Abstract: The invention relates to vitamin D amine and amide derivatives of general formula ##STR1## where R represents a hydrogen atom, an aliphatic, cycloaliphatic or araliphatic group, or an acyl group comprising an aliphatic, cycloaliphatic, arylaliphatic or aryl group linked to the nitrogen atom by way of a carbonyl group; R.sup.1 and R.sup.2 are each selected from lower alkyl and cycloalkyl groups or together with the carbon atom to which they are attached form a lower cycloalkyl group; R.sup.3 represents a methyl group having .alpha.- or .beta.-configuration; Y represents a lower alkylene, alkenylene or alkynylene group optionally substituted by a hydroxyl, etherified hydroxyl or esterified hydroxyl group; and A.dbd. represents a cyclohexylidene moiety characteristic of the A-ring of a 1 .alpha.-hydroxylated vitamin D or analogue thereof. Active compounds of the invention exhibit cell modulating activity and in certain cases may also have an effect on calcium metabolism.