vitamin Dvitamin D3
any of several fat-soluble vitamins that are essential for increased absorption of calcium and phosphorus from the intestinal tract, found in fish-liver oils, milk, egg yolk, etc. or produced by irradiation of provitamins; specif.,: a deficiency of vitamin D tends to cause rickets
- , CHOH, produced by irradiation of a derivative of ergosterol
- , CHOH, produced by irradiation of a derivative of sitosterol
A fat-soluble vitamin occurring in several forms, especially vitamin D2 or vitamin D3, that is required for normal growth of teeth and bones and is involved in many other metabolic processes, produced in the skin upon exposure to sunlight and present in fish, eggs, and fortified foods such as milk.
A white crystalline compound, C28H44O, produced commercially by ultraviolet irradiation of ergosterol obtained from fungi or plants, and used as a dietary supplement. Also called ergocalciferol .
A colorless crystalline compound, C27H44O, found in fish, eggs, and fortified foods and formed in the skin of humans and other vertebrates upon exposure to ultraviolet radiation, as in sunlight. It is often used as a dietary supplement. Also called cholecalciferol .