Ferritin is an iron-protein complex formed from an intracellular acceptor called Apoferritin. Apoferritin is a large molecular weight 450,000 protein produced by the liver. Iron as Fe (HO)3 linked to apoferritin is then stored in the cytoplasm of the reticuloendothelial system, liver, spleen and bone marrow. Ferritin is the body s iron storage protein functioning primarily as a site for iron storage from which iron may be mobilized in response to such stimuli a dietary change, blood loss or pregnancy.

The direct quantitation of serum ferritin offers the physician a convenient and accurate measure of total body iron stores, by means of diagnosing iron-deficiency and anemia due to such causes as inflammation and hepatic or renal disease. In addition, serum ferritin concentration may be useful in detecting iron overload, which may allow the detection of idiopathic hemachromatosis in the precirrhotic storage.