Posted by The Evidence Blog on February 27, 2014

by Jill Shuman, Manager of the Hayes News Service and Registered Dietitian

Media coverage following a trio of recently published studies in the Annals of Internal Medicine has been blasting the use of multivitamins in general, leading to a vocal and aggressive pushback from the supplement industry. So what’s the real story, and might the media seized the opportunity to promote an even more important message?

The use of multivitamin supplements has increased among U.S. adults from 30% between 1994 to 1998 to 39% between 2003 and 2006. Americans currently spend an estimated $11.8 billion each year on vitamin and mineral supplement, many in the hopes of preventing heart disease, cancer, cognition loss, or even multiple sclerosis. While overall use of supplements has gone up, use of certain individual supplements has gone down, for example beta-carotene and vitamin E. This decline followed reports of studies that showed these could be harmful.

Three articles in a recent issue of the Annals of Internal Medicine addressed the issue of whether vitamin and mineral supplements can prevent the occurrence or progression of chronic diseases. In the first study, the United States Preventive Services Task Force (USPTF) systematically reviewed evidence from 27 trials of more than 400,000 participants with regard to the efficacy of multivitamin supplements in preventing cardiovascular disease and cancer among community-dwelling adults with no dietary deficiencies.

A second trial evaluated the efficacy of a daily multivitamin to prevent cognitive decline among almost 6000 male physicians ages 65 years or older participating in the Physicians’ Health Study II over 12 years. And a third trial assessed the potential benefits of a high-dose, 28-component multivitamin supplement in 1700 men and women with a previous myocardial infarction participating in the TACT trial (Trial to Assess Chelation Therapy) with an average follow-up of 4.6 years.

Guess what? None of the trials showed a significant difference in any of the primary endpoints—all-cause mortality, cardiovascular disease, cancer, cognitive performance, or recurrent cardiovascular events. An editorial in the same issue offers the following recommendation, based upon the most current research: "Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided.” The editorial also states that vitamins are not beneficial for most of us; some higher doses of supplements, such as "beta-carotene, vitamin E, and possibly high doses of vitamin A, [might increase] the risk of death" in certain instances.

The bottom line is that we can’t rely on multivitamin supplements to prevent chronic diseases such as cardiovascular disease and cancer. But neither can antibiotics, flu shots, aspirin, and a host of other medicinal things. They all provide limited benefits in preventing disease, and all have associated harms.

Unfortunately, the media was hyping the wrong message. The real issue is whether we should expect any one pill or medicine to prevent chronic disease. The answer is a resounding ‘no;’ there is no medicinal short-cut to prevent disease and help us live longer. That’s a far more news-worthy message, but no one wants to hear it. So rather than seize a teaching moment and put the message in context, the media chose to report more sensational messages like ‘No benefits from multivitamins,’ and ‘Close the book on multivitamins.’

What these studies don’t address is the issue of whether taking one multivitamin per day is either beneficial or harmful. When taken at the recommended dietary level, a multivitamin is likely not harmful, especially for folks who for whatever reason, do not eat enough calories or nutrient-dense foods on a daily or weekly basis. A multivitamin/mineral supplement is designed to fill in the gaps that might be missing from our diets (think calcium and vitamin D), not to augment the nutrients we already get from your food.

The best way to protect ourselves from chronic disease is to stop smoking, eat foods rich in a wide array of vitamins and minerals, keep active to the best of your ability, and maintain a social network. Talk to your healthcare provider about adding a single multivitamin to your daily routine, but only as an added safeguard—not as a single step on the road to longevity.

Fortmann SP, Burdu BU, Senger CA, Lin JS, Whitlock EP. Vitamin and mineral supplements in the primary prevention of cardiovascular disease and cancer: An updated systematic evidence review for the U.S. Preventive Services Task Force. Ann Intern Med 2013;159:824-834.

Topics: Hayes Blog

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