. "A vitamin (US /\u02C8va\u026At\u0259m\u026An/ and UK /\u02C8v\u026At\u0259m\u026An/) is an organic compound and a vital nutrient that an organism requires in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient quantities, and it must be obtained through the diet; thus, the term \"vitamin\" is conditional upon the circumstances and the particular organism."@en . .