Iron Deficiency Diagnosis and Treatment Plan
The patient's laboratory results indicate iron deficiency anemia with a ferritin of 15 ng/mL and iron saturation of 15%, requiring immediate oral iron supplementation with ferrous sulfate 200 mg three times daily for at least three months. 1
Interpretation of Iron Studies
The patient's iron studies show:
- Ferritin: 15 ng/mL (severely low, <30 ng/mL indicates iron deficiency)
- Iron saturation: 15% (low, <20% indicates iron deficiency)
- TIBC: 448 μg/dL (elevated, normal range 250-450 μg/dL)
- UIBC: 381 μg/dL (elevated, normal range 111-343 μg/dL)
- Serum iron: 67 μg/dL (within normal range 38-169 μg/dL)
- HbA1c: 7.0% (indicates diabetes)
These findings are consistent with absolute iron deficiency, characterized by:
- Low ferritin (<30 ng/mL), which is the most specific indicator of iron deficiency 1
- Low transferrin saturation (<20%), indicating inadequate iron availability for erythropoiesis 2
- Elevated TIBC and UIBC, reflecting the body's attempt to increase iron transport capacity 1
Treatment Plan
1. Oral Iron Supplementation
- First-line therapy: Ferrous sulfate 200 mg three times daily (provides approximately 65 mg elemental iron per tablet) 1
- Duration: Continue for at least three months after correction of anemia to replenish iron stores 1
- Optimization: Take with vitamin C 250-500 mg to enhance absorption 1
- Administration: Take on an empty stomach, 1 hour before or 2 hours after meals
2. Monitoring Response
- Check hemoglobin and iron studies after 4 weeks of treatment 1
- Expected response: hemoglobin should rise by 2 g/dL after 3-4 weeks 1
- Continue supplementation until ferritin normalizes (>100 μg/L) 1
- Monitor iron parameters every 3 months for the first year after normalization 1
3. Alternative Options if Oral Iron Fails
Consider intravenous iron if:
- Intolerance to oral preparations (gastrointestinal side effects)
- Non-compliance with oral therapy
- Malabsorption
- Need for rapid iron repletion
- Ongoing blood loss
- Chronic inflammatory conditions 1
Addressing Diabetes Management
The patient's HbA1c of 7.0% indicates diabetes that is at target for glycemic control according to general guidelines, but optimization may be beneficial:
- Continue current diabetes management as the HbA1c is at the target of <7.0% for adults with diabetes
- Be aware that iron deficiency can falsely elevate HbA1c values, so reassess HbA1c after iron repletion 3
Investigation of Underlying Causes
Given the severe iron deficiency (ferritin 15 ng/mL), investigation of potential causes is essential:
- Gastrointestinal blood loss (most common cause in men and non-menstruating women)
- Menstrual blood loss (in women of reproductive age)
- Malabsorption (celiac disease, atrophic gastritis, H. pylori infection)
- Dietary insufficiency
- Pregnancy/recent childbirth 1, 3
Recommended Investigations:
- Complete blood count to assess severity of anemia
- Stool occult blood testing
- Consider upper and lower endoscopy to rule out GI bleeding sources
- Screen for celiac disease with tissue transglutaminase antibody 1
Common Pitfalls to Avoid
Misdiagnosis: Don't confuse iron deficiency with anemia of chronic disease, which typically has normal or elevated ferritin 4
Inadequate treatment duration: Continue iron therapy for three months after correction of anemia to fully replenish stores 1
Ignoring underlying causes: Always investigate the cause of iron deficiency, especially with ferritin as low as 15 ng/mL 1
Poor monitoring: Regular follow-up is essential to ensure adequate response and prevent recurrence 1
Overlooking diabetes interaction: Iron deficiency can affect HbA1c values, potentially leading to overestimation of glycemic control 3