How to manage iron deficiency anemia with low ferritin and high transferrin levels?

Management of Iron Deficiency Anemia with Low Ferritin and High Transferrin

Oral iron supplementation is strongly recommended as first-line treatment for this patient with absolute iron deficiency indicated by low ferritin (16 ng/mL) and high transferrin (286). 1

Diagnosis Confirmation

The patient's laboratory values clearly indicate absolute iron deficiency:

• Ferritin of 16 ng/mL (well below the 30 ng/mL threshold for absolute iron deficiency)
• Transferrin of 286 (elevated, indicating the body's attempt to increase iron transport)

This pattern represents classic iron deficiency anemia, with the body increasing transferrin production to maximize the transport of limited available iron.

Treatment Algorithm

First-Line Treatment

• Oral iron supplementation: Ferrous sulfate 324 mg (65 mg elemental iron) daily or on alternate days 2, 3
  • Start with daily dosing if anemia is severe
  • Consider alternate-day dosing if GI side effects occur (improves absorption and reduces side effects)
  • Expected response: Hemoglobin increase of 1-2 g/dL per month 4

Monitoring Response

• Check hemoglobin after 4 weeks of treatment 1
• If hemoglobin increases by 1-2 g/dL, continue treatment
• If no improvement after 4 weeks, evaluate for:
  • Poor adherence
  • Ongoing blood loss
  • Malabsorption issues
  • Need for intravenous iron

Duration of Treatment

• Continue oral iron for 3-6 months after hemoglobin normalizes to replenish iron stores
• Target ferritin >100 ng/mL and transferrin saturation >20% 4

Special Considerations

When to Consider IV Iron Instead

Intravenous iron should be considered as first-line treatment if any of these conditions are present:

• Clinically active inflammatory bowel disease 1
• Previous intolerance to oral iron 1
• Hemoglobin below 10 g/dL with severe symptoms 1
• Chronic kidney disease 5
• Congestive heart failure 1
• Malabsorption disorders 3

Evaluation for Underlying Causes

While treating the iron deficiency, investigate potential causes:

• Gastrointestinal blood loss (consider referral to gastroenterologist) 1, 3
• Menstrual blood loss in women of reproductive age 3
• Malabsorption disorders (celiac disease, post-bariatric surgery) 3
• Inadequate dietary intake 3
• Pregnancy 3

Common Pitfalls to Avoid

1. Failure to investigate the underlying cause: Iron deficiency is a symptom, not a diagnosis. Always determine the source of iron loss or poor absorption 3, 6

2. Inadequate duration of treatment: Stopping iron supplementation once hemoglobin normalizes without replenishing iron stores leads to recurrence 7

3. Ignoring side effects: GI side effects (constipation, nausea) are common with oral iron and may lead to non-adherence. Consider:

   • Taking with vitamin C to enhance absorption
   • Alternate-day dosing
   • Different iron formulations if side effects are severe

4. Misinterpreting laboratory values: In inflammatory states, ferritin can be falsely elevated despite iron deficiency. When inflammation is present, a higher ferritin threshold (<100 ng/mL) should be used to diagnose iron deficiency 1

5. Excessive iron supplementation: Continuing iron therapy when ferritin exceeds 500 ng/mL and transferrin saturation exceeds 50% can lead to iron overload 4

By following this approach, the patient's iron deficiency anemia should resolve while the underlying cause is identified and addressed.