■ Duodenal epithelial cell uptake of heme and nonheme iron is depicted.
■ When the storage sites of the body are replete with iron and erythropoietic
activity is normal, plasma hepcidin levels are high.
■ This leads to down-regulation of ferroportin and trapping of most of the
absorbed iron, which is lost when duodenal epithelial cells are shed into the gut.
■ Conversely, when body iron stores decrease or when erythropoiesis is
stimulated, hepcidin levels fall and ferroportin activity increases, allowing a
greater fraction of the absorbed iron to be transferred to plasma transferrin.