“Sunlight is the main source of vitamin D. Sunscreens can prevent sunburn and skin cancer, but there has been a lot of uncertainty about the effects of sunscreens on vitamin D. Our study, during a week of perfect weather in Tenerife, showed that sunscreens, even when used optimally to prevent sunburn, allowed excellent vitamin D synthesis.” says Antony Young, PhD.
UVB is essential for vitamin D synthesis which is contained in sunlight along with UVA. 2 sunscreens with the same SPF were compared, sunscreen with a high UVA protection factor was found to have enabled higher vitamin D synthesis than a low UVA factor sunscreen which was likely because it allowed more UVB transmission.
“Comparisons were made between two formulations, each with a sun protection factor of 15. The UVA protection factor (UVA‐PF) was low in one case and high in the other. Healthy Polish volunteers (n=20 per group) were given the sunscreens and advised on correct application. Comparisons were also made with discretionary sunscreen use (n=22) and non‐holiday groups (51o5N, n=17). Sunscreen use in the intervention groups was measured. Behavior, UVR exposure, clothing cover, and sunburn were monitored. Serum 25(OH)D, was assessed by HPLC MS/MS.” Both low and high UVA-PF groups showed significant increases in serum 25(OH)D produced during the metabolism of vitamin D in the body.
Based on their findings the researchers concluded that sunscreens can help to prevent sunburn while allowing vitamin D synthesis; higher UVA-PF sunscreens enable higher vitamin D synthesis than lower because by default higher formulations transmit more UVB. It was noted that additional research is needed in a larger population based double blind study to determine if these results can be replicated for all skin types and ethnic backgrounds.
