Procedure & Preparation of Vitamin B12 Deficiency Tests

Submitted on March 27, 2012

Vitamin B12 and folate are forms of vitamin B complex that are essential for the formation of new red blood cells, DNA synthesis, and tissue and cell repair. Any person suffering from either a Vitamin B12 or folate deficiency highlights an acute shortage of these essential vitamins. That is because the body stores over three to five years worth of Vitamin B12 and more than a few months supply of folate, in the liver. Unfortunately, these deficiencies are not immediately manifest in adults as they are in infants and very young children. Vitamin B12 or folate deficiencies can lead to a number of problems such as macrocytic anemia and neuropathy.

Vitamin B12 Deficiency Tests

A doctor may prescribe one of the following blood tests for Vitamin b12 deficiency. One blood test for Vitamin b12 deficiency is the complete blood count or CBC, which provides useful information about the types of cells in the blood and also notes the number of cells. A low red blood cell count points to the possibility that the person suffers from anemia. Anemia caused by a deficiency of Vitamin B12 causes the red blood cells to become larger than their normal size, this condition is called macrocytic anemia or megaloblastic anemia. Another test is the Vitamin B12 test. This test measures the level of Vitamin B12 in the blood. Folic acid is a type of Vitamin B; a deficiency in folic acid causes symptoms that are similar to a Vitamin B12 deficiency. The folic acid test is another test for Vitamin B12 deficiency; it measures the amount of folic acid in the blood.


The health care provider will wrap your upper arm with an elastic band to stop the blood flow. Then using a sterilized needle attached to a tube, the health care provider will pierce the vein below the bandage and draw out a small amount of blood. He or she will then remove the bandage to allow the blood to flow again and then apply a cotton ball over the punctured area and remove the needle. A small bandage may be placed over the puncture wound.


For the folic acid test the patient will have to fast for 8 to 10 hours before the test. He or she may drink a little water if required. Remember to inform your doctor of all your medications and dosages. Other than that no special preparation is required for the folic acid test.