Iron imports. III. Transfer of iron from the mucosa into circulation.

Transfer of iron from the mucosa is a critical step in dietary iron assimilation that is tightly regulated to ensure the appropriate amount of iron is absorbed to meet the body's demands. Too much iron is highly toxic, and failure to properly control intestinal iron export causes iron overload associated with hereditary forms of hemochromatosis. One form of genetic iron overload, ferroportin disease, originates due to defects in ferroportin, the membrane iron exporter. Ferroportin acts in conjunction with the intestinal ferroxidase hephaestin to mediate release of iron from the enterocyte. How iron is then acquired by transferrin and released into circulation remains an unknown step in this process.