Orotic acid is a heterocyclic compound and an acid; it is also known as pyrimidinecarboxylic acid. Historically it was believed to be part of the Vitamin B complex and was called vitamin B13, but it is now known that it is not a vitamin.
The compound is manufactured in the body by intestinal flora. It is sometimes used as a mineral carrier in some dietary supplements (to increase their bioavailability), most commonly for lithium orotate.
Read more about Orotic Acid: Synthesis of Orotate, Orotic Acid Diseases