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Test Code B6PA Pyridoxic Acid, Plasma

Reporting Name

Pyridoxic Acid (PA), P

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Determining the concentration of pyridoxic acid in the assessment of vitamin B6 status

Method Name

Only orderable as part of a profile. For more information see B6PRO / Vitamin B6 Profile (Pyridoxal 5-Phosphate and Pyridoxic Acid), Plasma.

 

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


Shipping 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. Patient should fast overnight (12-14 hours); 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. Centrifuge at 4° C within 2 hours of collection.

2. Aliquot all plasma into amber vial and freeze immediately.


Specimen Type

Plasma Heparin

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Heparin Frozen 29 days LIGHT PROTECTED

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

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

Interpretation

Levels for fasting individuals falling in the range of 3 to 30 mcg/L for pyridoxic acid (PA) and 5 to 50 mcg/L for pyridoxal 5-phosphate (PLP) are indicative of adequate nutrition.

 

PA results are not clinically significant by themselves and must be interpreted in conjugation with PLP concentrations. The following are interpretative guidelines based on PLP and PA results:

If PLP is >100 mcg/L and PA is ≤30 mcg/L:

-The increased PLP is suggestive of hypophosphatasia. Consider analysis of serum alkaline phosphatase isoenzymes (ALKI / Alkaline Phosphatase, Total and Isoenzymes, Serum) and urinary phosphoethanolamine (AAPD / Amino Acids, Quantitative, Random, Urine).

 

If PLP is >100 mcg/L and PA is 31 to 100 mcg/L or PLP is 81 to 100 mcg/L and PA is ≤30 mcg/L:

-The increased PLP is likely related to dietary supplementation; however, a mild expression of hypophosphatasia cannot be excluded. Consider analysis of serum alkaline phosphatase isoenzymes (ALKI / Alkaline Phosphatase, Total and Isoenzymes, Serum) and urinary phosphoethanolamine (AAPD / Amino Acids, Quantitative, Random, Urine).

 

If PLP is 51 to 80 mcg/L or PLP is 81 to 100 mcg/L and PA is >30 mcg/L or PLP is >100 mcg/L and PA is >100 mcg/L:

-The elevated PLP is likely due to dietary supplementation.

Day(s) Performed

Monday through Thursday, Saturday, Sunday

Report Available

3 to 7 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

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