Novel vitamin D3 derivatives which are substituted at the 2-position and epimerized at the 20-position and have -O- or -CH(CH3)- at the 22-position, as represented by general formula (I): wherein X is -O- or -CH(CH3)-; R<1> is a C1-C15 saturated or unsaturated aliphatic hydrocarbon group which may be substituted with one to three optionally protected hydroxyl groups; and R<2> is lower alkyl.
