Vitamin B12

Test Code
B12(SEND OUT) (927)

Quest Code

CPT Codes

Preferred Specimen
1 mL serum

Minimum Volume
0.5 mL

Minimize exposure to light during sample handling and storage

Please note: Although the reference range for vitamin B12 is 200-1100 pg/mL, it has been reported that between 5 and 10% of patients with values between 200 and 400 pg/mL may experience neuropsychiatric and hematologic abnormalities due to occult B12 deficiency; less than 1% of patients with values above 400 pg/mL will have symptoms.

Transport Temperature
Refrigerated (cold packs)
(Room temperature is acceptable if not ordered with Folate)

Specimen Stability
Room temperature: 7 days
Rrefrigerated: 7 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)


Immunoassay (IA)

Setup Schedule

Report Available
1 to 3 Day(s)

Reference Range
≤4 Years Not established
5-9 Years 250-1205 pg/mL
10-17 Years 260-935 pg/mL
>17 Years 200-1100 pg/mL

Clinical Significance
B12 is decreased in pernicious anemia, total or partial gastrectomy, malabsorption and certain congenital and biochemical disorders.

Performing Laboratory
Quest Diagnostics Nichols Institute
27027 Tourney Road
Valencia, CA 91355-5386

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.