{{Short description|Discoloration of urine after consuming beetroot}} [[File:Betanin.svg|thumb|Betanin, a beet pigment causing urine coloring]] '''Beeturia''' is the passing of red or pink urine after eating beetroots or foods colored with beetroot extract or beetroot betalain pigments.<ref name="sauder">{{cite web |author1=Sauder HM, Rawla P |title=Beeturia |url=https://www.ncbi.nlm.nih.gov/books/NBK537012/ |publisher=StatPearls, US National Library of Medicine |access-date=29 May 2024 |date=22 May 2023}}</ref> The color is caused by the excretion of the betalain pigments, such as betanin.
The coloring is highly variable between individuals and between different feeding occasions, and can vary in intensity from light pink urine to strongly-colored deep red urine.<ref name=sauder/> The condition is benign and dissipates promptly with avoidance of beet foods.<ref name=sauder/> Beeturia occurs in about 10-14% of the public, with higher frequency and intensity occurring in people with iron deficiency, pernicious anemia or digestive diseases.<ref name=sauder/>
The pigment is sensitive to oxidative degradation under strongly acidic conditions. Therefore, the urine coloring depends on stomach acidity and dwell time, as well as the presence in foods of betalain-protecting substances, such as oxalic acid.<ref name="Mitchell">{{cite journal | last=Mitchell |first = S. C. | date = 2001 | title = Food idiosyncrasies: beetroot and asparagus | journal = Drug Metab. Dispos. | volume = 29 | issue = 4 | pages = 539–543 | pmid = 11259347 | url = http://dmd.aspetjournals.org/content/29/4/539.abstract }}</ref><ref name="Watts">{{cite journal | pmid = 8148871 |year=1993 | last1 = Watts | first1 = AR | last2 = Lennard | first2 = MS | last3 = Mason | first3 = SL | last4 = Tucker | first4 = GT | last5 = Woods | first5 = HF | title = Beeturia and the biological fate of beetroot pigments | doi=10.1097/00008571-199312000-00004 | volume = 3 | issue = 6 | pages = 302–11 | journal = Pharmacogenetics }}</ref>
Beeturia is often associated with red or pink feces due to unabsorbed pigments ending up in feces.<ref name="Eastwood">{{cite journal | last1 = Eastwood | first1 = MA | last2 = Nyhlin | first2 = H | date = 1995 | title = Beeturia and colonic oxalic acid | journal = QJM | pmid = 7493168 | volume = 88 | issue = 10 | pages = 711–7 }}</ref>
==Cause== thumb|A selection of differently colored beetroot varieties The red color seen in beeturia is caused by the presence of unmetabolized betalain pigments such as betanin in beetroot passed through the body.<ref name="Mitchell"/><ref name="Watts"/> The pigments are absorbed in the colon.<ref name="Mitchell"/> Betalains are oxidation-sensitive redox indicators that are decolorized by hydrochloric acid, ferric ions, and colonic bacteria preparations.<ref name="Eastwood"/> The gut flora play a not-yet-evaluated role in the breakdown of the pigment.<ref name=sauder/>
==Differential diagnosis== The incidence of beeturia increases in people with pernicious anemia and iron deficiency.<ref name=sauder/><ref name=Watts/> There is no known relation to deficiencies in liver metabolism or removal from the body by the kidneys.<ref name=Watts/> There is no known direct genetic influence, and no single gene variant, that differentiates excreters from non-excreters.<ref name="Mitchell"/><ref name="Myths">{{cite web |last=McDonald |first=J. H. |date=2011 |title=Myths of Human Genetics: Beeturia |publisher=Sparky House Publishing |location=Baltimore, Maryland |url=http://udel.edu/~mcdonald/mythbeeturia.html |access-date=July 7, 2015}}</ref>
==Factors== The extent of excreted pigment depends on the beet pigment content of the meal, including the addition of concentrated beetroot extract as a food additive to certain processed foods.<ref name="Mitchell"/> Storage conditions of the beet foods, including light, heat, and oxygen exposure, and repeated freeze-thaw cycles could degrade the beet pigments.<ref name="Mitchell"/> Stomach acidity and dwell time may affect urine color intensity.<ref name=sauder/><ref name="Mitchell"/><ref name="Watts"/> The presence of beet pigment-protecting substances, such as oxalic acid, in the meal and during intestinal passage, increase the color intensity in the urine.<ref name=sauder/> Medications may affect stomach acidity, such as proton pump inhibitors, thereby affecting urine color.<ref name="Mitchell"/>
==See also== * Porphyria, a group of disorders that may cause reddish urine * Blue diaper syndrome
==References== {{reflist}}
Category:Symptoms and signs: Urinary system Category:Urine