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?
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
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
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
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
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
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
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.
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
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
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
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. www.primarymedicalcare.com