In recent years, concerns have been widely expressed about the sun and the potential damage it poses to our skin. Of course, you need to be careful – skin cancer is a real risk, and you shouldn't expose your skin to the sun without protective cream for longer than 20 minutes in summer, especially if you're fair-skinned. It's also particularly important to protect children's skin. But adults can take it too far, especially in the UK, where the sun's rays aren't especially strong.

A lot of people think they need to wear factor 30 to 50 every day, even in winter. But new evidence suggests that this can actually do you more harm than good. A little bit of sun exposure is good for us – both for our state of mind and for our skin's health.

To keep your vitamin D levels up, you should spend about 20 minutes every day in the sun during summer without sunscreen, making sure that you expose your face and arms to it. The summer months are when we replenish our vitamin D levels. We all lead busy lives, and most of us work in offices, so if you get up in the morning, cover your skin with sunscreen, then go straight to the office and only pop outside for a brief walk at lunchtime, you risk missing out on the beneficial effects that a short period of sun exposure could give you. There really is no need to worry about layering on the cream when you're popping outside for a few minutes.

Dr Veronique Bataille, a consultant dermatologist at the Princess Grace hospital, London, was talking to Laura Barnett