There are two types of multivitamins: the first is the fat-soluble vitamins, which contain vitamin A, vitamin D, vitamin E and vitamin K. These four vitamins are fat-soluble vitamins. The second category is water-soluble vitamins, which are vitamin B1, vitamin B2, vitamin B6, niacin, pantothenic acid, folic acid, vitamin B12, biotin, choline and vitamin C. These vitamins are water-soluble vitamins. Thus, a multivitamin would contain four classes of fat-soluble vitamins and 10 classes of water-soluble vitamins.