Vitamin B12 : 1004502

Test Code
VIB12 or 1004502

Alias/See Also
B(12); B12 Deficiency; CblC; Cobalamin; Cyanocobalamin; VB12

CPT Codes

Serum separator tube), green top plasma separator tube (lithium heparin), or plain red top tube.

Transport Container
Centrifuge the serum separator tube or plasma separator tube and transport; if a plain red top tube, centrifuge and aliquot serum (Min. 0.4 mL) into a standard transport tube.

Transport Temperature

Specimen Stability
After separation from cells: Ambient: 3 days; Refrigerated: 7 days: Frozen: 3 months, up to 3 freeze/thaw cycles acceptable

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


Setup Schedule
Sunday - Saturday

Report Available
1 day

Reference Range
211-911 pg/mL

Clinical Significance
This assay is used for quantitative determination of Vitamin B12 in human serum and plasma. Vitamin B12 (B12) is a cofactor for the conversion of methylmalonyl Coenzyme-A (CoA) to succinoyl CoA and also serves as a cofactor in the synthesis of methionine from Homocysteine. B12 is implicated in the formation of myelin, and, along with folate, is required for DNA synthesis.

Various conditions associated with low serum B12 levels include iron deficiency, normal near-term pregnancy, vegetarianism, partial gastrectomy/ileal damage, celiac disease, use of oral contraception, parasitic competition, pancreatic deficiency, treated epilepsy, and advancing age. Elevated serum B12 levels are observed in patients with renal failure, liver disease, and myeloproliferative diseases.

A serum B12 level below the expected range may indicate that tissue B12 levels are becoming depleted. However, a B12 level in the low normal range does not ensure that B12 levels are adequate and symptomatic patients should be further evaluated with tests for holotranscobalamin, homocysteine and methylmalonic acid. B12 levels above 300 or 400 pg/mL are rarely associated with B12 deficiency induced hematological or neurological disease, respectively. Further testing is recommended for symptomatic patients with B12 levels between 100 and 300 pg/mL (hematological abnormalities), and between 100 and 400 pg/mL (neurological abnormalities).

Performing Laboratory
med fusion

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.