Do you hear the word "vitamins" and envision pills? In fact, our main source of vitamins is the food that we eat. This video teaches the basics about these essentials to human nutrition. Learn what vitamins are, and how they keep us healthy. Get tips on the best ways to get all the vitamins you need. Explore the latest research about the dangers of "overdosing" on vitamins. Understand the signs of a vitamin shortage in your body. Discover whether vitamins can stop cancer, slow aging, or boost energy. And learn if we should take vitamins to counter stress, illness, or that "run down" feeling.