The Caltrate Weikang capsules made by us is a high potency calcitum preparaion, in which vitamin D can promote the body s calcium absorption and the bones calcification. A sensitive HPLC method for the determination of VD2 and VD3 in Caltrate Weikang capsules was established and VD stability was also examined The Caltrate Weikang capsules made by us is a high potency calcitum preparaion, in which vitamin D can promote the body s calcium absorption and the bones calcification. A sensitive HPLC method for the determination of VD2 and VD3 in Caltrate Weikang capsules was established and VD stability was also examined