Older Americans are hooked on vitamins despite scarce evidence they work

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When she was a young physician, Dr. Martha Gulati noticed that many of her mentors were prescribing vitamin E and folic acid to patients. Preliminary studies in the early 1990s had linked both supplements to a lower risk of heart disease.

She urged her father to pop the pills as well: "Dad, you should be on these vitamins, because every cardiologist is taking them or putting their patients on (them)," recalled Gulati, now chief of cardiology for the University of Arizona College of Medicine-Phoenix.

But just a few years later, she found herself reversing course, after rigorous clinical trials found neither vitamin E nor supplements did anything to protect the heart. Even worse, studies linked high-dose vitamin E to a higher risk of heart failure, and death from any cause.

"'You might want to stop taking (these),'" Gulati told her father.

More than half of Americans take , including 68 percent of those age 65 and older, according to a 2013 Gallup poll. Among older adults, 29 percent take four or more supplements of any kind, according to a Journal of Nutrition study published in 2017.

Often, preliminary studies fuel irrational exuberance about a promising dietary , leading millions of people to buy in to the trend. Many never stop. They continue even though more rigorous studies—which can take many years to complete—almost never find that vitamins prevent disease, and in some cases cause harm.

"The enthusiasm does tend to outpace the evidence," said Dr. JoAnn Manson, chief of preventive medicine at Boston's Brigham and Women's Hospital.

There's no conclusive evidence that prevent chronic disease in the average American, Manson said. And while a handful of vitamin and mineral studies have had positive results, those findings haven't been strong enough to recommend supplements to the general U.S. public, she said.

The National Institutes of Health has spent more than $2.4 billion since 1999 studying vitamins and minerals. Yet for "all the research we've done, we don't have much to show for it," said Dr. Barnett Kramer, director of cancer prevention at the National Cancer Institute.

A big part of the problem, Kramer said, could be that much nutrition research has been based on faulty assumptions, including the notion that people need more vitamins and minerals than a typical diet provides; that megadoses are always safe; and that scientists can boil down the benefits of vegetables like broccoli into a daily pill.

Vitamin-rich foods can cure diseases related to vitamin deficiency. Oranges and limes were famously shown to prevent scurvy in vitamin-deprived 18th-century sailors. And research has long shown that populations that eat a lot of fruits and vegetables tend to be healthier than others.

But when researchers tried to deliver the key ingredients of a healthy diet in a capsule, Kramer said, those efforts nearly always failed.

It's possible that the chemicals in the fruits and vegetables on your plate work together in ways that scientists don't fully understand—and which can't be replicated in a tablet, said Marjorie McCullough, strategic director of nutritional epidemiology for the American Cancer Society.

More important, perhaps, is that most Americans get plenty of the essentials, anyway. Although the Western diet has a lot of problems—too much sodium, sugar, saturated fat and calories, in general—it's not short on vitamins, said Alice Lichtenstein, a professor at the Friedman School of Nutrition Science and Policy at Tufts University.

And although there are more than 90,000 dietary supplements from which to choose, federal health agencies and advisers still recommend that Americans meet their nutritional needs with food, especially fruits and vegetables.

Also, American food is highly fortified—with vitamin D in milk, iodine in salt, B vitamins in flour, even calcium in some brands of orange juice.

Without even realizing it, someone who eats a typical lunch or breakfast "is essentially eating a multivitamin," said journalist Catherine Price, author of "Vitamania: How Vitamins Revolutionized the Way We Think About Food."

That can make studying vitamins even more complicated, Price said. Researchers may have trouble finding a true control group, with no exposure to supplemental vitamins. If everyone in a study is consuming fortified food, vitamins may appear less effective.

The body naturally regulates the levels of many nutrients, such as vitamin C and many B vitamins, Kramer said, by excreting what it doesn't need in urine. He added: "It's hard to avoid getting the full range of vitamins."

Not all experts agree. Dr. Walter Willett, a professor at the Harvard T.H. Chan School of Public Health, says it's reasonable to take a daily multivitamin "for insurance." Willett said that clinical trials underestimate supplements' true benefits because they aren't long enough, often lasting five to 10 years. It could take decades to notice a lower rate of cancer or heart disease in vitamin takers, he said.

For Charlsa Bentley, 67, keeping up with the latest nutrition research can be frustrating. She stopped taking calcium, for example, after studies found it doesn't protect against bone fractures. Additional studies suggest that calcium supplements increase the risk of kidney stones and heart disease.

"I faithfully chewed those , and then a study said they didn't do any good at all," said Bentley, from Austin, Texas. "It's hard to know what's effective and what's not."

Bentley still takes five supplements a day: a multivitamin to prevent dry eyes, magnesium to prevent cramps while exercising, red yeast rice to prevent diabetes, coenzyme Q10 for overall health and vitamin D based on her doctor's recommendation.

Like many people who take dietary supplements, Bentley also exercises regularly—playing tennis three to four times a week—and watches what she eats.

People who take vitamins tend to be healthier, wealthier and better educated than those who don't, Kramer said. They are probably less likely to succumb to heart disease or cancer, whether they take supplements or not. That can skew research results, making vitamin pills seem more effective than they really are.

Preliminary findings can also lead researchers to the wrong conclusions.

For example, scientists have long observed that people with high levels of an amino acid called homocysteine are more likely to have heart attacks. Because folic acid can lower homocysteine levels, researchers once hoped that would prevent heart attacks and strokes.

In a series of , folic acid pills lowered homocysteine levels but had no overall benefit for , Lichtenstein said.

Studies of also may have led researchers astray.

When studies of large populations showed that people who eat lots of seafood had fewer heart attacks, many assumed that the benefits came from the omega-3 fatty acids in fish oil, Lichtenstein said.

Rigorous studies have failed to show that prevent heart attacks. A clinical trial of fish oil pills and vitamin D, whose results are expected to be released within the year, may provide clearer questions about whether they prevent disease.

But it's possible the benefits of sardines and salmon have nothing to do with fish oil, Lichtenstein said. People who have fish for dinner may be healthier due to what they don't eat, such as meatloaf and cheeseburgers.

"Eating fish is probably a good thing, but we haven't been able to show that taking fish oil (supplements) does anything for you," said Dr. Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic Foundation.

Taking megadoses of vitamins and minerals, using amounts that people could never consume through food alone, could be even more problematic.

"There's something appealing about taking a natural product, even if you're taking it in a way that is totally unnatural," Price said.

Early studies, for example, suggested that , a substance found in carrots, might help prevent cancer.

In the tiny amounts provided by fruits and vegetables, beta carotene and similar substances appear to protect the body from a process called oxidation, which damages healthy cells, said Dr. Edgar Miller, a professor of medicine at Johns Hopkins School of Medicine.

Experts were shocked when two large, well-designed studies in the 1990s found that beta carotene pills actually increased lung cancer rates. Likewise, a clinical trial published in 2011 found that vitamin E, also an antioxidant, increased the risk of prostate cancer in men by 17 percent. Such studies reminded researchers that oxidation isn't all bad; it helps kill bacteria and malignant cells, wiping them out before they can grow into tumors, Miller said.

"Vitamins are not inert," said Dr. Eric Klein, a prostate cancer expert at the Cleveland Clinic who led the vitamin E study. "They are biologically active agents. We have to think of them in the same way as drugs. If you take too high a dose of them, they cause side effects."

Gulati, the physician in Phoenix, said her early experience with recommending supplements to her father taught her to be more cautious. She said she's waiting for the results of large studies—such as the trial of fish oil and D—to guide her advice on vitamins and supplements.

"We should be responsible physicians," she said, "and wait for the data."

Explore further

Epidemiologist aims to sort fact from fiction on dietary supplements

Journal information: Journal of Nutrition

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User comments

Apr 06, 2018
Why do we have such articles? Regular multivitamins, without mega-doses of vitamins cost pennies per day. Maybe there is scant evidence that they work. Most medications have no evidence that there additive affects of side affects don't on average cause more problems than they solve. These pills can cost 10 to 100 thousand dollars per year.
Just the placebo affect of multivitamins is worth it.

Apr 06, 2018
This is what nutritional supplements look like to low intelligence. The medical profession sells out to big pharmaceutical companies and is concerned more with their paychecks than human health. Doctors practice avoiding lawsuits rather than medicine. Failure to prevent disease increases income to the health care industry.

Apr 06, 2018
Several centuries ago, British sailors prevented scurvy with Vitamin C-rich limes, hence the "limey" moniker.
I've taken many different supplements for decades and have no joint pain and can walk for ten miles without fatigue.
Vitamins and herbs work, and anecdotal evidence from around the world is plenty adequate for me. Also, the
website ncbi (National Center for Biotechnology Information) provides clinical proof of the efficacy of vitamins and herbs.

Apr 06, 2018
If you look at a lot of the so-called main-stream scientific studies on vitamin and supplements - they have often been very flawed. Wrong dosages, wrong product/non-standardized products, etc. etc. Classic experimental screw up studies were made on Vit. E, wrong sources and does. Same with fish oil - species sources are critical - only wild krill feeding salmon.

It would be really hard to separate the for profit biases between the snake oil supplement industry and the grossly for profit and parasitic prescription big pharma industry.

About all any of us can do is stay up on current research, think critically about that research, carefully read health product labels - and then take our best shots at taking care of our own health.

Apr 07, 2018
Because you can't vitamin your way out of chronic diseases, when the rest of what's going into your body isn't good for it.

At almost 50, I changed over my diet to all plants - no animals or animal products, and it's the best thing I've ever done for myself, healthwise.

Not knocking vitamins/herbs/nutritionals - still take a handful of those a day since I was 20.

Apr 07, 2018
For ethical reasons doctors are unable to prescribe Placebo even though countless studies of the efficacy of drugs shows it works. That is why drug studies look for benefits in excess of that from Placebo in double blind studies. By taking harmless levels of supplements people get the powerful benefits of Placebo if nothing else. It only goes wrong if they take too much, spend money they can't afford or use them instead of actual medicine.

Apr 07, 2018
The article is a big pharma 'hit piece', against multivitamins and supplements. It's tied to a thing called 'agenda 21'.

Responsible well managed vitamin and supplement consumption is a good thing, otherwise it would not have evolved to what it is today.

The trillion dollar plus big pharma machine wants to own more ground, more profit ...and it has to find a way to do that. Attacking and tearing down supplements is the best path forward under such an agenda.

Apr 08, 2018
This is the most illiterate article I have read from a professional in a long time. I think as medical professionals we owe a duty to society to be intellectually honest. And my research has disclosed significant credible evidence to the contrary. There is a place for pharmaceuticals and there is a place for supplements and we should properly educate consumers about the benefits of both.

Apr 08, 2018
I would caution those blustering about 'Big Pharma' trying to deprive the public of their vitamin/mineral supplements. Most of the manufacturers of those products are using "Big Pharma' facilities and are or were themselves employees, researchers, executives of the corporate manufacturers.

The FDA persnickety regulators were skeptical of the bombastic claims of "Miracle Vitamins". So the pharmacy industry hedged their bets with spinoff labels to flog the high-profit, low-cost vitamins to a gullible public.

First of all, no one can agree on what vitamins are. Or specifically contribute to biological functions. In general, there some proven good usage such as niacin supplement for pregnant women.

If you eat a moderate diet, do not abuse alcohol, do not use tobacco or marijuana. Excise and enjoy the people you know, enjoy your work and just chill out. You have no discernable need for supplements.

Most of the placebos you take, just piss out.

Apr 08, 2018
The thing with vitamins (and any other nutrients) is: It's not how much you take in but how much your system takes up. if youre just going to excrecte the vitamins again then they're not doing anything - and that is happening with the multivitiamin pills and powders.

It's especially ridiculous with vitamins A, D, E and K, because these are only fat soluble (i.e. eating them in their raw form...as pills or raw carrots or whatnot) does absolutely nothing for you. You're literally just paying the producing company for something you're flushing down the toilet.

Apr 08, 2018
The needs humans have for certain nutrients is established knowledge. The lack of many of these nutrients in modern diets is well known, and not open to debate in intelligent circles
This article appears to have been written by some sort of low intelligence hack with little to no understanding of the subject matter. Sometimes you'll see some sad and suspect writing on this site - this is one of those times.

Apr 09, 2018
The needs humans have for certain nutrients is established knowledge. The lack of many of these nutrients in modern diets is well known, and not open to debate in intelligent circles

No doubt. But you have to give the human body the nutrients in a form that he can actually use. E.g. chomping down on raw carrots will not get you any vitamin A (although carrots are full of vitamin A) that is because the human body cannot absorb it in the form it is presented in raw carrots.
(For one the plant cells are too tough, so we can't break them down sufficiently. There is a reason why herbivores chew the cud, have several stomachs and several more meters of intestine than we do, but also because vitamin A is fat soluble. Without added fats we can't take it up very well. There is a reason we do something called 'cooking'. And it's not because we like stuff warm. In effect cooking is a form of external predigestion)

Apr 09, 2018
just going to excrecte the vitamins
There are ways around uptake limits.

"A liposome is a spherical vesicle having at least one lipid bilayer. The liposome can be used as a vehicle for administration of nutrients and pharmaceutical drugs... A liposome can be hence loaded with hydrophobic and/or hydrophilic molecules. To deliver the molecules to a site of action, the lipid bilayer can fuse with other bilayers such as the cell membrane, thus delivering the liposome contents... the natural encapsulation of lypophilic and hydrophilic nutrients within liposomes has made for a very effective method of bypassing the destructive elements of the gastric system and aiding the encapsulated nutrient to be delivered to the cells and tissues."

-Several supplements available but several are crap like Dr mercola garbage which claims to be liposomal but is an emulsion.

Making liposomes that can survive to delivery is a complex and expensive process.

Apr 09, 2018
Black pepper extract is also being added to supplements to increase uptake.

"Piperine is under preliminary research for its potential to affect bioavailability of other compounds in food and dietary supplements, such as a possible effect on the bioavailability of curcumin."
Sometimes you'll see some sad and suspect writing on this site - this is one of those times
According to the byline it wasn't written on this site. Articles here rarely are. You knew this didn't you??

Apr 09, 2018
In 70s there was a lot of research of vitamins, especially in socialist block, where medical research was much more 'honest'. It was established on, so called, 'hard science' but not on 'commercial enterprise' as in the West. Unfortunately it is not available online because of many reasons. United Nations all the time distributes vit A and other vitamins to kids in 3id world. E.g. google - Vitamin A deficiency - UNICEF DATA. Why, if it's useless? Why pregnant women are prescribed vitamins by 'mainstream' Western medicine? Why multivitamins are included in ALL baby formulas? Why some conditions still can be treated only by vitamins? Campaign against vitamins, herbs and other 'natural' treatments started already some time ago. Who is funding it - only the question?

Apr 10, 2018
pf, you wonder why? First hopeful wish fulfillment that distribution of vitamin supplements could make up for minimal to nonexistent professional healthcare.

And, who knows? Maybe it did help some of the impoverished who have very limited dietary choices.

Contrary to several generations of altright fairytails whining about 'Foreign Aid". By a number of laws and regulations, most of the funding is spent in the US of A, on American produced products.

Some goes to cover overseas administrative costs and salaries for professional trainers. Many of whom are American 'experts'.

Big Pharma makes biggly profits from the taxpayer paid corporate-state subsidies to the drug manufacturers. Who ship overseas products that are defective, proven toxic or useless, past the sale by date. All quite legally. Cause somebody has to pay for congressperson's reelection campaigns.

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