Why get tested?
To help detect early and/or mild vitamin B12 deficiency, especially at the tissue level; to help diagnose methylmalonic acidemia, a rare inherited metabolic disorder

When to get tested?
If you have a vitamin B12 concentration in the low end of the normal range and/or have symptoms of neuropathy, such as numbness and tingling in the hands and feet

Sample required?
A blood sample drawn from a vein in your arm or a random or 24-hour urine sample

Note: You may be instructed to fast before sample collection for this test.