The pharmaceutical drug cholecalciferol (synthetic vitamin D3) is produced by the ultraviolet irradiation of 7-dehydrocholesterol
extracted from lanolin in sheep's wool.
1,2] Ultraviolet (UV) B radiation with a wavelength of 290-320 nanometres penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol
to previtamin [D.
When ultraviolet rays from sunlight penetrate the skin, they react with 7-dehydrocholesterol
which is a precursor to cholesterol.
3] (the first form of vitamin D which comes from the cholesterol metabolite 7-dehydrocholesterol
under the effect of ultraviolet-B radiation) is transformed into vitamin [D.
3] is synthesized from cutaneous 7-dehydrocholesterol
upon exposure to ultraviolet B radiation (Feldman et al.
Vitamin D2 or ergocalciferol is derived from plants, vitamin D3 or cholecalciferol is synthesized in human skin from 7-dehydrocholesterol
, on exposure to ultraviolet B irradiation with wavelength 290 to 320 nm convert 7dehydrocholesterol to D32,3.
During the second trimester, the screening adds on checks for neural tube defects and Smith-Lemli-Opitz syndrome, also known as 7-dehydrocholesterol
It is produced in the skin from precursor 7-dehydrocholesterol
The somewhat lower within-person variability among the older ARIC participants is not entirely surprising, since older populations may have less variability in their expo sure to the sun and are known to have reduced dermal conversion of 7-dehydrocholesterol
to vitamin D3 (24).
Objective: This project develops a continuous flow microprocess for the synthesis of pure vitamin D3 from 7-dehydrocholesterol
In the skin 7-dehydrocholesterol
is synthesized in large amount.
A precursor of vitamin D, 7-Dehydrocholesterol
(7-DHC), is secreted on skin surface 3 and is converted by UVB radiations (290-315 nm) into pre-cholecalciferol (pre-D3).