Synthetic vitamins aren’t a good choice for your dog. That’s obvious. But nearly all commercial and some raw-pet foods contain them. China owns over 90% of the vitamin C market in the US and most of the vitamins in dog foods are manufactured in China and India. This should worry conscious pet parents because only 2 percent of all imported vitamins are inspected. And China’s top vitamin and supplement producing areas are among the most polluted in the world.