The only two things in theSunny Skies Vitamin D3formula are MCT oil and vitamin D3 (Cholecalciferol). MCT oil is derived from coconuts. Coconut oil is a very fresh, non-reactive, and stable oil.Vitamin D3(Cholecalciferol), is the naturally occurring form of vitamin D. It is produced by the human body when skin makes contact with direct sunlight. It is superior to vitamin D2 that is used in most supplements and fortified foods.