Iron Deficiency and Low Ferritin Levels

Diagnostic Criteria

• Low ferritin levels are primarily caused by iron deficiency, which can result from blood loss, inadequate dietary iron intake, impaired iron absorption, or increased iron requirements 1
• Absolute iron deficiency is defined as serum ferritin <30 ng/mL in individuals without inflammation 1
• Ferritin <15 μg/L confirms absolute iron deficiency with 98% specificity 5, 6

Evaluation and Interpretation

• In patients with inflammation, ferritin levels between 30-100 ng/mL may still indicate iron deficiency 1
• Transferrin saturation <16% suggests inadequate iron availability 5, 6
• With inflammation, ferritin <100 μg/L may indicate iron deficiency 2
• Without inflammation, ferritin <30 μg/L indicates iron deficiency 1

Clinical Considerations

• Inflammation can elevate ferritin levels, masking iron deficiency 1
• A comprehensive iron panel including transferrin saturation provides better diagnostic accuracy 1, 4
• Patients with chronic inflammatory conditions may have iron deficiency despite normal ferritin levels 2, 3