Common causes of vitamin B-12 deficiency include atrophic gastritis, pernicious anemia and surgery on the stomach or intestines, according to WebMD. Other causes of vitamin B-12 deficiency include Crohn's disease, heavy drinking, long-term use of acid-reducing drugs and immune system disorders.
Patients with mild cases of vitamin B-12 deficiency may not show any symptoms, but if not taken care of, it can lead to anemia, explains WebMD. Symptoms of this condition include weakness, heart palpitations, constipation, loss of appetite and vision loss. People may also experience numbness or tingling of the skin, mental problems, or memory loss. To diagnose a vitamin B-12 deficiency, a patient must see a doctor for a blood test, and if a deficiency is detected, the doctor may suggest a treatment depending on the person's lifestyle or situation.
There are several ways to treat vitamin B-12 deficiency including injections, diet changes and supplements, claims WebMD. Those who have pernicious anemia and cannot absorb B-12 must replace the vitamin with injections, oral replacements or with nasal therapy for the rest of their lives. People who not eat animal products may have low vitamin B-12 levels. In this case, it is best to include foods that contain vitamin B-12 in the diet.