How to manage a patient with low ferritin levels and normal haemoglobin?

Management of Low Ferritin with Normal Hemoglobin

Oral iron supplementation is recommended for patients with low ferritin (25 μg/L) even with normal hemoglobin levels to replenish iron stores and prevent progression to anemia.

Assessment of Iron Status

The patient presents with:

• Ferritin: 25 μg/L (low, reference range 20-450)
• Hemoglobin: 140 g/L (normal, reference range 130-175)
• Normal complete blood count parameters

This represents iron deficiency without anemia, as:

• Ferritin is the most established marker for stored iron 1
• Levels below 35 μg/L indicate iron deficiency even with normal hemoglobin 1
• Ferritin <30 μg/L is diagnostic of iron deficiency 2

Treatment Approach

Initial Management

• Start oral iron supplementation with ferrous sulfate 324 mg (65 mg elemental iron) daily 3
• Take on an empty stomach or with vitamin C to enhance absorption 2
• Avoid tea, coffee, and calcium-containing foods/supplements around the time of iron intake as they impair absorption 1

Dietary Recommendations

• Increase intake of iron-rich foods, particularly red meat which contains highly bioavailable heme iron 1
• Co-ingest vitamin C with non-heme iron sources (plant-based) to enhance absorption 1
• For vegetarians/vegans, pay special attention to iron intake as plant-based iron has lower bioavailability 1

Monitoring and Follow-up

• Recheck ferritin and hemoglobin in 3 months 1, 2
• Target ferritin level should be at least 100 μg/L 1
• Continue iron supplementation for 3 months after normalization of ferritin to ensure adequate replenishment of iron stores 2
• After successful treatment, monitor iron status every 3-6 months for at least a year 2

Special Considerations

If Oral Iron Is Not Tolerated

• Try alternate oral preparations (ferrous gluconate or ferrous fumarate) 2
• Consider liquid preparations if tablets are not tolerated 2
• Reduce dosage if gastrointestinal side effects occur (constipation, nausea) 1

When to Consider IV Iron

• If there is no response to oral iron after 3 months
• If oral iron is not tolerated due to gastrointestinal side effects
• If there is pathologically impaired iron absorption 1

When to Investigate Further

• If ferritin remains low despite adequate supplementation
• If there are other symptoms suggesting underlying disease
• Consider evaluation for potential causes of iron deficiency:
  • Gastrointestinal blood loss
  • Menstrual blood loss in females
  • Malabsorption disorders
  • Poor dietary intake 2

Potential Pitfalls

• Overlooking iron deficiency because hemoglobin is normal 2
• Premature discontinuation of iron therapy before stores are replenished 2
• Inadequate follow-up leading to recurrence of iron deficiency 2
• Not addressing the underlying cause of iron deficiency 2

Iron deficiency, even without anemia, can have negative implications for overall health and physical performance 1. Treating low ferritin proactively helps prevent progression to anemia and improves quality of life by addressing symptoms like fatigue, reduced cognitive function, and decreased exercise capacity that may be present even before anemia develops.