ARUP's Laboratory Test Directory

Vitamin B12 : 0070150

Mnemonic: B12

Ordering Recommendation: Aids in detection of vitamin B12 deficiency in individuals with macrocytic or unexplained anemia, or unexplained neurologic disease.
Methodology: Quantitative Chemiluminescent Immunoassay
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Collect: Serum separator tube or plasma separator tube. Also acceptable: Lavender (EDTA) or green (sodium or lithium heparin).

Specimen Preparation: Protect from light during collection, storage, and shipment. Allow specimen to clot completely at room temperature. Transfer 1 mL serum or plasma to an ARUP Amber Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Frozen.

Unacceptable Conditions: Hemolyzed specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 8 hours; Refrigerated: 48 hours; Frozen: 3 months
Reference Interval:
210-911 pg/mL
Note: Also refer to Methylmalonic Acid (MMA), Serum Quantitative (0099431).  Some references suggest that elevated methylmalonic acid is an early and sensitive indicator of vitamin B12 (cobalamin) deficiency.
CPT Code(s): 82607
Cross References: B12 Vitamin (Vitamin B12) , Cobalamin (Vitamin B12) , Methylcobalamin (Vitamin B12)