Your body needs vitamins on a daily basis to function, grow, and develop properly. Essential vitamins your body requires include vitamin A, B vitamins (folate, vitamin B12, vitamin B6, biotin, pantothenic acid, niacin, riboflavin and thiamin), vitamin C, vitamin D, vitamin E, vitamin K, and choline. The Institute of Medicine provides recommended dietary allowances (daily vitamin requirements) for each age and gender group.
What Vitamins Are
Vitamins are organic compounds (substances containing carbon) made by animals or plants that are crucial for normal human body functioning. Vitamins are either fat soluble (vitamins A, D, E and K) and dissolve in fat, or water soluble (dissolve in water). The water soluble vitamins are B vitamins and vitamin C, and your body doesn't store them for long. Because of this, you need a continuous supply of B vitamins and vitamin C daily. On the other hand, your body can store fat soluble vitamins for longer periods.
The function of each vitamin differs, and each nutrient works together in your body synergistically. For example, vitamin C helps your body absorb dietary iron and enhances healing, and it promotes healthy connective tissue, bones, and skin. Vitamin A is necessary for good vision, healthy bones, a strong immune system, and reproduction. Vitamin D helps you absorb calcium and is essential for strong bones, nerve function, a strong immune system, and proper muscle function. B vitamins and vitamin E play a role in your body's metabolism (absorbing and utilizing nutrients for energy), and vitamin K helps your body make proteins.