Is Your Dietary Supplement Safe?

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Scholars warn that FDA’s regulation of dietary supplements could pose health risks to consumers.

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From weight loss pills to protein powder, dietary supplement consumption is on the rise. But some dietary supplements boast unsubstantiated claims and may be contaminated with pesticides or toxic heavy metals.

The U.S. Food and Drug Administration (FDA) categorizes dietary supplements as products with ingredients such as herbs, vitamins, and minerals. Dietary supplement companies can market these products as powders, tablets, or liquids.

Dietary supplements have less stringent safety requirements than prescription and over-the-counter drugs. Companies can send their products to market without conducting any safety or quality testing—such as clinical trials to prove their products’ alleged health benefits. Current FDA regulations only require “reasonable assurance” that dietary supplements do not pose “a significant or unreasonable risk of illness or injury” when the product is used as directed, or with regular use if the label does not include directions.

The Dietary Supplement Health and Education Act (DSHEA) allows FDA to regulate dietary supplements as a special category distinct from conventional food and drug products. The statute also authorizes the agency to remove products it deems unsafe from the market.

FDA, however, lacks the ability to review the safety and effectiveness of dietary supplements before consumers can buy these products. Although the DSHEA allows FDA to remove a dietary supplement from the market, the agency can only do so after it demonstrates that the product in question presents a significant risk to consumers.

But this standard can be difficult to meet for two reasons. First, because dietary supplements are usually self-prescribed or available over-the-counter, medical professionals do not consistently monitor them for negative side effects. Second, because reporting adverse reactions to dietary supplements is voluntary for consumers and health professionals, toxic products can circulate in the market before FDA proves injury to consumers and pursues manufacturers.

Many dietary supplements, however, are safe. For example, millions of consumers take multivitamins regularly without harmful side effects, and many manufacturers provide detailed ingredient disclosures and claims on their products.

This week’s Saturday Seminar examines the regulatory framework for dietary supplements and highlights suggestions for how FDA can improve regulation of these products.

  • To protect consumers, FDA and other agencies should promote safety in dietary supplements by improving detection, deterrence, and prevention measures, Amy Christine Brown of the University of Hawai’i at Manoa claims in a Food and Chemical Toxicology article. Because FDA has limited resources to detect contamination in the dietary supplement marketplace, Brown advocates tightening labeling laws and imposing future criminal penalties under existing laws to hold corporations that violate regulations accountable. She further suggests that a centralized FDA reporting system and timely enforcement of existing laws and regulations against companies that adulterate drugs could improve the regulation of dietary supplements.
  • Pieter Cohen of Harvard Medical School explains the challenges of pharmaceutically adulterated supplements—products labeled as botanical dietary supplements, but which actually include active drugs—in a JAMA Network article. Cohen argues that FDA’s current voluntary recall process for these supplements is deficient because too many products remain in the marketplace, leaving consumers at risk of “inadvertently ingesting unknown quantities of pharmaceutical drugs.” Cohen suggests that the U.S. Congress amend the DSHEA to provide “FDA with more effective enforcement tools, such as immediately revoking a product’s registration if a supplement is found to be adulterated with pharmaceutical drugs.”
  • Even under a statute such as the DSHEA, the “quality and safety” of dietary supplements “can be highly variable,” Purdue University’s Regan L. Bailey argues in a Critical Reviews in Food Science and Nutrition article. For example, Bailey highlights that the DSHEA does not address bioavailability—whether a person’s body can absorb the ingredients in a dietary supplement. In addition, she calls for dietary supplements to face controlled trials to determine any health benefits and demonstrate a product’s efficacy. Although the DSHEA notes that dietary supplement products are not designed to treat diseases, most consumers “use supplements primarily for health-related reasons,” according to Bailey.
  • In an article in the Academy of Management Journal, the University of Oxford’s Pinar Ozcan and La Salle Ramon Llull University’s Kerem Gurses detail the regulatory battle between FDA and manufacturers over how to categorize dietary supplements. Ozcan and Gurses focus on the process of regulatory categorization, which determines the legal conditions of how a product is produced and distributed. They note that dietary supplement producers established an entirely new regulatory category by garnering public support with a national campaign against FDA. The agency’s “scientific approach,” efforts to educate the public, and policing of the industry “allowed supplement makers to portray the regulator as arrogant and aggressive, and themselves as victims,” Ozcan and Gurses claim.
  • Although dietary supplement regulations vary internationally, rules for these products often seem “directed more toward promoting commerce than protecting public health,” Mi Kyung Lee of Murdoch University and Colin W. Binns and Andy H. Lee of Curtin University argue. In an article in the Annual Review of Public Health, Binns and his coauthors claim that dietary supplement regulation should include minimum safety requirements, such as a uniform registration system for supplements, a list of permitted substances, and more standardized labeling requirements. Although consumers have increased their consumption of dietary supplements in recent years, Binns and his coauthors suggest that consumers may benefit more from choosing a diet of nutritious foods rather than relying on underregulated supplements with dubious ingredient compositions and benefits.
  • In a Regulatory Toxicology and Pharmacology article, FDA’s Shraddha Thakkar and her coauthors compare and contrast dietary supplement regulation internationally. Thakkar and her coauthors argue that countries often regulate similar products differently because “the regulatory definition and categorization” of medicines and supplements vary widely across different countries. For example, FDA treats green tea extract as both a dietary supplement and a medicine, but Canada and Australia classify it as a medicine, and the European Union, China, Japan, and New Zealand regulate it as a supplement. To harmonize dietary supplement regulation internationally, Thakkar and her coauthors encourage “establishing centralized information on botanical standards.”

The Saturday Seminar is a weekly feature that aims to put into written form the kind of content that would be conveyed in a live seminar involving regulatory experts. Each week, The Regulatory Review publishes a brief overview of a selected regulatory topic and then distills recent research and scholarly writing on that topic.