Intestinal iron absorption: current concepts circa 2000.

Iron is essential for all mammalian cells, and particularly needed for the production of erythrocyte haemoglobin. However, excess iron is toxic, and tissue iron concentrations must be strictly regulated. This regulation occurs at the sites of entrance of iron into the body: in the placenta before birth, and the small intestine after birth. Although iron homeostasis has been intensively studied for half a century, the molecular details have only recently begun to emerge. This review will cover current information on intestinal iron absorption.