Intrinsic factor is essential, in man, for the absorption of the small amounts of vitamin B12 normally present in the diet. There is evidence that the stomach is the only site of secretion of intrinsic factor.1 Following total gastrectomy, the human would be expected to experience difficulty in the absorption of vitamin B12 and eventually to develop a vitamin B12 deficiency state.
Difficulty in absorption can be readily demonstrated by giving such patients small oral doses of radioactive (CO60) vitamin B12 and estimating the amount of radioactivity excreted in the feces.* In normal persons a considerable amount of the dose is absorbed, whereas in gastrectomized patients most of the administered radioactivity subsequently appears in the feces. The administration of a source of intrinsic factor together with the radioactive vitamin B12 results in improved absorption and lessened fecal radioactivity.
Megaloblastic anemia may be a late complication of total gastrectomy. In four
PITNEY WR, BEARD MF. Vitamin B12 Deficiency Following Total Gastrectomy. AMA Arch Intern Med. 1955;95(4):591-593. doi:10.1001/archinte.1955.00250100097010