beta-carotene vs provitamin A

beta-carotene and provitamin A both are nouns.

Word	Noun	Adjective	Verb	Adverb
beta-carotene	Yes	No	No	No
provitamin A	Yes	No	No	No

As nouns, provitamin A is a hypernym of beta-carotene; that is, provitamin A is a word with a broader meaning than beta-carotene:

beta-carotene: an isomer of carotene that is found in dark green and dark yellow fruits and vegetables
provitamin A: an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver

Other hypernyms of beta-carotene include carotenoid, carotene, carotin.

beta-carotene (noun)	provitamin A (noun)
an isomer of carotene that is found in dark green and dark yellow fruits and vegetables	an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver