Orotic Acid (OA)

Orotic acid is a heterocyclic compound and an acid; it is also known as pyrimidinecarboxylic acid. It was once 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 but is instead manufactured in the body by intestinal flora.Its salts, known as orotates, are sometimes used as mineral carriers in some dietary supplements, to increase their bioavailability. Lithium orotate is the most frequently used in this manner.

Dihydroorotate is synthesized to Orotic Acid by Dihydroorate Dehydrogenase, where it later combines with PRPP (Phosphoribosyl Pyrophosphate) to form Orotidylate (OMP). A distinguishing characteristic of pyrimidine synthesis is that the pyrimidine ring is fully synthesized before being attached to the ribose sugar, whereas purine synthesis happens by building the base directly on the sugar.