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vitaminsReport Helps Clear Vitamin Confusion

Call it vitamania: About 40 percent of Americans pop vitamin pills. But just how much of each vitamin does your body need? When does food provide enough? And how much is too much?

A prestigious science group has just updated national guidelines on how much of every vitamin and mineral Americans should eat daily for good health - plus a never-before- complied list of which popular megadose vitamins could harm them.

But consumers will be hard-pressed to use the guidelines to make more nutritionally savvy food and supplement purchases. Don't expect food labels to be updated with the new "recommended dietary allowances" any time soon. The Food and Drug Administration hasn't begun considering whether to force vitamin bottles to list the safe upper doses.

It may take questioning a dietitian to learn that more than 1,000 milligrams a day of vitamin E - or 1,500 international units - could cause uncontrolled bleeding.

Or that many people over age 50 have trouble absorbing vitamin B-12 from natural food sources and thus should eat fortified foods, like breakfast cereals, or a daily supplement to ensure they get 2.4 micrograms a day.

Or that the amount of vitamin D older people need for strong bones has doubled, to 400 international units.

Munched a handful of almonds? Reveals that's 7.5 milligrams of vitamin E, half a day's supply in a single snack.

Consider vitamin C: Women need 75 milligrams a day, men 90. Smokers should add another 35 milligrams. But more than 2,000 milligrams a day can cause diarrhea.

Today's food labels are based on RDAs set in 1968. The FDA won't begin steps to add new vitamin numbers until the institute issues another report next year on how much protein, fat and fiber we also should eat.

Many RDAs haven't changed a lot. So nutritionists say a healthy daily diet, with at least five fruits and vegetables, can provide plenty of most vitamins.

More important: Until FDA updates supplement labels, nobody will know safe upper doses, even as sales of multivitamins with three times the RDA and larger "megadose" supplements rage.

Consider vitamin A. Enough - 900 micrograms a day for men, 700 for women - is important for good vision and immune function. But more than 3,000 micrograms daily can risk birth defects in pregnant women, and liver damage for others.

Yet many vitamin supplements are sold in "international units," very confusing because how to convert IUs into micrograms and milligrams differs from nutrient to nutrient. For vitamin A, the guidelines say a microgram equals 3.33 international units - so a popular megadose of 10,000 units hits the daily safety limit.

Another big question is how consumers with special needs with special needs will learn their new recommended dose, such as older people who should pay attention to vitamins B12 and D. Even updated food labels probably won't have enough space to tell them.

What's a consumer to do?

Try to get most vitamins from food and take only supplements your body really needs. People who don't eat much dairy, for instance, may need calcium supplements.

Alternatively, using a regular multivitamin with 100 percent of RDAs "is sensible," but remember taking the multivitamin is no excuse for eating a lousy diet.

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