Vitamin D (VD for short) is a fat-soluble vitamin. The most important ones are vitamin D3 and D2. Vitamin D3 is formed by ultraviolet radiation of 7-dehydrocholesterol in the human skin, and vitamin D2 is formed by ultraviolet radiation of ergosterol contained in plants or yeast. The main function of vitamin D is to promote the absorption of calcium and phosphorus by the small intestinal mucosal cells, so it can increase the blood calcium and phosphorus concentration, which is conducive to new bone formation and calcification.
| ITEMS | SPECIFICATION |
| Appearance | Meet the requirement |
| Identification | Meet the requirement |
| Examination | Dissolve 10mg of vitamin D2 into 2ml of 90% ethanol, add 2ml solution of digitalis saponin and incubate for 18 hours. No precipitation or cloud should be observed. |
| Melting Range | 115 ~ 119°C |
| Specific Rotation | +103°~+106 |
| Solubility | Freely soluble in alcohol |
| Reducing Substances | Max 20ppm |
| Ergosterol | none |
| Organic Volatility Impurities | Corresponding using method IV(467) |