Vitamin studies making headlines during the last few weeks has left consumers confused, and most clinicians scrambling for answers.

A sample of the supplement studies recently released include ones that supported supplement usage; for example, vitamin B12 deficiency plays a role in dementia and other neurological disorders, and supplementation can stave that off. Other vitamins are established treatments for a host of diseases: from vitamin C in scurvy to B12 in pernicious anemia, and vitamin D helps fight off tuberculosis. Other studies, on the other hand, have found that vitamin E raises the risk of prostate cancer, and that calcium does not improve outcomes for either mother or baby. One particular study reported an increased risk of death in postmenopausal women taking multivitamins, including vitamin B6, folic acid, iron, magnesium, zinc, and copper.

Similarly, vitamin C also apparently lacks benefits in preventing colds or cancer, B-complex vitamins do not lower heart disease risk or have clinical cardiovascular benefits, carotenoid antioxidants beta-carotene do not have any use in treating eye or heart disease, and lycopene has no benefit in prostate cancer. Perhaps as a result of this confusion, a recent survey conducted by the website Medpage found that 70% of clinicians said they still supported annual screening of specific vitamin levels to treat deficiencies. Whether patients heed their advice is another question, as recent research shows that 50% of Americans report taking a multivitamin or other dietary supplement, a 25% increase from a decade ago.

“Multivitamins were never recommended on the basis of strong evidence anyway,” wrote David Katz, MD, of the Yale University (New Haven, CT, USA) prevention research center, commenting on the Medpage survey. “What we had was a notion that this was an insurance policy. Many people don't eat the way they ought to, so they're not getting the optimal doses of nutrients from food. Instead, we can rely on a pill that ought to do you some good, and certainly couldn't do you harm. That was the thinking.”

“Patients should stop trying to look for health in a pill,” added Lee Green, MD, of the University of Michigan (Ann Arbor, USA), in another comment. “Health is not found in pills. It's found in good food and regular exercise. There's something in our psyche that makes us want to believe in magic, and that desire to believe has focused on vitamins.”

The question remains as to why these vitamins do not work as expected. The latest theory is that vitamin isolates do not work quite as well on their own; it may take the full blend of antioxidants and phytochemicals found within the context of a whole food in order to deliver any potential benefits.
 

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