A 2 plus sign for vitamin C means that a routine urine test is positive for vitamin C, but is not indicative of a disease. Vitamin C does not appear in the urine under normal circumstances, but when a large amount of vitamin C-rich foods, such as lemons, oranges, vitamin C tablets, etc., are consumed, it will cause the vitamin C in the urine to be elevated, and ultimately present a positive vitamin C test result, which is usually a normal physiological phenomenon, and does not represent any potential disease. The main significance of the vitamin C test in the routine urine examination is to reflect the reliability of the other indicators of the results of this routine urine examination. If C2+ appears in the urine routine examination, it suggests that the results of related items may be abnormal, for example, elevated levels of vitamin C in the urine will make the urinary nitrite test appear false negative, or cause false-positive Bainbridge test, which should be followed by the doctor’s instructions to review.