Since vitamin D production requires exposure to UVB radiation, it could be expected that sunscreen use inhibits vitamin D synthesis.
Sunscreen and vitamin DMany studies have investigated the effect of sunscreen use on vitamin D levels.
Overall, findings indicate that with typical use, sunscreen still allows sufficient vitamin D production to happen.
These findings align with two reviews that also examined real-world sunscreen use and vitamin D levels.
Most of the studies included in these reviews either reported that sunscreen use had no effect on vitamin D levels or that sunscreen use led to higher vitamin D levels.
Since vitamin D production requires exposure to UVB radiation, it could be expected that sunscreen use inhibits vitamin D synthesis.
Sunscreen acts as a filter, absorbing or reflecting solar UV radiation. The higher a product’s sun protection factor (SPF), the better it is at preventing sunburn (which is mainly caused by UVB radiation).
By preventing this radiation from reaching and mutating DNA in skin cells, sunscreens can lower skin cancer risk. Sunscreens have also been show to reduce UV-radiation-induced skin ageing.
However, sunscreens are not 100 per cent effective – mainly because most people don’t use them as directed. People typically only apply around one-quarter to one-third of the required amount of sunscreen – and most don’t reapply as instructed. This means some UVB is still able to reach the skin’s surface.
Sunscreen and vitamin D
Many studies have investigated the effect of sunscreen use on vitamin D levels.
Overall, findings indicate that with typical use, sunscreen still allows sufficient vitamin D production to happen.
In a study conducted by our research team, we performed a one-week experiment on 40 holidaymakers in Tenerife, Spain. Participants were taught to correctly apply an SPF 15 sunscreen to protect their skin.
Not only did the sunscreen protect participants from sunburn, their vitamin D levels improved. This showed us that even when sunscreen was used, a sufficient amount of UVB radiation still reached the skin, allowing vitamin D to be produced.
These findings align with two reviews that also examined real-world sunscreen use and vitamin D levels.
Most of the studies included in these reviews either reported that sunscreen use had no effect on vitamin D levels or that sunscreen use led to higher vitamin D levels. This was particularly true with field studies, which would have provided the best reflection of real-world sunscreen use and sun exposure.
However, these reviews also found several experimental studies (with more controlled conditions) that showed sunscreen use can prevent vitamin D synthesis.
However, these studies used UV sources that were not representative of solar UV radiation, which may limit their relevance for real-world conclusions
Another limitation of the studies evaluated in these reviews were that most used low SPF sunscreens (around SPF 15 or lower). Public health advice recommends the use of at least SPF 30 sunscreen, which potentially could have a greater inhibitory effect on vitamin D production.
And most of these studies only used white participants. White skin has less melanin pigment, which acts as natural sunscreens – protecting against UV damage (including sunburn).
