Does Sun Cream Block Vitamin D? - Chromatography Explores

It is the time of year where outer layers of clothing are left at home and many of us start to show a little bit more flesh. It is an important time of year for vitamin D production, especially for people living in more northern latitudes who miss out on getting enough sun during the winter.

However, as many of us know, exposure to the sun can cause sunburn and lead to more serious conditions including skin cancer. So, we have to make sure that any flesh exposed to the sun is protected from the damaging effects of sunlight by applying sunscreens. But does the application of sunscreen reduce our exposure to the beneficial rays that promote vitamin D manufacture in our bodies? A recent paper published in the British Journal of Dermatology explains that this is not the case, provided sunscreen is properly applied.

Making vitamin D

There are two main methods the body gets vitamin D. It can make vitamin D using sunlight or we eat foods or supplements that contain vitamin D. The most natural and efficient way is by exposing our skin to sunlight, specifically ultraviolet B rays. The more exposure, the more vitamin D - which is why in winter we need to take supplements as we cannot get enough sun in the UK. But what happens if you apply sunscreen - does it stop vitamin production?

Sunlight - good and bad

Sunlight is composed of rays at many different wavelengths - luckily for us some of them occur in the visible part of the spectrum so we have daylight. It also contains rays in the ultraviolet part of the spectrum that are named UVA, UVB and UVC. UVC rays are absorbed by the atmosphere before they get to the ground, but enough UVA and UVB rays reach ground level to affect us.

UVB rays are responsible for our vitamin D production - but also cause the harmful effects like skin cancer and sunburn. UVA is less intense and causes aging and minor skin damage. Luckily for us, the study published in the British Journal of Dermatology found that when sunscreen is applied correctly, you still get the protection of the sunscreen but you also make vitamin D.

Study in sunlight

In the study, the researchers compared the vitamin D levels of people before and after a one-week holiday in the sun - lucky participants. The researchers used high performance liquid chromatography to analyse the levels of 25(OH)D₃ - an indicator of vitamin D – in the volunteers. The use of liquid chromatography as an analytical tool is discussed in the article, Integration of MS and UV Data for Peak Tracking in HPLC Method Development. The researchers found that sunscreen applied correctly was effective at preventing sunburn and allowed sufficient vitamin D to be produced in the body.

So, keep applying the sunscreen while you enjoy the sun.