Vitamin D Levels May Affect Risk of Colon Cancer
People with the highest level found to be at 40 percent less risk than those with the lowest
FRIDAY Jan. 22 (HealthDay News) -- There is an inverse association between pre-diagnostic circulating levels of vitamin D and the risk of colorectal cancer, although more research is needed to see whether increasing vitamin D concentration could lower the risk of the cancer, according to a study published online Jan. 21 in BMJ.
Mazda Jenab, Ph.D., of the International Agency for Research on Cancer in Lyon, France, and colleagues conducted a study of 1,248 colorectal cancer patients and an equal number of matched controls recruited from a cohort of 520,000 people in 10 western European countries.
Questionnaires were used to ascertain information on diet and lifestyle, while vitamin D concentrations were measured using enzyme immunoassay, and the data revealed that there was a strong, dose-dependent, linear inverse relationship between circulating vitamin D levels and risk of colorectal cancer. Those in the highest quintile were at 40 percent less risk than those in the lowest quintile, the researchers found. Higher dietary intake of calcium was linked to a lower colorectal cancer risk, but dietary vitamin D was not associated with colorectal cancer risk.
"The results of this large observational study indicate a strong inverse association between levels of pre-diagnostic vitamin D concentration and risk of colorectal cancer in western European populations," the authors write. "However, before any public health recommendations can be made for vitamin D supplementation, new randomized trials are needed to test the hypothesis that increases in circulating vitamin D concentration are effective in reducing colorectal cancer risk without inducing serious adverse events."