Does pernicious anemia cause high serum b12?

Low vitamin B12.: pernicious anemia is a LOW vitamin B12 state. This occurs when the body fails to make enough of a specific protein to enable the body to absorb vitamin B12. This usually occurs when the immune system attacks a specific cell in the stomach that produces the needed protein. Since the body can't absorb vitamin B12 through the stomach it can be given in a shot and even under the tongue.