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Supplements
not always a plus
March 30, 2006
Suzanne Havala Hobbs
I’ve
got a money-saving tip that’s better than clipping coupons:
Cut back on the number of vitamin supplements you buy.
Three out of four American households buy vitamin and mineral
supplements, spending $7 billion last year, according to industry
figures reported earlier this month by The Wall Street Journal.
But you may be surprised to hear this: In most cases, there’s
actually little evidence to show most supplements are effective.
And, sometimes high doses can be harmful.
There are exceptions, of course. For example, there’s
good evidence that folic acid, a B vitamin, can help prevent
neural tube defects in babies if their mothers take supplements
before pregnancy.
But a long list of vitamins and minerals once thought to be
surefire ammo against heart disease and cancer have turned
out to be duds, according to recent research.
Antioxidants serve as a good example of how the science has
shifted.
Ten years ago, people were popping vitamin E to protect their
hearts and vitamin C was, well, vitamin C was good for whatever
ailed you.
But more recently, the Institute of Medicine concluded there
wasn’t enough evidence to support health claims for
supplements of antioxidants such as vitamins C and E, selenium
and beta-carotene. In the cases of vitamins C and E, the IOM
specifically recommends against intakes greater than daily
recommended levels to avoid adverse effects.
Personally, I don’t take supplements, aside from the
unintentional ones many of us get in a few fortified foods
such as breakfast cereals and vitamins A and D added to milk
or fortified soymilk, which I use. Early in my nutrition training
25 years ago, I concluded there wasn’t enough knowledge
about how nutrients interacted with each other and with the
other substances in foods to warrant taking isolated nutrients
in a concentrated form. More recent research continues to
affirm my opinion.
Plus, we know the body can to some extent adapt to varying
dietary conditions. If there’s a lot of a particular
nutrient in the diet, the body may absorb less. If the nutrient
is scarce, the body may be more efficient at absorbing what’s
available.
But in our quick-fix, pill-popping culture people are easily
sold on dietary supplements. Many people figure that if they
don’t eat well, a supplement serves as a little extra
insurance.
Some health professionals would agree with that point of view.
Others don’t.
Here’s how I size up the advice on vitamin and mineral
supplements:
* First, follow your doctor’s advice. If you are getting
individualized care for a health condition, discuss your needs
with your health care provider.
* Generally avoid high doses of single vitamins or minerals.
Some are sold in doses many times higher than amounts recommended
on a daily basis. High doses of single nutrients can have
drug-like effects or interfere with your body’s balance
of other nutrients.
* Avoid high potency, mega dose multivitamin and mineral formulations.
Like high doses of single nutrients, these provide multiple
vitamins and minerals in amounts far exceeding recommended
levels.
* If you want to take a multivitamin supplement, choose one
that provides no more than 100 percent of amounts recommended
on a daily basis. (You’ll find this information on the
label). Even then, there’s no need to take it daily.
If you’re hedging your bets and just want a little insurance,
take your vitamins every other day.
A good summary and analysis of vitamin supplements by brand
name was published in the March edition of Nutrition Action
Health Letter (http://www.cspinet.org/nah/).
Of course, the best dietary protection for your health is
a diet of whole foods that provide the vitamins, minerals
and phytochemicals you need packaged the way they’re
found in nature.
When it comes right down to it, it’s a lot less complicated,
too.
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