Optimal Ranges
What is the optimal range for Vitamin B6?
Clinical (NHS) Range
20-125 nmol/L
nmol/L
Performance-Optimised Range
50-125 nmol/L
nmol/L
| Range | Value | Unit |
|---|---|---|
| Clinical (NHS) reference range | 20-125 nmol/L | nmol/L |
| Performance-optimised range | 50-125 nmol/L | nmol/L |
The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best. A result in either range suggests typical status and is not a diagnosis; any individual reading should be interpreted by a qualified clinician.
Why It Matters
Why Vitamin B6 matters for performance
B6 is a cofactor in the production of key neurotransmitters — serotonin for mood, dopamine for motivation, and GABA for calm focus. Deficiency can directly impair mental performance and sleep quality. For active men, B6 supports the conversion of glycogen to glucose during exercise and is involved in steroid hormone modulation (it helps reduce excess oestrogen by supporting liver clearance). B6 also works with folate and B12 to regulate homocysteine — deficiency in any of the three raises cardiovascular risk.
Symptoms
What are the symptoms of low or high Vitamin B6?
Low / Deficiency
- Irritability and low mood
- Confusion and difficulty concentrating
- Cracked lips and sore tongue (glossitis)
- Weakened immune function
- Peripheral neuropathy (tingling in hands/feet)
High / Excess
- Nerve damage (peripheral neuropathy) with chronic high doses (>100mg/day)
- Photosensitivity
- Nausea and heartburn
Dietary Sources
Which foods support Vitamin B6 levels?
Supplementation
How do you improve Vitamin B6 levels?
Most B6 supplements use pyridoxine hydrochloride, but pyridoxal 5'-phosphate (P5P) is the active coenzyme form and may be better absorbed by those with liver impairment or genetic variants affecting conversion. Standard supplemental dose is 10-50mg daily. The UK tolerable upper limit is 200mg/day (long-term), but chronic doses above 100mg can cause reversible nerve damage. B6 is best taken as part of a B-complex rather than in isolation, as B vitamins work synergistically. Taking B6 in the morning may support daytime neurotransmitter production without disrupting sleep.
Testing
How is Vitamin B6 tested in the UK?
Vitamin B6 is measured from a blood sample. With Helvy, that means a finger-prick kit taken at home and posted to a UKAS-accredited UK laboratory, with results in around 5 days, reviewed by a qualified clinician. Your result is reported against both the clinical range (20-125 nmol/L) and the performance-optimal range (50-125 nmol/L), so you can see not just whether you are “normal” but whether you are optimal. If you make a change, retest after 8-12 weeks to confirm it worked.
Research
Key study
Vitamin B6 and its role in cell metabolism and physiology
Parra M, Stahl S, Hellmann H
Cells (2018)
DOI: 10.3390/cells7070084Related Biomarkers
Related Guides
Explore Vitamin B6 in depth
Test your Vitamin B6 levels
Vitamin B6 is included in the Helvy 50+ biomarker panel. Get your results in 5 days with a personalised protocol.
Order Your TestThis content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.