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Study Finds No Benefit for Dietary Supplements

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Eating healthy
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More than half of U.S. adults take dietary supplements [1]. I don’t, but some of my family members do. But does popping all of these vitamins, minerals, and other substances really lead to a longer, healthier life? A new nationwide study suggests it doesn’t.

Based on an analysis of survey data gathered from more than 27,000 people over a six-year period, the NIH-funded study found that individuals who reported taking dietary supplements had about the same risk of dying as those who got their nutrients through food. What’s more, the mortality benefits associated with adequate intake of vitamin A, vitamin K, magnesium, zinc, and copper were limited to food consumption.

The study, published in the Annals of Internal Medicine, also uncovered some evidence suggesting that certain supplements might even be harmful to health when taken in excess [2]. For instance, people who took more than 1,000 milligrams of supplemental calcium per day were more likely to die of cancer than those who didn’t.

The researchers, led by Fang Fang Zhang, Tufts University, Boston, were intrigued that so many people take dietary supplements, despite questions about their health benefits. While the overall evidence had suggested no benefits or harms, results of a limited number of studies had suggested that high doses of certain supplements could be harmful in some cases.

To take a broader look, Zhang’s team took advantage of survey data from tens of thousands of U.S. adults, age 20 or older, who had participated in six annual cycles of the National Health and Nutrition Examination Survey (NHANES) between 1999-2000 and 2009-2010. NHANES participants were asked whether they’d used any dietary supplements in the previous 30 days. Those who answered yes were then asked to provide further details on the specific product(s) and how long and often they’d taken them.

Just over half of participants reported use of dietary supplements in the previous 30 days. Nearly 40 percent reported use of multivitamins containing three or more vitamins.

Nutrient intake from foods was also assessed. Each year, the study’s participants were asked to recall what they’d eaten over the last 24 hours. The researchers then used that information to calculate participants’ nutrient intake from food. Those calculations indicated that more than half of the study’s participants had inadequate intake of vitamins D, E, and K, as well as choline and potassium.

Over the course of the study, more than 3,600 of the study’s participants died. Those deaths included 945 attributed to cardiovascular disease and 805 attributed to cancer. The next step was to look for any association between the nutrient intake and the mortality data.

The researchers found the use of dietary supplements had no influence on mortality. People with adequate intake of vitamin A, vitamin K, magnesium, zinc, and copper were less likely to die. However, that relationship only held for nutrient intake from food consumption.

People who reported taking more than 1,000 milligrams of calcium per day were more likely to die of cancer. There was also evidence that people who took supplemental vitamin D at a dose exceeding 10 micrograms (400 IU) per day without a vitamin D deficiency were more likely to die from cancer.

It’s worth noting that the researchers did initially see an association between the use of dietary supplements and a lower risk of death due to all causes. However, those associations vanished when they accounted for other potentially confounding factors.

For example, study participants who reported taking dietary supplements generally had a higher level of education and income. They also tended to enjoy a healthier lifestyle. They ate more nutritious food, were less likely to smoke or drink alcohol, and exercised more. So, it appears that people who take dietary supplements are likely to live a longer and healthier life for reasons that are unrelated to their supplement use.

While the study has some limitations, including the difficulty in distinguishing association from causation, and a reliance on self-reported data, its findings suggest that the regular use of dietary supplements should not be recommended for the general U.S. population. Of course, this doesn’t rule out the possibility that certain subgroups of people, including perhaps those following certain special diets or with known nutritional deficiencies, may benefit.

These findings serve up a reminder that dietary supplements are no substitute for other evidence-based approaches to health maintenance and eating nutritious food. Right now, the best way to live a long and healthy life is to follow the good advice offered by the rigorous and highly objective reviews provided by the U.S. Preventive Services Task Force [3]. Those tend to align with what I hope your parents offered: eat a balanced diet, including plenty of fruits, veggies, and healthy sources of calcium and protein. Don’t smoke. Use alcohol in moderation. Avoid recreational drugs. Get plenty of exercise.

References:

[1] Trends in Dietary Supplement Use Among US Adults From 1999-2012. Kantor ED, Rehm CD, Du M, White E, Giovannucci EL. JAMA. 2016 Oct 11;316(14):1464-1474.

[2] Association among dietary supplement use, nutrient intake, and mortality among U.S. adults. Chen F, Du M, Blumberg JB, Ho Chui KK, Ruan M, Rogers G, Shan Z, Zeng L, Zhang. Ann Intern Med. 2019 Apr 9. [Epub ahead of print].

[3] Vitamin Supplementation to Prevent Cancer and CVD: Preventive Medication. U.S. Preventive Services Task Force, February 2014.

Links:

Office of Dietary Supplements (NIH)

Healthy Eating Plan (National Heart, Lung, and Blood Institute/NIH)

National Health and Nutrition Examination Survey (Centers for Disease Control and Prevention, Atlanta)

U.S. Preventive Services Task Force (Rockville, MD)

Fang Fang Zhang (Tufts University, Boston)

NIH Support: National Institute on Minority Health and Health Disparities

47 Comments

  • cliffhan says:

    Thanks for sharing. Now I have another reason to show my wife not to buy those bottles.

    • Dan D'Onofrio says:

      You’ve noticed how they use ‘self reporting’ haven’t you? Do you actually trust these strangers enough to use their information to try and change your daughter’s mind?

  • Mike Hasan says:

    Thanks a lot for this article. Now I can give my argument to my daughter not to use these.

  • Dan says:

    It would be great to have the option of a printer friendly version to click on.

    • Moderator says:

      Thanks for your note. If you scroll down to the “Share This” button and hover over “More,” you’ll see the print icon in the drop-down menu. Hope this helps.

  • Carrie says:

    I don’t believe it. It’s impossible to make such a broad assumption from a single study. There are way too many variables.

  • Patrick newberg says:

    What were the parameters of the study? Who, why, what, where & when please!

  • Gary says:

    … I am 68 years old and been using supplements intensely for over 50 years.Cured all my ailments including Ms with supplements and dietary changes.this goes back over a hundred years when theRockefellers tried to discredit natural remedies so they could profit off pharmaceuticals. Sad to say most of the ignorant and ill-informed will suffer accordingly.

    • Katherine Farias says:

      Agreed!!

    • Karen M. says:

      This is a very misleading, highly generalized title. What about pregnant and lactating women? ….people with chronic conditions and those needing to take potent medications that may deplete nutrients at a higher rate? …Those who, for one reason or another, cannot obtain or eat highest quality food? There are too many examples to make such a broad statement.

    • Linda Riggio says:

      I agree with you 100%

    • ismorethanskindeep says:

      So true! Just pharmaceuticals trying to drown out healthy business competition!

    • Mel Yorks says:

      So who is profiting from your use of supplements if it isn’t a pharmaceutical company? So called “natural” products are made by drug companies, just different ones. And chemicals are the same whether taken from a plant or made in a factory. It’s the structure of vitamin C that makes it vitamin C for example, not where it came from. It all comes back to what my mother the nutritionist said- a balanced diet is the best way to get the nutrients/vitamins you need.

      • Kitty Farias says:

        Problem is, foods sold in stores are weak and most people don’t get a balanced diet. They are SUPPLEMENTS. This article is misleading. And whole foods supplements are not the same as drugs.

  • Nebraska girl says:

    I believe the title is misleading. According to the article, supplements were shown not to reduce mortality not that overall they are not effective.

    • Jess says:

      I wholeheartedly agree that the title is misleading. The study showed that supplements do not contribute to a longer life – it did not address their contributing to greater quality of life.

  • Genesis says:

    Vitamins work synergetically, within ratios and in proper combinations until the beneficial goal is reached. Drugs/meds are typically prescribed to everyone with the same conditions/symptoms and vitamins are designed and should be taken for specific needs, short-term. Healthy life-style and proper nutrition should be part of the regimen. It would be helpful to know if the participants also used medication that may have had as side-affects such negative results. Also, were the supplements organic or chemically combined? The links left me with some serious questions because the dates seemed off for some of the data.

  • Mary says:

    This is bull. Once i began taking specific nutrients from the health food store ,i no longer had medical issues andaemergency room visits.How do you explain that? I sincerely HOPE people reading this article seek further information for the sake of their health.

  • Katherine Farias says:

    Sorry .they have benefitted me immensley …

  • Katherine Farias says:

    Who paid for or is behind the study and subsequent articles .

  • KC says:

    I take supplements and I would say I fall into the category of a person who has deficiencies. But there are a lot of things unsaid or overlooked in the article (I have not reviewed the actual study). So here are a few thoughts: 1. I was working with healers and the vitamins were specific and prescribed in some cases but I also self prescribed to good effect. 2. The brands I used were either professional or high quality ethical formulations. 3. I started taking supplements because I was unwell. Seriously unwell, and the turnaround was amazing. But this is also a factor: why is a person taking supplements? For example, some taking calcium may have osteoporosis but this might also mean they are not assimilating calcium properly and taking a calcium supplement is exacerbating the situation. Someone sick, taking supplements, skews the result. Geographical influences (air quality etc), community, overall health patterns, support and love, religion, happiness, overall satisfaction with life – these are all also proven influences on health. Where are these numbers amongst the results?

    This article and study, to me, who has been reading these studies for a long time, is too random and arbitrary. I have even read about how studies shape depending on the amount of participants and how long. The bigger/broader the study, the more likely any positive or negative results will get “washed out”.
    And I do believe that food is the best medicine but this study is weak in its basic premise(although I do agree the subject is fascinating). If I did a study with the same parameters using any and all pharmaceuticals, what do you think might be the outcome? Do you think there would be a higher mortality among folks taking these medications? I know this too is a broad question, but it reveals some prejudices.
    This study has no gravitas.

  • Tashia says:

    So pharmaceutical rat poison is better for those suffering with medical issues regardless of their diet? There’s a lot to consider when taking supplements properly…quality, quantity, organic, vegan, vegetarian, etc…this article failed to mention all that. Do your own research. Most medical Doctors unless they are in the field of holistics, acupuncture or alternative health will do anything to keep you in their office. Pharmaceutical prescriptions will ultimately lead to ones demise.

  • Peter says:

    Don’t be such a stupid person to read the title and think that supplements don’t have any benefit. The point is that people are using suplements without any specific reason, just because is suppose to be healthy and forgeting about the importante of healthy food.

  • Sheila says:

    I have worked in various areas of the medical field and have found nature does a better job of actually healing than pharmaceuticals and without side effects.
    God gave us plants not only to nurture but to heal.
    I learned the hard way…congestive heart failure and dvts….all reversed through supplements and pure wholesome foods. Even my Dr. was asking me what was I doing as my labs came back normal as well.

  • Nick says:

    No, No, No. Do not believe this article. Report after report has been coming out for the past 6 months now saying supplements and aspirin are not helpful. Personal experience and those of people I know say otherwise, plus, my own research. Everyone, your being lied to. Do your own research. And make sure you research older info as well.

  • Sherry Lee says:

    Seems like a prejudicial study. Don’t trust anything the medical promotes regarding nutrition. Diagnosis for illness, broken bones and other body ailments yes go to a doctor. But nutrition, no way!

  • Melody Goss says:

    Starting with my grandma who grew and are a lot of her food but also took suppliments, to my Aunt who has always taken supplements and at 82 is not on prescriptions and now myself at 61 who takes supplements but no prescriptions. I have to disagree with this article.

  • Anna says:

    Curious why they show a bunch of fruit and vegetables on a plate. Why aren’t they showing bottles of supplements if this article is about supplements?

    • R.V. says:

      I think what they are trying to show is that nutritious foods, like fruits and vegetables, appear to be the most beneficial way to get your vitamins and minerals.

  • Mel Yorks says:

    if you take more of most vitamins than your body needs (the water soluble ones) you just pee them out. As someone said, Americans have the richest urine in the world. On the other hand, too much Vitamin D can kill you. And I repeat- the source of the vitamin does not matter; it’s the same wherever it came from. As for all the miracle cures- can you say placebo effect?

    • KC says:

      Thanks for shaming anyone who has had a positive experience taking vitamins. So let’s start with: are you a doctor or researcher? If so, back up this claim of placebo effect and begin by asking under what conditions we experienced change or healing. Or do your own study. It helps science and people when people are curious.

      People who have been sick, and who have recovered no matter the strategy, have the same right to truth. Belittling someone just makes you look bad. Of course you can find lots of agreement – this is a given. But success is success, And in this particular case, and it harms no one. But shaming can harm as well as turn someone away from maybe finding a cure. Would you like to be responsible for that? Directly influencing someone away from healing? There are lots of things that western medicine can’t cure – should we just agree to lay down and die if someone doesn’t have an answer?

      This study was based on a lot of anecdotal information which means it probably has a fair share of placebo effect and wishful thinking. And add to that the quantifiable physics that the observer influences the outcome by just being there or asking questions. Good luck making heads or tails of the outcome based on that alone.

      Lastly, there is a theory that much of pharmaceutical success is through placebo effects. And if placebo or pharmaceuticals have a positive effect? Good on them.

      I happen to think placebo effect is an amazing and fascinating subject and certainly not something to use to shame people. Your life is full of placebo effect no matter how gritty and realistic you try to make it!

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