Vitamin D (also referred to as calciferol), is a fat-soluble vitamin that is naturally present in a few foods and available as a dietary supplement. It is also produced endogenously when ultraviolet (UV) rays from sunlight strike your skin and trigger vitamin D synthesis; that is why vitamin D is often called "the sunshine vitamin." This vitamin is essential for strong bones, as it helps your body keep calcium and phosphorus which are the key building blocks for bones. Empower Your Health: Embrace the Sunshine Vitamin This Winter!