Vitamins and minerals, in the form of supplements, are notorious for getting overhyped. Some of the best examples are beta-carotene, vitamin C and vitamin E. In the 1980s, it was widely thought that beta-carotene and vitamin E could prevent cancer after scientists discovered their anti-oxidant properties. It was widely thought that supplementation of either could reduce mortality.
Although the doses used in studies have been all over the map, randomized controlled trials show that there is no consistent benefit in supplementing with these nutrients and may even increase mortality. A meta-analysis of randomized controlled trials of a handful of nutrients by Dr Bjelakovic and company found that both beta-carotene (RR, 1.07; 95% CI, 1.02-1.11) and vitamin E (RR, 1.04; 95% CI, 1.01-1.07) increase risk of all-cause mortality.
Perhaps the most famous case of overhype is Linus Pauling’s foray into vitamin C, and it is a story nutritionists and health professionals love to recite. Pauling is one of only four individuals to ever receive more than one Nobel Prize for his work in chemistry and peace. Later in his career, Pauling became intrigued by vitamin C after he noticed an improvement in his own well-being after taking three grams of vitamin C daily. He was so convinced that he wrote several books on vitamin C and even founded an institute dedicated to vitamin C research. The public and medical field called him a quack, and while vitamin C may be important (we’ll decline to comment), the vitamin, like others, turned out to be no panacea.
While the Vitamin D Council will decline to make recommendations on these nutrients (it’s outside of our expertise), the history of research on these nutrients only puts vitamin D under the same scope of healthy skepticism. In reference to previously hyped nutrients, JoAnn Manson, lead investigator of the VITAL Study, says, “You have to look at these previous randomized trials as cautionary tales because they show that time and time again, everyone jumped on the bandwagon and then the randomized trials did not have favorable results, and in fact, the risks outweighed the benefits.”
It begs the question, is vitamin D overhyped? Does the current hype outweigh the evidence? Is vitamin D the next vitamin C?
Just about every major media outlet attempts to answer these questions when a study they find interesting comes out. I think it’s important to have perspective here, however, and understand the grand scheme of vitamin D research. While the level of interest from the academic community certainly does not define the merits of a nutrient or drug, it can give you a sense of how much the public is hyping a vitamin relative to the amount of research that is being conducted. Let’s take a look at some figures on “vitamin C” and “vitamin D” for example at www.gopubmed.com.
The bar graphs show raw numbers of publications on the topics in any given year. As you can see, the academic interest in vitamin D has always been higher than vitamin C, dating all the way back to 1970. Even in 1970, over a thousand publications came out on vitamin D, compared to less than 800 on vitamin C in 2011. Even more telling is the relative research interest (lines) that compare the amount of publications to the amount of publications listed on PubMed in general. The keyword “vitamin D” appeared in .00325 of total publications last year, while the top year for “vitamin C” was about .0010, about a third of the amount of publications on vitamin D.
You can also see the trend of relative research interest in vitamin D and how it has skyrocketed in the last 3 or 4 years, while research on vitamin C peaked around 2003-2005. When we see a news outlet publish a story on the dangers of vitamin D or how it is the panacea of nutrients, it is important to understand that vitamin D research, while not in its infancy, is just taking off now, and there are a lot of questions to be answered. It is not fair to say that it’s overhyped (the interest in the academic community is too high); it is also not fair to say that it’s not hyped enough (amount of research hasn’t peaked).
While there are some flaws in using PubMed to gauge the direction of research, it gives us a vague idea where we’re heading. In this year to date, I have seen more randomized controlled trials come out on vitamin D than my prior seven months working for the Council. It’s an exciting time in the field of vitamin D and the Council is excited to relay the research that’s coming out in a hurry.
Only time will tell, but we don’t believe vitamin D is the next E or C, and the shear amount of research the academic community is pumping out supports that we’re not alone in this thought.