If the urine test is positive for vitamin C and (++), it is usually due to the following reasons: First, before the urine test, drink or eat drinks, vegetables and fruits rich in vitamin C, such as effervescent tablets containing more vitamin C, take vitamin C pills or eat and eat vegetables and fruits rich in vitamin C, such as tomatoes, cucumbers, bok choy, lettuce, broccoli and other fruits The vitamin C test will be positive and (++) in the urine test after the vegetables and fruits are rich in vitamin C. Second, in glomerular hypofunction, kidney disease, there will also be a urine test showing vitamin C (++), such as chronic hyperalgesia, glomerular function degeneration, renal failure, etc., will also appear the above symptoms.