Vitamin D3 is a great source of Vitamin D because few natural foods contain Vitamin D in sufficient quantity to meet Daily Value levels. In fact, Vitamin D3 is the same form of Vitamin D that the body manufactures when skin is exposed to ultraviolet radiation from the sun. What’s more, Vitamin D3 is a superior nutrient to Vitamin D2 as it may be more than three times as effective in raising concentrations of Vitamin D in the bloodstream and maintaining those levels for a longer time. This makes it a powerful vitamin for everyone because proper levels of Vitamin D create optimum conditions for bone formation and contribute to bone strength. Vitamin D also supports the proper functioning of the nervous and immune systems, contributes to healthy levels of Phosphorous in the body, and promotes the intestinal absorption of the Calcium.