Vitamin C seen as interfering with chemo

Tests in human and mouse cancer cells grown in laboratory dishes showed that vitamin C supplements reduced the efficacy of cancer drugs by 30% to 70%, researchers reported Wednesday in the journal Cancer Research.

Many patients take the vitamin as a supplement to their chemotherapy, and the researchers fear it might be reducing survival rates.

The team from Memorial Sloan-Kettering Cancer Center in New York found that the vitamin protects mitochondria in cancer cells from the damaging effects of the drugs, enhancing their survival.