In 1898, English biochemist Frederick Hopkins suggested that some foods contained "accessory factors" in addition to proteins, carbohydrates, fats, etc that were necessary for the functions of the human body. In 1912, Polish biochemist Kazimierz Funk proposed the name "vitamin” for an isolated micronutrient with certain health benefits. The name was derived from "vital” (from the Latin meaning “necessary to the maintenance of life”) and “amine" (an organic compound that contains a basic nitrogen atom). The name soon became synonymous with the accessory factors first observed by Hopkins.

By the time it was shown that not all vitamins were amines (e.g., vitamin C), the word was already ubiquitous. Vitamins do not share a common chemistry, but they do share certain characteristics. They are all organic nutrients that are necessary in small amounts for normal metabolism and good health. Most vitamins are provided in the diet or by supplements. The body can manufacture only three vitamins from non-dietary sources: vitamin Dvitamin K and vitamin B7 (biotin).