Tags: Protein.
Intrinsic factor (IF) also known as gastric intrinsic factor (GIF) is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B12 (cobalamin) later on in the small intestine. In humans the gastric intrinsic factor protein is encoded by the GIF gene.Upon entry into the stomach vitamin B12 becomes bound to haptocorrin (aka HC R factor transcobalamin I TCN1) a glycoprotein.