[vitamin D] n (1921): any or all of several fat-soluble vitamins chemically related to steroids, essential for normal bone and tooth structure, and found esp. in fish-liver oils, egg yolk, and milk or produced by activation (as by ultraviolet irradiation) of sterols: as a or vitamin D2 : calciferol b or vitamin D3 : cholecalciferol
VITAMIN D
Meaning of VITAMIN D in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012