Vitamin D is an essential nutrient that contributes to the normal function of the immune system and blood calcium levels which in turn supports the maintenance of normal bones and teeth.

Vitamin D3 is the form of vitamin D that our bodies produce naturally, following a biotransformation of cholesterol following exposure to ultra violet rays from the sun.

Specifically, Vitamin D3 is converted by the liver into the circulating form - 25(OH)D3.

The circulating form is then converted, by the kidneys and other tissues into 1-25(OH)2D3, the active form, which is then able to instigate the physiological effects associated with vitamin D.

This same conversion takes place with Vitamin D2 also, but some believe that the conversion is superior from D3. This is not true. The conversion of D3 to 25(OH)D is slightly more rapid than from D2.

Viridian Vitamin D3 400iu and 2000iu are derived from lichen.

Viridian Organic Vitamin D2 400iu is derived from organic mushrooms.

Viridian Vitamin D2 1000iu is produced via a fermentation process.