Vitamin B-12 Deficiency Anemia
What is vitamin B-12 deficiency anemia?
Vitamin B-12 deficiency anemia is a condition in which your body doesn't have enough
healthy red blood cells because of a lack of vitamin B-12. This vitamin is needed
to make red blood cells. These cells carry oxygen to all parts of your body. Without
enough red blood cells, your tissues and organs don’t get enough oxygen. Without enough
oxygen, your body can’t work as well.
Folic acid is also called folate. It is another B vitamin. Either a lack of vitamin
B-12 or a lack of folate causes a type of anemia called megaloblastic anemia (pernicious
anemia). With these types of anemia, the red blood cells don’t develop normally. They
are very large. And they are shaped like an oval. Healthy red blood cells are round.
This difference in shape causes the bone marrow to make fewer red blood cells. In
some cases, the red blood cells die sooner than normal.
What causes vitamin B-12 deficiency anemia?
Vitamin B-12 deficiency anemia is more common in people whose families come from northern
Europe. It is caused by:
Lack of intrinsic factor. Intrinsic factor is a protein made in the stomach. It is needed to absorb vitamin
B-12. This type of B-12 deficiency anemia is called pernicious anemia.
Inability to absorb vitamin B-12. Surgery that removes or bypasses the end of the small intestine may be one reason
that B-12 can't be absorbed. Other causes include changes in the small bowel that
limit how much vitamin B-12 you can absorb.
The inability to make intrinsic factor may be caused by several things, such as:
Surgery to remove all or part of the stomach (gastrectomy)
An autoimmune condition, where the body attacks its own tissues
Other types of megaloblastic anemia may be linked to type 1 diabetes, thyroid disease,
and a family history of the disease.
Who is at risk for vitamin B-12 deficiency anemia?
Risk factors for vitamin B-12 deficiency anemia include:
A family history of the disease
Surgery that removes part or all of your stomach or intestine
Autoimmune diseases, including type 1 diabetes
Strict vegetarian diets
What are the symptoms of vitamin B-12 deficiency anemia?
Each person’s symptoms may vary. Symptoms may include:
The symptoms of vitamin B-12 anemia may look like other blood conditions or health
problems. Always see your healthcare provider for a diagnosis.
How is vitamin B-12 deficiency anemia diagnosed?
This type of anemia is usually found during a health exam through a routine blood
test. Your healthcare provider will take your health history and give you a physical
You may also need other blood tests. You may also have other assessment procedures,
such as a bone marrow biopsy.
How is vitamin B-12 deficiency anemia treated?
Vitamin B-12 deficiency anemia and folate deficiency anemia often occur together and
can be hard to tell apart. Treatment may include vitamin B-12 shots (injections) or
folic acid pills.
Foods that are rich in folic acid include:
Foods that are rich in both folic acid and vitamin B-12 include:
Taking folic acid by mouth works better than eating foods rich in folic acid. Vitamin
B-12 is not as well absorbed by mouth as by injection.
Living with vitamin B-12 deficiency anemia
Depending on the cause of your vitamin B-12 deficiency, you may need to take vitamin
B-12 supplements for the rest of your life. These may be pills or shots. This may
seem difficult. But it will let you live a normal life without symptoms.
If your deficiency is from a restrictive diet, you may want to work with a nutritionist.
He or she can help ensure that you get enough vitamin B-12 and other vitamins. Tell
your healthcare provider about any symptoms and follow your treatment plan.
Key points about vitamin B-12 deficiency anemia
With this condition, your body does not have enough healthy red blood cells because
of a lack (deficiency) of vitamin B.
It is 1 of several types of megaloblastic anemia. This condition is when the red blood
cells don't develop normally. They become very large and oval shaped.
Without enough red blood cells, your tissues and organs don’t get enough oxygen. Without
enough oxygen, your body can’t work as well.
Symptoms include weak muscles, numbness, trouble walking, nausea, weight loss, irritability,
fatigue, and increased heart rate.
Treatment may include vitamin B-12 supplements. It is also important to eat a well-balanced
Tips to help you get the most from a visit to your healthcare provider:
Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your provider tells
At the visit, write down the name of a new diagnosis and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you.
Know why a new medicine or treatment is prescribed and how it will help you. Also
know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you do not take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that
Know how you can contact your provider if you have questions.