The best efforts of the scientific community to prove the health benefits of vitamins keep falling short.
Consumers don’t want to give up their vitamins. (Tony Cenicola/The New York Times)This week, researchers reported the disappointing results from a large clinical trial of almost 15,000 male doctors taking vitamins E and C for a decade. The study showed no meaningful effect on cancer rates.
Another recent study found no benefit of vitamins E and C for heart disease.
In October, a major trial studying whether vitamin E and selenium could lower a man’s risk for prostate cancer ended amidst worries that the treatments may do more harm than good.
And recently, doctors at Memorial Sloan-Kettering Cancer Center in New York warned that vitamin C seems to protect not just healthy cells but cancer cells, too.
Everyone needs vitamins, which are critical for the body. But for most people, the micronutrients we get from foods usually are adequate to prevent vitamin deficiency, which is rare in the United States. That said, some extra vitamins have proven benefits, such as vitamin B12 supplements for the elderly and folic acid for women of child-bearing age. And calcium and vitamin D in women over 65 appear to protect bone health.
But many people gobble down large doses of vitamins believing that they boost the body’s ability to mop up damaging free radicals that lead to cancer and heart disease. In addition to the more recent research, several reports in recent years have challenged the notion that megadoses of vitamins are good for you.
A Johns Hopkins School of Medicine review of 19 vitamin E clinical trials of more than 135,000 people showed high doses of vitamin E (greater than 400 IUs) increased a person’s risk for dying during the study period by 4 percent. Taking vitamin E with other vitamins and minerals resulted in a 6 percent higher risk of dying. Another study of daily vitamin E showed vitamin E takers had a 13 percent higher risk for heart failure.
The Journal of Clinical Oncology published a study of 540 patients with head and neck cancer who were being treated with radiation therapy. Vitamin E reduced side effects, but cancer recurrence rates among the vitamin users were higher, although the increase didn’t reach statistical significance.
A 1994 Finland study of smokers taking 20 milligrams a day of beta carotene showed an 18 percent higher incidence of lung cancer among beta carotene users. In 1996, a study called Caret looked at beta carotene and vitamin A use among smokers and workers exposed to asbestos, but the study was stopped when the vitamin users showed a 28 percent higher risk for lung cancer and a 26 percent higher risk of dying from heart disease.
A 2002 Harvard study of more than 72,000 nurses showed that those who consumed high levels of vitamin A from foods, multivitamins and supplements had a 48 percent higher risk for hip fractures than nurses who had the lowest intake of vitamin A.
The Cochrane Database of Systematic Reviews looked at vitamin C studies for treating colds. Among more than two dozen studies, there was no overall benefit for preventing colds, although the vitamin was linked with a 50 percent reduction in colds among people who engaged in extreme activities, such as marathon runners, skiers and soldiers, who were exposed to significant cold or physical stress. The data also suggested vitamin C use was linked with less severe and slightly shorter colds.
In October 2004, Copenhagen researchers reviewed seven randomized trials of beta carotene, selenium and vitamins A, C and E (alone or in combination) in colon, esophageal, gastric, pancreatic and liver cancer. The antioxidant users had a 6 percent higher death rate than placebo users.
Two studies presented to the American College of Cardiology in 2006 showed that vitamin B doesn’t prevent heart attacks, leading The New England Journal of Medicine to say that the consistency of the results “leads to the unequivocal conclusion” that the vitamins don’t help patients with established vascular disease.
The British Medical Journal looked at multivitamin use among elderly people for a year but found no difference in infection rates or visits to doctors.
Despite a lack of evidence that vitamins actually work, consumers appear largely unwilling to give them up. Many readers of the Well blog say the problem is not the vitamin but poorly designed studies that use the wrong type of vitamin, setting the vitamin up to fail. Industry groups such as the Council for Responsible Nutrition also say the research isn’t well designed to detect benefits in healthy vitamin users.
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From 1 to 25 of 573 Comments
Instead of relying on vitamin supplements, people should focus more on eating well in general.
Maybe one factor that wasn’t studied was that people who take multivitamins think they are allowed to “slack” in other areas of health. They may not eat their veggies or exercise as much. In other words, a feeling of false security due to supplements may encourage risky behavior that results in worse outcomes, as these studies show.
— ShanaWhy no significant mention of the one vitamin that does seem (preliminarily I admit) to have a beneficial effect on a variety of disorders? That would be vitamin D.
And to get enough for most of the year, it isn’t even necessary to take supplements. All we have to do is shed our sun phobia.
The post mentions vitamins A, B, C, E, and selenium. It mentions vitamin D only in the context of bone health in older women.
The evidence of the importance of vitamin D in preventing cancers and autoimmune disease is far more powerful than evidence that existed for any of these other vitamins.
In fairness, the NY Times has run several articles in the past few years pertinent to vitamin D research. But in light of how promising this research is, I would have thought that it might bear mentioning in this post.
— WigWagMuch of what is in a vitamin passes thru your system before it can be fully absorbed. You are much better off getting your nutrients from real food as they digest slower and are more easily assimilated by the body.
— nateIf the food we put on our tables weren’t so processed to death we wouldn’t have to worry about vitamins. We evolved from grabbing our food on the run, to settiling down and farming, to this thing we have today that looks to get the most yield, irregardless of quality, and the best bottom line.
And it isn’t cheap to eat healthy anymore, either.
I heard an inner city dweller refer to Whole Foods as
“whole paycheck.”
And have you seen the size of chicken breasts lately?
They’re the size of bicycle seats. What are they feeding them birds, anyway? I don’t want it, that’s for sure.
Maybe they should market that cereal they used in a Saturday Night Live skit many, many years ago. They called it “Colon Blow.”
— mercOne vitamin that seems to be needed in large doses is Vitamin D. Normally, this vitamin is synthesized in the skin when an individual is exposed to sunlight or UV radiation. With the increased use of sunscreens, and with many of us living in Northern Latitudes where there may be a lack of sunlight, especially during the winter months, we are beginning to see a tremendous number of people who are vitamin D deficient, when we actually measure their blood levels.
This has implications in the treatment of osteoporosis, and possibly, although the data is soft at this time in preventing or treating heart disease or cancer. But we know we need adequate Vitamin D levels to maintain normal bone health
We are currently starting to recommend Vitamin D supplementation of 1,000-2,000 IU per day to maintain adequate levels
— Stephen Kamelgarn MDI am a 59 year old runner. Coenzyme Q10 supplements really saved my running. I am on Statins and my running was failing. I couldn’t run very far before I had to walk. The day after starting 100mg of Q10 my running stamina was greatly improved. I don’t race or time myself anymore but I am running energetically. My plan is to keep running. Gosh, I hope the Q10 doesn’t kill me.
— Kin Folk Said.The study regarding vitamin C, colds, and marathon running was interesting to me. I take a multivitamin because I exercise a lot and figure I might need a bit more than I can get from food alone. Although it’s hard to say with any statistical precision, I get the sense that I stay healthier (less colds, less musculoskeletal issues) when I am taking a multivitamin. I wonder if there are any other studies relating vitamin use in athletic populations.
-Anne
— AnneSomehow Americans can never believe that if a little of something is important for your health, more, lots more of it, will not automatically make you a whole LOT healthier. The whole idea of balance, moderation, the right amount of something and no more is simply lacking from our list of the ‘Principles of Reason.’ And in a culture where corporations see a potential for profit in keeping people thinking this way, advertising dollars speak louder than careful scientific studies.
— RuthEvery time I read these studies I can only imagine that the studies are flawed in themselves. What populations do they use? What doses of vitamins do they try out? Are there longitudinal studies to compare with? And who is running the studies, drug companies? It is all too fuzzy, the NYT reportings and others’ reportings are too filled with holes for such blanket statements that “vitamins don’t work”, and there is an entire American medical establishment out there that knows nothing about herbs/vitamins/other healing methods who are trying to analyze these flawed results probably with unconscious bias.
For those of us who’ve studied the uses of vitamins and herbs for years, and have empirically proven their value in the happy smiles of our children, or the healthy sleep patterns in our partners, or the remediated effects of cancer or neurological diseases in our friends, we *know* the value of the ancient medicines that helped our ancestors survive, thrive, and give birth to us.
— AnneI’ve never been fond of vitamins anyway. Vitamins are supplements, not the replacements of healthy eating. It’s said that extremes are always dangerous and moderation the key to a long and fruitful life and I think this artcile proves it. Vitamins are like cosmetics, too much hoopla, but not much substance.
— Jorge I. GomezHas a study been done showing that people who eat exclusively organic food and live in low pollution areas suffer less cancer rates? It might not be the vitamins that prevent cancer, it might be avoiding the chemicals that cause cancer in the first place. One study I read about showed that children on exclusively organic diets had almost no level of pesticides and other chemicals in their blood and tissues. The study did not follow the children to see if they had lower cancer and disease rates. That’s what we need.
— HealthyTara,
I’ve followed you to the NY Times and read
your column with interest still, especially now– since you included all these references to actual studies! Thank you
very much. I did read one of the abstracts.
It really helps.
FROM TPP — Thanks, the great thing about blogging is you can actually provide the links!
— Alexandra OttawayIf these are studies using USP vitamin supplements then the results make sense to me. USP vitamins are chemicals that the body does not assimilate in the same way that nutrients from food-based sources are.
— selectorAre there any studies of people that just take a normal multivitamin each day of the recommended dosage? That’s the way most of us take them.
Most of the studies you refer to seem to be looking for payback in high doses as ‘treatment’, rather than just ensuring your body has the correct balance of vitamins and minerals each day.
— SeanI have never in my life taken a vitamin supplement and I never will. People who do so do not understand physiology. That includes all those MD’s and MD-PhD’s who take vitamins.
There is absolutely no need for vitamin or any other supplements. It is a waste of money, and one that can cause you serious illness too.
FDA should ban all vitamin supplements. People in general should stay away from pills as much as they can.
— Franksimply quoting little snippets about various so-called studies doesn’t provide an argument for or against. who funded the studies - how large and how long and how was the test conducted are the real questions people need answered. i always keep in mind that big pharm makes more money providing scripts for sick people than anything they could provide to keep them healthy.
FROM TPP — I don’t believe any of these studies are funded by industry. Most are by NIH, NCI or other non-industry sources.
— shamanAs a vegetarian, I do try to remember my vitamins, mostly so I’m guaranteed enough B-12, something found in most meats but not in very many vegetable products. A reasonable amount of egg on a frequent basis has enough B12, but I’m better at remembering to take my vitamins every day than remembering when I had eggs and how much.
— Miri“The data also suggested vitamin C use was linked with less severe and slightly shorter colds.”
This to me is more in alignment with what I expect from vitamins, and even these more cynical studies in this article confirm they do support good health. I didn’t know anyone was thinking they’d take vitamin C to cure cancer. Apparently that’s an idea that’s been circulating, but I wouldn’t need a study to tell me that’s unlikely.
All I know is, I feel better when I take vitamins than when I don’t and I definitely seem to fight off looming colds much more successfully. By all accounts I would call that “preventing” colds, because I just get tired and know I’m coming down with something, so load up on the Emergen-C for a day or two, and never wind up with a full blown cold.
That said, one statement in this article surprised me: “A 2002 Harvard study of more than 72,000 nurses showed that those who consumed high levels of vitamin A from foods, multivitamins and supplements had a 48 percent higher risk for hip fractures than nurses who had the lowest intake of vitamin A.”
I’d like to see a study on what is going on with vitamin A that is causing this shocking result. Clearly it is interfering with the absorption or utilization of some other nutrient that is essential for bone health. It would also be extremely helpful to know exactly what dosage constituted the “high levels” of vitamin A consumption among nurses in this study. Without that information it can be very misleading to use such a statistic to try to prove that taking Vitamin A is more likely to harm your health than help it. I’m guessing taking the amounts that most people actually would take would be more helpful than harmful, especially if you are on a low calorie diet and therefore eating less food each day. Those minimum daily requirements are really pretty low, so if you are taking a supplement that delivers those amounts, you’re really just playing it safe with no real downside risk.
— DuttonI read the most recent article about Vitamins C and E. It said nothing about how much the doctors took, on what schedule, with or without food, and so forth. That information is essential to assess the credibility of the study.
Such studies are very often conducted with sub-therapeutic dosages of vitamins, such as 60mg of Vitamin C instead of the multi-gram doses recommended by Linus Pauling and others. When the low doses fail to produce results, the study sponsors announce that “vitamin supplements have been proven valueless.” The study reported in the November 17th falls into that category.
— MilesI’ve also been of the belief, with admittedly no evidence, that maybe, for example, beta carotene needs the other elements of, lets say a carrot in order for the vitamins to work properly. in other words, maybe the fiber in a carrot allows the beta carotene to take a form that is most useful for the body to use that is beneficial.
— nickels flatbagI have seen these negative studies before, but my own experience consistently shows that vitamins help keep inflammations down and keep my skin clear. B5 is a wonder for sexual health and acne. Chromium Picolinate gives a great consistent energy through the day. That’s just the beggining, I’m sure the author has her own similar experiences. Can you discuss anecdotal evidence or studies on individuals sometime?
— DavidAre these randomized controlled trials? Or are vitamin takers self selected?
My parents eat a terrible diet and are completely sedentary, yet they take vitamins. My wife’s parents are vegetarians who get a lot of exercise but don’t take vitamins. Who do you think is more healthy?
When you describe research like this, you really need to distinguish whether you are talking about randomized, blinded studies or whether you are talking about self-selected subject cohorts.
— pierce moffettI’d be curious to read any recent studies on the use of other compounds, such as creatine and N-acetyl Cysteine (NAC). My therapist has placed me on NAC for combating depression (a few studies have suggested the link).
After a couple of months, it seems to be helping. (I take a teaspoon per day, much more than is suggested for its main selling point as an anti-oxidant). It’s very sulfurous and foul-smelling, but I hide it in a glass of strong OJ.) I understand NAC is a very good antioxidant too, and I credit it for doing away with any mucus problems I had been having.
— DanOh yes… Here we go again.
The medical industry, more often than not, conducts these studies using researchers who create a hypothesis (vitamins are useless) and then design the protocols to create “results” that fit their long view. We’ve seen this in cancer research for decades (”Alternative therapies bad; drugs good), when the big money from research is coming from the pharmaceutical companies.
Weren’t there those studies about coffee; oh yes, pancreatic cancer? Then, ooops… another study: coffee is wonderful!
Puhleeeze.
— BakuninThe poverty, and danger, of reductionist science.
— pluto