Folic acid is a B vitamin, I think it is B8. Also called Folacin, and the natural form in foods is Folate. It is essential for the synthesis of DNA. Deficiency symptoms are constipation, anemia, slowed metabolism, fatigue, depression. Deficiency also can cause birth defects. Best sources include liver, green leafy vegetables, especially spinach, broccoli, peanuts. We typically need 4-600 micrograms (.4 - .6 milligrams) daily, but for people with high blood levels of homocycteine doctors usually recommend 800mcg or more. Yes, folic acid does help prevent a heart attack by reducing the homocycteine which greatly facilitates buildup of plaque in the arteries. B vitamins work together, so your doctor will probably want you to supplement your intake of B12 and B6. There is an Rx form called Foltx, but it might not have enough 12 and 6. Some people think that Folate, the natural form in foods, is much better than Folic Acid. It also is available in a supplement. Be sure to talk to your doctor first before beginning any B vitamin supplements. Also, if you take a multiple vitamin, check its contents, many include 400mcg of folic acid. Be careful of what you might read on the internet. There s at least one site that confused milligrams with grams.