alimentation vs vitamin

alimentation and vitamin both are nouns.

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

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

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

alimentation (noun)	vitamin (noun)
the act of supplying food and nourishment	any of a group of organic substances essential in small quantities to normal metabolism
a source of materials to nourish the body