Vitamin B12 Deficiency

Not having enough vitamin B12 is called a deficiency. Vitamin B12 is an important vitamin. Your body needs vitamin B12 to:

  • Make red blood cells.

  • Make DNA. This is the genetic material inside all of your cells.

  • Help your nerves work properly so they can carry messages from your brain to your body.


  • Not eating enough foods that contain vitamin B12.

  • Not having enough stomach acid and digestive juices. The body needs these to absorb vitamin B12 from the food you eat.

  • Having certain digestive system diseases that make it hard to absorb vitamin B12. These diseases include Crohn's disease, chronic pancreatitis, and cystic fibrosis.

  • Having pernicious anemia, which is a condition where the body has too few red blood cells. People with this condition do not make enough of a protein called "intrinsic factor," which is needed to absorb vitamin B12.

  • Having a surgery in which part of the stomach or small intestine is removed.

  • Taking certain medicines that make it hard for the body to absorb vitamin B12. These medicines include:

  • Heartburn medicine (antacids and proton pump inhibitors).

  • A certain antibiotic medicine called neomycin, which fights infection.

  • Some medicines used to treat diabetes, tuberculosis, gout, and high cholesterol.


Risk factors are things that make you more likely to develop a vitamin B12 deficiency. They include:

  • Being older than 50.

  • Being a vegetarian.

  • Being pregnant and a vegetarian or having a poor diet.

  • Taking certain drugs.

  • Being an alcoholic.


You may have a vitamin B12 deficiency with no symptoms. However, a vitamin B12 deficiency can cause health problems like anemia and nerve damage. These health problems can lead to many possible symptoms, including:

  • Weakness.

  • Fatigue.

  • Loss of appetite.

  • Weight loss.

  • Numbness or tingling in your hands and feet.

  • Redness and burning of the tongue.

  • Confusion or memory problems.

  • Depression.

  • Dizziness.

  • Sensory problems, such as loss of taste, color blindness, and ringing in the ears.

  • Diarrhea or constipation.

  • Trouble walking.


Various types of tests can be given to help find the cause of your vitamin B12 deficiency. These tests include:

  • A complete blood count (CBC). This test gives your caregiver an overall picture of what makes up your blood.

  • A blood test to measure your B12 level.

  • A blood test to measure intrinsic factor.

  • An endoscopy. This procedure uses a thin tube with a camera on the end to look into your stomach or intestines.


Treatment for vitamin B12 deficiency depends on what is causing it. Common options include:

  • Changing your eating and drinking habits, such as:

  • Eating more foods that contain vitamin B12.

  • Not drinking as much alcohol or any alcohol.

  • Taking vitamin B12 supplements. Your caregiver will tell you what dose is best for you.

  • Getting vitamin B12 injections. Some people get these a few times a week. Others get them once a month.


  • Take all supplements as directed by your caregiver. Follow the directions carefully.

  • Get any injections your caregiver prescribes. Do not miss your appointments.

  • Eat lots of healthy foods that contain vitamin B12. Ask your caregiver if you should work with a nutritionist. Good things to include in your diet are:

  • Meat.

  • Poultry.

  • Fish.

  • Eggs.

  • Fortified cereal and dairy products. This means vitamin B12 has been added to the food. Check the label on the package to be sure.

  • Do not abuse alcohol.

  • Keep all follow-up appointments. Your caregiver will need to perform blood tests to make sure your vitamin B12 deficiency is going away.


  • You have any questions about your treatment.

  • Your symptoms come back.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.