A single daily dose of a common vitamin, folic acid, can help to reduce the risk of heart attack and stroke, according to Prof John Scott, head of the Trinity College's biochemistry department. Folic acid helps to reduce levels of homocysteine, a blood constituent which, when overproduced, is linked to increased incidence of cardiovascular disease. "Homocysteine is a normal constituent of blood, but a raised level greatly increases the risk of heart attack, stroke and leg artery disease," Dr Scott said. "However, it has also been discovered that folic acid supplements are capable of reducing homocysteine levels by about a quarter in most people."