A sterol isolated from yeast; when treated with ultraviolet light, it is converted to ergocalciferol; the main industrial source of vitamin D.
A plant sterol that, when irradiated with ultraviolet light, is converted to ergocalciferol (vitamin D2).
A sterol found in yeasts and fungi and in plant and animal fat. Under the action of sunlight or ultraviolet rays it produces vitamin D,. The substance produced in this way is known as calciferol, and is used for the prevention and cure of rickets and osteomalacia. A similar change in the ergosterol of the skin is produced when the body is freely exposed to sunlight. Calciferol is probably not so active as, and differs chemically from, the vitamin D occurring in fish-liver oils.
The primary steroid found in the cell membrane of some fungi; it stabilizes the membrane, as does cholesterol in human cells. Many antifungal drugs act on ergosterol to increase permeability of the cell membrane of the fungus, promoting its destruction.