Vitamin B12 Deficiency: Care Instructions

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A vitamin B12 deficiency means that your body doesn't have enough of this vitamin. You need vitamin B12 to keep red blood cells and nerve cells healthy. Not enough B12 can cause anemia. It can also damage nerves and cause trouble with memory and thinking.

Many things can cause low levels of vitamin B12. They include:

  • Not getting enough of this vitamin through food.
  • An autoimmune problem, like pernicious anemia.
  • Weight-loss surgery, like gastric bypass.
  • Long-term use of heartburn medicines.

Low levels of B12 may not cause symptoms. But symptoms may include fatigue, depression, and thinking or memory problems. You may have tingling in your hands or feet and changes in the way you walk.

Treatment depends on the reason for low vitamin B12. Eating more foods rich in B12 may be enough. Or you might take the vitamin as a pill, as shots, or as nasal spray.

How can you care for yourself?

  • Take vitamin B12 as your doctor recommends.
  • Go to your appointments if you are getting B12 shots.
  • Eat more foods rich in vitamin B12. Examples are:
    • Animal products. These include meat, seafood, milk products, poultry, and eggs.
    • Foods that have B12 added. These are called fortified foods. They include soy products, nutritional yeast, and dry cereals.
  • Work with a nutritionist or dietitian if you need help getting more vitamin B12 from food.
  • Talk to your doctor about stopping medicines if they are adding to your B12 deficiency.

When should you call for help?

Call 911 anytime you think you may need emergency care. For example, call if:

  • You passed out (lost consciousness).

Call your doctor now or seek immediate medical care if:

  • You are dizzy or lightheaded, or you feel like you may faint.

Watch closely for changes in your health. Be sure to call your doctor if:

  • You are confused or can't think clearly.
  • You don't get better as expected.

Where can you learn more?

Go to

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.