is pernicious anemia an autoimmune disease
Vitamin B12 is absorbed in the stomach. Pernicious anemia (PA) is an autoimmune condition of anemia caused by a deficiency of vitamin B12. Vitamin B12 deficiency can have many causes including PA, malabsorption syndromes, and food cobalmin deficiency.ernicious anemia (PA) is an autoimmune condition of anemia caused by a deficiency of vitamin B12. Vitamin B12 deficiency can have many causes including PA, malabsorption syndromes, and food cobalmin deficiency.