vitamin D \vitamin D\ n.
any of several chemically related fat-soluble vitamins that
prevent rickets. It is found in fish-liver oils, egg yolks
and milk. Component vitamin D2 is also called calciferol,
and vitamin D3 is called cholecalciferol.
Syn: calciferol, ergocalciferol, cholecalciferol.
[WordNet 1.5]