Ask the doctor: Should I worry about my homocysteine level?

Q. What's the current status of homocysteine as a risk factor for heart disease?

A. Homocysteine is a byproduct of digestion found in everyone's blood. "Normal" levels of homocysteine range from 5 to 15 micromoles per liter (?mol/L). People with levels of 50 or higher are at increased risk of cardiovascular events. A very few families have genetic defects that raise their levels to well over 100. In these families, even children younger than 10 can develop atherosclerosis and die of a heart attack or stroke.