citrin vs water-soluble vitamin

citrin and water-soluble vitamin both are nouns.

Word	Noun	Adjective	Verb	Adverb
citrin	Yes	No	No	No
water-soluble vitamin	Yes	No	No	No

As nouns, water-soluble vitamin is a hypernym of citrin; that is, water-soluble vitamin is a word with a broader meaning than citrin:

citrin: a vitamin that maintains the resistance of cell and capillary walls to permeation
water-soluble vitamin: any vitamin that is soluble in water

citrin (noun)	water-soluble vitamin (noun)
a vitamin that maintains the resistance of cell and capillary walls to permeation	any vitamin that is soluble in water