Vitamin
early 20th century: from Latin vita ‘life’ + amine, because vitamins were originally thought to contain an amino acid.
wiktionary
1920, originally vitamine (1912), from Latin vīta(“life”) (see vital) + amine (see amino acids). Vitamine coined by Polish biochemist Casimir Funk after the initial discovery of aberic acid (thiamine), when it was thought that all such nutrients would be amines. [1] The term had become ubiquitous by the time it was discovered that vitamin C, among others, had no amine component. In 1920, British biochemist Jack Drummond proposed that the final -e be dropped to deemphasize the amine reference. The ending -in was acceptable because it was used for neutral substances of undefined composition. Drummond also introduced the lettering system of nomenclature (Vitamin A, B, C, etc.) at this same time.
etymonline
vitamin (n.)
1920, originally vitamine (1912) coined by Polish biochemist Casimir Funk (1884-1967), from Latin vita "life" (from PIE root *gwei- "to live") + amine, because they were thought to contain amino acids. The terminal -e formally was stripped off when scientists learned the true nature of the substance; -in was acceptable because it was used for neutral substances of undefined composition. The lettering system of nomenclature (Vitamin A, B, C, etc.) was introduced at the same time (1920).
