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This article was written on 01 Jun 2008, and is filled under Vitamins.

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Vitamins – Three of the Bs: Folate, Vitamin B6, and Vitamin B12

Three of the Bs: Folate, Vitamin B6, and Vitamin B12

Whole grain Bread with wheat

One of the advances that changed the way we look at vitamins was the discovery that too little folate, one of the eight B vitamins, is linked to birth defects such as spina bifida and anencephaly.

Fifty years ago, no one knew what caused these birth defects, which occur when the early development of tissues that eventually become the spinal cord, the tissues that surround it, or the brain goes awry. More than three decades ago, British researchers found that mothers of children with spina bifida had low vitamin levels. Eventually, two large trials in which women were randomly assigned to take folic acid (the form of folate added to multivitamins or fortified foods) or a placebo showed that getting too little folate increased a woman’s chances of having a baby with spina bifida or anencephaly and that getting enough folate could prevent these birth defects.

Timing of folate is critical: For folate to be effective, it must be taken in the first few weeks after conception, often before a woman knows she is pregnant.

Enough folate, at least 400 micrograms a day, isn’t always easy to get from food. That’s why women of childbearing age are urged to take extra folic acid as a supplement. It’s also why the US Food and Drug Administration now requires that folic acid be added to most enriched breads, flour, cornmeal, pastas, rice, and other grain products, along with the iron and other micronutrients that have been added for years.

Since the advent of mandatory folate fortification in 1998, neural tube birth defects have dropped by 20 to 30 percent, and studies have shown that far fewer people have low levels of folate in their blood.

The other exciting discovery about folate and two other B vitamins, vitamin B6 and vitamin B12, is that they may help fight heart disease and some types of cancer. It’s too early to tell if there’s merely an association between increased intake of folate, vitamin B6, and vitamin B12 and heart disease or cancer, or if high intakes prevent these chronic diseases.

B Vitamins and Heart Disease

In 1968, a Boston pathologist investigated the deaths of two children from massive strokes. Both had inherited conditions that caused them to have extremely high levels of a protein breakdown product in their blood, and both had arteries as clogged with cholesterol as those of a 65-year-old fast-food addict. Putting one and one together, he hypothesized that lower, but still elevated levels of homocysteine would contribute to the artery-clogging process of atherosclerosis. Since then, most—but not all—studies have linked high levels of this breakdown product, called homocysteine, with increased risks of heart disease and stroke. However, linking higher levels of homocysteine with heart disease risk does not necessarily mean that lowering homocysteine levels will lower risk. That requires testing in randomized trials.

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