Vitamin D may boost colon cancer survival

"We found that patients who had vitamin D levels at the highest category had improved survival and improved progression-free survival, compared with patients in the lowest category," said lead author Dr. Kimmie Ng, an assistant professor of medicine at Harvard Medical School in Boston, HealthDay reported.

Those patients survived one-third longer than patients with low levels of vitamin D, an average 32.6 months, compared with 24.5 months, the researchers found.

The report adds more weight to suspicions that vitamin D might be a valuable cancer-fighting supplement.

However, colon cancer patients shouldn't try to boost vitamin D levels beyond the normal range, one expert said.

The study only found an association between vitamin D levels and colon cancer survival rates. It did not prove cause and effect.

Researchers for years have investigated vitamin D as a potential anti-cancer tool, but none of the findings have been strong enough to warrant a recommendation, said Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society.

In this study, researchers measured blood levels of vitamin D in 1,043 patients enrolled in a phase 3 clinical trial comparing three first-line treatments for newly diagnosed and advanced colon cancer. All of the treatments involved chemotherapy combined with the targeted anti-cancer drugs bevacizumab and/or cetuximab.