They're added to breakfast cereal, bread, and even Pop-Tarts, giving the sweetest, most processed treats a halo of health. Most people pop an extra dose for good measure, perhaps washing it down with fortified milk. But what are vitamins—and how did their discovery make America's processed food revolution possible? On this episode of Gastropod, author Catherine Price helps us tell the story of vitamins, from Indonesian chickens to Gwyneth Paltrow. (encore) Learn more about your ad choices. Visit podcastchoices.com/adchoices