A high intravenous dose of vitamin C could one day reduce the size of cancerous tumors in people, new studies say. When tested on mice, intravenous vitamin C produced hydrogen peroxide, which proceeded to reduce cancerous tumors in the mice by 43 percent to 51 percent.

The mice had ovarian, pancreatic and brain cancer. The normal cells remained unharmed by the therapy.

The doses of vitamin injected into their abdominal cavity was far greater than any that could be achieved using diet or vitamin pills, as the digestive system does not absorb more than a fixed amount taken orally.

However, the scientists from National Institutes of Health's Molecular and Clinical Nutrition Section added that the findings are preliminary and still must be confirmed in humans. The new study is published in the Aug. 4-8 issue of the Proceedings of the National Academy of Sciences.