Questionable health trends are recurring, but rarely are they as dangerous as this one: Some people deliberately do without sunscreen – for fear of vitamin D deficiency. Does this make sense?
In fact, there are articles on the internet that describe sunscreens as a “disruptive factor in vitamin D formation” and advise you to sit in the blazing sunshine unprotected. Finally, a vitamin D deficiency can have as devastating consequences as an excess of UV radiation, so the argument: osteoporosis, diabetes, cardiovascular diseases, multiple sclerosis, rheumatism, allergies and, yes: even cancer!
Is that correct? Does sunscreen do more harm than good? Should you prefer to remove sunscreen from the packing list for the summer holiday? The short but definite answer is no, sunscreen is and will always be important.
The differentiated answer is a bit more complicated. It is true that vitamin D is a very important vitamin which, among other things, keeps the bones healthy and protects and supports the immune system. It is also correct that the skin needs sun to form the vitamin (see box), and that many Germans lack it. To compensate for this lack, you do not have to spend hours in the blazing sun – certainly not without sunscreen.
In fact, sunscreen blocks about 95 percent of the sun’s rays and prevents the UV-B radiation, which is important for vitamin D formation, from penetrating the deeper layers of the skin. However, those who spend two or three times a week for a short period of time in the open air do not have to worry about anything.
How long exactly one should go into the sun, can not be fixed flat rate. It depends mainly on the skin type, so how fast you get a sunburn. The Federal Office for Radiation Protection (BfS) recommends spending about half the time in the sun, as it would normally take to get sunburned unprotected. Of course you do not have to try this first. It is advisable to ask the dermatologist which of the six skin types counts and how long it takes for people with this skin type to get sunburned.
Excessive sunbathing without sunscreen is therefore not healthy, but risky. Above all, the sensitive skin of children is to protect from the sun. As it is thinner than that produced by adults and less protective pigments, it is much more susceptible to sunburn and genital damage. Infants under the age of one should never be exposed to direct sunlight. For her, the Robert Koch Institute recommends vitamin D supplements.
Incidentally, studies suggest that most people apply sunscreen too thin anyway to be effective. An average adult, as a rule of thumb, needs about 35 grams of sunscreen to completely moisturize the body, which is equivalent to about four tablespoons.