Vitamin C does not directly fight candida. While large amounts of vitamin C have been shown to successfully treat bacterial and viral infection, this is not the case with candida and other yeast/fungal infections. Vitamin C is not effective against fungal infections.
However vitamin C is good for neutralising the endotoxins released when you kill off a host of candida cells. It assists in the absorption of various nutrients/minerals. It helps remove heavy metals from the body. It is a precursor to hundreds of chemical reactions. It is required for immune function. Vitamin C helps regulate blood Sugar level.