What is homocysteine?

Homocysteine is an amino acid made in our bodies from dietary protein:

homocysteine process diagram

Homocysteine is regulated by enzymes which need vitamins B6, B12 and folic acid to work properly.

If intake of these vitamins is insufficient, or if they are depleted by oxidative stress and ageing, homocysteine accumulates in the blood.

High blood levels of homocysteine are a risk factor for stroke and neuro-degenerative diseases including dementia and Alzheimer’s disease.

What are normal levels of homocysteine?