Pernicious anemia occurs due to the deficiency of red blood cells (RBCs) when the body fails to absorb vitamin B12. It is a type of autoimmune disease. Vitamin B12 is required by the body to make new red blood cells. Absorption of vitamin B12 in the body requires the help of an intrinsic factor (a protein which is produced by the stomach). This vitamin combines with the intrinsic factor in the stomach and gets absorbed in the small intestine. When the stomach fails to make enough intrinsic factor (because antibodies are formed against it), the absorption of vitamin B12 is reduced, resulting in a low RBC count. This leads to pernicious anemia. Certain pathological conditions in the stomach or gut like atrophic gastritis, stomach surgery and Crohn’s disease make it difficult for the body to absorb adequate vitamin B12 and thus cause anemia. Pernicious anemia can be treated by replenishing your body’s supplies of this vitamin. Usually, lifelong treatment is suggested by physicians for the treatment of pernicious anemia.