Sun avoidance will not reduce cancer

Avoiding the sun is not the best strategy for reducing overall rates of cancer, claims a senior doctor in a letter to this week’s BMJ. Recommending moderate exposure to the sun would be more prudent.

Sun exposure is the main source of vitamin D, which reduces the risk of colon, breast, prostate, and other cancers, writes Professor Cedric Garland at the University of California.

People in the United Kingdom cannot synthesise vitamin D from November to March, so become deficient by December, he says. Therefore, supplementation of the diet with vitamin D would be helpful, in addition to encouraging moderate exposure to the sun.

Residents of the United Kingdom should aim for 10-15 minutes a day in the sun when the weather allows, without sunscreen, to allow adequate synthesis of vitamin D, he concludes.