25,26-Dihydroxyvitamin D3 (25,26-Dihydroxycholecalciferol) is a dihydroxylated derivative and metabolite of Vitamin D3 (HY-15398). 25,26-Dihydroxyvitamin D3 moderately increases serum calcium levels when the initial serum calcium level is low. 25,26-Dihydroxyvitamin D3 promotes intestinal calcium absorption in vitamin D-deficient rats fed a low-calcium diet. 25,26-Dihydroxyvitamin D3 is applicable to research related to osteomalacia[1][2][3].