1. Petroleum refinery process in which large heavy oil molecules are broken down into smaller ones. If conducted only with the application of heat, it is called thermal cracking. If a catalyst is also used, it is called catalytic cracking. If hydrogen is used in addition to heat and catalysts, it is called hydrocracking. 2. Deciphering of a code or encrypted data.
Vitamin D3 is the form of vitamin D called cholecalciferol. Cholecalciferol is the most widely known of the vitamin D series and is a fat soluble vitamin that is stored to some degree in the body. It is used as a dietary supplement and for the treatment and prevention of vitamin D deficiency.
You should not use cholecalciferol if you have ever had an allergic reaction to vitamin D, or if you have: 1  high levels of calcium in your blood (hypercalcemia); 2  high levels of vitamin D in your body (hypervitaminosis D); or. 3  any condition that makes it hard for your body to absorb nutrients from food (malabsorption).