Vitamin D3
Vitamin D3 is a steroid hormone manufactured from the irradiated skins of
animals [which could include pig], which is processed and added to milk. Not all
milk with Vitamin D added is from D3, so check with the dairy as to which it is,
D1, D2, or D3.
"1. a hormone synthesized in the skin on irradiation of 7-dehydrocholesterol
or obtained as a vitamin from dietary sources; it is activated when metabolized
to 1,25-dihydroxycholecalciferol.
See table. See also ergocalciferol.
Called also vitamin
D3. 2. [USP] a
preparation of this compound, derived from animal tissues and used in the
prophylaxis and treatment of vitamin D deficiencies due to low intake, high
requirement, or impaired absorption of the vitamin. It is also used in the
treatment of hypocalcemic tetany and hypoparathyroidism." This
found here
"Vitamin D3 can be produced photochemically by the action of sunlight or ultraviolet light from the precursor sterol 7-dehydrocholesterol which is present in the epidermis or skin of most higher animals." This found here
"Windaus isolated three forms of the vitamin: two derived from irradiated plant sterols, which he called D1 and D2, and one derived from irradiated skin, which he called D3." This found here
The term vitamin D actually refers to a group of steroid molecules. Vitamin D3, also known as cholecalciferol is generated in the skin of animals when light energy is absorbed by a precursor molecule 7-dehydrocholesterol. Vitamin D is thus not a true vitamin, This found here
"produced in human and other animal tissue by photoactivation (normally sunlight on skin) of 7\-dehydrocholesterol.(Source: CRISP)" This found here
