Vitamin D analogues

A compound of the formula I ##STR47## in which formula, n is 0 or 1, m is 0 or an integer from 1-7, R.sup.1 and R.sup.2, which may be the same or different, stand for hydrogen or C.sub.1 -C.sub.8 -hydrocarbyl, hydrocarbyl indicating the residue after removal of a hydrogen atom from a straight, branched or cyclic saturated or unsaturated hydrocarbon, or, taken together with the carbon bearing the hydroxyl group (starred in formula I), R.sup.1 and R.sup.2 form a saturated or unsaturated C.sub.3 -C.sub.8 carbocyclic ring;

• and in addition, R.sup.1 and/or R.sup.2 and/or one of the m carbons designated by the ".degree." are optionally substituted with a hydroxyl group or one or more chlorine or fluorine atom(s);
• and finally one of the carbons designated ".degree." are optionally substituted by one or two C.sub.1 -C.sub.2 alkyl group(s);
• and prodrugs and derivatives of the compounds of formula I in which one or more hydroxy groups have been transformed into --O-acyl or --O-glycosyl or phosphate ester groups;
• such masked groups being hydrolyzable in vivo. prodrugs thereof.