After such a long glorious summer, we probably all suspect that we might have had a bit more sun exposure than is safe. Although getting your daily dose of vitamin D is important, most of us are unsure exactly how much sun you need to generate enough of this essential nutrient while at the same time balancing skin cancer risk.
Attempting to answer this question is Professor Lesley Rhodes of the University of Manchester in a recently published Cancer Research funded study.
Rhodes and her team analysed the impact of exposing different skin types to low levels of UV, in terms of generating vitamin D and assessing DNA damage. Understanding the differences in skin types was important as Rhodes explains: “Quite a lot of information has been gathered on white-skinned people, but there’s been very little for people with darker skin. We needed to firm up our knowledge by looking at the major benefit and the major harm of sunlight at the same time in each person.”
The study found that for darker skin types DNA damage wasn’t detected at the lower level of the dermis where damage is most likely to result in skin cancer. In lighter skin types, DNA damage occurs throughout the layers of the skin, increasing the skin cancer risk.
The other aim of the study was to define a formula for how much sunlight you actually need in the UK to produce enough vitamin D. She teamed up with Professor Ann Webb, a physicist with expertise in the atmosphere and sunlight, and they estimated that we require nine minutes of lunchtime sun throughout the summer months to produce enough vitamin D throughout the winter when production declines drastically.
After those nine minutes, sun protection is key, so don’t forget to protect yourself with sunscreen that is suitable for your skin type and amount of exposure.