Damaged, the stomach cells are unable to create the protein intrinsic factor.
Intrinsic factor is needed in order for the gut to be able to reabsorb vitamin B12 from the foods eaten.
Foods rich in vitamin B12 include meat and eggs, as well as dairy products.
Thus, even if you have a diet full of vitamin B12, if you have pernicious anaemia, the body is unable to hold onto the vitamin.