![Vitamin E CAS No. 10191-41-0](https://www.foodsweeteners.com/wp-content/uploads/2015/08/Vitamin-E-CAS-No.-10191-41-0-270x250.jpg)
A vitamin is an supplement and an essential 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.