Vitamin B12 deficiency
About Vitamin B12 deficiency
Vitamin B12 deficiency is a decreased amount of vitamin B12 in the body. Vitamin B12 is essential for the normal production of red blood cells and for the normal functioning of nerves. Vitamin B12 can be obtained only from animal products (meat and dairy) or yeast (brewer's yeast). People with this deficiency have a decreased number of red blood cells (anemia). The deficiency can occur for a number of reasons. Some individuals lack something called intrinsic factor. Intrinsic factor is a protein produced from the lining of the stomach and helps with the absorption of vitamin B12. Some individuals are born with a decreased amount of the factor. Others lose the ability to produce the factor as a result of certain diseases (Graves disease, hypothyroidism, vitiligo, addison's disease) or surgical removal of the stomach. Other individuals lack vitamin B12 because of an overgrowth of bacteria that steals the vitamin B12 for it's own use (scleroderma, diabetes, diverticula). Finally, some individuals lack enough vitamin B12 in their diet (vegans, bulemia, anorexia nervosa).Symptoms
Symptoms may include weakness, fatigue, a rapid heart rate, nausea, shortness of breath or poor appetite. If the vitamin deficiency goes on for a long time, symptoms may include numbness in the arms or legs, difficulty walking, confusion, memory loss and depression.Tests & Diagnostics
A history and physical exam will be performed. Blood tests will be performed to make the diagnosis. In some cases, a bone marrow biopsy may be recommended.Common tests: Complete blood count (CBC), Comprehensive metabolic panel (CMP).
Prescription medications
Conventional treatment summary
Treatment is directed at replacing vitamin B12. Injections or pills as well as dietary changes may be recommended. If the cause of the vitamin B12 deficiency is related to bacterial overgrowth in the intestines, the doctor may recommend antibiotic treatment such as tetracycline. If anemia is severe a blood transfusion may be required.Medical specialties
Internal Medicine · Pediatrics · Family Practice · Hematology and Oncology
This page is educational content, not medical advice. Always consult a qualified clinician for diagnosis and treatment of Vitamin B12 deficiency.