Tacalcitol (1,24 (R) -Dihydroxyvitamin D3; 1.alpha.,24R-Dihydroxyvitamin D3) can promote normal bone growth by regulating calcium ions. Tacalcitol inhibits cancer cell proliferation and migration. Tacalcitol can be used in the research of inflammation, cancer, and skin diseases[1][2][3][4][5].