CanPrev's D3 Drops offer a convenient way to supplement this critical vitamin. Each D3 drop provides 1,000 IU of vitamin D3 (cholecalciferol), which is the naturally occurring form of vitamin D made when sunlight strikes the skin. It has been shown to offer superior bioavailability compared to vitamin D2 (ergocalciferol). D3 Drops from CanPrev are fat-soluble vitamins are suspended in a medium chain triglyceride (MCT) oil base. MCT oil consists of stable fatty acids that enhance the absorption of fat-soluble nutrients.