Prehranski vir citidina predstavlja hrana, ki je bogata z RNK,<ref name=Jonas>{{cite journal |authorauthors=Jonas DA, Elmadfa I, Engel KH,|display-authors= ''et al.'' |title=Safety considerations of DNA in food |journal=Ann Nutr Metab. |volume=45 |issue=6 |pages=235–254 |year=2001 |pmid=11786646 |url=http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=anm45235 |doi=10.1159/000046734}}</ref> na primer [[meso]], [[pivski kvas]], ter hrana, bogata s [[pirimidin]]i (npr. [[pivo]]). Pri prebavljanju se RNK razcepi na ribozilpirimidine ([[citidin]] in [[uridin]]), le-ti pa se absorbirajo skozi [[prebavila]].<ref name=Jonas/> Pri ljudeh se citidin iz prehranskih virov pretvori v uridin. <ref>{{cite journal |authorauthors=Wurtman RJ, Regan M, Ulus I, Yu L |title=Effect of oral CDP-choline on plasma choline and uridine levels in humans |journal=Biochem Pharmacol. |volume=60 |issue=7 |pages=989–992 |year=2000 |pmid=10974208 |url=http://linkinghub.elsevier.com/retrieve/pii/S0006-2952(00)00436-6 |doi=10.1016/S0006-2952(00)00436-6}}</ref>
