Novel vitamin D analogs, markedly active in the fields of cell proliferation and differentiation, are selected from among (4E,6E)-7-{3-[2-(3,4-bis-hydroxymethylphenyl)-ethyl]phenyl}-3-ethylnona-4- ,6-dien-3-ol, (E)-6-[3-(3,4-bis-hydroxymethylbenzyloxy)phenyl]1,1,1-trifluoro-2-trifluo- romethyloct-5-en-3-yn-2-ol, (3E,5E)-6-[3-(3,4-bis-hydroxymethylbenzyloxy)-phenyl]-1,1,1-trifluoro-2-t- rifluoromethylocta-3,5-dien-2-ol, (E)-6-{3-[2-(3,4-bis-hydroxymethylphenyl)ethyl]phenyl}-1,1,1-trifluoro-2-- trifluoromethyloct-5-en-3-yn-2-ol, and (3E,5E)-6-{3-[2-(3,4-bis-hydroxymethylphenyl)-ethyl]phenyl-1,1,1-trifluor- o-2-trifluoromethylocta-3,5-dien-2-ol, and the geometric isomers thereof and these compounds in which one or more of the hydroxyl functions are protected by a protective group --(C.dbd.O)--R, in which R is a linear or branched alkyl radical having from 1 to 6 carbon atoms, an aryl radical having from 6 to 10 carbon atoms, or an aralkyl radical having from 7 to 11 carbon atoms, the aryl radical or the aralkyl radical optionally being mono- or disubstituted by a hydroxy group, an alkoxy radical having from 1 to 3 carbon atoms, a halogen atom, a nitro function or by an amino function, and mixtures thereof.