manifestation of pernicious anemia is caused by what
Pernicious anemia is one form of anemia, an abnormal condition in which there is a decrease in the number of red blood cells in the blood. Pernicious anemia is caused by a lack of vitamin B12, which is vital to the normal develoment of red blood cells. Pernicious anemia is also called vitamin B12 deficiency anemia, and is the most common form of a variety of types of vitamin deficiency anemias. Pernicious anemia can be serious, even life-threatening, if untreated. Vitamin B12 is crucial to the process of producing red blood cells in the body.