How are low ferritin levels treated?

Causes and Treatment of Low Ferritin Levels

Low ferritin levels are primarily caused by iron deficiency, which can result from blood loss, malabsorption, or inadequate dietary intake, and should be treated with iron supplementation tailored to the severity and underlying cause. 1

Causes of Low Ferritin

Low serum ferritin is the most specific indicator of depleted iron stores in the body 2. Common causes include:

• Blood loss:

  • Gastrointestinal bleeding
  • Heavy menstrual bleeding (most common in women of reproductive age)
  • Frequent blood donation

• Malabsorption conditions:

  • Celiac disease
  • Post-bariatric surgery
  • Atrophic gastritis
  • Inflammatory bowel disease

• Inadequate dietary intake:

  • Vegetarian/vegan diets (lower bioavailability of non-heme iron)
  • Poor nutrition

• Increased iron requirements:

  • Pregnancy (especially third trimester)
  • Endurance athletes
  • Periods of rapid growth (infancy, adolescence)

• Genetic disorders:

  • Iron-refractory iron deficiency anemia (IRIDA) 2

Diagnostic Parameters

Ferritin is the most specific indicator for iron deficiency 2:

• Normal values:

  • Men: ~135 μg/L
  • Women: ~43 μg/L
  • Children (6-24 months): ~30 μg/L

• Diagnostic cutoffs:

  • Iron deficiency: <30 μg/L (without inflammation) 1
  • In presence of inflammation: <100 μg/L may still indicate iron deficiency 1

Treatment Approach

Oral Iron Supplementation

For most patients with uncomplicated iron deficiency, standard oral iron supplementation with ferrous sulfate 324 mg (65 mg elemental iron) once daily is recommended as first-line therapy. 1, 3

• Dosing options:

  • Standard: 50-100 mg elemental iron daily
  • Alternative: One tablet every other day if daily dosing not tolerated
  • Duration: Continue for 3 months after correction of anemia to replenish iron stores

• Expected response:

  • Hemoglobin increase of approximately 2 g/dL after 3-4 weeks
  • Improvement in ferritin levels within 8-10 weeks

• Enhancing absorption:

  • Take on empty stomach
  • Take with vitamin C-rich foods
  • Avoid tea, coffee, calcium supplements, and dairy products within 2 hours of iron supplementation

Intravenous Iron Therapy

Indications for IV iron therapy 1:

• Oral iron intolerance
• No improvement in ferritin levels with oral iron trial
• Conditions with impaired iron absorption
• Hemoglobin below 10 g/dL
• Ongoing blood loss exceeding oral absorption capacity
• Active inflammatory bowel disease
• Patients requiring erythropoiesis-stimulating agents

Dietary Recommendations

• Increase consumption of iron-rich foods:

  • Red meat, poultry, fish (heme iron sources)
  • Beans, lentils, spinach, fortified cereals (non-heme iron sources)

• Optimize iron absorption:

  • Consume vitamin C-rich foods with meals
  • Avoid tea, coffee, and calcium supplements with meals

Monitoring and Follow-up

• Monitor hemoglobin and ferritin levels after 8-10 weeks of treatment 1
• Once normalized, monitor every 3 months for one year, then annually
• After IV iron therapy, monitor complete blood count at 3 months, then every 3 months for 12 months

Special Considerations

• Athletes: Iron deficiency is common in athletes (15-35% in female athletes, 5-11% in male athletes) 2
• Pregnancy: Iron deficiency affects up to 84% of pregnant women in the third trimester 4
• Chronic inflammatory conditions: May have elevated ferritin despite iron deficiency due to ferritin being an acute-phase reactant 2, 5

Potential Pitfalls

• Failing to investigate underlying cause: Always identify and address the source of iron loss or malabsorption 1
• Misinterpreting ferritin in inflammatory states: Ferritin is an acute-phase reactant and can be elevated in inflammation, masking iron deficiency 2, 6
• Overlooking non-anemic iron deficiency: Symptoms like fatigue can occur before anemia develops 4
• Inadequate duration of treatment: Continuing treatment for 3 months after normalization of hemoglobin is essential to replenish iron stores 1

By addressing the underlying cause and providing appropriate iron supplementation, most patients with low ferritin levels can achieve normal iron stores and resolution of associated symptoms.