The Sunshine Vitamin - Vitamin D is an essential vitamin that can be found in cells throughout the entire body. It is necessary for calcium and phosphorus absorption to help build and maintain strong bones and teeth, provide immune system support, and for healthy muscle function. Vitamin D3 is synthesized when bare skin is exposed to ultraviolet B (UVB) light. However, studies show that most people do not get the recommended amount from sunlight alone. NatureWise Vitamin D3 delivers the same biologically active form of Vitamin D produced in the body as a result of direct sunlight - without the risk of unprotected UVB exposure. Since Vitamin D is fat-soluble, we include certified organic olive oil as a healthy fat source for better absorption. NatureWise supplements are proudly manufactured in USA-based facilities that comply to the strictest cGMP standards and are carefully tested by third party laboratories for purity and potency, as well as physical and chemical contamination..