Vitamins allow your body to grow and develop. They also play important roles in bodily functions such as metabolism, immunity, and digestion. There are 13 essential vitamins, including vitamins A, C, D, E, and K, and B vitamins such as riboflavin and folate. According to the U.S. National Library of Medicine, the best way to meet your vitamin needs is to eat a balanced diet containing a variety of foods. If you can’t meet your needs through food alone, you may require dietary supplements. Seek guidance from your doctor or dietitian before taking supplements, however.