Vitamin C (+) in urine indicates elevated vitamin levels, mostly through diet or ingestion of medications such as vitamin C. In urine testing, vitamin C is not used as an indicator of disease, but as a contrast agent. When vitamin C is high in the urine and a urine dry chemistry program is performed, it may result in a false positive result for occult blood in the urine, or a false positive result for the nitrite program, which means that the vitamin C in the urine reacts with the reagents in a redox reaction and results in a positive result for the relevant indicator, so the urine vitamin C is added to the urine routine as a comparison indicator. If vitamin C is positive with occult blood or with a positive nitrite result, it is considered that the increase in vitamin C interferes with the reagents and results in a false positive rather than a disease state. When the state of vitamin C is negative and the urine is positive for occult blood or nitrite, it is a disease state. Therefore, vitamin C in urine is only a comparative agent and does not have any practical significance.