How to treat severe iron deficiency?

Treatment of Severe Iron Deficiency

Severe iron deficiency should be treated with daily oral iron supplementation (ferrous sulfate 200 mg, ferrous fumarate 210 mg, or ferrous gluconate 300 mg) for 3 months after hemoglobin normalization, with intravenous iron reserved for specific indications such as oral intolerance, malabsorption, or need for rapid correction. 1

Diagnosis Confirmation

Before initiating treatment, confirm iron deficiency through:

• Complete blood count (CBC) to assess for anemia
• Serum ferritin (<15 μg/L indicates deficiency)
• Transferrin saturation (<20% indicates deficiency)
• Peripheral blood smear
• C-reactive protein to exclude acute phase reactions that may falsely elevate ferritin 1, 2

Oral Iron Therapy (First-Line)

• Dosage: One tablet daily of:

  • Ferrous sulfate 200 mg (65 mg elemental iron) 1, 3
  • Ferrous fumarate 210 mg (69 mg elemental iron) 1
  • Ferrous gluconate 300 mg (37 mg elemental iron) 1

• Administration:

  • Take in the morning on an empty stomach 1
  • Add vitamin C (500 mg) with the dose to enhance absorption 1
  • Avoid concurrent intake of tea, coffee, calcium supplements, and high-fiber foods 1

• Duration:

  • Continue for 3 months after hemoglobin normalization to ensure adequate replenishment of iron stores 1

Monitoring Response

• Check hemoglobin response within 4 weeks of starting therapy 1
• Expect hemoglobin to increase by approximately 2 g/dL after 3-4 weeks of treatment 1
• Monitor blood count periodically (every 6 months initially) after treatment to detect recurrence 1
• Check iron studies (ferritin, transferrin saturation) after 3 months of therapy 1
• Target values: ferritin >30 μg/L and transferrin saturation >20% 1, 4

Intravenous Iron Therapy (Second-Line)

Consider intravenous iron when:

• Oral iron is contraindicated
• Oral iron is ineffective despite compliance
• Oral iron is not tolerated despite dose adjustments
• Chronic inflammatory conditions affecting absorption (IBD, chronic kidney disease, heart failure)
• Severe anemia requiring rapid correction
• Malabsorption syndromes 1, 4

Ferric carboxymaltose is a preferred formulation that can be administered as 500-1000 mg in a single dose 1

Dietary Recommendations

• Increase intake of:

  • Heme iron sources (red meat, poultry, fish)
  • Non-heme iron sources (leafy greens, legumes, fortified cereals)
  • Vitamin C-rich foods with meals to enhance absorption 1

• For plant-based diets:

  • Require approximately 1.8 times more dietary iron due to lower bioavailability 1

Special Populations

• Pregnant women:

  • Start with low-dose oral iron (30 mg/day) at first prenatal visit
  • Increase to 60-120 mg/day if anemia develops
  • Continue for 2-3 months after hemoglobin normalization 1

• Female athletes with restrictive diets:

  • Higher iron requirements (22 mg/day recommended)
  • More aggressive supplementation
  • Closer monitoring of ferritin levels 1

Common Pitfalls to Avoid

• Stopping treatment too early before iron stores are replenished 1
• Failing to investigate underlying causes, particularly in men and postmenopausal women 1, 5
• Inadequate monitoring leading to delayed detection of recurrence 1
• Administering oral iron with absorption inhibitors 1
• Not adding vitamin C to enhance absorption 1
• Excessive iron supplementation causing iron overload in high-risk patients 5

Underlying Cause Investigation

For men and postmenopausal women, evaluate for sources of blood loss, especially gastrointestinal (e.g., colon cancer) 5, 4

Common causes of iron deficiency include:

• Menstrual blood loss
• Pregnancy
• Gastrointestinal blood loss
• Malabsorption
• Inadequate dietary intake 6, 4