Vitamins are often categorized as water-soluble or fat-soluble. Water-soluble vitamins dissolve in water and aren’t stored in the body, while fat-soluble vitamins are absorbed with fats and are stored in the body. You should take water-soluble vitamins with water and fat-soluble vitamins with a fatty meal. The water-soluble vitamins include Vitamin C and the eight B Vitamins. The fat-soluble vitamins include Vitamins A, D, E, and K.