Still, given the demonstrated benefits and the fact that it hasn't been shown to cause any harm, vitamin D might be worth taking as a supplement on a consistent basis.ДЄ mounting pile of research is showing how crucial the trillions of bacterial cells that live inside usВ are in regulating our health, and how harmful it can be to suddenly wipe them out with an antibiotic.

In this case, the biggest one is that these studies can't tell us much about the mechanism by which vitamin D seems to reduce mortality or provide other health benefits. Of course, even though they're widely recognized as the best way to test a treatment's effectiveness, randomized controlled trials have limitations. Other research has found that in kids, taking vitamin D supplements can reduce the chance of catching the flu, and that in older adults, it can improve bone health and reduce the incidence of fractures. In other words, by randomly deciding which participants took the supplement and which didn't and tightly controlling other variablesВ (thereby reducing theВ effect of confounding factors), the researchers found thatВ adults who took vitamin D supplements daily lived longer than those who didn't. A 2013 meta-analysisВ of 42 randomized controlled trials came to the same conclusion. Of all the 'classic' vitamins-the vital organic compounds discovered between 19В and termed vitamin A, B, C, etc.-vitamin D could be the mostВ beneficial to take in supplement form.ДЄ 2008 meta-analysisВ (a review of a number of studies conducted on the same topic)В of 17 randomized controlled trials concluded that it decreased overall mortality in adults. Here's our rundown of some of the most promising. Information is Beautiful, a data visualization website,В has a thought-provoking interactiveВ that shows supplements charted by the strength of evidence that indicates they're beneficial. Nevertheless, there are a handful of vitamins and supplements that, studies suggest, mightВ actually be worth taking for people with specific conditions. In many cases, taking high amounts of them in a refined form (especially vitamins A, C and E and beta carotene)В can actually be harmful, increasing the risk of cancer and other diseases by excessively inflating the concentration of antioxidants in the body. Of course, our bodies do need these vitamins to live-it's just that the diet of most people who live in developed countries in the 21st century already includes themВ in abundance.

Study after study has shown that vitamin C does nothing to preventВ common cold, a misbelief that dates to a theoretical suggestion made by a scientist in the 1970's. Controlled, randomized studies-where one group of people take supplements and another takes placebos, and the groups are compared-have produced little evidence that antioxidants protect against cancer. Multivitamins don't reduce the chance of cancer or cardiovascular disease. This goes for a tremendous range of supplements that you might imagine to be beneficial.

' Enough is enough: stop wasting money on vitamin and mineral supplements,' declared an editorialВ that was published in the December 2013В issue. In the last few years, a number of studies published in the Annals of Internal MedicineВ underscored a fact that scientists have become increasingly sure of: The vast majority of vitamins and mineral supplements are simply not worth taking.

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