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Folic Acid

Definition

Folic acid is one of the B-complex vitamins.

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Description

Folic acid, long unheralded even by health food enthusiasts, suddenly has been thrust into the nutritional limelight. A series of recent studies suggest that this B vitamin may be a major player in warding off heart attacks, strokes, and certain common cancers.

Often called folacin or folate (its biologically active form), folic acid is already well established as critically important in preventing spina bifida and anencephaly, both devastating birth defects of the neural tube.

The federal government has always told healthy consumers to obtain all of their essential nutrients from food rather than supplement pills. But that advice has become harder to follow for almost 25 percent of the U.S. population, namely women of childbearing years. This is because the U.S. Public Health Service is now recommending that the 58 million who have the potential to become pregnant consume more than twice their Recommended Daily Allowance of folic acid.

Folic Acid And Pregnancy

Fueling the new advice is a growing body of evidence indicating that when a woman consumes an adequate amount of folic acid, she reduces her risk of bearing a baby with neural tube defects - abnormalities that include spina bifida (the incomplete closing of the bony casing around the spinal cord that results in partial paralysis), and anencephaly (a condition in which major parts of the brain are missing). Neural tube defects disable and/or kill nearly 2,500 infants born in the U.S. each year.

The folic acid that appears to protect against these devastating deformities is found in a number of foods, including dark green leafy vegetables, citrus fruits and juice, yeast, bread, and fortified cereals. But a woman would have to eat, for example, more than a cup of cooked broccoli, two-thirds of a cup of cooked spinach, and about a cup of cooked turnip greens each day to obtain the 0.4 milligram of the nutrient government officials recommend. Most women typically consume foods that provide only about half that amount.

Complicating the matter further is that to protect an unborn child, the higher level of folic acid must be consumed before and during the first few weeks of pregnancy - the period during which the embryo's neural tube is closing - but most women are not yet aware that they are expecting. For that reason, it might be prudent for all women capable of conceiving to routinely take folic acid supplements as a hedge.

Other Benefits Of Folic Acid

A collaborative study of nearly 15,000 male physicians by researchers in Massachusetts and Oregon revealed that the risk of suffering a heart attack was elevated more than three-fold by a common metabolic abnormality that is correctable by folate. Vitamin supplementation can normalize homocysteine levels and may lower the incidence of atherothrombotic vascular disease.

Folate appears to protect against cancer by aiding in the production of chemical units called methyl groups. These, in turn, enable DNA to resist the action of cancer-causing genes. In one study of people with ulcerative colitis, who face an abnormally high risk of developing colon cancer, precancerous changes in the colon were less often found in those who took folate supplements.

Low levels of folate have also been linked to the development of cellular abnormalities that precede cancer of the cervix in women infected with a cancer-causing strain of human papillomavirus. In women with adequate folate intake, the virus appears to be harmless.

Still other studies have suggested that low levels of folate may increase the risk of cancers of the lung, breast, and esophagus, perhaps by impairing the ability of DNA to repair itself when assaulted by carcinogens, such as those of tobacco smoke.

The Food and Drug Administration announced in 1996 that it would require enriched breads, flour, pasta, and other grains to be fortified with folic acid to reduce the risk of neural tube defects. The new policy is the first new fortification order to be issued in the U.S. since 1943.

The amount of folic acid added to fortified foods will range from 0.43 mg to 1.4 mg per pound of product. The fortified foods will contain about 10 percent of the recommended daily intake of folic acid per serving. This level of fortification was chosen in order to keep the intake of folic acid below 1 mg, to avoid masking the symptoms of pernicious anemia. It does not guarantee that every woman will receive enough folic acid from her diet to minimize the risk of neural tube defects.

In announcing the new requirement, the FDA said that the fortification was necessary because more than a half of all pregnancies are unplanned, and many neural tube defects occur before the mother even knows that she is pregnant. To help prevent neural tube defects, adequate amounts of folic acid must be consumed in the six weeks before and after conception.

Makers of foods with high levels of folic acid will be able to say in their advertising and on product labels that the vitamin can help prevent neural tube defects. This is the eighth health claim that the FDA has allowed for foods.

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