vitamin D3

noun

1. a D vitamin, C 27 H 43 OH, occurring in fish-liver oils, that differs from vitamin D 2 by slight structural differences in the molecule.

vitamin D3

noun

1. another name for cholecalciferol

vitamin D3

1. A colorless, crystalline steroid hormone that the body synthesizes in the skin when its precursor, a derivative of cholesterol, is irradiated by sunlight. Vitamin D ₃ is also found in fish-liver oils, irradiated milk, and all irradiated animal foodstuffs. Also called calciferol, cholecalciferol. Chemical formula: C ₂₇ H ₄₄ O.