Ferritin

Ferritin is the body's main iron-storage protein, and serum ferritin usually reflects total iron stores. It is also an acute-phase reactant, meaning it rises with inflammation independent of iron.

Ferritin is the best single test for iron deficiency — the world's most common nutritional deficiency — and for iron overload. Its dual nature (iron store and inflammation marker) makes careful interpretation essential.

1. 1

   FoundationNutritionThe parent guide to the dietary patterns that most improve health.
2. 2

   ConditionIron Deficiency & AnaemiaThe commonest nutritional deficiency in the world — and a finding that always has a cause
3. 3

   Body SystemImmuneDefense, inflammation, and resilience to illness.

1. Measure it
2. Understand your result
3. See what raises and lowers it
4. Apply evidence-based interventions
5. Recheck on your review cadence

An orientation to how this topic is typically approached — not medical advice.

Low ferritin is specific for depleted iron stores and warrants finding the cause (e.g., blood loss, low intake, malabsorption). High ferritin needs context — it may signal iron overload (e.g., hemochromatosis) or simply inflammation.

• Serum ferritin blood test
• Often ordered with iron, transferrin saturation, and CRP

Ferritin is a validated, first-line marker for iron status; its main limitation — elevation by inflammation — is well characterized and managed with adjunct tests.

• WHO guidance on ferritin for assessing iron status
• Hematology society iron-deficiency guidelines

Sources are named authoritative guidelines and scientific bodies. Biomarker pages present established clinical context; calibrated evidence verdicts on specific interventions live in the linked Signal Records.