It’s December 2013, which means it’s time for another round of popular news articles proclaiming “supplements are useless and maybe even dangerous.” This time they’re based on a recent editorial  published in the Annals of Internal Medicine entitled “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” in which the authors looked at (some of) the research on vitamin and mineral supplementation and prevention of various ailments. Understandably, I got a bunch of emails from people worried that their supplements were useless or might even be hurting them. Let’s look at one of them and see what people are saying:
I thought Mark might want to write a post on this article:
Hear that? The “case is closed.” Or not.
One of the papers the authors examined was pulled from the Physicians’ Health Study II  (PHSII), a long-running study of nearly 15,000 US doctors at least 50 years of age or older. Researchers have run a number of studies using this data, mostly examining how taking supplements (either a Centrum Silver multivitamin, vitamin C, vitamin E, beta-carotene, placebo, or some combination thereof) affected various end points like cancer, cardiovascular disease, visual decline, or cognitive decline. The study the authors of the editorial chose to examine looked at the effect of multivitamins on cognitive decline and memory. Turns out multivitamin intake had no effect on cognitive decline or memory when compared to placebo.
Of course, even if multivitamins have no effect on cognitive health it doesn’t say anything about other health conditions. Just last year, a study using the same PHSII data found a beneficial effect on cancer incidence from multivitamin use, with daily multivitamin use predicted a moderate but significant reduction in overall cancer risk , particularly in men with a history of cancer. And although an early PHSII study on cardiovascular disease found no overall effect, multivitamins did reduce the risk of fatal myocardial infarction  (your basic heart attack). I’d wager that most people are highly interested in avoiding heart attacks that kill them. Wouldn’t you?
That’s actually pretty impressive when you consider that Centrum Silver is a cheap, relatively low-quality, poorly absorbed multivitamin. That Centrum Silver is a known quantity and inexpensive makes it a good candidate for large trials, but a poor candidate for someone interested in improving their nutrient status when there are so many better options are on the market.
You also have to consider the population studied and how that impacts the effect of a supplement. How do the male doctors included in PHSII differ from other types of people?
According to the latest research (much of it culled from the PHSII), male physicians are a generally healthy bunch . They tend to be wealthier and better-educated than average, which usually results in better health and a greater life expectancy . They rarely smoke, drink, or do (illicit) drugs. They’re thinner than most and rarely suffer from obesity-related diseases like diabetes and cardiovascular disease. They have higher cholesterol  than average men, which could actually be a good thing depending on how high it actually is and which lipids are responsible for the elevated readings. High cholesterol could also be a function of access to health care; other Americans may be “free” of high cholesterol simply because they’ve never had it checked. They drink a lot of coffee , which is a great source of antioxidants and has been consistently linked to better health outcomes.
In other words, doctors are starting from a healthier spot than the rest of us. They have less ground to make up. Their diets are less likely to leave them vitamin or mineral deficient, and multivitamins are less likely to have an effect on the vitamin and mineral replete .
You’ll notice that supplement critics usually sneak in an important qualifier that drastically changes the context: “nutrient deficiencies.” As in, “multivitamins may be helpful in combating vitamin or mineral deficiencies, but those are incredibly rare in today’s food environment.” They seem to assume that because so many people are overweight or obese, they couldn’t possibly be missing anything because they’re eating plenty of food to cover their bases. Is it really so rare to have a vitamin or mineral deficiency, though? Are Americans and other people from industrialized nations really eating healthy, nutrient-rich diets? I’m not so sure. Just look around at the way people eat. Obesity doesn’t mean nutrient-replete. An immense macronutrient intake doesn’t ensure a high micronutrient diet if you’re eating modern, industrial foods designed to taste good. Most homeless people I see are sadly overweight, but they overwhelmingly suffer from nutrient deficiencies  just the same.
People may not be dying of pellagra or beriberi or getting scurvy or rickets (well, maybe rickets) in industrialized nations, but that doesn’t preclude deficiencies. The true face of modern nutritional deficiency is a subtle one that sneaks up on you and saps at your health over the long term.
Vitamin D deficiency is widespread , which the authors acknowledge. We’re either actively avoiding the sun, using sunscreen at the slightest hint of it, or spending most of our hours indoors. Vitamin D supplementation lowers the risk of falls in susceptible populations  (high doses only; lower doses weren’t very effective), reduces body fat , and lowers the risk of fractures  (in case you do fall). It and prenatal folic acid were the only supplements given the green light.
Magnesium deficiency is epidemic , too, with a number of factors negatively affecting a person’s serum magnesium levels, including high stress , sweating, alcohol  intake, a low selenium intake, and low vitamin D. The biggest factor in magnesium deficiency, though, is inadequate intake, either from poor diets, soft, low-mineral drinking water , or depleted soils .
Should people not obtain more of those nutrients, either through lifestyle modification (diet, sun) or supplementation, if they are deficient? After all, magnesium supplementation has been shown to improve beta cell function  in diabetics, insulin sensitivity in non-diabetics  and type 2 diabetics , and blood pressure in people with low magnesium status .
And multivitamins themselves have had positive effects. Three recent clinical trials (AREDS , AREDS2 , and LAST ) found that specifically-formulated multivitamins can help prevent age-related macular degeneration. Multivitamin supplementation can also positively impact fertility , psychological health  (mood, perceived stress which is really just stress in the end), and neural efficiency . The problem is that the endpoints that supplementation seems to undoubtedly help aren’t cancer or cardiovascular disease. Improved insulin sensitivity and lower body fat, better vision and lower stress are all well and good, but they aren’t sexy clinical endpoints with the impact of death from cancer or cardiovascular disease. A “lower risk of fractures and falls” doesn’t make headlines.
There are also nutrients that are difficult to obtain from food alone. Take vitamin K2 , which can be found in natto (slimy fermented soybeans), goose liver, and gouda, but not in the amounts shown to be protective or restorative in clinical trials. Supplements will help fill in the blanks.
You know, I actually have no beef with the title of the editorial. People absolutely should not be wasting money on mineral and vitamin supplements they don’t need. That’s just common sense. Where we differ is how to define a wasteful supplement. They think all supplements qualify. I don’t. You can find plenty of evidence showing that supplementation of certain nutrients is unhelpful, harmful, or barely helpful in nutrient-replete, healthy populations. You can find plenty of evidence showing that smart supplementation  of certain nutrients is extremely helpful or even life-saving in other groups. So-called skeptics love pointing to the former as resounding evidence that supplementation is pointless for everyone. More reasonable folks naturally see the totality of evidence as supportive of a more nuanced position: some supplements are good for some people, some are bad for some people, some are good for most.
Talking about “this study” or “that study” invalidating (or universally validating) the consumption of supplements is ridiculous. Specific supplements work in specific cases. Multivitamins can be helpful for certain conditions, particularly if you eat a poor diet, or they can be mostly useless. Supplement quality matters, too. There’s a lot of research to parse when it comes to evaluating the worthiness of supplements, too much for nice neat headlines – or even two page articles.
What do you think, folks? Be sure to share your thoughts below.
Thanks for reading. Take care and Grok on!