Homocysteine Plasma Homocysteine
A waste product your body clears with the help of B vitamins.
Also printed asHcy · Total Homocysteine · tHcy
What it measures
An amino acid your body clears using B12, folate and B6.
Builds up when any of those three run short, and a high level is associated with damage to blood vessel linings.
Why it matters for how long you stay well
Treat it as a B-vitamin signal rather than a target in itself: trials that lowered it with B vitamins did not reduce heart attacks or strokes, so the value is in what it reveals, not in the number.
How it shows up in daily life
You will not feel it. It rises quietly when B12 or folate has been running short for a while.
High and low readings
When it reads high
Usually a B12, folate or B6 shortfall; reduced kidney clearance is the other cause.
When it reads low
Low is fine.
What moves it
Daily life
- B12 and folate in your diet
- vitamin B6 intake
- kidney filtering
- smoking
- coffee in large amounts
Medicines known to shift it
- vitamin B12 supplements (lower it)
Listed so a result can be read in context. It is not advice to start, stop or change any medicine; that decision belongs with your physician.
Read it with
Markers that move this one, or that this one moves. One number read alone can mislead.
- Vitamin B12Known mechanism
Vitamin B12 pulls it down
B12 is one of the tools your body clears homocysteine with. When B12 runs short, homocysteine has nowhere to go and backs up.
- FolateKnown mechanism
Folate pulls it down
Folate does the same clearing job in the same chemistry. So a folate shortage pushes homocysteine up exactly the way a B12 shortage does.
Common questions
What does Plasma Homocysteine measure?
An amino acid your body clears using B12, folate and B6. Builds up when any of those three run short, and a high level is associated with damage to blood vessel linings.
What does a high Homocysteine result usually mean?
Usually a B12, folate or B6 shortfall; reduced kidney clearance is the other cause.
What does a low Homocysteine result usually mean?
Low is fine.
What is the usual reference range for Homocysteine?
A broad adult reference band is 5–15 µmol/L. Labs differ, so read your result against the band printed on your own report.
Educational only, not a diagnosis. A single number means little without your history and the rest of your panel, so discuss your own results with your physician.
Typical adult reference band
- Adults
- 5–15 µmol/L
Labs differ. The band printed on your own report is the one that applies to your result.
Reported in µmol/L
Ageing relevance
4/5
A strong independent predictor of illness and mortality in large cohorts.
Indian reference data
Published data on this marker in Indian adults: Yajnik et al. 2006, 441 men in Pune (PMID 17214273): 58% above 15 μmol/L; Naik et al. 2011, Pune (PMID 22419201): men's median 16.2 μmol/L, women's 9.5.
Worth knowing
It builds up only when the B vitamins that clear it run short, which is what makes it a B-vitamin signal.
Have a report with this marker on it? Read it in context.
Upload it to Oraia, our health-intelligence tool, for a plain-language read of your markers that a Genoryx doctor can review.
Your biological age is a number you can measure.
Start with the 400+ parameter entry assessment and a 60-minute physician consultation at either Hyderabad clinic. Open seven days, 11 AM to 9 PM.
Book a consultation