Vitamins are organic molecules required by every living organism and are important for our immune system. (antioxidants, production of enzymes, etc.) Vitamins are essential for your normal growth and development. Every vitamin has a different function in your body. Some are good for the skin or for the eyes, others are antioxidants. Eating enough protein and carbohydrates, but forgetting about the vitamins would be like driving a car with enough gas but without oil and coolant. There are water soluble and fat soluble Vitamins. Fat soluble vitamins A, D, E and K are absorbed by fat. All the other ones are absorbed by water. The advantage of fat soluble vitamins is, that they can be stored in the body for a long period of time (a few weeks). The problem is, that if you ingest too many fat soluble vitamins, their storage in your body can reach toxic concentrations. Water soluble vitamins on the other hand, can only stay in your body for a couple of days. If you don't ingest enough water soluble vitamins, you will soon show deficiency symptoms.