The discoloration of urine following the consumption of beetroot
Beeturia is the passing of red or pink
urine after eating
beetroots or
foods colored with beetroot extract or beetroot
pigments. The color is caused by the excretion of
betalain (betacyanin) pigments such as
betanin. The coloring is highly variable between individuals and between different occasions, and can vary in intensity from invisible to strong. 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 of protecting substances such as
oxalic acid.[1][2] Beeturia is often associated with red or pink feces.[3][4]
Cause
The red color seen in beeturia is caused by the presence of
unmetabolized betalain pigments such as betanin in beetroot passed through the body.[1][2] The pigments are absorbed in the
colon.[1] Betalains are oxidation-sensitive
redox indicators that are decolorized by
hydrochloric acid,
ferric ions, and colonic bacteria preparations.[3] The
gut flora play a not-yet-evaluated role in the breakdown of the pigment.[4]