מינון גבוהה מאוד של ויטמין C ריפא חוקר בכיר מניו זילנד שעבד באוניברסיטת HARWARD בארה"ב וחלה בסרטן

• Vitamin C is a nutrient found in food and dietary supplements. It is an antioxidant and also plays a key role in making collagen (see Question 1).
  
  
• High-dose vitamin C may be taken by mouth or given by an intravenous (IV) infusion (through a vein into the bloodstream). When taken by IV infusion, vitamin C can reach higher levels in the blood than when the same amount is taken by mouth (see Question 2).
  
  
• Some studies of IV high-dose vitamin C in patients with cancer have shown improved quality of life, as well as fewer side effects (see Question 4).
  
  
• In general, high-dose vitamin C given by IV has caused very few side effects in clinical trials. However, IV vitamin C may cause serious side effects in patients with kidney disease, G6PD deficiency, or hemochromatosis (see Question 5).
  
  
• The U.S. Food and Drug Administration (FDA) has not approved the use of IV high-dose vitamin C as a treatment for cancer (see Question 7).
  
  

Questions and Answers About High-Dose Vitamin C

• Two studies found that patients who received IV vitamin C had better quality of life and fewer side effects than those who did not.
  
  
• In a study of healthy volunteers and cancer patients, vitamin C was shown to be safe at doses up to 1.5 g/kg in patients who do not have kidney stones, other kidney diseases, or G6PD deficiency. Studies have also shown that vitamin C levels in the blood are higher when given by IV than when taken by mouth, and last for more than 4 hours.
  
  

• In a small study of 14 patients with advanced pancreatic cancer, IV vitamin C was given along with chemotherapy and targeted therapy (erlotinib). Five patients did not complete the treatment because the tumor continued to grow during treatment. The nine patients who completed the treatment had stable disease as shown by imaging studies. Patients had very few side effects from the vitamin C treatment.
  
  
• In another small study of 9 patients with advanced pancreatic cancer, patients were given chemotherapy once a week for 3 weeks along with IV vitamin C twice a week for 4 weeks during each treatment cycle. The disease did not progress over an average of 6 months in these patients. No serious side effects were reported with the combined treatment.
  
  
• In a 2014 study of 27 patients with advanced ovarian cancer, chemotherapy alone was compared with chemotherapy and IV vitamin C. IV vitamin C was given during chemotherapy and for 6 months after chemotherapy ended. Patients who received IV vitamin C had fewer side effects from the chemotherapy.
  
  
• Patients with refractory metastatic colorectal cancer or metastatic melanoma were treated with IV vitamin C combined with other drugs. The treatment had no anticancer effect, the tumor continued to grow during treatment, and patients had serious side effects. These studies did not have a comparison group, so it is unclear how much the IV vitamin C affected the side effects.
  
  
• Patients with non-small cell lung cancer or glioblastoma multiforme in two pilot trials were given standard therapy plus IV vitamin C. Patients had better overall survival and fewer side effects compared to the control groups.
  
  

• In patients with a history of kidney disease, kidney failure has been reported after treatment with high-dose vitamin C. Patients who are likely to develop kidney stones should not be treated with high-dose vitamin C.
  
  
• Case reports have shown that patients with an inherited disorder called G6PD deficiency should not be given high doses of vitamin C, because it may cause hemolysis (a condition in which red blood cells are destroyed).
  
  
• Because vitamin C may make iron more easily absorbed and used by the body, high doses of vitamin C are not recommended for patients with hemochromatosis (a condition in which the body takes up and stores more iron than it needs).
  
  

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