In 2002, the entire U.S. dietary supplement industry generated about $18.7 billion in sales. In 2024, Utah’s dietary supplement industry alone was valued at over $16 billion, making it the state’s third-largest industry, behind only tech and tourism.
Suffice to say, dietary supplement use across the country has been rising dramatically, and Utah, with over 300 nutraceutical companies, has been pegged as the heart of supplement industry and even the "supplement capital" of the U.S. But what exactly is a dietary supplement anyway?
“So, supplements are kind of a broad definition, because a lot of things can fall in the supplement category," said Thunder Jalili, a professor of nutrition and integrated physiology at University of Utah.
“Generally, a supplement is anything that people take to try to enhance their health or improve a certain aspect of their physiology," he said.
However, that definition includes everything from significantly diluted plant extracts to highly refined concentrations of vitamins, proteins, and other compounds. So, does that make supplements a medicine?
“In a general sense, most supplements aren't really that effective at treating a medical condition," Jalili said.
Granted, there are prescription grade levels for some supplements. Vitamin B12, fish oil, and vitamin D can all be purchased over the counter, but they can also be prescribed by doctors at levels tailored to an individual’s needs.
“The thing with prescription medications is that they're usually tested really extensively for a very specific thing in a very specific dosage," Jalili said. "That means we know if they work or they don't work, and supplements don't quite have that same level of rigor with testing. There's actually no requirement that a supplement does what it says.”
And that is a major difference. Medications are regulated by the Food, Drug, Cosmetic Act of 1938, amended in 1962 to protect consumers.
However, supplements are addressed in the Dietary Supplement Health and Education Act of 1994 that prohibits distributors from marketing adulterated or misbranded products. Though it allows the FDA to act against infractions, it does say that the testing and safety evaluations of dietary supplements fall on the firms that make the them, not the government.
But surely there is a law about what is and isn’t a supplement, right?
“There's no law for that," Jalili said. "You and I can make up a supplement and say, ‘This is good for strong bones.’ We don't have to prove it. We can just make it and say that it supports bones. And that's such an amorphous statement that we can market that, and most people will likely see that and say, ‘Oh, it's good for my bones.’ Well, no, we're not saying that. We're just saying it's 'supporting bone health,' and that's a different thing.”
And that vague wording makes all the difference. Granted, supplements can’t legally make disease-treatment claims. In the bone health example, a supplement can’t legally claim to treat osteoporosis — but they can legally claim to "support bones." A supplement couldn’t claim to "lower cholesterol" without rigorous testing to prove it, but it could claim to be "good for cardiovascular health," and for many consumers that sounds close enough. But is it?
“Again, there's no legal requirement to test anything to back up a specific claim," Jalili said.
Because there’s no legal requirement to test anything, most supplements are simply untested.
“I mean, if you put yourself in the shoes of the manufacturer. You're making a supplement, you're selling it, you're making a bunch of money," Jalili said. "Why would you test it and risk the thing not working if you already have good sales?”
While some supplements likely do receive some levels of testing, Jalili said they probably never get to the level of prescription medication testing. That requires an extremely lengthy preclinical phase, before passing to numerous phases of human testing, and then continued post-market monitoring and oversight by a federal agency.
In addition, since some supplements might have different forms of untested but medically significant drugs, they could interfere with or boost prescribed medications to a dangerous degree.
Ultimately, Jalili emphasized a simple but critical takeaway.
“The one thing I wish people would always remember is that a lot of supplements don't have really good scientific testing behind them, so we don't really know if they do what the manufacturer is claiming they do," he said.
He recommends that anyone considering taking a supplement talk with their health care provider first.
Check the following links for more information:
Harvard School of Public Health: What is a supplement?
NIH: Dietary Supplement Factsheets.
Medline Plus: Dietary Supplements.
