Vit B6
A vitamin involved in neurotransmitter and amino-acid metabolism.
What is it
Pyridoxal-5-phosphate (P5P) is the active form of vitamin B6. It serves as a cofactor in dozens of enzymatic reactions including neurotransmitter synthesis.
Why it's measured
B6 deficiency has been associated with neurologic symptoms and elevated homocysteine in research literature.
Reference range
Standard laboratory reference
5 – 50 ng/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Very high values can be associated with neuropathy in research literature, typically from high-dose supplementation.
Lower
Has been associated with neurologic symptoms in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Used in evaluating elevated homocysteine and neurologic symptoms.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.