Vitamin B12

Cobalamin Test, Cyanocobalamin Test

What To Think About

• Vitamin B12 values that are slightly lower than normal (borderline) do not always mean that a person needs vitamin B12 injections. Borderline values should be evaluated with other tests.
• Folic acid levels can be high in people who lack vitamin B12. A folic acid test is often done at the same time as a vitamin B12 test. For more information, see the medical test Folic Acid.
• A Schilling test can check the body's ability to absorb vitamin B12. This test measures the amount of vitamin B12 lost in urine. For more information, see the medical test Schilling Test.
• Methylmalonic acid is a substance in the blood that increases when vitamin B12 levels decrease. A methylmalonic acid (MMA) blood test may be done to help evaluate vitamin B12 test results.
• A change in homocysteine levels may also affect a change in vitamin B12 levels because of metabolism changes. For more information, see the medical test Homocysteine.

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Author:	Jan Nissl, RN, BS	Last Updated: February 14, 2007
Medical Review:	Kathleen Romito, MD - Family Medicine Brian Leber, MDCM, FRCPC - Hematology
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