenish iron stores. 1

Diagnosis Confirmation

Before initiating treatment, proper diagnosis is essential:

• Serum ferritin is the most reliable diagnostic test for iron deficiency:

  • <30 μg/L: Definitive iron deficiency
  • 30-100 μg/L with transferrin saturation <20%: Possible iron deficiency, especially with inflammation

  • 100 μg/L with normal transferrin saturation: Iron deficiency unlikely 1

• In patients with inflammation, chronic disease, or malignancy, the ferritin cutoff should be raised to <100 μg/L, with transferrin saturation <16% supporting the diagnosis 1

Oral Iron Therapy

First-Line Treatment

• Ferrous sulfate is the preferred agent, providing approximately 65mg of elemental iron per tablet 1
• Recent evidence suggests alternate-day dosing may improve absorption and reduce side effects:
  • Doses ≥60 mg in iron-deficient women stimulate hepcidin, which persists for 24 hours but subsides by 48 hours
  • Morning doses are preferable as the circadian increase in plasma hepcidin is augmented by morning iron doses 2

Dosing Recommendations

• Traditional dosing: 100-200 mg/day elemental iron in divided doses 3
• Optimized dosing based on recent evidence:
  • 60-120 mg elemental iron as a morning single dose on alternate days 2
  • Taking with vitamin C improves absorption 3

Expected Response

• Hemoglobin should increase by ≥1 g/dL within 4 weeks of starting therapy 1
• If no response is seen despite compliance, further evaluation is needed 1

Duration of Treatment

• Continue iron supplementation for 3 months after normalization of hemoglobin to replenish iron stores 1

Intravenous Iron Therapy

Intravenous iron is indicated in specific situations:

• Oral iron intolerance or poor response
• Malabsorption syndromes (celiac disease, post-bariatric surgery)
• Inflammatory conditions (inflammatory bowel disease, chronic kidney disease, heart failure)
• Ongoing blood loss exceeding oral replacement capacity
• During second and third trimesters of pregnancy when rapid repletion is needed 4

When IV iron is required:

• Ferric carboxymaltose is well-studied and can be infused over 15 minutes 3
• Risk of reactions is very infrequent (<1:250,000 administrations with recent formulations) 3

Addressing Underlying Causes

Identifying and treating the underlying cause of iron deficiency is essential:

• In men and postmenopausal women: Evaluate for gastrointestinal blood loss
• In premenopausal women: Assess for heavy menstrual bleeding
• Screen for malabsorption conditions (celiac disease, H. pylori infection)
• Evaluate dietary intake patterns 1, 3

Common Pitfalls to Avoid

• Failing to identify the underlying cause of iron deficiency, particularly in men and postmenopausal women
• Using inappropriate ferritin cutoffs in patients with inflammation
• Relying solely on hemoglobin for diagnosis
• Discontinuing treatment too early before iron stores are replenished
• Not addressing gastrointestinal side effects that reduce compliance 1

Follow-up

• Check hemoglobin levels within 4 weeks of starting iron therapy
• Monitor for response (increase of at least 1 g/dL in hemoglobin)
• Continue monitoring after treatment completion as iron deficiency often recurs 1

Iron deficiency treatment should be tailored based on severity, underlying cause, and patient factors, with oral iron supplementation being the cornerstone of therapy for most patients.