We report on the use of recombinant human intrinsic factor (rhIF) in a new vitamin B12 absorption test. Holotranscobalamin (holoTC) was measured before and 24 hours after intake of three 9-mg doses of vitamin B12 (B12) and again 24 hours after intake of the same dose of B12 together with rhIF (rhIF-B12). Nine patients with evident vitamin B12 deficiency had a significantly higher increase in ho...

vitamin b12 (cobalamin) is an essential coenzyme for nucleic acid synthesis. animal protein is the major dietary source of vitamin b12. deficiency of vitamin b12 leads to megaloblastic anemia, degeneration of the brain, spinal cord, peripheral nerves, and abnormalities of epithelial tissues. two factors are necessary for the cure of megaloblastic anemia: one in food (extrinsic factor) and one i...