Vitamin B complex is a group of eight vitamins that are water-soluble and play an important role in maintaining good health and well-being. These As we mentioned before, Vitamin B Complex is an essential group of nutrients for your overall health. This group is composed of eight vitamins, which include thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12). Each of these vitamins plays a crucial role in keeping your body functioning at its best.