Normal values are 200 - 900 pg/mL (picograms per milliliter).
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about what your specific test results mean.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
Values of less than 200 pg/mL are a sign of a vitamin B12 deficiency. People with this deficiency are likely to have or develop symptoms. Older adults with vitamin B12 levels between 200 and 500 pg/mL may also have symptoms.
Causes of vitamin B12 deficiency include:
Increased vitamin B12 levels are uncommon. Usually excess vitamin B12 is removed in the urine.
Conditions that can increase B12 levels include:
Mason JB. Vitamins, Trace Minerals, and Other Micronutrients. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 237.
Kumar N. Neurologic presentations of nutritional deficiencies. Neurol Clin. 2010 Feb;28(1):107-70.
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