Patient Information Resource:
Benign Hematologic (Blood) DisordersA collaborative project of the Arizona Telemedicine Program, the Arizona Health Sciences Library and the Arizona Cancer Center.
See: GENERAL DISCLAIMER
Vitamin B12 Deficiency: Pernicious Anemia
Vitamin B12 is essential for the bone marrow’s production of blood cells. Among these cells are the red blood cells (RBCs) which are responsible for delivering oxygen to the tissues. Therefore vitamin B12 deficiency results in anemia, an RBC deficiency limiting the amount of oxygen in the tissues.
Vitamin B12 deficiency is usually caused by pernicious anemia, a condition in which the digestive system is altered and cannot absorb vitamin B12. This damage can occur as a result of gastrointestinal surgery, inherited disease, autoimmune disorders (such as Graves’ disease, systemic lupus erythematosus, myxedema), or drug action. Among the drugs that may inhibit absorption are histamine blockers, such as cimetidine (Tagamet) and ranitidine (Zantac).
Multiple symptoms result from malabsorption of vitamin B12. Anemia, mentioned above, is associated with weakness, pallor, elevated heart rate, and elevated breathing rate (see Anemia). In addition, the patient may be especially prone to infection and may bruise or bleed easily (see Neutropenia and Thrombocytopenia). Other symptoms include sore tongue, numbness, and tingling.
Vitamin B12 deficiency is diagnosed with the help of the patient history and physical examination for symptoms. In addition, laboratory tests are often performed. Treatment includes iron replacement for life and administration of vitamin B12 injections.
GENERAL DISCLAIMER: This web site and its contents are designed for educational purposes only. This web site does not render medical advice or professional services. The information provided should not be used for diagnosing or treating a health problem or disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, you should consult your health care provider.
Updated: October 30, 2000