To be sure, most people are aware that the line between actual medicine and homeopathic quackery can at times be blurry. That’s especially true when factoring in slick marketing language and spurious, unregulated buzzwords like “natural.” What most people don’t expect, though, is for something like the humble multivitamin to fall into the “doesn’t do jack for your health” category. After all, they’re vitamins! The essence of life! Fruits have them!

Sadly, it’s true: According to new research by medical experts, taking a daily multivitamin has no obvious positive impact on health, and in fact might even be dangerous.

“We believe that the case is closed— supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough.” Those are strong words, and they come from five physicians from Johns Hopkins School of Public Health and Warwick Medical School in the U.K. Each of them, The Atlantic notes, have five letters-worth of education and training tacked onto the ends of their names.

“Beta-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful,” they specify. “Other antioxidants, folic acid, and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases.”

Are you reading the back of your vitamin bottle right now? How’s it looking? Folic acid, it’s noted should still be taken as a supplement by pregnant women.

The largely unregulated U.S. supplement industry is big business, growing to $28 billion in sales in 2010. According to analysts, it continues to grow, despite mounting evidence against the efficacy of supplements.

Get the full editorial, titled “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” at Annals of Internal Medicine.