Recent advances in intestinal iron transport.

Our understanding of intestinal iron absorption and its regulation has expanded enormously in recent years. Dietary iron crosses the enterocyte brush border membrane through the transporter DMT1 after first being reduced by the ferric reductase Dcytb. The subsequent movement of iron across the basolateral membrane and into the circulation is mediated by ferroportin1 in conjunction with the iron oxidase hephaestin. The activity of ferroportin1 is controlled by the liver-derived peptide hepcidin, and the expression of hepcidin in turn is influenced by plasma transferrin saturation via a pathway that involves HFE, TfR2, and hemojuvelin. Future studies investigating how these molecules interact will provide a comprehensive understanding of this essential physiologic process.