Dietary supplements are one of the most popular and widely used of the treatments. Surveys find dietary supplement use varies from country to country, but in many developed nations 50-70 percent of adults report using some kind of supplement, and many children are given supplements, as well.1–9 Pet owners also commonly give supplements to their animals, though at somewhat lower rates. About 30 percent of dog owners and 20 percent of cat owners in one survey reported using dietary supplements for their pets.10
The popularity of supplements makes them a very profitable product. The dietary supplement industry is worth hundreds of billions of dollars worldwide, and while the majority of this is the market for humans, veterinary supplements are still a billion-dollar a year business.11,12