sustenance vs vitamin

sustenance and vitamin both are nouns.

Word	Noun	Adjective	Verb	Adverb
sustenance	Yes	No	No	No
vitamin	Yes	No	No	No

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

sustenance: a source of materials to nourish the body
vitamin: any of a group of organic substances essential in small quantities to normal metabolism

sustenance (noun)	vitamin (noun)
the act of sustaining life by food or providing a means of subsistence	any of a group of organic substances essential in small quantities to normal metabolism
a source of materials to nourish the body
the financial means whereby one lives