Ergosterol is converted by ultraviolet irradiation into ergocalciferol
, or synthetic vitamin D2.
Cholecalciferol (Vitamin D3) and ergocalciferol
(Vitamin D2) are the primary sources of Vitamin D in vivo .
Diet is a minor source available in the form of ergocalciferol
from plant sources and cholecalciferol from animal sources although both forms are biologically equivalent.
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.
The vitamin D content of food is composed of the parent vitamin D, cholecalciferol (vitD3) and ergocalciferol
(vitD2), and the metabolites, 25-hydroxyvitamin D3 (25OHD3) and 25-hydroxyvitamin D2 (250HD2).
Meanwhile, its Vitamin D product portfolio has been extended through the launch of capsules in both branded and generic versions, as well as Ergocalciferol
50,000 IU (international unit) capsules.
In this group the most important compounds in humans are ergocalciferol
(vitamin D2) and cholecalciferol (vitamin D3)  The biologically active vitamin D is formed in the kidneys by the conversion of a part of calcidiol into calcitriol , that is released into the circulation.
A sufficient supply of native vitamin D (25(OH) D) in the form of ergocalciferol
(vitamin D2) or cholecalciferol (vitamin D3) is required for its synthesis in the kidney's proximal convoluted tubule (1-3).
Vitamin D2 is also known as Ergocalciferol
which is present in plants, and a few fish, while vitamin D3 also known as Cholecalciferol, is synthesized in the skin when exposed to the sunlight.
Existen dos fuentes primarias de vitamina D: una es endogena, que esta dada por la sintesis en la piel cuando se la expone a rayos ultravioleta en el rango de 290-315 nm; y la otra es exogena y que proviene de la dieta como colecalciferol (fuente animal) y ergocalciferol
Vitamin D-2, sometimes on labels as ergocalciferol
, is from yeast, so it is completely vegan.
Coyne, "Prevalence of vitamin D deficiency and the safety and effectiveness of monthly ergocalciferol
in hemodialysis patients," Nephron Clinical Practice, vol.