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Vitamin B12 Deficiency


Vitamin B12 deficiency is a low level of vitamin B12 in your body. Vitamin B12 is only found in foods that come from animal sources such as fish, beef, dairy products, and eggs. Vitamin B12 deficiency should be treated as early as possible. Without treatment, it can cause permanent nerve damage over time.


Call your doctor or dietitian if:

  • You continue to have symptoms, or your symptoms get worse.
  • You have questions or concerns about your condition or care.


  • Vitamin B12 supplements may be needed to increase your levels back to normal.
  • Take your medicine as directed. Contact your healthcare provider if you think your medicine is not helping or if you have side effects. Tell him or her if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

Good sources of vitamin B12:

Sources of Vitamin B
  • 3 ounces of cooked clams, 84.1 mcg
  • 3 ounces of cooked beef liver, 70.7 mcg
  • Fortified breakfast cereals, 1.5 to 6 mcg per serving
  • 3 ounces of salmon, rainbow trout, or canned tuna fish, 2.5 to 4.8 mcg
  • 3 ounces of top sirloin beef, 1.4 mcg
  • 1 cup of milk or yogurt, 1.1 to 1.2 mcg
  • 1 cup of a soy milk product, 0.9 to 3.3 mcg
  • 1 ounce of a meat substitute, 0.5 to 1.2 mcg
  • 1 ounce Swiss cheese, 0.9 mcg
  • 1 large egg, 0.6 mcg

Amount of vitamin B12 you need each day:

  • Infants 0 to 12 months: 0.4 micrograms (mcg) to 0.5 mcg
  • Children 1 to 3 years: 0.9 mcg
  • Children 4 to 8 years: 1.2 mcg
  • Children 9 to 13 years: 1.8 mcg
  • Children over 14 years and adults: 1.8 mcg
  • Pregnant women and adolescents (over 14 years): 2.6 mcg
  • Breastfeeding women and adolescents (over 14 years): 2.8 mcg

Follow up with your doctor or dietitian as directed:

Write down your questions so you remember to ask them during your visits.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Learn more about Vitamin B12 Deficiency (Aftercare Instructions)

Associated drugs

IBM Watson Micromedex

Symptoms and treatments

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.