A colorless crystalline compound, C27H44O, found in fish-liver oils, irradiated milk, and all irradiated animal foodstuffs. It has essentially the same biological activity as vitamin D2. Also called cholecalciferol.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.