'avitaminosis' originates from Neo-Latin/modern medical formation, specifically the elements 'a-' (from Greek 'a-' meaning 'not' or 'without'), 'vitamin' (coined from Latin 'vita' meaning 'life' + 'amine'), and the Greek suffix '-osis' meaning 'disease'.

'avitaminosis' arose in early 20th-century medical literature by combining the then-new word 'vitamin' (coined c.1912) with the privative 'a-' and the disease-forming suffix '-osis', and it entered English medical usage to denote diseases caused by lack of vitamins.

Initially it meant 'diseases resulting from absence of vitamins'; over time the sense has remained largely the same, referring generally to vitamin deficiency diseases.