orotic acid

(biochemistry) C₄H₄O₄N₂ A crystalline acid which is a growth factor for certain bacteria and is also a pyrimidine precursor.

An intermediate in the biosynthesis of pyrimidines; a growth factor for some micro-organisms and at one time called vitamin B₁₃. There is no evidence that it is a human dietary requirement.

A water-soluble substance often found with the B complex vitamins. It was once known as vitamin B₁₃, but it is no longer regarded as a vitamin because it can be synthesized by the body. It plays a role in the metabolism of DNA and RNA, but no symptoms of deficiency have been reported.

An important intermediate in the formation of pyrimidine nucleotides.