vitamin d3 (cholecalciferol) is the optimal form of vitamin dcholecalciferol is the most active form of vitamin d that covers the body s need for efficient propertiesTake one capsule weekly with a meal or as directed by your doctor.Hi Dee Vitamin D3 10000 IU Capsule 30s is a dietary supplement that contains a high dose of vitamin D3 (cholecalciferol) as the active ingredient.