How many classes of vitamins?

Vitamins are classified into two main categories: water-soluble vitamins and fat-soluble vitamins. Water-soluble vitamins include the B-complex vitamins and vitamin C, which dissolve in water and are not stored in the body. Fat-soluble vitamins include vitamins A, D, E, and K, which are stored in the body's fatty tissues and liver. This classification helps in understanding their absorption and storage in the body.