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HelpTest Code VITB12 Vitamin B12, LAB67
Performing Laboratory
St. Luke's Hospital Cedar Rapids
Specimen Requirements
Specimen must be drawn prior to any blood transfusions.
Container/Tube:
Preferred: Green-top (lithium heparin) tube Hemolyzed specimen is not acceptable.
Acceptable: Gold-top serum gel tube, plain red-top tube, or lavender-top (EDTA) plasma
Minimum Specimen Volume: 9 µL plus a dead volume
Stability: Stable for 2 hours at 15‑25 °C, 48 hours at 2‑8 °C, 56 days at ‑20 °C (± 5 °C). Freeze only once. Stability of serum obtained with separating tubes: 24 hours at 2-8 °C.
Note: 1. This assay is affected by biotin interference.
Reference Values
232-1245 pg/mL
Day(s) Test Set Up
Monday through Friday
Useful For
Early diagnosis of B12 deficiency is crucial because of the latent nature of this disorder and the risk of irreversible neurological damage. Recent studies suggest that in addition to serum B12 levels, folic acid, methylmalonic acid and homocysteine should be measured to improve the specificity of the diagnosis.
Elevated B12 levels are seen in hematological disorders (chronic myelogenous leukemia, promyelocytic leukemia, polycythemia vera) and in liver disorders (acute hepatitis, cirrhosis, hepatocellular carcinoma).
Methodology
Chemiluminescence/Competitive Binding Immunoenzymatic Assay
Test Classification and CPT Coding
82607
Report Available
STAT within 1 hour of receipt. Routine within 2 hours of receipt.