The primary goals of this research were to evaluate the impact of diet supplemented with 25-hydroxyvitamin D (Hy･D®) on sow’s body condition and reproduction performance. A total of sixteen multiparous sows [(Landrace×Yorkshire), average parity = 3.79 ± 0.32] and their litters were randomly allotted to 2 treatments to give 8 replicates per treatment. Diet treatments were randomized to receive a non-active (ND) or active 25-hydroxyvitamin D (AD) diet (0.36 mg cholecalciferol/g) during pregnancy. The results of this experiment were observed at the gestation of d 58 - 75, d 76 - 95, d 96 - 110, and d 111 - 115. A corn- soybean meal-based diet was formulated to meet or exceed the nutrient requirements recommended by NRC (2012). Results indicated that the sows’ farrowing duration was shortened (4.71, 5.38 h), and the average number of mummified fetuses decreased significantly (p < 0.05) in AD treatment compared with ND treatment (0.1, 0.5) while birth weight was significantly (p < 0.05) improved (1.44, 1.18 kg). There were no significant effects on body weight, backfat thickness, and fecal score during the gestation of sows in different phases (p > 0.05). And the total birth, stillbirth, live birth, and survival rates of the litter did not change (p > 0.05). The results of this study suggest that the farrowing duration of sow pigs will be shortened and the number of mummies will be decreased while their litters’ body weight may be improved, if fed active 25-hydroxyvitamin D (0.36 mg/g) during pregnancy phase.