![]()
Are Vitamins Really Good For You?
As far back as the mid-1700s a Scottish surgeon proposed that lemons and
limes could prevent and cure scurvy, a potentially fatal disease common to
sailors and others without access to fresh foods. But it wasn’t until the early
1900s that scientists figured out the fruits contained a chemical we now call
vitamin C.
Today, we know a lot more about vitamins and they way they
influence our health. But, misinformation still abounds. This article will help
you decide whether you need vitamin supplements and how to get the most
inexpensive, effective dosages.
You Need Your Vitamins
Vitamins
are micronutrients – substances your body needs in very small amounts for
growth, digestion and the healthy function of nerves.
In most cases the
body can’t make its own micronutrients. Ideally, they’re supplied by a
well-balanced diet. Fruits, vegetables, whole grains and fresh meats are good
sources of a wide range of vitamins and other essentials.
Although
severe vitamin-deficiency diseases such as scurvy, beriberi (caused by a lack of
vitamin B1), and rickets (the result of inadequate vitamin D) have been all but
eliminated in developed countries, more subtle deficiencies are not uncommon
even in North America.
According to a scientific review published in the
Journal of the American Medical Association (JAMA) in June 2002, less than
optimum vitamin intakes, “even well above those causing deficiency syndromes,
are risk factors for chronic diseases such as cardiovascular disease, cancer and
osteoporosis.”
Vitamin deficiency can also reduce resistance to
infections and increase the risk of birth defects.
The article goes on to
say that “A large proportion of the general population is apparently at
increased risk for this reason.” The authors conclude that it seems “prudent”
for all adults to take a vitamin supplement.
That doesn’t mean vitamins
can prevent all diseases or that more than the recommended dietary allowance
(RDA) is better. Indeed, the RDAs of vitamins meet the needs of an estimated 97
percent to 98 percent of healthy individuals, says the National Academy of
Sciences.
Who Should Take Vitamins?
Whether you should take
vitamin supplements depends mostly on how well-balanced your diet is. You’re
more likely to need a vitamin supplement if you:
-
Don’t eat five servings of fruits and vegetables
daily
-
Are a vegetarian
-
Are on a low-calorie diet or tend to skip
meals
-
Have a limited diet as a result of food
allergies
-
Have a digestive disorder
-
Smoke
-
Drink alcohol to excess
-
Are pregnant
Don’t confuse vitamins
with other forms of dietary supplements. The supplement category includes
vitamins as well as minerals, herbal and botanical preparations, enzymes and
other ingredients. Although the body has daily requirements for vitamins and
minerals, no need for the other kinds of supplements has been
established.
If you’re unsure about the contents of a product, check the
package. All supplements must include a Supplement Facts Label indicating how
much of the daily requirement the product contains. If you see an asterisk (*)
instead of a number in the Daily Value column, it means no daily value has been
established.
If your eating habits could be better, a daily multivitamin
that offers no more than 100 percent of daily requirements does no harm and may
do you good. If you have a chronic illness or take prescription medicines,
discuss it with your doctor first.
For most people a single multivitamin
tablet fills the bill. The authors of the 2002 JAMA article recommend
multivitamins rather than a handful of specific vitamin pills because
“multivitamins are simpler to take and cheaper than the individual vitamins
taken separately.”
Bottom line: Think of vitamins as an inexpensive
insurance policy and a complement to, not a substitute for, a healthy
diet.
Take The Right Vitamins For Your Age
Children need
vitamins formulated specifically for them because their RDAs are lower than
those for adults, and overdoses can be harmful.
After age 18, young
people can take adult multivitamins.
Healthy men and women under 50 have
similar daily requirements for most vitamins, but there are some special
cases.
Pregnant women should ask their physician about prenatal vitamins,
and women of childbearing age may benefit from supplemental folate (vitamin B9)
to help prevent birth defects of the brain and spinal cord.
Adults over
age 50 have a few specific needs. The RDA for vitamin B6 (found primarily in
fortified cereals) increases about 30 percent for men and 15 percent for women.
The requirement for vitamin D, needed especially for bone health, doubles in
both sexes. And because some older people are less able to absorb vitamin B12
from food, some experts recommend they take a supplement.
Those who need
higher doses of specific vitamins should buy them as individual supplements
rather than double up on multivitamins, doctors advise.
Be Cautious
When Taking Vitamins
The primary caveat with multivitamins is that more
than the RDA is not better – and can be harmful.
Too much vitamin A can
reduce bone density and cause liver problems. In pregnant women, it can cause
birth defects. Excessive vitamin D can also be toxic and cause calcium deposits.
Overdoses of vitamin B6 may cause damage to nerves in the arms and
legs.
Megadoses of vitamin E pose dangers, too. An analysis of 19
studies, reported in the Annals of Internal Medicine in 2004, indicates that
people who take more than 400 IU of vitamin E daily for at least a year had a
higher death rate from all causes.
In a few cases vitamins don’t combine
well with drugs. For instance, vitamins E and K both have blood thinning
effects, so taking them along with a prescription drug such as Coumadin – or
even aspirin or herbal supplements such as ginkgo biloba – could make internal
bleeding more likely.
Also be aware that taking a multivitamin doesn’t
exempt you from eating your veggies and whole grains. These food groups also
contain fiber and biologically valuable compounds that build health and help
prevent disease. Scientists are continually learning more about these food
components, and it’s unlikely all will ever be available from pills
alone.
If you’re healthy, there’s probably no need to make a special
appointment with your physician before taking vitamins. The next time you visit
your doctor, discuss the fact that you’re taking a multivitamin or thinking
about it.
But if you have questions about supplementation or have health
problems, talk things over with your doctor. The FDA’s Center for Food Safety
and Applied Nutrition advises, “If you are pregnant, nursing a baby, or have a
chronic medical condition such as diabetes, hypertension or heart disease, be
sure to consult your doctor or pharmacist before purchasing or taking any
supplement.”
Finally, if you’re a candidate for surgery, you may need to
discontinue some supplements several weeks beforehand. Inform your doctor about
everything you’re taking.
Weigh The Cost Of Vitamins
Vitamins
are inexpensive to produce, yet manufacturers offer hundreds of options whose
annual cost ranges from less than $10 (basic formulas) to $600 or more. In 2003
alone the U.S. supplement industry as a whole pulled in an estimated $18.8
billion in sales, according to a report published in Nutrition Business
Journal.
Companies charge more for vitamins in liquid, chewable and
time-release formulas as well as those with added herbs, botanical ingredients
or antioxidants and those touted as “all-natural.”
Of course, big-name
brands with heavy marketing and advertising expenses cost more than house
brands.
For example, you could spend more than $650 a year on Dr. Weil’s
Select Formulas Memory Support, which includes a mix of multivitamins,
antioxidants and herbs.
But there’s no need to get fancy. You can buy a
year’s supply of Rite Aid One Daily multivitamins for about $6, Walgreen’s Gold
Seal for around $8, and One-A-Day Essential for approximately $26.
Does
brand matter? Not really. The JAMA report notes that “the contents of basic
multivitamins are remarkably similar across brands.”
In addition, in
June 2007 the FDA announced a ruling that established stronger
good-manufacturing-practice requirements for the makers of all dietary
supplements, including vitamins. In a 2007 news release the FDA states that the
rule “ensures that dietary supplements are produced in a quality manner, do not
contain contaminants or impurities, and are accurately labeled.”
For
More Information
To learn more, visit these government-sponsored and
independent Web sites.
The National Institutes of Health Office of
Dietary Supplements
News, nutrient recommendations and a searchable
database of supplements
http://dietary-supplements.info.nih.gov/ Consumerlab.com
An
independent site with news on supplements, and prescription and over-the-counter
medications
http://consumerlab.com Vitamins A to K
A
patient page prepared by the Journal of the American Medical Association and
published in June 2002
http://jama.ama-assn.org/cgi/reprint/287/23/3166.pdf