Vitamin B12 & Folate (Folic Acid) Test

Vitamin B12 and folate (Vitamin B9) are two vitamins that are part of the B complex of vitamins. B12 and folate work with vitamin C to help the body make new proteins. They are necessary for normal red blood cell (RBC) and white blood cell (WBC) formation, repair of tissues and cells, and synthesis of DNA. Both are nutrients that cannot be produced in the body and must be supplied by the diet.

A deficiency in either B12 or folate can lead to macrocytic anemia, where red blood cells are larger than normal. Megaloblastic anemia, a type of macrocytic anemia, is characterized by the production of fewer but larger RBCs called macrocytes, in addition to some cellular changes in the bone marrow. B12 is also important for nerve health and a deficiency can lead to varying degrees of neuropathy, nerve damage that can cause tingling and numbness in the affected person's hands and feet. Folate is necessary for cell division such as is seen in a developing fetus. Folate deficiency during early pregnancy can increase the risk of neural tube defects such as spina bifida in a growing fetus.

Both are nutrients that cannot be produced in the body and must be supplied by the diet. Vitamin B12, also called cobalamin, is found in foods from animals, such as red meat, fish, poultry, milk, yogurt, and eggs. Folate (Vitamin B9) refers to a natural occurring form of the vitamin, whereas folic acid refers to the supplement added to foods and drinks. Folate is found in leafy green vegetables, citrus fruits, dry beans and peas, liver, and yeast.