BAsic information description An anemia that prevents the body from absorbing enough vitamin B12 from the digestive tract. Vitamin B12 (also called cobalamin) is needed for making red blood cells and keeping the nervous system functioning. This type of anemia usually affects adults of both sexes, between ages 40 and 70. frequent signs and symptoms Symptoms develop slowly. It may take time to notice. Weakness, especially in the arms and legs. Sore tongue. Nausea, appetite loss, and...