Vitamin B6 (Pyridoxine), Plasma

Test Code

CPT Codes

Preferred Specimen
1 mL plasma collected in an EDTA (lavender-top) tube - protected from light

Minimum Volume
0.5 mL

Draw blood into light-protected (lavender-top) evacuated tube, following an overnight fast.

If separation of cells can't be performed immediately after collection, keep the whole blood refrigerated and protected from light. The separation of cells must be completed within 6 hours. Separate cells by centrifugation at 2-8ºC (2200-2500 rpm, 800-1000 x g) for 5-10 minutes. Transfer plasma to dark brown polypropelene or polyethylene transport tubes to protect from light. Alternately, neutral color polypropylene or polyethylene tubes can be used if wrapped in aluminum foil. Freeze the tubes -10ºC to -30ºC. Ship frozen.

Transport Container
Plastic screw-cap vial protected from light

Transport Temperature

Specimen Stability

Room temperature: 6 hours
Refrigerated: 12 hours
Frozen -20°C: 6 days
Frozen -70°C: 42 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Specimens not protected from light •  Received refrigerated • Received room temperatures • Collected in tubes other than (lavender-top) tubes • Lipemia • Hemolysis • Improperly labeled tubes

Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)

Reference Range
2-17 Years 3.0-35.0 ng/mL
Adult 2.1-21.7 ng/mL

Clinical Significance
Vitamin B6 is a cofactor in many metabolic pathways including heme synthesis. Vitamin B6 deficiency may be observed in patients with metabolic disorders, secondary to therapeutic drug use, or alcoholism. Deficiency affects the function of the immune system.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

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.