iron is absorbed in the human body at the duodenum.
iron is absorbed in the human body at the duodenum.
where is iron absorbed in the human body?
the duodenum
like most mineral nutrients, the majority of the iron absorbed from digested food or supplements is absorbed in the duodenum by enterocytes of the duodenal lining. these cells have special molecules that allow them to move iron into the body. to be absorbed, dietary iron can be absorbed as part of a protein such as heme protein or iron must be in its ferrous fe form. a ferric reductase enzyme on the enterocytes’ brush border, duodenal cytochrome b (dcytb), reduces ferric fe to fe. a protein called divalent metal transporter 1 (dmt1), which can transport several divalent metals across the plasma membrane, then transports iron across the enterocyte’s cell membrane into the cell. if the iron is bound to heme it is instead transported across the apical membrane by heme carrier protein 1 (hcp1).
human iron metabolism
for less severe cases, treatment of iron-deficiency anemia includes dietary changes to incorporate iron-rich foods into regular oral intake and oral iron supplementation. foods rich in ascorbic acid (vitamin c) can also be beneficial, since ascorbic acid enhances iron absorption. oral iron supplements are available in multiple forms. some are in the form of pills and some are drops for children. most forms of oral iron replacement therapy are absorbed well by the small intestine; however, there are certain preparations of iron supplements that are designed for longer release in the small intestine than other preparations. oral iron supplements are best taken up by the body on an empty stomach because food can decrease the amount of iron absorbed from the small intestine. the dosing of oral iron replacement therapy is as much as 200 mg per day. this is generally spread out as 3-4 pills taken throughout the day. the various forms of treatment are not without possible adverse side effects. iron supplementation by mouth commonly causes negative gastrointestinal effects, including constipation. constipation is reported by 15-20% of patients taking oral iron therapy. preparations of iron therapy that take longer to be absorbed by the small intestine (extended release iron therapy) are less likely to cause constipation. it can take six months to one year to get blood levels of iron up to a normal range and provide the body with iron stores.
iron-deficiency anemia