Hem Iron is more easily absorbed by human body, compared to inorganic iron. This is due to the fact that Hem iron’s intake is not influenced by the many ligands in the diet; furthermore, it is directly taken up into enterocytes by an absorption pathway different from that of inorganic iron. Hem iron is also unaffected by the high pH of the upper small bowel, which renders some forms of inorganic iron insoluble.
Intrinsic factor is a glycoprotein secreted by parietal cells of the gastric mucosa. In humans, it plays an important part in the absorption of vitamin B12 (cobalamin) in the intestine, and failure to produce or utilize intrinsic factor results in the condition pernicious anemia.