B vitamins play an important role in maintaining good health and well-being. As building blocks of a healthy body, B vitamins have a direct effect on your energy levels, brain function, and cellular metabolism. The B vitamin complex consists of eight B vitamins: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), B12 (cobalamin). Each of these important vitamins contributes to your overall body function.