Treatment of Iron Deficiency in a 43-Year-Old Male with Ferritin 11 ng/mL
This patient has absolute iron deficiency anemia (ferritin <30 ng/mL) and should be treated with oral iron supplementation as first-line therapy, specifically ferrous sulfate 325 mg daily or every other day, while investigating the underlying cause of iron deficiency. 1, 2
Diagnostic Confirmation and Workup
- A ferritin of 11 ng/mL definitively confirms absolute iron deficiency (AIDA), as this is well below the diagnostic threshold of 30-45 ng/mL in adults without inflammation 3, 1, 2
- In men and postmenopausal women, bidirectional endoscopy should be performed to identify gastrointestinal blood loss, which accounts for 94% of iron deficiency cases in this population 1
- Noninvasive testing for Helicobacter pylori infection and celiac disease is recommended, as both are common treatable causes 1
- Obtain additional baseline labs including hemoglobin, mean cellular volume (MCV), mean cellular hemoglobin (MCH), and transferrin saturation (TSAT) to assess severity and guide monitoring 3, 4
- Check C-reactive protein to exclude inflammation that could falsely elevate ferritin levels 4
First-Line Treatment: Oral Iron
Oral iron therapy is the appropriate first-line treatment for most patients with iron deficiency anemia 1, 2:
- Prescribe ferrous sulfate 325 mg daily OR every-other-day dosing 1, 2
- Every-other-day dosing improves iron absorption and may reduce gastrointestinal side effects, which cause decreased adherence in approximately 50% of patients 1
- Alternative preparations with 28-50 mg elemental iron content can be used if gastrointestinal side effects occur 4
- Counsel on dietary iron intake: incorporate heme iron sources, identify enhancers (vitamin C), and avoid inhibitors (tea, coffee, calcium) of iron absorption 4, 5
Monitoring Response
- Reassess in 2-4 weeks to evaluate response to oral iron therapy 1
- Repeat complete blood count and iron studies (ferritin, TSAT) at 8-10 weeks to measure treatment success 4
- Expected response includes rising hemoglobin (typically 1-2 g/dL increase) and increasing ferritin levels 3
When to Consider Intravenous Iron
Intravenous iron is indicated if the patient: 1, 2
- Cannot tolerate oral iron due to gastrointestinal side effects
- Has inadequate response after 8-10 weeks of oral therapy
- Has impaired iron absorption (celiac disease, inflammatory bowel disease, post-bariatric surgery)
- Has ongoing blood loss that cannot be controlled
- Has chronic inflammatory conditions (chronic kidney disease, heart failure, cancer)
For IV iron, ferric carboxymaltose is an option with dosing based on body weight and hemoglobin deficit 6. Hypersensitivity reactions to newer IV iron formulations occur in less than 1% of patients 1.
Common Pitfalls to Avoid
- Do not prescribe iron supplementation without investigating the underlying cause in adult men, as occult gastrointestinal malignancy must be excluded 1
- Avoid excessive iron supplementation once ferritin normalizes, as long-term daily oral iron with normal or high ferritin is potentially harmful 4
- Do not discontinue oral iron prematurely; continue for several months after hemoglobin normalizes to replenish iron stores 4, 5
- If ferritin remains low despite treatment, consider intermittent oral supplementation and long-term follow-up every 6-12 months 4