Ascorbic acid is neither component of urine or sign of diseases but the presence of ascorbic acid has substantial implications on chemical experiments. In o.blood, glucose, bilirubin, nitrite, and leucocytes portions, the principle of color change is based on oxidation reaction and ascorbic acid in urine can interfere in those parameters as a strong reducing agent.  For glucose, nitrite, and leucocytes, they have a lower interference rate from a clinical influence, but the test areas of o.blood and bilirubin have a high frequency of a false negative.  When ascorbic acid portion shows more than 2+(25mg/dL), the result on other portions has some doubt.  In this case, take another test after stopping intake of vitamin C for 24 hours.