The study was aimed to evaluate the role of vitamin D on redox balance and insulin resistance in pregnant ewes and its predicting ability for subclinical pregnancy toxemia (SPT). At 4 weeks pre-lambing 15 healthy pregnant ewes were divided into two groups based on their vitamin D (25-hydroxyvitamin D (25VitD) content. Ewes having sufficient 25VitD (SVD) and ewes having insufficient 25VitD (ISVD). Study concluded that 25VitD has a profound effect on redox balance, energy balance and good predicting ability for SPT in pregnant sheep.