provitamin A vs carotin

provitamin A and carotin both are nouns.

Word	Noun	Adjective	Verb	Adverb
provitamin A	Yes	No	No	No
carotin	Yes	No	No	No

As nouns, provitamin A and carotin are synonyms defined as:

provitamin A and carotin: an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver

Other synonyms of provitamin A include carotene.

provitamin A (noun)	carotin (noun)
an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver	an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver