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HelpTest Code B6PA Pyridoxic Acid, Plasma
Reporting Name
Pyridoxic Acid (PA), PSpecimen Type
Plasma HeparinShipping Instructions
Ship specimen in amber vial to protect from light.
Specimen Required
Only orderable as part of a profile. For more information see B6PRO / Vitamin B6 Profile (Pyridoxal 5-Phosphate and Pyridoxic Acid), Plasma.
Patient Preparation:
1. Fasting: 12 hours, required; Infants-should have specimen collected before next feeding, water can be taken as needed
2. For 24 hours before specimen collection, patient must not take multivitamins or vitamin supplements.
Supplies: Amber Frosted Tube, 5 mL (T915)
Collection Container/Tube: Green top (sodium or lithium heparin) or plasma gel separator (PST)
Submission Container/Tube: Amber vial
Specimen Volume: 1 mL
Collection Instructions:
1. Within 2 hours of collection, centrifuge at 4° C.
2. Aliquot all plasma into amber vial and freeze immediately.
Specimen Minimum Volume
Plasma: 0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Heparin | Frozen | 29 days | LIGHT PROTECTED |
Reference Values
Only orderable as part of a profile. For more information see B6PRO / Vitamin B6 Profile (Pyridoxal 5-Phosphate and Pyridoxic Acid), Plasma.
3-30 mcg/L
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| B6PA | Pyridoxic Acid (PA), P | 1688-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 61065 | Pyridoxic Acid (PA), P | 1688-1 |
Useful For
Determining vitamin B6 status, including in individuals who present with progressive nerve compression disorders, such as carpal tunnel and tarsal tunnel syndromes
Determining the overall success of a vitamin B6 supplementation program
Diagnosis and evaluation of hypophosphatasia
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Description
The stable isotope pyridoxal 5-phosphate-d3 and/or pyridoxic acid-d3 is added to plasma as an internal standard. Meta-phosphoric acid solution is then added to precipitate the proteins. Following sedimentation of the proteins, an aliquot of the clarified supernatant fluid is subjected to separation of pyridoxal 5-phosphate, pyridoxic acid, and internal standards from other plasma components by reverse-phase high-performance liquid chromatography with quantitation by tandem mass spectrometry.(Maus A, Girtman A, Kiesling J, Faber J, Grebe SKG. Overcoming the chromatographic challenges when performing LC-MS/MS measurements of pyridoxal-5'-phosphate. J Chromatogr B Analyt Technol Biomed Life Sci. 2023;1217:123605 doi:10.1016/j.jchromb.2023.123605)
Day(s) Performed
Monday through Thursday, Saturday, Sunday