"How can I make sure I'm getting my vitamins?" is actually a very loaded question. The answer? It depends on who you ask.If you're talking to someone hawking supplements, they're going to tell you about the latest nutritional miracle and may not even answer your question. A traditional MD might just plainly direct you to buy a bottle of multivitamins and quit worrying about it, while a registered dietician might start listing from their encyclopedic vegetable knowledge, confusing you in the process.It's hard to get a straight answer. This is partly because experts don't know the exact answer and the science of nutrition it constantly changing as researchers try to figure it all out.What we do know, however, is that there are 13 essential vitamins , so named because your body truly could not function without them. These compounds keep your heart pumping, your cells growing, and your food digesting. Without them, people develop old-timey-sounding conditions including scurvy (vitamin C deficiency), anemia (iron deficiency), and rickets (vitamin D deficiency).We also know quite a bit about each one of the vitamins' basic properties. Some vitamins are fat-soluble, such as vitamin D, meaning your body can store excess amounts of them. But others, such as the B vitamins, are water-soluble, meaning that you'll just pee out the excess, rather than stocking up. Luckily (as you'll see in this article), it's pretty easy to get everything you need just by eating a balanced, healthy diet and going outside every once in a while.That's why most Americans don't need to take vitamin supplements at all. You also don't need to be taking extra amounts of these compounds. For instance, despite the hype, a megadose of vitamin C will not prevent a cold. In fact, if you consistently take too much, you can actually overdose on vitamins and have a dangerous reaction to some. That said, there are instances when certain supplements become necessary.