Homocysteine

An underappreciated marker for cardiovascular and inflammatory risk.

What it is

Homocysteine is an amino acid produced during methionine metabolism. Elevated levels indicate impaired methylation — often due to B12, B6, or folate deficiency — and are associated with vascular damage and increased clotting risk.

Why it matters

Elevated homocysteine is directly correctable with B vitamins. In cancer patients undergoing chemotherapy, impaired methylation can accelerate vascular and neurological side effects. It is also an independent cardiovascular risk factor. A simple, actionable marker.

How to test

Blood test, fasted. No special preparation beyond standard fasting panel.

This information is for educational purposes only. Always discuss testing and interpretation of results with your care team.

Optimal range

Below 10 µmol/L

optimal

10–15 µmol/L

borderline elevated

Above 15 µmol/L

elevated — address B vitamin status

How often

Every 6–12 months.