Sunscreen And Vitamin D Deficiency
Should We Ever Go Out In The Sun Without Sunscreen?
The impression we get these days from sunscreen manufacturers and health advice is that we should never go out in the sun without sunscreen. However, a certain amount of sunlight on our skin is crucial to health. We make Vitamin D in our skin on exposure to sunlight, and staying out of the sun or preventing the sun from reaching our skin with sunscreen or clothes can leave us deficient in this vitamin. Although most often recognised as important for healthy bones, Vitamin D is increasingly recognised as playing a vital role in many other aspects of our health, especially cancer prevention.
The important thing is to get enough sunshine to make a healthy amount of Vitamin D, but not to stay out in it so long without clothing or sunscreen protection that we get burnt. There's no danger of making too much Vitamin D, as once the vitamin reaches saturation point our skin automatically stops making it. This point is reached when your skin goes just slightly pink in the sun, way before you're in danger of getting sunburnt.
However, if we want to stay out in the sun beyond that point, and not cover up with clothes, then we do need a good sunscreen. But it's important to understand the different types, as we see below.
Does your sunscreen filter out UVA?
Most sunscreens filter out UVB wavelengths, but fewer filter out UVA. Consider the following:
- Although experts still believe UVB is responsible for much of the skin damage caused by sunlight, sunburn in particular, they now think that UVA may be more important in causing skin cancer.
- It is the UVB rays which are crucial for the production of Vitamin D by the skin.
- UVB is more easily filtered out by clouds than UVA. UVA can still get through on cloudy days.
- If your sunscreen doesn't say it screens out UVA too, you're only filtering out the UVB. This means you're reducing your defences against cancer (preventing your skin from making Vitamin D) at the same time as you're increasing your cancer risk (from exposure to UVA).
What's in your sunscreen?
Sunscreens can be physical or chemical. The physical ones contain zinc oxide and / or titanium dioxide, forming a film on top of the skin that reflects both the UVA and UVB rays. Chemical ones work by absorbing UVB rays before they can do any damage.
An ingredient of many chemical sunscreens is OMC or octyl methoxycinnamate, which is highly toxic. Many of the other ingredients used in chemical sunscreens are also believed to be toxic. Using a physical sunscreen containing titanium dioxide and zinc oxide is safer. Titanium dioxide gives considerable protection from UVA and extensive protection from UVB. Zinc oxide gives extensive protection from both types.
So the bottom line is: our health will suffer if we become so afraid of the sun that we never allow ourselves to be exposed to it. We should get plenty of sensible exposure but make sure we don't get sunburnt, choosing the least toxic UVA- and UVB-filtering sunscreen we can when staying out of the sun or covering up is not an option.