Multivitamins Are Fabulous. Probably. (April 28, 2015)
Those of us who are of a Certain Age remember when medical doctors knew everything there was to know about health and disease. (Ok. But that’s what they SAID, and most people believed them.) These doctors told us that we could get all the nutrients we needed from food, which sounded very logical – after all, we know that health predates vitamin manufacturers.
But then, and I’m thinking that it might have been right about the time that Jack LaLanne started getting a lot of attention, those same doctors started telling us that we all ought to be taking a multivitamin because even if it didn’t help, it couldn’t hurt. Not all of them changed their minds, though. Sometimes you’d hear one thing, sometimes the other. Just like now.
If you pay attention to medical headlines, you may remember that a couple of years ago there was a pivotal report stating that multivitamins had been found to be ineffective in the prevention of cancer and heart disease. This resulted in headlines such as “Multivitamins Are Worthless” because “Multivitamins Do Not Produce A Meaningful Statistical Improvement In Your Chances Of Developing Cardiovascular Disease” is not nearly as sexy, even if it is more accurate.
Now, there are indeed studies showing multivitamins to be unhelpful. Or worse. There’s one showing a 2% increased likelihood of death in women over 60 who regularly took a multivitamin versus those who didn't. But that study, and similar studies, are observational (asking people what they are doing) and not interventional (making them do something and then analyzing the results). Asking a bunch of people what they've been doing is a whole lot cheaper and easier than splitting them up into groups, assigning them various tasks and then sorting out the results. It's also not nearly as productive of accurate results. But there, money is hard to come by unless someone with a financial interest in the outcome is sponsoring you, so we see a lot of observational studies.
Ragging on multivitamins frankly makes me a little nuts. I will grant that anything that produces a beneficial effect in the body can theoretically produce a harmful effect as well. But is there even one documented case of anyone dying, or even being definitely harmed in some way, from taking a multivitamin? I can’t find any. Multivitamins have been ‘impressively harm-free in most trials’ (to quote Dr. David Katz, who is a very smart guy) so I certainly wouldn’t quit taking a multivitamin on the basis of any of those studies -- or even all of them together.
Set this against the fact that there’s one study showing an 8% less risk of cancer in male physicians who took a daily multivitamin. Another showing that women who took a multivitamin with minerals lived on average three years longer than those who didn’t. And one that found that multivitamin use did not prevent cardiovascular disease in men DID find that those men had less cancer and fewer cataracts.
Confused yet? Join the club.
Beginning at the beginning here, we cannot get all the nutrients we need from food. At least not anymore. We eat far fewer calories than we did at the turn of the 20th century (on average, about half as many) and the foods that we DO eat (even the healthy ones) don't have as many nutrients as they used to. That is not even taking into account how badly processing depletes food of nutrients, and what a large part sugar makes up of most people's daily food consumption. As a result,
- 25% of us do not get enough Vitamin C in our diets.
- 34% do not get enough Vitamin A.
- 38% do not get enough Calcium.
- 45% do not get enough Magnesium.
- 60% do not get enough Vitamin E.
- 70% do not get enough Vitamin D.
Of course we are talking here about the inadequacy of what we are eating. When you hunker down and peer a little more closely, and look at people’s blood levels of nutrients and do other testing like the CDC does, the numbers of people who run measurable deficiencies of those nutrients are lower than the percentages above suggest. This is at least partly due to the nanny-state socialist practice of compulsory fortification of nutrients in certain foods. It can sometimes also be due to the valiant attempts of your body to keep blood levels of things adequate even if its storehouses are depleted (for example, your blood levels of calcium may be normal the entire time your bones are softening because your body is frantically trying to keep your calcium levels normal in the face of insufficient consumption). But fewer actual deficiencies in the population in spite of multiple deficiencies in our diet most likely is at least partly due to PEOPLE TAKING SUPPLEMENTS. After all, about half of us do take a daily multivitamin.
Nutritional disease as such is not all that common. By that I mean (for example) that severe vitamin D deficiency produces rickets in children and osteomalacia in adults. Now you don’t see a whole lot of rickets these days, so the deficiencies present are not that severe. But there are more than a few diseases where improving the vitamin D status of people who are somewhat deficient in it results in a whole lot less disease -- like heart disease, dementia and prostate cancer, to name a few. So even mild deficiencies can have measurable negative health effects.
The thing about "deficiency" is that the levels the requirements are set at are low to begin with. If you get less than your requirement consistently, you can certainly expect disease. But the level at which the nutrient is actually required by your body to be healthy is likely to be a whole lot higher. And when you also start looking at the increased levels of stress that people are enduring, the common lack of sleep, the increase in sensory input and all the extra chemicals and radiation we are coping with compared to a couple of hundred years ago, your requirements for adequate nutrition are probably much higher than they are commonly considered to be.
Yet right now there’s no final word on whether the general population would be a little better off, a tiny bit worse off, or unaffected by taking multivitamins.
So that leaves us where exactly? My takeaway from all this is that if you are a crappy eater (and you all know who you are) you most likely need a multivitamin. If you are on some kind of odd diet or unable to eat normally, you could probably use one as well. But if you are not in those categories, despite all this logic I threw at you, there really is not enough evidence for me to push a multivitamin on you.
(By the way, please note that I am talking ONLY about your basic multivitamin/multimineral here, not about supplementing individual nutrients for particular problems or supplementing with nutrient-dense foods.)
If you’re going to take a multi, though, can you just grab something cheap off the shelves? I used to recommend that. Not anymore. Next week I will talk about finding a suitable multivitamin because it turns out that it is a subject worth a little thought and effort. In the meantime, you may as well just finish off what you've got on your shelf. Even if it doesn't help, it won't do you any harm :-)
--dr. diane holmes
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