Consuming beets can result in beeturia (pink/red urine containing betanin) for some 10-14% of the population.

This is known as beeturia.

The red color seen in beeturia is caused by the presence of unmetabolized betalain pigments such as betanin in beetroot passed through the body.

Reddish or brown urine may be caused by porphyria (not to be confused with the harmless, temporary pink or reddish tint caused by beeturia).

The red colour compound betanin is not broken down in the body, and in higher concentration may temporarily cause urine (termed beeturia) and stool to assume a reddish colour.