The word vitamin was coined in 1912 by Polish chemist Casimir Funk as a combination of the Latin word vita for life and amine because vitamins were thought to contain amino acids. By 1920 the -e- was removed from the end to reflect the new science of the day that recognized that vitamins were not in fact related to amino acids. Today a vitamin is defined as an organic compound required for proper nutrition by an organism that cannot be synthesized by the organism. Since their discovery and classification the list of vitamins has changed over time, notably the arrangement of compounds into the B-complex family.
Today 13 vitamins are recognized: Vitamins A, B1, C, B2, D, E, B12, K1, B5, B7, B6, B3, B9.
Image of riboflavin (vitamin B2) by PatriciaR under CC 3.0 license.