Vitamin D, the sunshine vitamin is really a hormone but categorized as a vitamin. This is because a deficiency is associated with the diseasesrickets (bone deformities) in children and osteomalacia (poor bone mineralization leading to weak, painful bones) in adults. The body is able to synthesize pre-vitamin D3 in the skin when exposed to sunlight. The pre-vitamin D3 is rapidly converted into vitamin D3. Vitamin D3 is then transported through the blood to the liver and kidney where it is converted into the hormone calcitriol, the active form of vitamin D. Only a few foods naturally contain vitamin D including: fatty fish and cod liver oil. Fortified foods such as milk and cereal are the major dietary sources of vitamin D. It is estimated that 40% of the U.S. population is vitamin D deficient, therefore supplementing the diet with extra vitamin D is essential for optimal health. Numerous factors influence the skins synthesis of pre-vitamin D3 including, location, climate, sun exposure, skin color, age and use of sunscreen. When you combine all of the factors that influence vitamin D synthesis with the existing widespread deficiency, vitamin D supplementation is the most efficient and convenient way to ensure optimal vitamin D intake.*