Eating dragon fruit usually causes urine to turn red, which is a very common phenomenon. First of all, the main ingredients of dragon fruit contain a large amount of red pigment and some fiber, vitamins, etc. After eating, these red pigments are digested and absorbed in the stomach and enter the blood circulation. A large amount of red pigment will not be absorbed and utilized by the body, but will be excreted through the kidneys and urine. In this case, the urine will be red.