Washington, Mar 6 : Challenging a recent study, an Arizona nutritionist has claimed that vitamin C does not reduce the effectiveness of chemotherapeutic drugs in cancer treatment.

A study published in Cancer Research concluded that vitamin C, given to mice or cultured cells treated with common anti-cancer drugs, reduces the anti-tumour effects of the chemotherapeutic agents.

Jack Challem, a personal nutrition coach and nutrition author from Tucson, Arizona, pointed out two main problems with the study.

The problems were: the oxidized form of vitamin C (dehydroascorbic acid) and not actual vitamin C (ascorbic acid) was used; and in the mouse experiments, the animals were given toxic doses of dehydroascorbic acid, a compound that is not used as a dietary supplement in humans.

"This study and the subsequent headlines [it generated] were a grievous disservice to physicians and patients with cancer," said Challem.

He added: "Considerable positive research. has shown striking benefits from high-dose vitamin C (ascorbic acid) in cancer cells and animals-and in actual human beings."

High-dose intravenous vitamin C is a common form of alternative and complementary therapy for patients receiving chemotherapeutic drugs, and is believed to help bring about tumour cell death.

It may also promote post-surgical healing by enhancing collagen formation, and increase tissue resistance to tumour spread.

"The ideal therapeutic approach would be to tailor individual treatment, including IV vitamin C, from a menu of options," suggested Challem.

Challem made his claims in the Medical Journal Watch column in the current issue of Alternative and Complementary Therapies, a journal published by Mary Ann Liebert, Inc. (ANI)