Beets can cause urine to turn red, states Mayo Clinic. Other foods that cause the urine to turn red or pink include blackberries and rhubarb. Sometimes food dyes also cause the urine to turn red.
When the urine turns red from eating too many beets, the condition is called beeturia. This condition only effects about 10 to 14 percent of people. The condition is caused by chemical compounds in the food called betacyanins, and some people do not have digestive systems that break them down enough. Scientists believes this happens because the stomach acids do not break down the chemicals enough, so they pass into the intestines and colon, and then into the blood stream to be filtered out of the body by the kidneys.