Vitamin D, also known as the sunshine vitamin is an essential fat-soluble vitamin that plays many important roles in the proper functioning of the body. Though classified as a vitamin, vitamin D is actually a key regulatory hormone for calcium and bone metabolism. Adequate vitamin D status is essential for ensuring normal calcium absorption and maintenance of healthy calcium plasma levels. Besides bone support, vitamin D has many other roles in the body, including modulation of cell growth, neuromuscular and immune function and inflammatory support. € Supplemental vitamin D is available in 2 distinct forms: synthetic ergocalciferol (vitamin D2) and natural cholecalciferol (vitamin D3). Despite an emerging body of evidence suggesting greater bioefficacy of vitamin D3, the form of vitamin D used in pharmaceutical prescriptions in North America is vitamin D2. Clinical studies show vitamin D2 potency is less than one third that of vitamin D3 and has a shorter duration of activity. For example, 50,000 IU of vitamin D2 may be similar to a dose of 15,000 IU of vitamin D3. Therefore, vitamin D2 should not be considered equivalent to vitamin D3 based on differences in their efficacy at raising serum 25-hydroxyvitamin D, reduced binding of vitamin D2 metabolites to vitamin D binding protein in plasma, and distinct differences in metabolism. Since vitamin D is fat-soluble, it may be difficult for one to adequately absorb and utilize it, especially for those individuals with fat malabsorption. D-Sorbª is unique among vitamin D products because it utilizes the patented VESIsorb¨ technology to deliver vitamin D3 and therefore enhance absorption. When mixed with an aqueous system, this patented technology results in the formation of a nano-colloid containing solubilized vitamin D. This colloid delivery system contains a highly uniform distribution of droplets that are less than 100 nm in diameter. The size and structure of these droplets allow for enhanced solubility and absorption of vitamin D. This image represents the structure of a nano-colloid droplet which consists of a monolayer with the vitamin D contained within the core. The formation of the colloidal system upon contact with an aqueous environment (such as the lumen of the intestine) enables the solubilized vitamin D to more easily diffuse across the unstirred water layer that is present between the enterocyte and the lumen of the intestine.