Q. I’m confused about the sun. We are told not to sunbathe because it causes skin cancer, then to sunbathe because the extra vitamin D protects us against heart attacks and internal cancers. What should we do?

A. Sunbathing is fine as long as you don’t BURN (tanning is a form of burning in fair skinned people). Your skin cancer risk rises with each episode of burning or tanning. On the other hand, we make vitamin D from the reaction of sunlight on the skin, and lower than average vitamin D blood levels puts us at higher risk of heart attacks than if they were normal. (For purists the cut-off point is 15 nanograms per millilitre – the source is the long-running US Framingham study.) Taking vitamin D improves your survival if you have cancer of the prostate, breast or colon, but paradoxically, there are more of these cancers per head of population in countries at low latitudes, in which you would have expected much more exposure to the sun. We Brits get most of our vitamin D from food – fish, other oily and fatty foods, including supplemented dairy products - so sunbathing isn’t our only source of it. The message is to enjoy the sun sensibly, not just for the vitamin D but also for the sheer pleasure of its warmth. Don’t we all need it after such a long winter?