Why It’s an Essential Vitamin Vitamin D can be found in cells throughout the entire body. It is necessary for calcium and phosphorus absorption to build and maintain strong bones and teeth, provide immune system support, and for healthy muscle function.* Can’t You Get Vitamin D From the Sun? Often referred to as the “sunshine vitamin,” 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. Factors that can inhibit vitamin D3 production include the time of day sun exposure occurs, season, latitude, skin color, age, clothing, and sunscreen use. In fact, according to Mayo Clinic, 25% to 50% or more of the general population may be vitamin D deficient. 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. Symptoms of Vitamin D Deficiency Bone pain and brittleness, muscle weakness, and tiredness can all indicate a deficiency in vitamin D. People who may be at higher risk for deficiency include those who spend a lot of time indoors, have darker skin pigmentation, are elderly, or overweight. Our Vitamin D3 is Third Party Tested for Quality, Purity, and Potency NatureWise Vitamin D3 contains 100% natural, USP grade, non-GMO, certified organic olive oil. Our vitamin D3 is made following strict GMP standards. We utilize specialized ISO 17025 third party laboratories to test for physical, chemical, and microbial contamination. potency, and safety. No artificial additives. * These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, or cure any disease.