Large doses of vitamin C may boost chemotherapy’s ability to kill cancer cells, US researchers have found.
Intravenous vitamin C could be a potentially safe, effective and low-cost treatment for ovarian and other cancers, said scientists at the University of Kansas.
Reporting in Science Translational Medicine, they outlined the results of tests carried out in the lab, on mice and on patients with advanced ovarian cancer, and called for “larger clinical trials”.
In a study of 27 patients newly diagnosed with stage 3 or 4 ovarian cancer, researchers found that patients who were injected with a high dose of vitamin C, along with their chemotherapy, experienced fewer negative side effects from their treatment.
They also found that vitamin C can help to kill cancer cells without harming healthy cells.
Vitamin C was used as an early, unorthodox cancer therapy.
In the 1970s, chemist Linus Pauling extolled the benefits of using vitamin C to treat cancer.
However, clinical trials of vitamin C administered orally were ineffective and the research was abandoned.
In the intervening years it has been discovered that the body quickly excretes vitamin C that is taken by mouth.
But when it is injected, vitamin C is able to inhibit the growth of cancer cells.
Co-researcher Dr Jeanne Drisko told BBC News that there was growing interest in the use of vitamin C by oncologists.
"Patients are looking for safe and low-cost choices in their management of cancer," said.
"Intravenous vitamin C has that potential based on our basic science research and early clinical data."
However, pharmaceutical companies are unlikely to run further clinical trials as vitamins cannot be patented.
"Because vitamin C has no patent potential, its development will not be supported by pharmaceutical companies," lead researcher Qi Chen told BBC News.
"We believe that the time has arrived for research agencies to vigorously support thoughtful and meticulous clinical trials with intravenous vitamin C."