Vitamin D fights colon cancer

22nd January 2010 - People with high levels of vitamin D in their bloodstream appear to be at much lower risk of getting cancer of the colon, say researchers. The risk was cut by as much as 40% in those with the highest levels of the vitamin.

Vitamin D can be obtained from diet, but for most people it’s derived from exposure to the sun.

Several studies have already suggested there could be a link between vitamin D and colorectal cancer, but the evidence has been inconclusive. So, researchers from across Europe set out to see what impact vitamin D circulating in the blood, as well as dietary intakes of vitamin D and calcium, had on colorectal cancer rates in western Europe.

Their conclusions are published on bmj.com - the online edition of the British Medical Journal.

Large scale European study

The researchers used data from a study of more than half-a-million people drawn from 10 European countries.

Between 1992 and 1998 participants filled out questionnaires about their diet and lifestyle and gave blood samples. The subjects were monitored for several years, during which time 1,248 of them were diagnosed with colorectal cancer. These participants were then matched against the same number of people who had not been diagnosed with the disease.

The researchers found that those with the highest levels of vitamin D in their blood were almost 40% less likely to develop colorectal cancer compared to those with the lowest levels.

More research needed

However, the authors sound a note of caution about the findings, warning that very little is known about the effects of taking vitamin D supplements or eating food which has been fortified with the vitamin. They also say that it remains a matter of debate about whether vitamin D levels are better boosted through supplementation or via a balanced diet coupled with moderate exposure to sunlight.

The report’s authors say more research is needed on the topic.

Ed Yong, head of health evidence and information at Cancer Research UK, agrees. However, he tells us in an email that “This large study confirms that low levels of vitamin D are linked to an increased risk of bowel cancer.”

He adds that “vitamin D is important for good health” and says “Enjoying the sun safely while taking care not to burn should help people strike a balance between making enough vitamin D and avoiding a higher risk of skin cancer.”

Prevention

Cancer of the large bowel (the most common form of colon cancer) is the third most common cancer in the UK. 37,500 people are diagnosed with bowel cancer each year. An estimated 16,000 people die each year as a result of bowel cancer.

The charity Bowel Cancer UK says people can reduce their risk of colorectal cancer by making some dietary and lifestyle changes. These include:

• eating more fibre, such as fruit and vegetables
• cutting down on red meat and replacing it with fish, poultry and pulses
• reducing fat intake and going easy on chocolate, biscuits, cakes and crisps
• drinking more water
• stopping smoking
• taking 30 minutes of moderate exercise every day
• losing weight if you are overweight or obese
• cutting down on alcohol

You can find out more about colon cancer by clicking here.