The antioxidant perhaps most widely used in complementary oncology is vitamin C, 
particularly by intravenous injection. In light of the recent clinical 
pharmacokinetic findings, the in vitro evidence of anti-tumour mechanisms and 
some well-documented cases of advanced cancers the role of high-dose intravenous 
vitamin C therapy in cancer treatment should be reassessed. High dose 
intravenous vitamin C therapy may have benefits in patients with advanced 
cancers, and cancers with poor prognosis and limited therapeutic options, but 
further clinical studies regarding the safety and efficacy of this therapy are 
necessary, especially in Germany.