Deficiency of Intrinsic Factor
To absorb vitamin B12 properly, the body needs a special form of protein known as intrinsic factor. It is produced in the stomach by the parietal cells. Once vitamin B12 is taken in, it is transported to the stomach in which intrinsic factor binds to it. Later, both are absorbed in the last portion of the small intestine. In people with pernicious anemia, the immune system attacks and damages parietal cells, which are responsible for producing intrinsic factors. As a result, the small intestine cannot absorb vitamin B12 from food. [5]
Risk Factors
The risk of developing pernicious anemia tends to be higher in some people. Possible risk factors include:
– Being more than 60 years old.
– Having a portion of the stomach removed during surgery.
– Having some intestinal disorders, an autoimmune condition, or type 1 diabetes mellitus.
– Being of Scandinavian or Northern European descent.
– Having a family history of pernicious anemia.
The risk of having pernicious anemia is likely to increase with age as well. [6]
