Ferritin: Iron Storage and Inflammation
Ferritin is a spherical protein shell that safely stores up to 4,500 iron atoms per molecule. Under normal conditions, serum ferritin reflects total body iron stores. However, ferritin gene expression is also upregulated by pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha) through NF-kB signaling, independently of iron status. This dual role means elevated ferritin can indicate either true iron overload or chronic inflammation. Distinguishing between these causes requires additional testing including transferrin saturation and inflammatory markers.
Dual Interpretation
Elevated ferritin can mean iron overload OR inflammation. Always test iron saturation and hs-CRP alongside ferritin to distinguish the cause.
Low Ferritin Is Common
Iron deficiency (ferritin < 30 ng/mL) is extremely common, especially in menstruating women, causing fatigue, hair loss, poor exercise tolerance, and brain fog even without anemia.
Optimal Ferritin Benchmarks
Common Questions
What does high ferritin mean?
Elevated ferritin can indicate iron overload (hemochromatosis), chronic inflammation, liver disease, metabolic syndrome, or infection. Additional tests are needed to determine the cause.
What should my ferritin be?
Optimal ferritin is 50-150 ng/mL for men and 40-100 ng/mL for women. Below 30 ng/mL indicates iron depletion. Above 200 ng/mL warrants investigation.