Overview Vitamin B12 (Cobalamin) absorption occurs in terminal ileum requires intrinsic factor (IF) gastrectomy IF deficiency as a consequence of loss of parietal cells login to view 3 more bullets Iron (Fe) absorption occurs in duodenum absorption across apical membrane of intestinal epithelial cells occurs as free iron (Fe2+) in intestinal epithelial cells, free iron (Fe2+) binds apoferritin login to view 2 more bullets absorption across apical membrane of intestinal epithelial cells may also occur as heme iron in intestinal epithelial cells, heme iron (iron bound to hemoglobin) is digested by lysosomal enzymes login to view 1 more bullet Folic acid (folate) absorption occurs in the jejunum small reserve pool stored in the liver