vitamin D vs viosterol

vitamin D and viosterol both are nouns.

Word	Noun	Adjective	Verb	Adverb
vitamin D	Yes	No	No	No
viosterol	Yes	No	No	No

As nouns, vitamin D and viosterol are synonyms defined as:

Other synonyms of vitamin D include calciferol, cholecalciferol, D, ergocalciferol.

vitamin D (noun)	viosterol (noun)
a fat-soluble vitamin that prevents rickets	a fat-soluble vitamin that prevents rickets