Biaromatic vitamin D analogs

A compound according to formula (I):

• wherein
• X and Y, are either both —CH2—, or one of X and Y is —CH2— and the other is —O—;
• R1 is a methyl group or an ethyl group;
• A is either a carbon atom, CH group, CH2 group or an oxygen atom;
• one of Z1 and Z2 represents a hydroxyl group and the other one is a hydrogen atom;
• R2 and R3, independently of each other, represent a hydrogen atom, a methyl group, an ethyl group, or a CF3 group or R2 and R3, together with the carbon they are bound to, form a cyclopropyl group;
• the dotted/solid lines () represent either a single carbon-carbon bond or a double carbon-carbon bond, with the proviso that, if two of said bonds are double bonds, the double bonds are conjugated;
• one of R6 and R7 represents a hydrogen atom and the other one represents a radical R8, wherein
• wherein R4 represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a (CH2)nOR9 group where n is 1, 2, 3 or 4;
• and R5 represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, or a (CH2)nOR10 group where n is 1, 2 or 3, and wherein
• R9 and R10, independently of each other, represent a hydrogen atom, a methyl group, or an ethyl group.