It seems there’s a pill for every type of disease imaginable these days. And when it comes to vitamins, in particular, we’re a supplement-happy bunch. Americans spend $14 billion a year on vitamins and supplements. And around 40 percent of adults in the U.S. take multivitamins regularly. But are regular multivitamin users actually benefiting from them? The research might suggest otherwise.

The Multivitamin Debate

The “should I/shouldn’t I take a multivitamin” question began heating up back in the 1970s when Nobel prize-winning scientist Linus Pauling wrote Vitamin C and the Common Cold. In it, Pauling recommended taking 3,000 milligrams of vitamin C every day to ward off colds and prevent degenerative and sometimes incurable diseases. This was quite the stark contrast to the 60 mg recommended daily allowance (RDA) at the time. And boy did people listen. Sales of vitamin C quadrupled, and an estimated 50 million people in the U.S. were supplementing with vitamin C by the mid-70’s. A range of studies followed to discredit Pauling’s claims, but that did little to discourage vitamin marketers from taking advantage of the hypeVitamin C for preventing and treating the common cold. Douglas R.M., Hemilä H., et al. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD000980.Effect of vitamin C supplements on cell-mediated immunity in old people. Kennes B., Dumont I. et al. Gerontology. 1983;29(5):305-10..

Today, the debate rages on. We use dietary supplements for a variety of reasons, mostly to improve or maintain overall healthMultivitamins in the prevention of cancer in men: the Physicians’ Health Study II randomized controlled trial. Gaziano J.M., Sesso H.D. et al. Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School. JAMA, 2012 Nov; 308(18):1871-80.. And many of us aren’t getting enough basic nutrients from sources like fruits and vegetables. Research shows a significant amount of people in the U.S. had total usage intakes below the recommendation daily amount for vitamins A, C, D, and E (34, 25, 70, and 60 percent, respectively), calcium (38 percent), and magnesium (45 percent)Foods, fortificants, and supplements: Where do Americans get their nutrients? Fulgoni V.L. 3rd, Keast D.R. et al. Nutrition Impact LLC, Battle Creek, MI, USA. Journal of Nutrition, 2011 Oct;141(10):1847-54..

So we take vitamin supplements to help make up for these nutritional deficiencies. The question remains, do these supplements actually work or are they doing more harm than good?

Should You Take a Multivitamin?

Here’s where things get tricky. There’s been plenty of research on the efficacy of multivitamins. Problem is, the science is sending mixed signals. For example, researchers in one study of 38,772 women found that multivitamins may be associated with an increased risk of dyingDietary supplements and mortality rate in older women: the Iowa Women’s Health Study. Mursu J., Robien K. et al. Department of Health Sciences, Institute of Public Health and Clinical Nutrition, 2011 Oct; 171(18):1625-33.. Another study found people who take multivitamins do not live any longer on average than those who don’tMultivitamin-multimineral supplementation and mortality: a meta-analysis of randomized controlled trials. Macpherson H., Pipingas A. et al. Center for Human Psychopharmacology, Swinburne University of Technology. The American Journal of Clinical Nutrition, 2013 Feb;97(2):437-44..

But what about multivitamins and cancer? One study showed multivitamins may help reduce prostate cancer risk by eight percent in men 50 years and olderMultivitamins in the prevention of cancer in men: the Physicians’ Health Study II randomized controlled trial. Gaziano JM., Sesso H.D. et al. Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School. JAMA, 2012 Nov 14;308(18):1871-80.. However, others have found an increased risk of cancer associated with high antioxidant intakeAlpha-Tocopherol and beta-carotene supplements and lung cancer incidence in the alpha-tocopherol, beta-carotene cancer prevention study: effects of base-line characteristics and study compliance. Albanes D., Heinonen OP. et al. Division of Cancer Prevention and Control, National Cancer Institute. Journal of the National Cancer Institute. 1996 Nov 6;88(21):1560-70..

And when it comes to heart health, a recent study of U.S. male physicians found multivitamins do not protect against major cardiovascular events, myocardial infarction, stroke, and death from cardiovascular diseaseMultivitamins in the prevention of cardiovascular disease in men: the Physicians’ Health Study II randomized controlled trial. Sesso H.D., Christen W.G. et al. Division of Preventive Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School. JAMA, 2012 Nov 7;308(17):1751-60..

A recent study entitled, “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” concluded that popping pills does not help prevent against chronic diseases and can even harm overall health. Instead of shelling out bucks for vitamins and minerals from A to Z, the study’s authors believe that people should focus on incorporating all food groups into their diets.

The Takeaway

There’s still fierce debate on the effectiveness of multivitamins. For some, specific supplements have a clear benefit. For example, women who are or may become pregnant need folate, a B vitamin that’s important for lowering the risk of having a baby with conditions spina bifida or anencephaly (400 micrograms per day according to the Centers for Disease Control and Prevention). People over 50 might also experience low levels of vitamin B12 and could benefit from supplementation.

Regardless of which side of the fence you’re on when it comes to multivitamins, there’s research to support your argument. If you’re struggling to eat the recommended amount of fruits and vegetables per day (which varies depending on your age, sex, and activity level), then taking a daily multivitamin can be a good insurance policy, and it appears the benefits outweigh the potential harm. But if you live a healthy and active lifestyle and eat a balanced diet, you probably won’t get much benefit from taking one.