Figure 7.

Model of iron absorption and excretion. Dietary non-heme iron (Fe) is absorbed by enterocytes in the small intestine. Enterocytes export Fe into the blood; this process can be inhibited by hepcidin. Fe is then transported to the liver for storage, excretion, or distribution to other organs in the body. Fe can be excreted by the liver into bile and transported into the small intestine, where it can undergo enterohepatic circulation or can be eliminated from the body via the feces. Fe can also be excreted from the body by turnover of epithelial cells lining the intestines or from minor trauma to intestinal epithelium leading to blood loss. Dashed lines indicate minor routes of Fe excretion, which include blood loss, exfoliation of dead skin, and excretion via the urine. For the sake of simplicity, not all organs or pathways of Fe transport are shown, including those that mediate heme Fe absorption.