Vitamin and Mineral
Supplements: Which Ones Work?
One
of my favorite nutrition authors, Dr. Walter Willett, wrote an article in the New
England Journal of Medicine in December 2001 titled
“What Supplements Should I take, Doctor?” (345:1819-1824).
He summarized research showing that only a few vitamin supplements are
proven to enhance health and that many reported successes of vitamin supplement
therapy have vanished under close research scrutiny. This is good news for those who want to eat a healthy diet
and minimize their intake of expensive supplements. It’s bad news for those who believe that taking many
supplements will make them healthy, lean, or more muscular. I won’t try to talk you out of taking your favorite
supplements, but I can give you factual information about vitamin and mineral
supplements that have stood the tests of long-term research studies.
It’s
hard to get reliable information about nutritional supplements because no one
wants to fund objective research. The
U.S. government spends little money in this area.
Just as with drug research, many manufacturers with a financial interest
in results favorable to their product fund their own supplement research.
On top of that, if manufacturers word their labels just right, they get
away with ridiculous and outlandish claims.
If you see an info-mercial for an electronic waist belt that promises to
dissolve abdominal fat and give you hard abs in 2 weeks, you know it’s false
advertising, even if it shows convincing before and after photographs.
The same inflated claims are found in the nutrition supplement industry,
so it pays to be wary.
High Quality Supplements Do
Not Make Up For A Low Quality Diet
You
can take every natural organic supplement from your health food store and still
be missing essential nutrients that come only from food. Scientists have
isolated only a small fraction of the nutrients found in whole foods. For
example, it’s known that blueberries contain protective anti-oxidants, but
which of the many anti-oxidants in blueberries are the active ones? Have
the most important anti-oxidants even been isolated? Is it the particular
combination that matters? We just don't know. So, your highest
nutritional priority should be whole foods. Eat a wide variety of
vegetables and fruits in all colors and all seasons. Enhance your recovery
system with the nutritious essential oils found in fresh nuts, ground flax or
hemp seed, avocado, or cold-water fish. Take in protein, vitamins, and
minerals in low-fat, bovine-growth-hormone free dairy products, soy foods,
chicken, and fish. Rely on the fiber, B vitamins, and fuel found in whole
grains.
It's
clear that you need to give your body the raw materials for vitality and
strength by eating a healthy diet. But even with the best diet, most of us
can benefit from a few vitamin supplements. Here's what I suggest.
Basic Recommendations
A
low potency multiple vitamin or vitamin/mineral supplement without iron
as a nutritional insurance policy. If
you don’t always eat the best food, take a multi-vitamin of around 200-500% of
the recommended daily allowance (RDA) each day.
Unless you have special needs, no extra benefit has been proven from high
potency vitamins that make the liver and kidneys excrete excessive amounts of
unabsorbed nutrients, plus high dosage supplements can produce unintended
drug-like reactions.
B
Vitamins, including Folic Acid. If your diet is excellent and you
don’t take a multiple vitamin, take a B complex vitamin containing B6, B12,
and folic acid. These B vitamins
help lower homocysteine levels, and high homocysteine levels are associated with
heart disease, stroke, and Alzheimer’s disease.
Folic acid warrants special mention, since 400 micrograms a day for women
of child-bearing age prevents early birth defects and the same amount reduces
homocysteine levels in all individuals.
Calcium,
Magnesium, and Vitamin D.
Men of all ages need 800-1000 mg of calcium a day.
Women under 50 need 1000-1200 mg a day to mineralize strong bones that
will last a lifetime. Women over 50
need 1200-1500 mg a day to prevent bone loss after menopause.
Calculate the amount of calcium in the food you eat over a few days, and
if you aren't getting the amount you need, supplement calcium/magnesium (2 parts
calcium citrate to 1 part magnesium) to increase your intake to recommended
levels. Calcium citrate absorbs
more easily than most calcium supplements. Don't use antacids such as Tums to get your calcium.
Antacids lower stomach acidity, and low stomach acid inhibits digestion
of many nutrients, including calcium and protein.
You also need vitamin D, and most of us benefit from a supplement.
Unless you live where it’s warm and sunny year round, you can’t get
enough vitamin D from the sun during the cold, dark season, so supplement with
400-800 IUs of vitamin D. Supplement
with the higher amount if you have bone density problems or rarely expose your
skin to direct sunlight without a sunscreen.
Omega-3
Fatty Acids. If you aren’t eating deep-sea fish like salmon,
sardines, or mackerel a few times a week or using ground flax meal or oils high
in omega-3s like flax or hemp on a daily basis, supplement daily with omega-3
fatty acids.
Antioxidants?
Antioxidants in food help prevent cell damage caused by oxidation, and
because of this, they are especially important for people who exercise
strenuously. Unfortunately,
research shows that antioxidant supplements are not
as protective against degeneration and disease
as was once hoped. For example, a population-based study in the June 26, 2002, Journal
of the American Medical Association (2002; 287: 3223-3229) found that a diet
rich in foods containing vitamin E helps protect some people against Alzheimer's
disease (AD), but that vitamin E supplements did not reduce risk of AD.
Good food sources of vitamin E are meats, poultry, fish, legumes, soy,
whole grains, and nuts.
For
years, Dr. Andrew Weil has suggested supplementing with natural vitamin E
containing mixed tocopherols rather than the less expensive d-tocopherols, but
even he is becoming less enthusiastic about vitamin E supplementation as the
research results come in. For now,
supplementing with vitamin E doesn’t seem harmful unless you’re taking
statin drugs to lower cholesterol or are at high risk for stroke.
Get
other antioxidants by eating a wide variety of unrefined foods—vitamins A,
betacarotene, and C from vegetables and fruits and selenium from protein-rich
plant foods like nuts and seeds. While
antioxidant supplement research is inconclusive, it is increasingly clear that
high anti-oxidant food intake is
extremely beneficial. Use the money
you'd spend on supplements to buy fresh fruits and vegetables. We simply don’t understand the chemistry of plants enough
to synthesize their healthful effects in pill form, and besides it’s more fun
to eat blueberries!
Iron?
Only take iron if a blood test shows you’re anemic.
We need iron in red blood cells for oxygen transport, but excess iron
doesn’t enhance our oxygen carrying capacity.
Instead, it increases risk for cardiovascular disease and cancer.
I
haven’t tackled the complex world of supplements that supposedly enhance
strength and power such as DHEA, L-carnitine, and creatine.
I don’t know enough about these supplements to comment adequately,
nevertheless I’m skeptical about their long-term effects, even if there are
short-term benefits. Doctors and
the media spent decades trying to convince women that hormone replacement
therapy is safe and health enhancing. I
remained skeptical, and with recent research results, I’m glad I did.
Similarly, it may be true that creatine or some other supplement enhances
short-term performance, but what are the effects in the long run?
No one knows, and for me, it’s not worth the risk.
If you’re involved in resistance training for your health, I suggest
you keep it simple. Eat healthy
food, take a few well-researched supplements to complement your good diet, and
keep exercising.
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This
article was published in Master Trainer, Dec. 2003. An earlier
version appeared at Cyberpump.com in 2002.
©
2003 Elaine Mansfield