Big Bad Buzz on Vitamins

You work hard to maximize your health. Are supplements working against you?

They’re good for you. They’re a waste of money. Good for you. A waste. Good. Waste. Good. Waste. And so it goes—50 years of medical opinion on dietary supplements. Perhaps we should be consoled that scientists are inching their way toward the “truth,” but the ping-ponging of expert advice has left consumers in a predictable state: whiplashed and utterly confused.

The good-waste argument is one thing. But this year brought alarming news that certain supplements—even daily multivitamins—may actually be bad for you. Some may increase the risk of heart attacks. Others are tentatively linked with cancer. And then there’s the alarming finding by a leading consumer group that many supplements contain contaminated or weak ingredients.

With all the ups, downs, reversals, and wild-eyed conjecture, consumers have never been more confused. To understand what’s best for you, let’s look at the potential downside of supplementation and then examine who many actually benefit from them. And finally, let’s work in a few dietary pointers from the experts.

Can’t Hurt, May Help?

When a Nobel laureate in chemistry takes megadoses of vitamin C, declaring that it improves health, fights cancer, and lengthens life, who’s to argue—especially when he lives to a spry 92.

Until his death in 1994, Linus Pauling did just that, faithfully gobbling down some 12,000 milligrams of vitamin C daily. When he felt a cold coming on, he upped his daily ante to the equivalent of four hundred 100-milligram pills. At 667 times the Recommended Daily Allowance (RDA), the nonagenarian was devouring a nearly two-year supply every single day.

Pauling inspired droves of 1980s-era Americans to hop aboard the megadose bandwagon. But lost in the public stampede was this inconvenient truth: Not a single credible study in the last 100 years has shown you can megadose your way to good health. At the time, nutrition experts scoffed at his headline-grabbing claims but had little rigorous data to back them up. Now they do, and they’re turning Pauling’s “more is better” philosophy on its head. But in so doing, they’re going a step further and challenging conventional wisdom about supplementation itself.

Consider vitamins A, C, and E. Die-hard enthusiasts have long hailed this iconic trio for their allegedly miraculous properties, but a raft of recent research raises troubling questions:

• Researchers announced in 2005 that supplemental vitamin E does not reduce the risk of cancer or major cardiovascular events and is instead associated with a higher risk of death.

• In 2007, a massive European study concluded that high doses of antioxidant supplements can cause cancer by inducing gene mutations.

• In 2008, Danish researchers determined that even RDA levels of supplemental beta-carotene and vitamins A and E increase mortality. “The antioxidants also appeared to offer no benefit to people with gastrointestinal, heart, neurological, eye, skin, rheumatoid, kidney and endocrine diseases,” they noted.

• Also in 2008, American researchers found that multivitamins, folate, and vitamins C and E do not lower the risk of lung cancer and that continued high levels of vitamin E may increase that risk.

These studies add to other recent ones underscoring two major points: Instead of optimizing health, megadoses can boomerang on people in nasty ways. And even moderate amounts of certain supplements may be problematic.

Concerning this second point, more research is clearly needed, but these recent findings echo the decades-long mantra of the American Dietetic Association (ADA): Eat your vitamins, don’t pop them.

ADA spokesperson Roberta Anding, MS, RD, LD, CDE, cautions against chasing headlines. since the 1960s, manufacturers have trumpeted supplemental chromium and selenium as superstars, nevermind that excessive levels of these heavy metals are now conclusively linked with liver disease, heart abnormalities, chronic fatigue, and irritability.

Same goes for vitamin B6 (thiamin) supplements. In the 1990s, “progressive” voices sold women suffering from PMS on supersized doses of supplemental B6, reasoning they would effortlessly excrete the excess. Today, we know not only that B6 doesn’t do much for PMS, but boosting your intake can trigger frightening complications, ones that medical experts sometimes have great difficulty in linking to B6 overuse.

Anding recalls a female gymnast who sought her expertise after an odd injury. “She went to grip the uneven bars, couldn’t hang on, fell backwards, and fractured her C-4 vertebrae,” the Houston-based dietitian explains. After the teen displayed an unsteady gait and complained of numb feet and hands, Anding’s nutritional sleuthing uncovered the culprit. The coach had “amped up” the girl’s B6 intake to give her more energy. But by ingesting 5,000 times the RDA, she was suffering from vitamin B6 poisoning.

Christine Gerbstadt, MD, MPH, RD, LDN, also an ADA spokesperson, says mass consumer confusion is to be expected. While bona fide nutrition experts drown each other out in a windstorm of conflicting opinion, dietary product manufacturers broadcast a loud, steady message that supplementation is wise—even natural. And the nation’s leading medical authorities haven’t always helped.

In 2002, the American Medical Association made a dramatic policy reversal and endorsed taking multivitamins. But four years later, the National Institutes of Health declared there’s no evidence that supplements ward off illness and that they may cause harm when taken above RDA levels. Nor are Harvard experts on the same page. While a prominent Harvard Web site today declares that “a daily multivitamin is a great nutrition insurance policy,” a Harvard health newsletter recently railed against multivitamins and an irrational “vitamania” sweeping the nation.

As contradictions pile upon ironies, public health officials once worried about vitamin deficiencies in the American diet are today wringing their hands about the unintended consequence of widespread overdosing. With all the supplemental pill popping, vitamin-spiked waters, and fortified “functional” foods, Americans may be in danger of getting too much of a good thing. So knowing what’s best is key.

Who Needs What

While researchers slowly tease fact from fiction, most authorities agree on this central point: If you are eating well, you probably don’t need a supplement. The FDA’s Dietary Guidelines for Americans advises that consumers adopt an overall strategy for achieving adequate vitamin intake and suggests meeting those needs primarily through foods “with targeted supplementation recommended for certain sensitive populations.” These groups include women, seniors, certain minorities, people with chronic health issues, vegans and vegetarians, the perpetually stressed, the chronically ill, and alcoholics.

Let’s look at three of these groups:

• Girls: A 2007 study confirms that teenage girls in general, and black adolescents in particular, don’t get enough vitamin A, vitamin D, calcium, and magnesium compared with their white counterparts. It also determined that most girls fall short of the recommended levels of vitamin E, magnesium, and folate, and that girls of color generally get far fewer micronutrients than white girls. The study’s authors recommended improved diets for all girls.

• Women: The Centers for Disease Control and Prevention (CDC) urged all women, especially those aged 18 to 24, get at least 400 micrograms of synthetic folic acid every day to lessen their chances of having a baby with a serious birth defect. The CDC specifically recommended taking supplements and fortified foods in addition to a folate-rich diet. Because these deformities occur during the first few weeks of pregnancy—when many women are unaware they are pregnant—all women of childbearing age are included in this advisory.

Good sources of folate include breakfast cereals, leafy green vegetables, black-eyed peas, orange juice, and dried beans. If you eat a rich, balanced diet, you probably are getting enough folate, but the CDC urges supplementation just in case. Pregnant women should also consume iron-rich foods, along with foods high in vitamin C, which enhances absorption of iron.

• Seniors: The FDA suggests that individuals over the age of 50 consider consuming vitamin B12 in its crystalline form. Older adults may also need to take extra vitamin D if they are not exposed to sufficient sunlight.

It’s also important for seniors to keep their doctors in the loop, as some dietary supplements interact adversely with certain medications. Vitamin E supplements, for instance, may seem perfectly harmless, but taking them with aspirin and Coumadin can thin your blood enough to cause internal bleeding and a stroke. And the herbal supplement St. John’s wort may interfere with medication for depression and heart disease.

Anding notes that vitamin D insufficiency “is probably the most common vitamin deficiency that we have.” But overdosing is associated with nausea, weakness, confusion, constipation, and heart arrhythmia. She adds, “I see a lot of iron overload in men. With all these highly fortified foods—breakfast cereal with iron, energy bars with iron, bread with iron—we don’t ever think that we are poisoning people.”

The ADA has long championed good, nutritious meals instead of multivitamins, but many Americans ignore the message as old fashioned—nevermind that the latest research seems to buttress the ADA’s position. Some of us take supplements to offset a lifestyle of fast food, overindulgence, and chronic stress and sleep debt. Others see supplements as their best line of defense against familial vulnerability to cancer, heart disease, eye disease, thinning bones, and more. The best answer we have today is to eat a diet rich in fruit, veggies, and grains; get plenty of rest and exercise, keep your alcohol intake within moderate guidelines, and otherwise enjoy life.

“If people have a good diet, they don’t need a supplement, and if they have a bad diet, a supplement isn’t going to help them,” says Gerbstadt.

“Human beings are designed to eat food and not designed to eat nutrients. The more I can fill my plate with whole grains and plant-based foods, the better off I am going to be,” adds Anding.

Tod Cooperman, MD, president of ConsumerLab.com, a provider of independent test results and information to help consumers and healthcare professional evaluate health, wellness, and nutrition products, admits that with all the conflicting science, “Sometimes it’s difficult for consumers to know what to do. I remember one thing we learned in medical school: Too much of anything is not a good thing.”

While researchers continue their game of ping-pong, Gerbstadt offers her best guidance: “There is no better insurance for a healthy diet than moderation and seeing a registered dietitian.”

— Matthew Robb