Ferritin is a protein produced in the liver for the storage of iron. Ferritin is a sensitive and specific test to diagnose iron deficiency anemia. In general, a healthy ferritin level is greater than 20 ng/mL. Higher levels of ferritin, greater than 400 ng/mL, are consistent with iron overload which is called hemochromatosis. Fasting is not required for this test. Take all medications as prescribed.