vitamin K vs menadione

vitamin K and menadione both are nouns.

Word	Noun	Adjective	Verb	Adverb
vitamin K	Yes	No	No	No
menadione	Yes	No	No	No

As nouns, menadione is a hyponym of vitamin K; that is, menadione is a word with a more specific, narrower meaning than vitamin K:

vitamin K: a fat-soluble vitamin that helps in the clotting of blood
menadione: a synthetic chemical compound that is a form of vitamin K, it is an analog of 1,4-naphthoquinone with a methyl group in the 2-position

Other hyponyms of vitamin K include phylloquinone, phytonadione, vitamin K1, vitamin K3.

vitamin K (noun)	menadione (noun)
a fat-soluble vitamin that helps in the clotting of blood	a synthetic chemical compound that is a form of vitamin K, it is an analog of 1,4-naphthoquinone with a methyl group in the 2-position