Some clinicians and alternative therapy practitioners advocate megadose 
intravenous and oral ascorbate treatment of cancer. Randomized control studies 
using oral ascorbate showed no benefit. Recent data show that intravenous but 
not oral administration of ascorbate can produce millimolar plasma 
concentrations, which are toxic to many cancer cell lines. We propose that 
ascorbate treatment of cancer should be reexamined by rigorous scientific 
scrutiny in the light of new evidence.