Vitamin D3, also known as cholecalciferol, is a kind of vitamin D. Cholecalciferol can be formed from 7-dehydrocholesterol after dehydrogenation of cholesterol by ultraviolet radiation, so that means the provitamin D of cholecalciferol is 7-dehydrocholesterol.

Vitamin D3 (cholecalciferol)

Density:0.9717 g/cm3

Melt Point:83-86 °C(lit.)

Boiling Point:496.4ºC at 760 mmHg

Flashing Point:214.2ºC

Refractive index:1.507 (15ºC)

Storage:2-8ºC

Vitamin D3 is most abundant in sea liver, for example, the liver of cod, flounder and swordfish contains 3200~750 micrograms, 500~ 10,000 micrograms and 25,000 micrograms of vitamin D3 per 100 grams respectively. Other such as herring, salmon, sardines and pompano whale contain small amounts; Livestock liver, eggs and milk also contain small amounts of less than 100 micrograms per 100 grams. In general, it is not easy to get enough vitamin D3 from food alone, so the synthesis of vitamin D3 in the body through sunbathing is a particularly important route.