Vitamin D and Colorectal Cancer

Several small studies have suggested that higher blood levels of vitamin D are associated with lower risk for colorectal cancer (CRC). To examine this association further, investigators conducted a nested, case-control study involving 520,000 participants from the general population in 10 European countries.

Dietary information and blood samples were collected at study enrollment, and circulating 25-hydroxy vitamin D (25[OH]D) levels were measured. The researchers identified 1248 individuals who received diagnoses of incident CRC approximately 4 years, on average, after enrollment. These individuals were matched to 1248 healthy controls. CRC risk estimates were adjusted for potential confounding factors, including body-mass index, smoking st…