Your Health Checkup: A Life Free from Chronic Diseases Cannot Be Found in a Pill Bottle

“Your Health Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive. 

Order Dr. Zipes’ new book, Bear’s Promise, and check out his website


As I was sitting at my computer contemplating what to write for this column, an email blast appeared listing five supplements it said I should be taking. They included magnesium, vitamin C, B vitamins, fish oil and iron. I take none of them.

I have written previously about dietary supplements, noting that half of American adults consume at least one dietary supplement daily. I also stated that randomized clinical trials of vitamin and mineral supplements have not demonstrated clear benefits in preventing chronic diseases unrelated to nutritional deficiency, and stressed the fact that the Food and Drug Administration does not review dietary supplements for safety and efficacy. That means some may be harmful, may interact adversely with some medicines, and may not contain the precise ingredients stated on the label. I recently made the point that fish oil is one of the few dietary supplements with well-established efficacy.

Sadly, most of us would rather swallow a pill than change our behavior. Yet it is the latter that can most impact future health. For example, a recent study showed that healthy behavior at middle age was most important if you want to live your life free from cancer, heart disease, and type 2 diabetes.

Investigators analyzed information taken from 73,196 women in the Nurses’ Health Study, who were followed for 34 years, and 38,366 men in the Health Professionals Follow-up Study, who were followed for 28 years. Healthy behavior was defined by five parameters: never smoking, body mass index of 18.5-24.9, moderate to vigorous physical activity (at least 30 minutes/day), moderate alcohol intake (women: 5-15 g/day — about one drink per day; men 5-30 g/day — about two drinks per day), and a higher diet quality score (upper 40 percent — such as from eating the Mediterranean diet).

Women who practiced four or five of the healthy habits at age 50 lived almost 11 years longer without developing diabetes, cardiovascular diseases, and cancer compared to women who practiced none of these behaviors (34.4 years versus 23.7 years). Similarly, men practicing four or five healthy habits at age 50 lived more than seven years longer without these three chronic diseases than did men who practiced none of them (31.1 years versus 23.5 years). The lowest expectancy of disease-free life was found in men who were current heavy smokers (greater than 15 cigarettes/day) and obese men and women (body mass index greater than 30).

The take-away message from this important study is that your chances of living a life without type 2 diabetes, cancer, or cardiovascular disease are better by adopting a healthy lifestyle than popping dietary supplement pills.

Naturally, you should not stop medicines prescribed for heart or other conditions. Those types of pills can be lifesaving.

There may be a dietary supplement that proves worthwhile in today’s climate. Vitamin D supplements may help prevent acute respiratory tract infections. In a study published several years ago, investigators analyzed data from 25 randomized controlled trials containing 10,933 participants taking vitamin D supplements. They found that vitamin D supplements were well tolerated and reduced the risk of acute respiratory tract infection, particularly in those who were vitamin D deficient to start, perhaps by supporting the immune system response. Whether vitamin D supplements protect against the COVID-19 viral infection should be determined by a prospective randomized trial, as researchers point out that there currently isn’t sufficient scientific evidence to support claims that high-dose vitamin D supplementation will be effective in preventing or treating COVID-19.

That said, there may be advantages in taking Vitamin D for some. It would be reasonable to check with your health care professional before starting.

Featured image: Shutterstock

Your Weekly Checkup: Can Dietary Supplements Harm You?

“Your Weekly Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive.  

Order Dr. Zipes’ new book, Damn the Naysayers: A Doctor’s Memoir.

I have written previously about dietary supplements and noted that half of American adults consume at least one dietary supplement daily. Most randomized clinical trials of vitamin and mineral supplements have not demonstrated clear benefits in preventing chronic diseases unrelated to nutritional deficiency. Moreover, the Food and Drug Administration does not review dietary supplements for safety and efficacy.

Dietary supplements include vitamins, minerals, botanicals, amino acids, and enzymes that are not intended to treat or prevent disease and are classified as a category of food not subject to the premarket safety and effectiveness testing required by the FDA for drugs. Many consumers think that these supplements are carefully regulated and that the label accurately lists the ingredients. This is often not the case because a less expensive ingredient can be substituted for a more expensive one listed on the label, or an active drug might be included in what is labeled as only a botanical supplement (see below).

While the FDA is tasked with identifying and removing unsafe products from the market to help ensure that products marketed as dietary supplements are safe, well-manufactured, and accurately labeled, it is often ineffective in doing so because of cumbersome, outdated, and unenforced regulations. The FDA relies on surveillance efforts after the drug is marketed, including review of adverse event reports and consumer complaints, inspection of dietary supplement firms, screening of imported products, and adverse reports from the dietary supplement firm.

When such a product is identified, the FDA frequently requests that the responsible firm voluntarily recall the product. However, many supplements subject to recalls remain on sale still adulterated with pharmaceutical drugs, sometimes years after the initial recall. Consumers of a supplement subject to a voluntary recall sometimes are unaware of the recall and continue to purchase the product.

An analysis of FDA warnings of contaminated supplements from 2007 through 2016 published recently found unapproved and sometimes dangerous drugs in 746 dietary supplements, almost all of them marketed for three categories: sexual enhancement, weight loss, or muscle growth. The most common adulterants were sildenafil (Viagra) for sexual enhancement supplements, sibutramine (an adrenaline-like drug sold under the brand name Meridia and withdrawn from the U.S. market in 2010) for weight loss supplements, and synthetic steroids or steroid-like ingredients for muscle building supplements. Fluoxetine, a prescription antidepressant (Prozac), was found in 17 of 317 weight loss products.

About 80 percent of the supplements were contaminated by one pharmaceutical, 20 percent contained more than one unapproved ingredient, and two of the supplements contained six unapproved drugs. Despite these contaminants, fewer than half the products were recalled.

Twenty-eight products were named in multiple FDA warnings, with nineteen (67.9%) still containing new unapproved ingredients in the second or third warning, indicating the FDA found the product to be adulterated more than once.

An editorial accompanying the article cited above noted that in the current study, the FDA discovered 746 supplements to be adulterated but announced voluntary recalls for only 360, leaving more than 350 adulterated supplements still available for sale. The editorial called for reform of the Dietary Supplement Health and Education Act of 1994.

It is clear that active drugs continue to be found in dietary supplements, even after FDA warnings, because of major deficiencies in the FDA’s regulation of supplements. The drug ingredients in these dietary supplements have the potential to cause serious adverse health effects owing to inappropriate use, interaction with other medications, underlying health conditions, or other pharmaceuticals within the supplement.

In the meantime, my advice for those who ingest dietary supplements: Caveat emptor. Let the buyer beware.

Also read Vitamin Hype: Are You Wasting Your Money on Supplements?

Vitamin Hype: Are You Wasting Your Money on Supplements?

We love our vitamins. Half of all American adults take a multivitamin or another vitamin or mineral supplement regularly. And 70 percent of people who are 65 or older take them. That amounts to more than $12 billion per year. According to Johns Hopkins, that money might be better spent on real sources of vitamins such as fruits, vegetables, healthy carbohydrates, and dairy products. In a 2013 editorial in the journal Annals of Internal Medicine titled “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements,” Johns Hopkins researchers reviewed the data, homing in on three particularly alarming studies. One was an analysis of research involving 450,000 people, finding that multivitamins did not lower risk for cancer or heart disease. Another tracked multivitamin use of 5,947 men and their mental functioning over 12 years and found that multivitamins did not reduce risk for mental declines such as slowed thinking or memory loss. The third was a study of 1,708 heart attack survivors who were randomly split into two groups. For up to five years, one group took a high-dose multivitamin and minerals and the other took a placebo (the patients, the physicians caring for them, and study personnel did not know who was receiving a placebo or multivitamin-and-mineral pills). Rates of heart attacks, heart surgeries, and deaths later on were similar in the two groups.

Cover for the book Hype, by Nina Shapiro, M.D. with Kristin Loberg
From Hype by Nina Shapiro, M.D. with Kristin Loberg. Copyright © 2018 by the author and reprinted by permission of St. Martin’s Press

What’s more, two other prominent studies spanning more than a decade, completed in 1995 and following tens of thousands of people, showed that beta-carotene and vitamin E supplementation in particular can be downright harmful, significantly increasing the risk of cancer. One of these entailed the landmark Framingham Heart Study, which had to end early because the investigators found that taking too much beta-carotene, at first thought to be a cancer-preventing supplement, was associated with significant increase in cancer-related deaths. All of these studies have been routinely reported in the media, but they don’t seem to change people’s nutritional-­supplement habits. They don’t even sway me. I take a daily multivitamin. And vitamin C. When I have a cold, I go wild and take two Cs. And I even take vitamin D and calcium when I’m in the mood. My husband, also a doctor and a researcher, takes his share, and until our dentist implored me to stop, my kids had their gummy multis every morning.

The chief reason I take vitamins is for their placebo effect. This is the idea that if one thinks something helps, it does. I feel “healthier” taking vitamins. I feel that if my kids go heavy on the fries one day and skip their green beans, they may have gotten some much-needed nutrients in their vitamin.

I will not, however, megadose on anything (double- or even triple-dosing vitamin C, even up to 1,000 mg, is useless, but if used rarely is quite safe), and I would never rely on vitamin supplements to support genuine nutritional health or well-being. Vitamin boosts in drinks are powdery wastes of time and money. Are they dangerous? Probably not. Is there any evidence anywhere that they improve health? No. I work with nurses and doctors who are highly educated in science and medicine and are also quite health conscious. They exercise regularly and often follow their workouts with high-dose protein shakes and mega-vitamin-boosted juices. Will their muscles get bigger because of these drinks? No. But will these boosted drinks harm them? No. Their muscles get bigger because they lift weights, swim, or run. But again, I fall victim. As a busy surgeon, a protein bar of my brand of the month is often my lunch.

I routinely take completely unscientifically validated, yet entertaining, polls of medical staff — surgeons, nurses, residents, and medical assistants — regarding their vitamin intake. The simple question “Do you take vitamins?” leads to some pretty interesting answers, and no two are the same:

“I don’t… but I should.”

“No. Should I?”

“No, but my mom, who’s a pharmacist, ships me calcium from Amazon Prime.”

“I stopped taking multivitamins because I ran out of them.”

“I take E, C, D, B12, a multi, glucosamine, calcium, and fish oil.”

“Not really. Why? Okay — no, I don’t.”

“Every day.”

“No, but my kids do.”


Because of the minimal regulation of the contents of supplements, be they traditional vitamins or homeopathic herbs, one can never be sure of the actual contents. In 2012, the Department of Health and Human Services recommended that the FDA have more regulatory input on contents of supplements. Despite this, the FDA has no control. analyzed the actual vitamin content of several major vitamin supplements and found drastic differences in the amount of each vitamin compared to what the labels claimed. So aside from the quandary over whether to take vitamins, minerals, or homeopathic herbal supplements, we must question, Are we even getting what we think we are?

Investigators found that taking too much beta-carotene, at first thought to be cancer-preventing supplement, was associated with significant increase in cancer-related deaths.

Vitamins are essential for life and, by definition, are organic compounds required by a living organism. Currently there are 13 of them. The two main subsets of vitamins are fat soluble (can be dissolved in fat) and water soluble (can be dissolved in water). The fat-soluble vitamins — A, D, E, and K — can be stored in the liver and fatty tissues until they are needed, which is why we can get by without consuming them regularly. The water-soluble vitamins, B (which has several forms) and C, cannot be stored, which is why we need to consume them more regularly, and why “megadosing” or overdosing on them carries less danger.

Early primates lived in tropical regions containing vitamin-­filled fruits and vegetables. Access to these in the diet of our ancestors likely led to the loss of certain gene activity that had been responsible for vitamin production in earlier life-forms. While vitamins are made by living cells, humans can synthesize only two of the necessary 13 — vitamin D is made in our skin, as sunlight enables the breakdown of a form of cholesterol, and vitamin K is produced in our livers. Other than those two, we need to take in vitamins from other sources, including bacteria, fungi, and plants. One hundred million years ago, our primate ancestors made their own vitamin C, but then because of mutations in our human code, we lost the ability to carry out all the steps in synthesizing vitamin C. Now we rely on plants for this vitamin, as did the hunter-gatherers tens of thousands of years ago.

Some may say that the term limey is pejorative when referring to Englishmen. But they earned this title for good reason. Despite its connotations in modern times, the term is a compliment. In the 17th and 18th centuries, as well as in many prior, likely including when Columbus was headed west, explorers and sailors at sea for weeks or months on end would often become deathly ill from an unknown cause — they would develop full-body aches, purple spots on their skin, swollen gums, rotting teeth, and sudden death. Unbeknownst to them, they were suffering from scurvy, a severe form of vitamin C deficiency. British sailors in the late 1800s realized that the lack of fruits and vegetables on these long voyages led to this disease and would travel with limes and lemon juice to avoid the illness. It worked (though at the time no one knew why). Thus the nickname limey. Not until the 20th century did the ingredient that prevented, and also cured, scurvy become known: vitamin C. In 1928, Albert Szent-Györgyi, a Hungarian biochemist, was one of several scientists to discover that the body requires certain organic substances, known as vital amines, in small amounts, the absence or deficiency of which would lead to various diseases such as scurvy.

Also in the 1800s, manufacturers began to process rice in mills, which stripped the outer layer of the rice grain. Soon after this, and as the consumption of rice became more widespread, people began losing feeling in their legs and were soon unable to walk. A few decades later, chickens developed a similar disorder. Those chickens had been fed primarily white rice. Once chickens were fed unprocessed (cheaper) rice, they remained healthy. In 1880, the Dutch physician Christiaan Eijkman found that both humans and avians eating processed rice were suffering from the ailment beriberi due to thiamine, or vitamin B1, deficiency. The outer layer of the rice grain is high in vitamin B1, and stripping this away led to vitamin deficiency.

Vitamin deficiencies are usually reviewed in biology classes, and even in medical school, in a historical context. In my daughter’s middle school science class, the students learned about rickets, a bone disorder caused by vitamin D deficiency. She learned that, in the 18th century, this ­deficiency was not due to lack of vitamin D pills but due to lack of sunlight for children working in a factory all day, then spending minimal time outdoors in fume-filled, sun-obscuring air. Many of these deficiencies still exist in developing nations, as well as in pockets of poverty in the United States. But for the most part, our overfed society is anything but vitamin deficient. So why are we under the impression that vitamin supplements, or “boosts,” make us healthier? The overwhelming majority of people get substantially more vitamins than are needed for sustenance and growth from a standard (even unbalanced) diet. So why are over half of us hooked on our daily pills?


In 1931, when American-bred Linus Pauling was just 30 years old, he published a paper in The Journal of the American Chemical Society providing an esoteric explanation of how chemical bonds are more complex than previously thought. This led to his winning the Nobel Prize in chemistry in 1954. Subsequent to this landmark study, he published several historically significant articles about protein structure, evolutionary biology, and molecular biology. He was also a world-renowned pacifist who opposed Japanese internment camps in the United States during World War II. He derided Robert Oppenheimer’s work on the Manhattan Project and declined an offer to work for it, and he vocally opposed nuclear arms. This led to his second Nobel — the Peace Prize — in 1962. He racked up multiple honorary degrees and awards over his lifetime, including the National Medal of Science and being one of 15 scientists named as Time magazine’s “Men of the Year” in 1961. He was a hero on so many fronts — a scientist, a humanitarian, a peace activist. But then things got strange.

The placebo effect is not fake. It is a real physiologic reaction.

In 1965, he attended a talk from a so-called doctor, Irwin Stone, a recipient of an honorary Ph.D. from the Los Angeles College of Chiropractics. Dr. Stone offered that the secret to longevity and feeling great while living a long life was vitamin C. He suggested that Pauling, then living the good life in Southern California, take a whopping 3,000 mg per day of vitamin C to feel better and live longer. Maybe it was the California sunshine that is so known to fry one’s brain that fried Linus Pauling’s into believing this. He soon claimed that taking 50 times the recommended daily dose of vitamin C (yes, that’s right, adults only need 60 mg per day, even though today’s vitamin C supplements range from 250 mg to 1,000 mg) made him feel more vibrant. And the “vitamin C fights a cold” myth came from this one quote: “… the severe colds I had suffered several times a year all my life no longer occurred. … I increased my intake of vitamin C to 10 times, then 20 times, and then 300 times the RDA: now 18,000 milligrams per day.” The first bona fide megadoser. And vitamin C — not protein chemistry, the advent of molecular biology, evolutionary biology, or peace activism — is what Linus Pauling will evermore be remembered for.

Maybe it was his advanced age (although 65 is hardly advanced in this day and age). Maybe it was the warm California sun. Maybe it was the positive vibes of his alternative lifestyle, the likes of which always seem to start on the West Coast. Maybe because he had been such a superstar in science at such a young age, he began to believe his own press releases. For whatever reason, Dr. Pauling had clearly gone off the deep end with vitamin C. Soon after he started making his claims in the early 1970s, he wrote an international bestseller at age 70 called Vitamin C and the Common Cold, later reprinted as Vitamin C, the Common Cold, and the Flu. In both books he recommends at least 3,000 mg per day of vitamin C to ward off these pesky common ills. What followed was the beginning of the vitamin C craze, with over 50 million Americans, me and my family included, taking vitamin C supplements to avoid and treat colds. I remember the slightly chalky, tart orange chewables I took daily as a kid. And I’d take two when I had a cold. Sometimes I didn’t feel like taking them, so I snuck them to my dog.

But here’s the irony: Countless large studies, looking at thousands of subjects, in a multitude of medical centers in the United States, Canada, and abroad, found no benefits from vitamin C supplements — no reduction in the incidence, severity, or duration of colds or the flu. But to this day, vitamin C remains not only one of the most common supplements sold, it’s now also sold as boosts in smoothies, or in packets to repel the evil humors while traveling. There is no evidence that these superboosts make any difference in frequency, severity, or duration of colds.

Most vitamins, taken without megadosing, are harmless, but the placebo effect that goes along with taking them is more powerful than most can imagine. The placebo effect is not fake — it is a real physiologic reaction that the body has when something people feel they do will make that change. This has been examined in countless drug studies, and, before stricter guidelines on human subjects were created, in sham surgery studies. I’m not suggesting that you should go out and take supplements because you can trick yourself into making them help you, even if you know they won’t. But I am saying that, for the most part, supplements taken in moderation (for instance, one multivitamin per day instead of seven) are less likely to harm you than help you. This is because people take supplements as part of a healthy lifestyle, and all that goes along with this, including eating well, exercising, and getting sleep. They’re simply part of the package. The science may show that vitamin X does not prevent disease Y, but if you feel that your vitamins help, then go for it.

However, I firmly believe that even though a prescription is not needed, these should each be discussed with one’s doctor. If a patient has had kidney or liver problems, a doctor needs to advise which vitamins should be avoided. If a patient is on certain prescribed or over-the-counter medications, the doctor needs to know so as to advise which herbal supplements should be avoided. If a patient is to undergo surgery, the surgeon needs the whole list, including supplements and herbs. Many patients don’t consider vitamins or herbal supplements medications, so they often leave this critical piece out of the puzzle.

I can’t tell you how many times I’ve asked, “What medications do you take?”

And the answer is “None.”

“No vitamins or supplements?”

“Oh, of course I take a multi, two Ds, ginkgo, fish oil, and a powder I received from my holistic specialist. But I don’t take any medications.”


Dr. Nina Shapiro is the award-winning Director of Pediatric Otolaryngology and a Professor of Head and Neck Surgery at UCLA, who has been featured in The New York Times, NPR, and Kristin Loberg is the No. 1 New York Times bestselling co-author of Grain Brain, A Short Look at a Long Life, and others.

This article is from the November/December 2018 issue of The Saturday Evening Post. Subscribe to the magazine for more art, inspiring stories, fiction, humor, and features from our archives.

A Century of Hope and Hype

Vitamin C tablets on a wooden surface with sliced oranges
Over the top? Linus Pauling argued that vitamin C could reduce the incidence of all diseases by one-half, a claim that is disputed by contemporary studies. (Shutterstock)

Like most publications, the Post reported on preliminary findings about the benefits of vitamin supplements – sometimes with exuberance, sometimes with caution.

No Panacea

Where the concentrated [vitamin] tablets become indispensable is in medicine — in the emergency treatment of advanced deficiency disease sufferers. … Some family doctors go further. On the theory that if thiamine is a good thing, then twice as much is better, they prescribe the tablets in addition to diet.

Conscientious scientists don’t want people to get the idea that vitamins are the panacea for every human ailment. They are worried lest this impression grow too widespread and that the eventual reaction will tend to nullify the genuine progress that has been made.

—“Morale in a Test Tube” by John Kobler and James Rorty, November 1, 1941

Pill Pusher

“America’s Foremost Nutritionist” is the distinction claimed by Dr. Carlton Fredericks, a glib, sleek radio showman of 51 who saturates the airwaves with a medley of heterodox health theories, gibes at established scientific bodies, lame jokes, and hard-sell patter in behalf of his sponsors’ wares. According to Fredericks’ pet theme, modern food-processing methods so impair natural nutrients that many people need vitamin and mineral supplements. He estimates his radio audience at about a million, droves of whom, he contends, might be victims of dire dietary deficiencies had they not heeded his instructions.

In promulgating his views, Fredericks labors at a frantic pace. Early every evening, he ducks into an acoustically paneled study full of audio equipment and ad-libs material for his broadcasts, often until morning. The ensuing performance is unique.

“An allergist (to sample some typical tapes) gave a girl vitamin E. Six months later she had to get a bigger bra. So an experiment was organized. Vitamin E seems to move fat from one place to another where needed. If you want to join the experiment, have your physician contact me.”

Authoritative agencies, however, like the American Medical Association, feel that the doctor (of philosophy, not medicine) overvalues himself. Last November, the FDA confiscated copies of Eat, Live and Be Merry, along with $1,000 worth of vitamin preparations. The FCC has begun an investigation of Fredericks’ program.

—“Radio’s Pill Pusher” by John Kobler, June 16, 1962

Vitamin C for Longevity

For several years, beginning about 1935, physicians made considerable use of vitamin C and other vitamins in the prevention and treatment of the common cold and other diseases. Then an extraordinary event occurred, an event that has, I fear, been responsible for much unnecessary suffering during the past quarter of a century. The leading authorities in medicine and nutrition decided that an increased intake of vitamin C and other vitamins has no value in controlling the common cold and other diseases.

It is unfortunate that during the last 25 years physicians have neglected this field. On the basis of the existing evidence, which is better for the common cold than for other diseases, I make the estimate that the combined incidence of all diseases, at a given age, can be reduced one half by the regular ingestion of between one and five grams of vitamin C per day.

My conclusion is that by eating good unadulterated natural food, with emphasis on green and yellow or red vegetables, by a proper intake of vitamin C, vitamin E, and other vitamins, by largely eliminating ordinary sugar from the diet, and by some physical exercise every day, the process of deterioration that ultimately leads to death can be postponed an average of 20 years.

—“Five Ways to Live Longer” by Linus Pauling, October 1, 1974


Your Weekly Checkup: Should You Take Vitamin and Mineral Supplements?

“Your Weekly Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive.  

Order Dr. Zipes’ new book, Damn the Naysayers: A Doctor’s Memoir.


For many years I began each day ingesting fish oil, adding my contribution to the $30 billion industry of dietary supplementation. I stopped when the available evidence did not support its benefits for people not at high risk for cardiovascular disease. (Fish oil supplements may be reasonable for some people after a heart attack.)

Half of American adults consume at least one dietary supplement daily, 48% swallowing vitamins and 39% ingesting minerals, hoping to maintain health and ward off disease. Many do so because their daily pressures prevent them from eating a healthful and balanced diet, and they rationalize that the supplements will provide nutrition absent from their fast food regimen.

But is that true? Most randomized clinical trials of vitamin and mineral supplements have not demonstrated clear benefits in preventing chronic diseases unrelated to nutritional deficiency. In fact, ingesting vitamins and minerals in amounts exceeding the recommended daily allowance may actually be harmful, increasing mortality, cancer, and strokes. Some supplements can counteract the beneficial action of specific medications. In most cases, dietary supplements provide little if any benefit beyond that obtained in a nutritious diet.

Also, the nutrients in food usually are better absorbed by the body, are associated with fewer potential adverse effects, and provide optimal and balanced amounts as opposed to ingesting isolated compounds in highly concentrated form. Positive health outcomes are more strongly related to dietary patterns and foods than to individual supplements.

It’s also important to remember that the Food and Drug Administration does not review dietary supplements for safety and efficacy and, while manufacturers must adhere to Good Manufacturing Practice regulations, compliance monitoring may be less than optimal. A good practice is to choose a supplement certified by an independent tester who verifies that the supplement contains the labeled doses and is not contaminated with microbes, heavy metals or other toxins. Check the website of the Office of Dietary Supplements of the National Institutes of Health for accurate information.

While routine supplementation is not recommended for the general public, diet alone may not provide the necessary nutritional requirements in some groups. Pregnant women need higher amounts of folic acid and prenatal vitamins, and some mid-life and older adults require supplemental vitamin B12 and vitamin D. Calcium is best obtained by calcium-rich foods, with calcium supplements used only if the daily goal is not met. A recent analysis of multiple randomized trials found that supplements that included calcium, vitamin D, or both compared with placebo or no treatment was not associated with a lower risk of fractures among community-dwelling older adults. I have often joked that the urine of many Americans has the highest concentration of vitamins found anywhere, since multivitamin/multimineral supplementation is not recommended for generally healthy adults and the excess is just excreted.

A final word: be sure to tell your doctor about any dietary supplement you are taking to be certain it is compatible with your other medications and overall medical condition.

Common Causes of Irregular Heart Rhythms

Several foods and supplements can alter the heart’s electrical system and trigger heart rhythm disorders. Keep your heart in sync with this quick guide.

Caffeine: You’re probably well aware that coffee can cause erratic or rapid heartbeats. It can also lead to atrial fibrillation in susceptible people. Some feel palpitations when they consume caffeinated soda, tea, or chocolate.

Overeating: For some individuals over-indulging at the buffet table may cause symptoms. Why? A full stomach can irritate nearby nerves, stimulating the heart and triggering extra heartbeats.

Red Wine: Small amounts of alcohol, particularly red wine, can benefit the heart. In excess, however, alcohol may cause heart arrhythmias and “holiday heart,” or palpitations on Monday after a weekend binge.

Supplements: It’s impossible to say which dietary supplements can potentially affect the heartbeat (or interfere with heart medicines) because most are unregulated and untested. “Natural” does not mean “safe,” and consumers can unknowingly take products that contain hidden and potentially harmful ingredients. Diet pills can be especially dangerous. For example, the FDA warned last October that 20 brands of dietary supplements for weight loss were tainted with sibutramine—the active ingredient in prescription weight-loss drug Meridia that was linked to elevated blood pressure, heart rhythm problems, heart attacks, and stroke and removed from the U.S. market in 2010.