Does sunscreen cause skin cancer?
In the middle of the record-high summer heat of 2018, a movement emerged on Facebook that warned against the use of sunscreen seeing as it could result in skin cancer. The theory behind the claim stated that because vitamin D prevents skin cancer and sunscreen inhibits the absorption of vitamin D in the body, sunscreen must then leads to skin cancer.
However, this theory was subsequently disproved by several sources and the theory has not received any scientific support. It is true that when using sunscreen, the absorption of vitamin D is inhibited in the body because vitamin D is indeed created when the rays of the sun hit the skin.
But... the amount of sunlight needed for the body to produce the amount of vitamin D it needs is so small that it only takes a few minutes in the summer sun before the need is fulfilled - even when wearing sunscreen.
Videnskab.dk has also investigated whether the lack of vitamin D results in skin cancer at all. According to professor and consultant doctor Hans Christian Wulf, who has helped make the guidelines of the Danish Health Authority, there is very little research which suggests this.
Sunscreen prevents skin cancer
Sunscreen really gained momentum in the 1970s, which was very convenient seeing as tourism and beach holidays boomed during the same period. The purpose of sunscreen is to limit the penetration of UV rays into the skin cells. When the skin is covered with sunscreen, it acts as a barrier to the UV rays so that up to 95 percent of the rays cannot penetrate the skin. The higher the SPF of the sunscreen, the more the skin will be protected.
When pale people easily get burned and red in the sun, it is because they have a lower amount of melanin in their bodies. Melanin is a natural protective agent against sunrays so the more light-skinned you are, the more you will need sunscreen to protect yourself.
The main cause of skin cancer is overexposure to UV rays. The DNA of the skin cells is damaged by the UV rays and if the damage recurs over a long period of time, the cells can develop into cancer cells.
Do you absorb enough vitamin D when using sunscreen?
Sunscreen does not prevent the effect of UV rays on the skin 100 percent, it merely slows it down. Furthermore, there is no beneficial effect in “overexposing” the body to sunlight in order to build up a large stock of vitamin D in the body.
The body functions in such a way that when it has obtained the amount of a particular vitamin it needs, it stops the absorption and/or production of that vitamin. This also applies to vitamin D.
Studies have been made of people who use sunscreen and the studies show very clearly that the need for vitamin D is easily fulfilled on summer days in the sun, even when you listen to the advice of the Danish Health Authority and use sunscreen.
What is the cause of vitamin D deficiency?
Vitamin D deficiency occurs most frequently in winter. This is due to the limited amount of sunlight as well as the UV rays not being particularly strong due to the sun hanging low in sky in our part of the world during winter. In addition, the cold causes us to hide most of our skin under several layers of clothing when we freeze. All this inhibits the production of vitamin D.
Several people can therefore benefit from increasing their intake of fatty fish such as salmon, herring and mackerel during the winter because these fish contain large amounts of vitamin D. If you do not like fish, you can also get vitamin D supplements as tablets.