The Vitamin Myth
While some vitamin supplements can boost your health, others may actually harm.
Google “vitamins” and you get 50 million results and the wildest claims you can imagine. That’s almost six times more than what you get for “Brad Pitt,” but the descriptions are just as breathless. As you navigate the maze of sites, you see phrases claiming vitamin supplements can “increase energy,” “stimulate brain function” and “improve sex drive.” There are promises of “reversing cancer” and “removing plaque” from your arteries. It all helps explain why Americans shell out $7.5 billion a year on vitamins, hoping to prolong life, slow aging and protect against a bevy of illnesses.
But new research not only refutes many of these claims, it also shows that some of these vitamins may in fact be harmful.
- A February report in the Journal of the American Medical Association found that taking antioxidant vitamins actually increased a person’s risk of dying by up to 16 percent.
- A study by researchers at the University of Washington last May found that high doses of vitamin E taken over ten years slightly elevated lung cancer risk in smokers.
- Researchers at the National Cancer Institute found that men who took more than one multivitamin daily had a higher risk of prostate cancer.
The antioxidant study, in particular, surprised a lot of people and has prompted a heated debate. Antioxidants such as vitamins A, beta carotene (another form of vitamin A), E and C have long enjoyed a reputation as disease fighters because they’re thought to protect against free radicals that can damage cells and speed up aging. But in 47 randomized trials involving almost 181,000 adults, researchers found that taking vitamins A, beta carotene and E, alone or in combination, actually increased a person’s risk of dying by up to 16 percent.These latest findings made headlines, but they haven’t convinced everyone. A number of leading health experts criticized the JAMA review, including Jeffrey Blumberg, PhD, head of the Antioxidants Research Laboratory at the USDA Human Nutrition Research Center on Aging at Tufts University. He argued that the results were skewed because the studies it reviewed were too diverse and could not be easily compared. It also included deaths from all causes, not just health-related ones.
Based on these flaws, Bernadine Healy, MD, former head of the NIH and the American Red Cross, deemed the study alarmist and silly. Still, others wonder, why take the risk if you can get what you need from the produce aisle or the farmers’ market?
“Unless your doctor says you need supplements for a specific diagnosis, there is no reason to take them and no need to spend the money,” says the review’s senior author, Christian Gluud, MD, of Copenhagen University Hospital in Denmark.
The prostate cancer findings from the National Cancer Institute were even more startling because the culprit was the innocuous multivitamin. Researchers found that men taking multivitamins more than once a day increased their risk of advanced prostate cancer by 32 percent and nearly doubled their risk of fatal cancer, compared with men who didn’t take multivitamins. The risk was highest in those who had a family history and also took selenium, beta carotene or zinc supplements.
Don’t throw away those bottles yet, though. Many experts agree that taking a daily multivitamin is a smart move, especially for those of us who don’t regularly eat whole grains, fresh veggies and fruit. Still, you may want to think twice about swallowing handfuls of certain supplements.
C Is for Colds
Even if a vitamin does no harm, it may do, well, nothing. Take the ever popular myth that popping vitamin C will stave off colds. A review of 30 studies involving more than 11,000 people who took at least 200 mg of vitamin C daily found that it offered little protection in reducing the length or severity of common colds for most people. It did work for some people, such as marathon runners and skiers, who undergo periods of high stress, but the study’s authors say the rest of us shouldn’t bother taking it.
Most people think of vitamins as natural and safe since they’re sold over the counter everywhere, including health food stores. And many consumers figure you can’t get too much of a good thing. But you can, particularly if you’re on prescription drugs.
Megadoses of E, for example, can increase the risk of bleeding if you’re already on heart meds like blood thinners. An earlier 2004 analysis by Johns Hopkins researchers found consuming 400 IU or more of vitamin E a day alone (some products on the market today contain 1,000 IU per capsule) was associated with a higher risk of dying and should be avoided. (One theory says high doses may alter your natural immune function and actually become pro-oxidant.) Taking too much niacin without a doctor’s okay can lead to liver damage and other problems over time. And too much vitamin A increases the risk of liver and lung cancers, and can cause birth defects and reduce bone density.
What consumers tend to forget is that many processed foods and so-called diet foods, from crackers to energy bars, are “fortified” with additional vitamins and minerals. Even some bottled waters, juices and sodas have added them in an effort to appear more healthy. Eat and drink enough of these products, take a few pills, and you could be overdosing. Though rare, bad side effects and even deaths do happen from a vitamin overdose, reports show.
“Taking more than a DRI [dietary reference intake] of vitamins is associated with problems,” says Michael Roizen, MD, Cleveland Clinic’s chief wellness officer and coauthor with Mehmet Oz, MD, of the You series of health books. “These include osteoporosis, which is caused by too much vitamin A, and neurological problems such as headaches, wobbliness and confusion, caused by too much folate without enough B6 or B12, or too much B12 without enough B6 or folate”
Vitamins and supplements also lack the government oversight that medical drugs get, and this adds to the confusion and potential dangers. Consumers have no real way of knowing whether labels accurately reflect what’s actually in a pill.
ConsumerLab.com, a supplement industry watchdog site, recently tested 21 different brands of multivitamins and found that 11 failed quality standards, including meeting their own label claims. For example, their test showed that one product had only about half the calcium its label boasted, and another had almost 300 percent more. One product was found to be tainted with lead. Three didn’t break apart properly, violating the U.S. Pharmacopeia’s 30-minute limit on how quickly a pill should dissolve (to make sure you get the full dose).
Another study discovered that half of the B-complex supplements analyzed didn’t provide the claimed amounts of folic acid. But that should change over the next few years, thanks to a new FDA ruling that says supplement manufacturers must ensure their products are tested for purity and accurately labeled.
The Real Benefits
Not all the news is disappointing. Studies show that vitamin D plays an important role in the absorption of calcium and in boosting bone health. The National Osteoporosis Foundation recommends that adults under 50 get 1,000 mg of calcium and 400 to 800 IU daily of vitamin D3 (the form of D that best supports bone health), and those 50 and older get 1,200 mg of calcium and 800 to 1,000 IU of D3 from food and supplements. But vitamin D may do even more, as Reader’s Digest reported in September 2006. Several studies suggest a link between vitamin D deficiency and cancer, as well as other diseases. And there seems to be little downside to taking vitamin D supplements.
But some people may need more than the standard recommended amounts of certain vitamins, including pregnant women, who require extra folic acid to help prevent birth defects, and the millions of young women with anemia, who may benefit from iron supplements. Postmenopausal women can take calcium and vitamin D to reduce fracture risk, and those at risk for age-related macular degeneration may benefit from antioxidant and zinc supplements.
Food Versus a Pill
Clearly, the jury’s still out on what vitamin supplements can really do. An NIH panel determined last year that there wasn’t yet enough evidence either for or against the use of multivitamins to make a recommendation. One thing that’s clear, though: Getting vitamins and minerals from pills is not as effective as getting them from food, says Dr. Roizen. No one knows for sure why a food source may be more beneficial, but one theory is that nature provides a perfect balance of compounds that isn’t fully replicable in the lab.
While there’s evidence that vitamins C and E and beta carotene protect the heart when you get them from food, a recent Harvard study found that they don’t provide protection when you get them from a supplement. The Women’s Antioxidant Cardiovascular Study followed 8,100 women with strong risk factors for heart disease for nine years, and the researchers concluded that “widespread use of these individual agents for cardiovascular protection does not appear warranted.”
Rather than just turning to pills as a remedy, eating a healthy, balanced diet may help you avoid those conditions in the first place, says Robert Eckel, MD, who specializes in preventive cardiology at the University of Colorado School of Medicine and is the immediate past president of the American Heart Association.
“I believe in getting the DRI from food as a way of preventing deficiency diseases,” says Dr. Roizen. “But I take a vitamin and mineral supplement as an insurance policy against a less than perfect diet.”
“There have been many studies looking at supplements,” says Blumberg, “but the most consistent evidence we’ve had over the past 30 years is that eating a healthy diet, low in salt and saturated fat, losing extra weight, exercising moderately, reducing stress, and quitting smoking are our best guarantees against disease and premature death.”
Everyone needs vitamins and minerals, which are crucial for good health and long life. What we don’t need are megadoses of these essential nutrients in pill form. The greatest health benefits come when we get our vitamins from a balanced diet — but only 3 percent of us eat well enough for that. So unless your doctor has advised you to take a supplement for a specific medical reason, a daily multivitamin is all most healthy individuals need. Read labels to see how much youâ€™re getting of each nutrient, and ask your doctor before starting any vitamin regimen, especially if you already take prescription drugs. Based on the latest studies, here are ten you can skip:
Vitamin A: Excess amounts accumulate and can be toxic. Too much A can blur vision, cause headaches and vomiting, and also lead to liver, bone and central nervous system problems, among others.
RDA*: Men – 900 mcg. Women – 700 mcg. One 7-inch carrot has 600 mcg. Other food sources: fortified cereals, dark leafy greens, fruits, sweet potatoes.
Beta Carotene: The body converts this into vitamin A. Supplementation is not recommended for the general public and should be avoided especially by smokers, who have a greater risk of lung cancer with regular use. Another recent study found that high levels of beta carotene in the blood were linked to three times the risk of aggressive prostate cancer.
RDA: None established. You can get what you need from dark green and orange fruits and veggies.
Vitamin C: There’s no conclusive evidence that it prevents colds, heart disease, cataracts or cancer.
RDA: Men – 90 mg. Women – 75 mg. Smokers need an extra 35 mg. A glass of OJ will give you almost all you need.
Vitamin E: Large doses can thin the blood and may increase the risk of hemorrhagic stroke in those with uncontrolled blood pressure. Has not been proven to protect the heart or prevent cancer.
RDA: 15 mg. An ounce of dry-roasted almonds will provide almost half your daily needs.
Selenium: Most Americans get enough of this trace mineral in their diet. One new study suggests that adding more via a pill may increase the risk of developing type 2 diabetes.
RDA: 55 mcg. Grab a tuna sandwich or a handful of Brazil nuts instead.
*RDA is for general adult population. Some groups, such as pregnant or breast-feeding women, need more.
Folic acid: Itâ€™s a must during pregnancy to help prevent birth defects, but recent studies show no real effect for the rest of us against heart disease, cancer or depression. The connection between folate and reduced risk of Alzheimer’s is not yet conclusive either.
RDA: 400 mcg. Find it in dark green leafy vegetables, fortified cereals and whole-grain breads.
Niacin: This B vitamin can be used to treat high cholesterol, but only under a doctor’s supervision due to the risk of potentially serious side effects, including liver damage.
RDA: Men – 16 mg. Women – 14 mg. A multivitamin gives you 20 mg. Some products will give you 500 mg. Stick to meat, fish, poultry, nuts and eggs instead.
Lycopene: Two studies, one by the FDA, recently concluded that consuming lycopene as a supplement or in rich food sources, such as tomatoes, does not offer strong cancer-fighting protection, as was previously promoted.
RDA: None established. You should still eat tomatoes (tomato sauce is even better) because they’re full of other important nutrients.
Iron: Only women who are pregnant or have heavy periods, as well as people with diagnosed deficiency disorders such as anemia, need extra amounts of this mineral. Iron supplements can interact with meds, other dietary supplements and food, and can worsen conditions like ulcers.
RDA: Women over 50 and all men – 8 mg. Women ages 19 to 50 – 18 mg. Red meat, poultry, fortified cereals, dried beans and lentils, and dark leafy greens are good sources.
Zinc: High doses can interfere with how the body metabolizes copper and iron, may weaken the immune system and may also reduce levels of HDL (good) cholesterol. Studies are mixed about its effect on the common cold. Zinc supplements can also interact with certain drugs, including some antibiotics, blood pressure medications and NSAIDs.
RDA: Men – 11 mg. Women – 8 mg. Meat and poultry are high in zinc; vegetarians should eat plenty of grains, beans, nuts, lentils and dairy products.
*RDA is for general adult population. Some groups, such as pregnant or breast-feeding women, need more.