Bottom line: The body needs folate to produce and maintain cells. A healthful intake is about 400 micrograms (mcg) per day. You can get all you need — but are highly unlikely to get too much — from diet alone, whether from foods that contain folate naturally (dark leafy greens, legumes, oranges, peanuts) or from foods fortified with folic acid (bread, cereal, rice).
Due to the aforementioned risks, taking additional supplements of folic acid is generally not a good idea. However, there are exceptions. It is hard to find a multivitamin that does not contain folic acid — so if you want to take a daily multivitamin, be sure to choose one with no more than 400 mcg of folic acid. If you are pregnant or might get pregnant, ask your doctor about supplementing with 400 mcg to 1,000 mcg of folic acid per day… or with a higher dosage if you or a close relative previously had a baby with a neural tube defect. Your doctor may recommend supplementation if you have a diagnosed folate deficiency or type of anemia caused by low folate… have celiac disease or inflammatory bowel disease, as these conditions impair folate absorption… have high homocysteine levels… or take methotrexate (Trexall) for psoriasis or rheumatoid arthritis, because this drug depletes folate levels.