D31000 Chewable has a great-tasting, natural blackcurrant flavor and uses lanolin as a precursor, providing 1000 IU per tablet. USP and European pharmacopeia compliant, this product is also Food Codex grade. Rigorous independent testing includes supplier medicinal test results verified through independent 3rd party laboratories, thus ensuring the highest quality product. Natural conversion in the body occurs when Ultraviolet B (UVB) rays from the sun penetrate the skin and converts 7-dehydrocholesterol to pre-vitamin D3, which in turn becomes vitamin D3 (cholecalciferol). Cholecalciferol is hydroxylated in the liver to form 25(OH)D3. 25(OH)D3 is then converted in the kidneys to the most active form of vitamin D, 1, 25(OH)2D3. Vitamin D production is reduced when there is a decrease in the intensity of the suns rays. There are very few dietary sources of vitamin D, especially if consumed sparingly. Hence, vitamin D supplementation is required. Product ideal for vegetarians.