Vitamin B5, also known as Pantothenic Acid, is one of eight B vitamins. It is a water-soluble vitamin needed to synthesize and metabolize proteins, carbohydrates, and fats. Vitamin B5 is critical in manufacturing red blood cells, as well as hormones produced in the adrenal glands, the small glands that sit on top of the kidneys. Vitamin B5 is also important in helping maintain a healthy digestive tract.