The efficacy of high - dose vitamin C HDVC treatment for tumors is fragile and requires precise and intensified treatment. However there is not only an absence of standardized therapeutic schedule of HDVC for cancers but also a lack of high-quality guidelines for precise and intensive treatment of HDVC for tumors which seriously affects the therapeutic effect and clinical application of HDVC. Based on in-depth discussions on the anti-tumor mechanisms and the pharmacokinetic characteristics of of HDVC experts with rich experience in the Nutrition Therapy Professional Committee of China Anti - Cancer Association the Research Committee of New Anti-Cancer Drugs for Chinese and Western Integrated Tumor Control and the Nutrition Metabolism Branch of China Elderly Care Association have reached a consensus on the indications and contraindications of HDVC clinical advantage administration the prevention and treatment of side effects the sensitivity and precision treatment of metabolic molecular phenotype the intensive treatment strategy and efficacy monitoring. This consensus will help improve the the standardization and efficacy of of high dose vitamin C treatment against cancer.