Test Detail
Understanding the Test
Test Measures
Interpreting Results
FAQ's
Other Tests
Content created by
Written by
Dr. Betina Chandolia
BDS, MDS - Oral Pathology and Microbiology
Reviewed by
Dr. Ashish Ranjan
MBBS, MD (Pharmacology)
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Vitamin B12

Also known as Cyanocobalamin, Methylcobalamin
Vitamin B12 Includes 2 testsView All
You need to provide
Blood 2
This test is for
Male, Female
Test Preparation
  1. No special preparation required

Understanding Vitamin B12


What is Vitamin B12?

Vitamin B12 test measures the levels of Vitamin B12 in blood. Vitamin B12 is needed for brain health, blood cell production, and proper nerve functioning. People who are obese or eat a lot of meat also tend to have higher-than-normal levels of this vitamin and are more prone to liver disease and diabetes.

 For people with high levels of B-12, treatment involves adjusting diet by eating fewer animal products, while for people with low levels, the treatment includes use of Vitamin B12 injection and supplements.

What is Vitamin B12 used for?

The Vitamin B12 test is performed:
 
  • To diagnose anemia

  • To diagnose neuropathy (numbness and pain due to nerve damage)

  • To evaluate nutritional status

  • To monitor the treatment for Vitamin B12

 

What does Vitamin B12 measure?

Contains 2 tests

Vitamin B12 is a part of B complex of vitamins. Vitamin B12 is also called as Cobalamin. It is a water soluble vitamin. Vitamin B12 plays an important role in formation of normal red blood cells, repair of tissues, DNA synthesis and genetic material in cells. It is not produced in the body and has to be taken in diet. The diet sources include red meat, fish, milk, poultry, yoghurt, eggs, fortified cereals, breads and other grain products. It can also be taken in the form of Vitamin B12 tablets or multivitamin pills. The deficiency of Vitamin B12 results in macrocytic anemia (size of red blood cells larger than normal).

Megaloblastic anemia is a type of macrocytic anemia, in which large size red blood cells called as macrocytes are produced. These red blood cells are fewer in number. There is a decrease in white blood cell count and platelet count. Megaloblastic anemia occurs due to acquired deficiency of Vitamin B12. The reason can be an inadequate dietary intake of Vitamin B12 or any problem in the absorption of Vitamin B12 from the intestines.

In case of problem in the absorption of Vitamin B12 from intestines, it is known as Pernicious anemia. It occurs due to lack of intrinsic factor which is present in secretions of the stomach.

Vitamin B12 is also important for nerve health and is taken as a nutritional supplement for the treatment of nerve damage.

Vitamin B12 binds with intrinsic factor (protein secreted by cells in the stomach). After binding, a complex is formed which is absorbed by the small intestine. In case of any disease interfering in this process can cause weakening of absorption of Vitamin B12.   

Bacteria

Interpreting Vitamin B12 results


Interpretations

The normal range is 211 - 911 pg/mL irrespective of sex and age.

High levels of Vitamin B12 may be seen in:

  • Kidney failure

  • Diabetes

  • Liver disease

 

Low levels of Vitamin B12 may be seen in:

  • Anemia

  • Hyperthyroidism (high levels of thyroid)

  • Worm infection

Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Vitamin B12


Frequently Asked Questions about Vitamin B12

Q. What are the risks associated with deficiency of Vitamin B12?

If deficiency of Vitamin B12 is not treated quickly, it can lead to memory loss, confusional states, paranoia (mental condition in which person loses touch with reality) especially in old age patients.

Q. What are the signs and symptoms of Vitamin B12 deficiency?

The signs and symptoms of Vitamin B12 deficiency include delirium (confusional states), paranoia (an unrealistic distrust of others), dizziness, diarrhea, muscle weakness, loss of appetite, and pale skin. Some may also experience fast heart rate, irregular heart beat, shortness of breath, painful tongue and mouth, tingling or numbness or burning sensation in feet, hands, arms, and legs.

Q. Is there any risk associated with this test?

There is no risk associated with the test. However, since this test involves a needle prick to withdraw the blood sample, in very rare cases, a patient may experience increased bleeding, hematoma formation (blood collection under the skin), bruising or infection at the site of needle prick.

Q. In what conditions there can be malabsorption of Vitamin B12 test?

Conditions like pernicious anemia (decrease in red blood cells due to deficiency of Vitamin B12), celiac disease (immune reaction to gluten), inflammatory bowel diseases (inflammation of digestive tract), and gastric bypass (surgery that removes part of the stomach) can cause malabsorption of vitamin B12 test. However, other conditions can also cause malabsorption such as overgrowth of bacteria or presence of parasites such as tapeworms in the intestines, reduction in stomach acid production (due to long-term use of antacids), and insufficiency of pancreas (inability to digest food properly).

Q. When does the doctor advise Vitamin B12 test?

The doctor advises Vitamin B12 test in people with a history of malnutrition or any condition leading to malabsorption (improper absorption).

Q. Can any medicine cause deficiency of Vitamin B12?

Yes, some medicines such as metformin, omeprazole, methotrexate or phenytoin can cause deficiency of Vitamin B12.

Q. Are there any other factors which cause deficiency of Vitamin B12?

Yes, factors such as smoking, drinking heavy alcohol or chronic (from a long time) alcoholism, pregnancy can cause deficiency of Vitamin B12.
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