Intestinal absorption of iron Intestinal absorption of iron. Fe3+ is converted to Fe2+ by the ferric reductase DCYTB, and Fe2+ is transported into the enterocyte by the apical membrane iron transporter DMT1. Heme is transported into the enterocyte by a separate heme transporter (most likely heme carrier protein 1, HCP1), and heme oxygenase-2 (HO2) releases Fe2+ from the heme. Some of the intracellular Fe2+ is converted to Fe3+ and bound to ferritin. The rest binds to the basolateral Fe2+ transporter ferroportin-1 (FPN1) and is transported to the interstitial fluid. The transport is aided by hephaestin (Heph) which converts Fe2+ to Fe3+. In plasma, Fe3+ is transported bound to the iron transport protein transferrin (TF). Source: Digestion, Absorption, & Nutritional Principles, Ganong’s Review of Medical Physiology, 25e Citation: Barrett KE, Barman SM, Boitano S, Brooks HL. Ganong’s Review of Medical Physiology, 25e; 2016 Available at: http://accesspharmacy.mhmedical.com/DownloadImage.aspx?image=/data/books/1587/bar_ch26_f008.png&sec=97165251&BookID=1587&ChapterSecID=97165178&imagename= Accessed: October 19, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved