Vitamin D levels tied to colorectal cancer survival

Patients diagnosed with colorectal cancer who had abundant vitamin D in their blood prior to diagnosis were less likely to die during a follow-up period than those who were deficient in the vitamin, researchers report. "Although our findings are premature and require further exploration," lead investigator Dr. Kimmie Ng told Reuters Health, "they raise the possibility that vitamin D may have treatment benefits for colorectal cancer." Previous research has shown that higher levels of vitamin D reduce the risk of developing colon and rectal cancer by about 50 percent, but the effect on outcomes wasn't known. To investigate, Ng of the Dana-Farber Cancer Institute, Boston and colleagues took a look back at data on 304 participants in a large health study. All had been diagnosed with colorectal cancer between 1991 and 2002 and had had blood samples taken at least 2 years prior to diagnosis. The researchers followed the patients until they died or until 2005, whichever occurred first. During this time, 123 patients died, with 96 of them dying from colon or rectal cancer. Results showed that patients with the highest vitamin D levels were 48 percent less likely to die (from any cause, including colon cancer) than those with the lowest vitamin D levels. The odds of dying from colon cancer specifically were 39 percent lower, the investigators found. Given these findings, Ng concludes that "vitamin D should be studied further in colorectal cancer, including in the context of a clinical trial."