What does an iron level of 22 indicate?

Interpreting an Iron Level of 22

An iron level of 22 µg/dL strongly indicates iron deficiency and warrants further investigation to determine the underlying cause and appropriate treatment. 1

Understanding Iron Levels and Iron Deficiency

• Serum iron is one of several laboratory parameters used to assess iron status, but it should not be interpreted in isolation 1
• Normal serum iron values vary by laboratory, but low values (like 22 µg/dL) generally suggest depleted iron stores 1
• Iron deficiency progresses through stages before anemia develops, and early detection is crucial for preventing complications 2

Comprehensive Iron Status Assessment

To properly interpret an iron level of 22, additional tests should be ordered:

• Serum ferritin: The most specific indicator of depleted iron stores; values <15 µg/L confirm iron deficiency with high specificity (99%) 1
• Transferrin saturation: Calculated as (serum iron/TIBC) × 100; values <20% indicate iron deficiency 1, 2
• Complete blood count: Including hemoglobin, hematocrit, MCV, MCH, and RDW to determine if anemia is present 1, 3
• Erythrocyte protoporphyrin: Elevated in iron deficiency; values >30 µg/dL of whole blood indicate iron deficiency 1

Clinical Significance and Implications

• Iron deficiency without anemia (non-anemic iron deficiency or NAID) can cause significant symptoms even before anemia develops 1, 2
• Common symptoms include fatigue, irritability, difficulty concentrating, restless legs syndrome, and exercise intolerance 2
• If anemia is present with iron deficiency (iron deficiency anemia), symptoms may be more severe and include dyspnea and worsening heart failure 2

Common Causes to Investigate

• Blood loss: Menstrual bleeding in women, gastrointestinal bleeding 2, 4
• Impaired absorption: Atrophic gastritis, celiac disease, bariatric surgical procedures 2
• Inadequate dietary intake: Particularly in vegetarians/vegans or those with restricted diets 1, 4
• Increased requirements: Pregnancy, intense physical training (especially in female athletes) 1, 4
• Chronic inflammatory conditions: IBD, chronic kidney disease, heart failure, cancer 2

Management Approach

1. Confirm iron deficiency with additional iron studies (ferritin, transferrin saturation) 1
2. Identify and treat the underlying cause of iron deficiency 2, 5
3. Initiate iron replacement therapy:
   • Oral iron (ferrous sulfate 325 mg daily or on alternate days) is typically first-line therapy 2, 1
   • Continue iron supplementation for three months after correction of anemia to replenish iron stores 1
   • Intravenous iron may be indicated for those with oral iron intolerance, poor absorption, chronic inflammatory conditions, or ongoing blood loss 2, 5

Important Considerations and Pitfalls

• Relying solely on hemoglobin and hematocrit without measuring iron status indicators can miss iron deficiency before anemia develops 3, 6
• Serum ferritin is an acute-phase reactant and can be falsely elevated in inflammatory conditions, potentially masking iron deficiency 1
• A good response to iron therapy (Hb rise ≥10 g/L within 2 weeks) is highly suggestive of absolute iron deficiency, even with equivocal iron studies 1
• Men and postmenopausal women with iron deficiency anemia should undergo gastrointestinal endoscopy to rule out serious underlying pathology 5