Anne Hathaway and Heidi Klum depend on New York City-based trainer David Kirsch not just for his killer workouts but also for his tasty line of vitamin supplements. When his celeb clients are on the go, Kirsch ships them cases of his fruit-flavored Super Juice Packets – which add only 30 calories and your daily vitamins to a bottle of water – and energy-boosting Thermo Bubbles drinks. Learn about what vitamins you really need at Health.com. – Melissa Liebling-Goldberg