SLBIO High Quality CAS 67-97-0 Cholecalciferol Powder 40,000,000IU/g Vitamin D3 Powder

   Vitamin D is a fat-soluble vitamin and is also considered a hormone precursor that acts on calcium and phosphorus metabolism. It is closely related to sunlight, hence its nickname "sunshine vitamin." Vitamin D is a collective term for a group of complexes with identical A, B, C, and D ring structures but different side chains. The structures of the A, B, C, and D rings originate from the cyclopentanenylphenanthrene ring structure. At least 10 types of vitamin D are currently known, but the most important are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

   Vitamin D3 (cholecalciferol) is primarily synthesized by the human body. Human skin contains cholesterol, which is converted into vitamin D3 upon exposure to sunlight. Therefore, if children receive direct sunlight for 4-6 hours or more, their own vitamin D3 synthesis can generally meet their needs. However, due to factors such as increased skin cancer caused by ultraviolet radiation, air pollution, and varying weather patterns, the amount of time people in various countries are exposed to sunlight is decreasing, and many countries have explicitly stipulated restrictions on the duration of sun exposure. As a result, vitamin D deficiency is widespread worldwide. In addition, vitamin D3 can also be obtained from animal foods, such as liver, especially cod liver oil extracted from the liver of seafood. Aside from a few animal foods, vitamin D3 is mainly formed from 7-dehydrocholesterol in the skin after exposure to ultraviolet radiation. 7-dehydrocholesterol is converted from cholesterol, hence the nickname "sun vitamin."

   Vitamin D3 is fat-soluble, insoluble in water, and only soluble in fats or fat solvents. It is resistant to high temperatures and oxidation in neutral and alkaline solutions. Experiments have shown that heating at 130 degrees Celsius for 90 minutes does not destroy its physiological properties, but it gradually decomposes and is destroyed under acidic conditions. It is generally not lost during food cooking and processing, but rancidity of fatty acids can cause the destruction of vitamin D3.