Lay opinion vs evidence: Ferritin Labor

Ferritin is a storage protein for iron, commonly measured in lab tests to assess body iron reserves. Lay opinion often assumes that low ferritin equals iron deficiency and high ferritin equals iron overload. Evidence, however, shows that ferritin is an acute-phase reactant: it rises during inflammation, infection, liver disease, or malignancy, independent of actual iron status. A normal or elevated ferritin level can mask functional iron deficiency when chronic inflammation is present. Conversely, low ferritin reliably indicates depleted iron stores, but should be interpreted alongside hemoglobin, transferrin saturation, and CRP. Measuring ferritin alone without clinical context is misleading. In consumer tests like MyBody-X's Nährstoff VitalCheck Basic, ferritin is offered as a biomarker, but the test is a lifestyle tool, not a medical diagnosis. Users may misinterpret results, leading to unnecessary iron supplementation when ferritin is falsely elevated due to inflammation. Safety note: iron should only be supplemented after confirmed deficiency and medical consultation, as excess iron causes oxidative stress. The evidence is practice-based: ferritin is a useful but non-definitive marker. Always correlate with clinical history and additional lab values.