Vitamin can be divided into two types of water-soluble and fat-soluble:
1. Fat soluble vitamins are soluble in most organic solvents, insoluble in water, including vitamin A, vitamin D2, vitamin E, betacarotene, calcitriol, Alfa calcitriol, dihydrotestosterol and cod liver oil and so on.
2. Water-soluble vitamins are soluble in water, including vitamin B1, vitamin B2, vitamin B6, vitamin C and nicotinamide and so on.