Helvy
Liver & Bone
In the UK, the standard clinical (NHS) reference range for Alkaline Phosphatase (ALP) is 30-130 U/L, with 40-90 U/L considered the performance-optimised range. A result within these ranges suggests typical status; only a qualified clinician can interpret an individual reading.
Alkaline phosphatase is an enzyme present throughout the body but concentrated in liver, bone, intestine, and placenta. Total serum ALP reflects the combined activity of these isoenzymes — most often dominated by the liver and bone forms in adults. It is the second biomarker in the Levine PhenoAge composite, where steadily rising values track biological ageing.
Optimal range · UK
40-90 U/L
Performance-optimised band · clinical (NHS) range 30-130 U/L
Reference ranges for ALP, not a personal result. Any individual reading should be interpreted by a qualified clinician.
Optimal ranges
| Range | Value |
|---|---|
| Clinical (NHS) reference range | 30-130 U/L |
| Performance-optimised range | 40-90 U/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
Elevated ALP is the earliest blood signal of cholestatic liver problems (where bile flow is blocked) and is also a sensitive marker of bone turnover — useful in osteopenia, fracture risk, and vitamin D deficiency contexts. Low ALP is less common but can flag zinc or magnesium deficiency, hypothyroidism, or rare metabolic conditions. For longevity scoring, a stable ALP in the lower-middle of the reference range correlates with slower biological ageing.
Symptoms
Low / Deficiency
High / Excess
Dietary sources
Supplementation
If ALP is suboptimal-low, investigate zinc, magnesium, and B6 status first — these are the enzymatic cofactors. If ALP is rising, the next step is fractionation (bone vs liver) and a vitamin D check, not a supplement. ALP is read alongside GGT (liver) and calcium (bone) to localise the source.
Testing
ALP 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 (30-130 U/L) and the performance-optimal range (40-90 U/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
An epigenetic biomarker of aging for lifespan and healthspan
Levine ME, Lu AT, Quach A, et al.
Aging (Albany NY) (2018)
DOI: 10.18632/aging.101414Related biomarkers
Related guides
This 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.
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