Does a patient with normal hemoglobin (Hb) and mean corpuscular volume (MCV), elevated ferritin, and low vitamin D require iron supplementation?

Does This Patient Need Iron Supplementation?

No, this 35-year-old woman does not need iron supplementation. Her normal hemoglobin, normal MCV (91 fL), and elevated ferritin (288 ng/ml) indicate adequate iron stores, and iron supplementation in the presence of normal or high ferritin values is not recommended and is potentially harmful 1.

Laboratory Interpretation

Iron Status Assessment

This patient's laboratory values demonstrate:

• Normal hemoglobin and MCV (91 fL): No evidence of anemia or microcytosis 1
• Ferritin 288 ng/ml: Well above the threshold for iron deficiency (ferritin <30 µg/L for adult females >15 years) 2
• Low serum iron (44) with elevated transferrin (1.5): This pattern suggests functional iron deficiency or inflammation, NOT true iron depletion 1

The elevated ferritin level is the critical finding here. Ferritin is an acute phase reactant and can be falsely elevated in inflammatory conditions, but even accounting for this, a ferritin of 288 ng/ml indicates adequate or excessive iron stores 1.

Why Iron Supplementation Is Contraindicated

Iron supplementation in the presence of normal or elevated ferritin values is potentially harmful 1. The guidelines are explicit:

• Iron deficiency should only be treated when associated with anemia AND/OR low ferritin levels 1
• Treatment without evidence of classic iron deficiency (ferritin <25 ng/ml in males, <11 ng/ml in females, or <30 µg/L in general adult populations) is not justified 1, 2
• Long-term iron supplementation with normal or high ferritin is not recommended and carries risk of iron overload 2

Clinical Reasoning Algorithm

Step 1: Assess for anemia

• Hemoglobin normal ✓
• MCV normal (91 fL) ✓
• Conclusion: No anemia present 1

Step 2: Assess iron stores

• Ferritin 288 ng/ml (well above 30 µg/L threshold) ✓
• Conclusion: Iron stores are adequate to replete 2

Step 3: Interpret low serum iron

• Low serum iron with normal hemoglobin and elevated ferritin suggests either:
  • Inflammation affecting iron distribution 1
  • Normal diurnal variation in serum iron
  • NOT true iron deficiency 3

Step 4: Decision

• No iron supplementation indicated 1, 2

Important Caveats

The Low Vitamin D Finding

The low vitamin D is a separate issue requiring supplementation, but this does not change the iron assessment 1.

When to Reconsider

Iron supplementation would only be appropriate if:

• Hemoglobin falls below normal range AND ferritin drops below 30 µg/L 1, 2
• MCV becomes microcytic (<80 fL) with corresponding drop in ferritin 1
• Patient develops transfusion-dependent anemia 1

Monitoring Recommendations

For this premenopausal woman:

• Recheck hemoglobin and ferritin if symptoms of anemia develop (fatigue, weakness, dyspnea) 1
• Consider evaluation for menorrhagia if heavy menstrual bleeding is reported, as this is a common cause of iron deficiency in this population 1
• Address the vitamin D deficiency separately 1

Common Pitfall to Avoid

Do not treat based on serum iron alone. Serum iron fluctuates significantly and is affected by inflammation, time of day, and recent dietary intake 1, 3. The combination of normal hemoglobin, normal MCV, and adequate ferritin definitively rules out iron deficiency requiring treatment 2, 3, 4.