Homocysteine

What this test is

Homocysteine is an amino acid in your blood. Your body normally clears it using vitamins B12, B6, and folate. Some clinics check it as a heart disease risk marker. Large studies tested whether lowering homocysteine with B vitamins prevents heart attacks or death. It does not. So even a high result does not change what helps your heart most, like blood pressure, cholesterol, and activity. Homocysteine does have one real use. If your B12 test is borderline and your symptoms do not match, homocysteine can help show if you are truly low in B12. Outside that situation, it is not usually a useful test to add.