In May 2019 researchers from the UK, Poland and Denmark published the results of their study to assess the impact of sunscreens on vitamin D levels. Sunlight contains both UVA and UVB radiation and although the latter is essential for vitamin D synthesis, UVB is also the main cause of sunburn and skin cancer. A total of 40 healthy individuals were involved in the study and given either a low or high UVA protection sunscreen which was used during a one week’s holiday. Each sunscreen had a sun protection factor of 15 (an indicator of UVB protection). Sunscreen use, UV radiation exposure, clothing cover and sunburn were also monitored. Results showed that the use of both high and low UVA sunscreens was about the same and that both sunscreens helped to prevent sunburn. In addition both sunscreens allowed statistically significant increases in vitamin D levels, with the increase being higher with the use of the high UVA protection sunscreen than the low UVA protection sunscreen.
Young AR et al. Optimal sunscreen use, during a sun-holiday with a very high UV index, allows vitamin D synthesis without sunburn. Br J Dermatol. 2019 Nov;181(5):1052-1062.