A derivative of cholesterol present in the skin. It can be converted to cholecalciferol (vitamin D₃) by the action of ultraviolet radiation.
Chemical formula: C₂₇H₄₄O
- ‘In the skin 7 - dehydrocholesterol is converted to cholecalciferol following UV irradiation.’
- ‘The most important source of vitamin D for all individuals is the sunlight-driven conversion in skin of 7 - dehydrocholesterol to cholecalciferol.’
- ‘Other types of UV dosimeters are based on the photodamage of DNA in spores, bacteria or bacteriophages or the conversion of 7 - dehydrocholesterol to previtamin D.’
- ‘Since 7 - dehydrocholesterol is present in the skin in large quantities and only needs sunlight to be activated, vitamin D is often called the ‘sunshine vitamin.’’
- ‘High energy ultraviolet light enters the skin and causes the photochemical conversion of 7 - dehydrocholesterol to previtamin D 3, which at body temperature undergoes isomerization to vitamin D 3.’
1930s from dehydro- ‘that has lost hydrogen’ + cholesterol.
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