Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N1-glycosidic bond.

PRPP is created from ribose-5-phosphate by a further phosphorylation, serving as an energetic molecule to drive the reaction forward, while orotate is generated in several steps from carbamoyl phosphate and aspartate.

[2] Uridine is regarded as a non-essential nutrient, as it is produced by the human body as needed and supplementation is not generally recommended, though it has been explored for specific applications.

This is contradicted by Yamamoto et al.,[5] plasma uridine levels rose 1.8-fold 30 minutes after beer ingestion, suggesting, at the very least, conflicting data.

[14] Harvard researchers report that omega-3 fatty acids and uridine, two substances in foods such as fish, walnuts, molasses, and sugar beets, prevented depression in rats as effectively as antidepressant drugs.