Yes, you can safely take Rocaltrol (calcitriol) and Nurokind OD (mecobalamin) together at the same time. There are no known harmful interactions between these two medications. Calcitriol is an active form of Vitamin D that helps your body absorb calcium for bone health, while mecobalamin is a form of Vitamin B12 that supports nerve health. Taking them together is perfectly fine and can be very beneficial for your overall well-being. For the best absorption, you can take them with a meal. Please continue to follow your doctor's specific dosing instructions.