moon blindness vs avitaminosis

moon blindness and avitaminosis both are nouns.

Word	Noun	Adjective	Verb	Adverb
moon blindness	Yes	No	No	No
avitaminosis	Yes	No	No	No

As nouns, avitaminosis is a hypernym of moon blindness; that is, avitaminosis is a word with a broader meaning than moon blindness:

moon blindness: inability to see clearly in dim light; due to a deficiency of vitamin A or to a retinal disorder
avitaminosis: any of several diseases caused by deficiency of one or more vitamins

Other hypernyms of moon blindness include hypovitaminosis, vision defect, visual defect, visual disorder, visual impairment.

moon blindness (noun)	avitaminosis (noun)
recurrent eye inflammation in horses; sometimes resulting in blindness	any of several diseases caused by deficiency of one or more vitamins
inability to see clearly in dim light; due to a deficiency of vitamin A or to a retinal disorder