They have shown that the combined administration of these agents can retard cancer growth and metastasis in tumor-bearing rodents. They also report that this therapy is well tolerated, without any evident damage to healthy tissues. They also demonstrate that the vitamin C/vitamin K3 combination can interact synergistically with certain cytotoxic chemotherapy drugs in killing cancer cells.
This is logical since, as I mentioned before, some chemotherapy drugs work by increasing the levels of oxidative stress within cancer cells. Indeed, there are reports that vitamin K3 alone can increase the cytotoxicity of certain chemotherapy agents, presumably because, in sufficiently high concentrations, vitamin K3 helps generate oxidative stress by transferring electrons from intracellular molecules to oxygen.