Biomarker · Cardiovascular
Homocysteine
Homocysteine is an amino acid linked to B-vitamin status. What a homocysteine test can show, why levels rise, and what is and isn't known about heart risk.
Written by LON6EVITY Editorial Team · Last updated
What it measures
Homocysteine is an amino acid produced when the body breaks down protein. Vitamins B12, B6 and folate help convert it into other substances, so levels can rise when these vitamins are low.
When the test is used
MedlinePlus describes the test as a way to help find vitamin B12, B6 or folate deficiency and to check for homocystinuria, a rare inherited disorder. High levels have also been associated with a higher risk of heart disease and stroke.
Association is not a target
Although high homocysteine is associated with cardiovascular disease, an association does not mean that lowering homocysteine on its own lowers risk. It is best read together with established risk factors such as blood pressure, LDL cholesterol or ApoB, smoking and diabetes.
Reference ranges
Reference ranges differ between laboratories, units and methods, and depend on age, sex and your overall clinical picture. A single result is not a diagnosis — interpret it with a qualified clinician.
Factors that can affect the result
- Vitamin B12, B6 and folate status
- Kidney function
- Some medicines
- Genetic factors
Questions people commonly ask
- Should I take B vitamins if my homocysteine is high?
- Discuss it with a clinician. The first step is to find out why it is high, for example a vitamin deficiency or reduced kidney function.
Related biomarkers
Related topics
Understand your biomarkers in context
What does this mean for your own health data? Log your results, follow trends over time and bring an organised summary to your next doctor's appointment.
Sources
- Homocysteine Test. MedlinePlus, U.S. National Library of Medicine.