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Vitamin buyer's guide
Before
they choose a supplement, your patients should
always:
Read
labels carefully Product labels can tell you
what the active ingredients are, which nutrients
are included, the serving size — for example,
capsule, packet or teaspoonful — and the
amount of nutrients in each serving.
Avoid
supplements that boast of "megadoses" In general,
choose a multivitamin-mineral supplement that
provides about 100% of the Daily Value (DV) of
all the vitamins and minerals, rather than one
which has, for example, 500% of the DV for one
vitamin and only 20% of the DV for another. The
exception to this is calcium — if they provided
100% of the DV, the tablets would be too large
to swallow!
Look
for "USP" on the label This ensures that the
supplement meets the standards for strength, purity,
disintegration and dissolution established by
the testing organization US Pharmacopeia (USP).
Beware
of gimmicks Synthetic vitamins are usually
the same as so-called "natural" vitamins, but
"natural" vitamins usually cost more. And don't
give in to the temptation of added herbs, enzymes
or amino acids — they add mostly cost.
Look
for expiration dates Dietary supplements can
lose potency over time, especially in hot and
humid climates.
Source:
Dietary supplements: Using vitamin and mineral
supplements wisely, Mayo Clinic
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Last week, the US watchdog ConsumerLab.com
reported evidence of dangerous amounts of lead in several
popular brands of multivitamins. They even found a kids
multivitamin that contained a staggering 216% more vitamin
A than stated on the label. Of the 21 products tested,
only 10 met their claims and quality standards.
News like that is enough to cause
your patients to run screaming from the supplement aisle.
Yet it's clear most Canadians aren't getting anywhere
near the recommended intake of vitamins and minerals
from their increasingly fatty, vegetable-sparse diets.
In fact, less than half your patients are getting all
the nutrients they need out of the food they eat, according
to Dr Sam Kacew, PhD, a professor of pharmacology at
the University of Ottawa.
But your patients should proceed
back to the supplement aisle with caution. As you well
know, taking too much of the wrong type of vitamin can
be dangerous. Here are some tips on how to help your
patients get the extra nutrients their bodies need safely.
MYTHS
AND MISCONCEPTIONS
Lots of people probably think they can get away with
unhealthy eating habits if they pop a multivitamin with
their morning coffee. And they've no doubt heard the
stories that taking megadoses of certain vitamins —
quantities well above the minimum daily requirement
— may prevent things like heart disease, cancer,
osteoporosis and other chronic diseases. But Dr Kacew
says the reality is that there's no good evidence that
any of it's true — quite the contrary in fact.
The important thing to remember, he says, is that not
all vitamins are created equal.
Water-soluble vitamins include
the B group of vitamins, vitamins C, H and folic acid.
Explain to your patients that while the body absorbs
these vitamins easily, any excess is excreted in urine,
so loading up on them won't do them any good. There
are exceptions, though. Too much vitamin B6 and vitamin
C can have unpleasant side effects (see Vitamins 101).
No matter what they may have heard, you should tell
your patients that while vitamin C certainly plays a
role in helping the body fight off infections, there's
no evidence that loading up on it will prevent colds,
heart disease, cancer, or eye diseases such as cataract
and macular degeneration.
Another important exception, of
course, is folic acid. Pregnant women need to get at
least 400 micrograms a day to prevent severe birth defects
like spina bifida. In fact, you should tell women who
are considering having a baby to start taking the supplements
immediately, because the potential defects occur very
early on in development.
Fat-soluble vitamins A,
D, E and K, on the other hand, are stored in body fat
and people who don't get enough digestible dietary fats
are susceptible to shortages. But you should impart
to your patients that only you can diagnose a vitamin
deficiency, and they should only take supplements of
fat-soluble vitamins under your supervision. "Individuals
deficient in fat soluble vitamins must take supplements,
but this needs to be cautioned as excess results in
toxicity," says Dr Kacew.
Symptoms of vitamin A deficiency
include night blindness, dry eyes and inflammation;
rough, dry skin; and vulnerability to respiratory and
urinary tract infections. Patients with insufficient
stores of vitamin D will experience bone pain or tenderness,
skeletal and dental deformities and muscle cramps. Also,
be sure to warn your patients on blood thinners that
vitamin E and K can interfere with their medication
— they shouldn't take them without your consent.
WHO
NEEDS 'EM?
Generally speaking, most dietary supplements won't do
any harm. Multivitamins, Dr Kacew points out, contain
mostly water-soluble vitamins and a good portion of
the preparation is excreted. "But they are absolutely
not necessary for individuals ingesting an adequate
diet," he emphasizes.
Unfortunately that's often not
the case. The following patients in particular may be
in need of a vitamin boost:
- Those who consume less than
1,200 calories per day
- Elderly patients who don't eat
as much as they should; don't get enough sun; are
lactose intolerant; or don't absorb and utilize Vitamin
B12 because of changes in their gastric secretions
- Strict vegetarians
- Patients who are lactose intolerant
- Chronically ill individuals
who take medications regularly or are recovering from
surgery or trauma
- Alcoholics usually have trouble
absorbing the B-complex vitamins
- Smokers may need more vitamin
C
- Post-menopausal women generally
need more calcium and vitamin D
Before they buy, though, be sure
to remind your patients that like the vitamins they
contain, not all supplements are created equal. Hand
them a copy of our vitamin buyer's guide for some handy
tips.
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