Problem: What can i say to respond to this posting? Pernicious anemia is a type of megaloblastic anemia, meaning abnormally large red blood cells (RBCs), that is believed to be an autoimmune disorder that causes a deficiency in vitamin B12 due to the body's inability to absorb it from the digestive tract (Norris, p. 579, 2019). This occurs when the immune system attacks parietal cells in the stomach, damaging the mucosal lining and producing intrinsic factor antibodies, preventing the production or function of intrinsic factor, a protein necessary for B12 absorption (Means & Fairfield, 2024a). Vitamin B12 is important for RBC production because "It is essential for DNA synthesis and nuclear maturation, which, in turn, lead to normal red cell maturation and division. Vitamin B12 is also involved in a reaction that prevents abnormal fatty acids from being incorporated into neuronal lipids. This abnormality may predispose to myelin breakdown and produce some of the neurologic complications of vitamin B12 deficiency" Need Professional Help?