Symptoms of vitamin B-12 deficiency include diarrhea, constipation, lack of appetite, pale skin or heart palpitations, according to WebMD. Fatigue, weakness, a smooth tongue and vision problems also indicate vitamin B-12 deficiency.
Mental issues, such as memory loss or depression, and nerve problems, such as numbness or a tingling sensation, are other possible symptoms of vitamin B-12 deficiency, states WebMD. Individuals with a mild deficiency typically do not experience symptoms, whereas an untreated vitamin B-12 deficiency may cause symptoms and lead to anemia.
To treat the deficiency, doctors usually recommend vitamin B-12 injections in patients with absorption difficulty or pernicious anemia, states WebMD. Long-term nasal therapy or high doses of an oral vitamin are also possible treatment options. People who refuse to consume animal products may opt for grains fortified with vitamin B-12, high doses of an oral vitamin or injections. For older people, doctors advise taking a multivitamin containing B-12 or a B-12 supplement every day.
To prevent vitamin B-12 deficiency, it helps to eat sufficient amounts of eggs, dairy products, poultry, seafood and meat, suggests WebMD. Consuming B-12 supplements or foods rich in B-12 is essential, because the body cannot produce the vitamin. It is important to consult a doctor when taking a vitamin B-12 supplement to ensure the supplement does not affect any medications a person is currently taking.