The American Heart Association does not recommend widespread use of folic acid and B vitamins to reduce the risk of heart disease and stroke. The AHA advises a healthy, balanced diet that includes five servings of fruits and vegetables a day. For folic acid, the recommended daily value is 400 micrograms.

Good sources are citrus fruits, tomatoes, vegetables and grain products. In January 1998, wheat flour became fortified with folic acid to add an estimated 100 micrograms per day to the average diet. Supplements should only be used when diet is not adequate to achieve these intakes.

The AHA Dietary Guidelines are appropriate for children older than 2 years. Children between the ages of 2 and 5 can gradually adopt the dietary habits of the family. Like adults, children should eat foods from all food groups, including lean meats, low-fat dairy products, whole-grain enriched cereal products, fruits, vegetables and legumes. They should not rely on foods containing fat or sugar substitutes, which are often of little nutritional value. The primary emphasis of diets for children is on providing adequate calories and nutrients for normal physical activity, growth and development.

Understanding Folic Acid, Homocysteine and Artherosclerosis
Homocysteine is an amino acid in the blood. Some epidemiological studies have shown that too much homocysteine in the blood (plasma) is related to an increased risk of coronary heart disease, stroke and peripheral vascular disease. However, other studies have not.

How do folic acid and other B vitamins affect homocysteine levels?
Plasma homocysteine levels are strongly influenced by diet, as well as genetic factors. The dietary components with the greatest effects are folic acid and vitamins B6 and B12. Folic acid and other B vitamins help to break down homocysteine in the body. Scientific evidence shows that low blood levels of folic acid are linked with an increased risk of fatal coronary heart disease and stroke. Vitamin B12 deficiency is not associated with vascular disease.

As yet, however, there has been no controlled treatment study showing that folic acid supplements reduce the risk of atherosclerosis, or that taking these vitamins has an effect on the development or recurrence of cardiovascular disease. Researchers have studied varying amounts of folic acid to lower homocysteine levels, but it is still not clear what an optimal dose might be and to what extent a dietary supplement might be required to lower homocysteine levels. Recent findings suggest that laboratory testing for plasma homocysteine levels can improve the assessment of risk, particularly in patients with a personal or family history of cardiovascular disease. Although evidence for the benefit of lowering homocysteine levels is lacking, patients at high risk should be strongly advised to follow an overall diet that ensures adequate intake of folic acid and vitamins B6 and B12.