What is the ideal ferritin level?

Ideal Ferritin Levels

The ideal ferritin level depends on clinical context: for screening iron deficiency in healthy individuals, ferritin <15 μg/L indicates deficiency, but in the presence of inflammation, this threshold should be raised to <30 μg/L, with optimal target levels of 50-100 μg/L for maintaining adequate iron stores in most clinical scenarios. 1

Context-Specific Ferritin Targets

Healthy Populations (No Inflammation)

• Ferritin <15 μg/L confirms iron deficiency in women of childbearing age with 98% specificity 1
• Ferritin <12 μg/L provides 100% specificity but lower sensitivity (61%) for detecting absent bone marrow iron stores 1
• Average normal values are 135 μg/L for men and 43 μg/L for women in the United States 1
• Emerging evidence suggests 50 ng/mL represents the body's physiologic ferritin threshold for adequate iron stores 2

Inflammatory Conditions

When inflammation is present (elevated CRP, active disease), ferritin thresholds must be adjusted upward because ferritin is an acute-phase reactant that rises independently of iron status 1:

• Ferritin <30 μg/L indicates iron deficiency in patients without inflammation 1
• Ferritin <100 μg/L may still indicate iron deficiency when inflammation is present 1
• Ferritin >100 μg/L with transferrin saturation <16-20% suggests anemia of chronic disease 1
• Ferritin 30-100 μg/L in inflammatory states likely represents combined iron deficiency and anemia of chronic disease 1

Specific Clinical Populations

Inflammatory Bowel Disease

• Target ferritin ≥50 ng/mL after iron repletion 1
• Re-treatment should be initiated when ferritin drops below 100 μg/L 1
• Transferrin saturation <20% has high sensitivity for diagnosing absolute or functional iron deficiency 1

Chronic Kidney Disease on Hemodialysis

• Maintain ferritin ≥100 ng/mL and transferrin saturation ≥20% to prevent functional iron deficiency 1
• Upper safety limit: avoid chronically maintaining ferritin >800 ng/mL 1
• Optimal range for oral iron therapy in hemodialysis patients with minor inflammation: 30-40 ng/mL (67.4-89.9 pmol/L) 3

Hemochromatosis (Iron Overload)

• Target ferritin of 50 μg/L during induction phase of phlebotomy, but not lower to avoid iron deficiency 1
• Maintenance phase: 50-100 μg/L range with some flexibility 1
• More relaxed targets may be tolerated in elderly patients (<200 μg/L for women, <300 μg/L for men) 1

Key Clinical Caveats

Ferritin Limitations

• Ferritin is elevated by infection, inflammation, liver disease, malignancy, and tissue damage independent of iron status, potentially masking iron deficiency 1, 4
• Extremely elevated ferritin (>1000 μg/L) is most commonly associated with malignancy or infection rather than rheumatologic conditions 4
• Within-individual variation can be substantial due to factors beyond iron stores 1

Diagnostic Approach

• Always assess inflammatory markers (CRP, ESR) when interpreting ferritin to determine appropriate diagnostic thresholds 1
• Transferrin saturation <20% is highly sensitive for iron deficiency even when ferritin is equivocal 1
• Consider soluble transferrin receptor or reticulocyte hemoglobin content when ferritin and transferrin saturation are discordant in inflammatory states 1

Treatment Monitoring

• Do not check iron parameters within 4 weeks of IV iron administration as circulating iron interferes with assays 1
• Optimal timing for post-treatment assessment is 4-8 weeks after last infusion 1
• Hemoglobin should increase by 1-2 g/dL within 4-8 weeks of adequate iron therapy 1