For decades we've known that vitamins are essential for health--indeed, for life itself. But, for almost as long, researchers and nutritionists have debated whether vitamin supplements are necessary to boost the amount of these nutrients we get naturally from food.
Most of the attention in this controversy has been given to the so-called antioxidant vitamins: C, E and A. And the discussion continues, because continuing research seems to support both sides of the argument, in some cases showing benefits for supplementation, and, in others, revealing some potentially detrimental effects. Ironically, one of the least publicized nutrients, the B vitamin known as folic acid, has now received almost universal endorsement for supplementation.
Research has conclusively demonstrated that folic acid deficiency increases the risk of serious birth defects of the brain and spine, known as neural tube defects, and there is strong evidence that folic acid supplementation can prevent these defects. The two most common NTDs--spina bifida (failure of the spine to close properly) and anencephaly (incomplete development of the brain)--affect about one of every 1,000 pregnancies in the United States. Experts estimate that 50% to 70% of these birth defects could be prevented if women consumed sufficient amounts of folic acid leading up to and during the first several weeks of pregnancy.
Substantial amounts of folic acid can be found in dark green leafy vegetables such as broccoli and spinach, citrus fruits such as oranges and grapefruit, and beans and legumes. Liver and other types of organ meats are also rich in folic acid. Enriched grain products, such as pasta, rice, bread, flour and cereals, are another excellent source. But in spite of the wide variety of foods that are rich in folic acid, surveys show that most Americans still do not consume adequate amounts of this important nutrient through dietary sources alone.
The evidence in support of folic acid supplementation is now so strong that the U.S. Public Health Service recommends that all women of childbearing age consume 400 micrograms (0.4 milligrams) of folic acid every day. Many experts (including the highly respected National Institute of Medicine) recommend that women of childbearing age rely on synthetic folic acid contained in fortified foods or vitamin supplements to reach this level.
