Research has shown that folic acid is important in red blood cell formation and that folic acid supplementation can reduce blood levels of homocysteine. Some studies have shown a decreased risk of heart disease among people with the highest intakes of folic acid and vitamin B-6, either from diet or multivitamin supplements. The American Heart Association does not recommend widespread use of folic acid and B vitamin supplements to reduce the risk of heart disease and stroke. Instead, eat a healthy, balanced diet that includes five servings of fruits and vegetables a day. For folic acid, the recommended daily value is 400 mcg.
Good sources are citrus fruits, tomatoes, vegetables and grains.
In January 1998, wheat flour became fortified with folic acid to add an estimated 100 mcg a day to the average diet. Supplements only should be used when diet isn't adequate to achieve these intakes. Vitamin B-12 has a lesser role in homocysteine levels and helps lower homocysteine only in people who are deficient in this vitamin. The absence of Vitamin B-12 can cause anemia, and supplements are recommended for vegetarians who eliminate all animal foods from their diets. Injections of B-12 are recommended for people whose digestive tracts, due to surgery, bowel disease or a heredity problem, can't absorb the vitamin.