What is the appropriate management for a 20-year-old male with iron deficiency anemia, normal ferritin levels, and symptoms of fatigue?

Management of Iron Deficiency in a 20-Year-Old Male with Fatigue

The 20-year-old male patient has iron deficiency without anemia that requires oral iron supplementation with ferrous sulfate 325 mg daily or on alternate days.

Laboratory Interpretation

The patient's laboratory values show clear evidence of iron deficiency:

• Iron: 39 mcg/dL (low, reference range 59-158 mcg/dL)
• TIBC: 433 mcg/dL (high, reference range 228-428 mcg/dL)
• Iron saturation: 9% (low, reference range 20-55%)
• Ferritin: 98 ng/mL (normal, reference range 11-336 ng/mL)
• Hemoglobin: 14.8 g/dL (normal, reference range 13.5-17.5 g/dL)
• MCH: 26.9 pcg (low, reference range 27.0-34.0 pcg)

This represents a case of iron deficiency without anemia, as the hemoglobin level is within normal limits but iron parameters indicate deficiency 1.

Diagnostic Assessment

The diagnosis is iron deficiency based on:

• Low serum iron
• Elevated TIBC
• Low transferrin saturation (<20%)
• Normal ferritin (which can be misleading)

While ferritin is often considered the most powerful test for iron deficiency 2, it can be falsely normal in the presence of inflammation 2. In this case, the transferrin saturation of 9% is a more reliable indicator of iron deficiency, as values below 20% strongly suggest iron deficiency 1.

Treatment Approach

First-line Treatment:

• Oral iron supplementation with ferrous sulfate 325 mg (65 mg elemental iron) daily or on alternate days 1, 3
• Alternate-day dosing may improve absorption and reduce gastrointestinal side effects 2
• Take on an empty stomach with vitamin C to enhance absorption
• Avoid taking with tea, coffee, calcium, or antacids which can impair absorption

Monitoring:

• Check hemoglobin after 3-4 weeks to assess response
• A good response (Hb rise ≥10 g/L within 2 weeks) confirms iron deficiency 2
• Monitor iron parameters after 4-8 weeks of treatment 1
• Continue treatment for 3 months after normalization of parameters to replenish iron stores 1

Investigation of Underlying Causes

Given that this is a young male with iron deficiency, investigation of the underlying cause is essential:

1. Gastrointestinal evaluation:

   • Consider upper and lower GI endoscopy to rule out sources of blood loss 1
   • GI tract blood loss is the most common cause of iron deficiency in adult males 2

2. Screening for celiac disease:

   • Found in 3-5% of cases of iron deficiency 1
   • Consider tissue transglutaminase antibody testing

3. Medication review:

   • Assess for NSAID or aspirin use which may cause GI blood loss 2, 1

4. Dietary assessment:

   • Evaluate iron intake, especially if patient follows a vegetarian or vegan diet 2
   • Low dietary intake alone is rarely the sole cause in males

Common Pitfalls to Avoid

1. Misinterpreting normal ferritin:

   • Normal ferritin (as in this case) does not exclude iron deficiency, especially with low transferrin saturation 1
   • Recent research suggests higher ferritin cutoffs (up to 50 ng/mL) may be more appropriate 4

2. Failure to investigate underlying cause:

   • Iron deficiency in males always warrants investigation for potential sources of blood loss 1

3. Inadequate duration of treatment:

   • Treatment should continue for 3 months after normalization of parameters 1

4. Ignoring symptoms despite normal hemoglobin:

   • Iron deficiency without anemia can still cause fatigue and reduced quality of life 5

Follow-up Plan

• Reassess iron parameters after 4-8 weeks of treatment

• If no improvement in iron parameters or symptoms, consider:

  • Poor compliance
  • Ongoing blood loss
  • Malabsorption
  • Need for parenteral iron therapy

• Monitor for recurrent iron deficiency every 3 months for at least a year after correction 2

By addressing both the iron deficiency and investigating its underlying cause, this approach will improve the patient's symptoms of fatigue while potentially identifying and treating any serious underlying conditions.