Vitamins from a nutritional point of view there are two main categories: 1, fat-soluble vitamins, including vitamin A, vitamin D, vitamin E and vitamin K, these four types of vitamins belong to the fat-soluble vitamins; 2, water-soluble vitamins, which contains the types of vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, pantothenic acid, folate, biotin, choline, and often referred to as Vitamin C, which belong to the water-soluble vitamins.