vitamin D: Meaning and Definition of

vitamin D

Pronunciation: [key]
  1. any of the several fat-soluble, antirachitic vitamins D, D, D, occurring in milk and fish-liver oils, esp. cod and halibut, or obtained by irradiating provitamin D with ultraviolet light, essential for the formation of normal bones and teeth.

vitamin D1

Pronunciation: [key]
  1. a mixture of lumisterol and calciferol, obtained by ultraviolet irradiation of ergosterol.

vitamin D2

Pronunciation: [key]
  1. calciferol.

vitamin D3

Pronunciation: [key]
  1. a D vitamin, CHOH, occurring in fish-liver oils, that differs from vitamin D by slight structural differences in the molecule. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.