By Yvette Martyn
Higher levels of circulating vitamin D are associated with a reduced risk of colorectal cancer, a study has found.
Researchers identified 1248 cases of incidental colon cancer in 10 European countries including the UK and compared them to the same number of cancer free controls.
They then studied the association of prediagnostic circulating vitamin D levels, dietary vitamin D and dietary calcium on the risk of developing colorectal cancer.
Lower levels of circulating vitamin D were associated with a higher risk of developing colorectal cancer, while higher levels were associated with a decreased risk.
Cases with over 100 nmol/l circulating vitamin D had a 40% lower risk of developing colorectal cancer compared to cases who had under 25 nmol/l. The association was strong for colon cancer but not rectal cancer.
The study, published in the latest issue of the BMJ, also found that dietary calcium lowered the risk of colorectal cancer, with a 10% increase in intake lowering the risk by 3%.
Lead author Dr Mazda Jenab, a research scientist at the International Agency for Research on Cancer in Lyon said the research evidence was growing to show a possible beneficial role of increased circulating vitamin D levels in reducing the risk of a range of different diseases. He said: ‘There is growing advocacy for vitamin D supplementation [to maintain] higher circulating levels.'
BMJ 2010; 340: b5500
