The first and only concentrated active vitamin d skincare treatment. A unique serum-oil emulsion that delivers your skin"s daily dose of vitamin D. Great for all skin types and ages including combination/oily additional background info. Dr. Dennis gross observed the majority of his patients (skin cancer patients in general) were experiencing vitamin D deficiencies because they were overtly careful about exposing themselves to uv rays and using high levels of sunscreen. In order for the body to synthesize vitamin D, it must be converted from uvb sun exposure or through supplementation/diet.