Using sunscreen causes vitamin D deficiency
Vitamin D plays an important role in bone health and the immune system, which makes it an important nutrient for our bodies. Ultraviolet radiation from the sun is the best natural source of vitamin D. However, the amount of sun exposure needed to produce the vitamin D that you require is much less than what people think. In fact, you need about one third of the sun exposure required to cause sunburn to fulfil your vitamin D needs. This is why tests have shown that, in people who do and do not wear sunscreen every day, there is no significant difference in vitamin D levels.
Sunscreen is toxic
This is a dangerous myth that’s been around for a while, but there is little evidence of toxicity compared to the significant benefits that sunscreen provides. One of the things that people often point to as potentially toxic is the nanoparticles in sunscreen, such as zinc-oxide or titanium dioxide. Thorough studies however have shown that these nanoparticles minimally penetrate the stratum corneum, which is the layer of dead cells that make up the top layer of the skin. This makes absorption very unlikely. It is important to keep in mind that Australian sunscreen is highly regulated and tested to make sure that it is safe for human use.
You don’t need to reapply sunscreen after swimming if it is waterproof
It is a myth that you can buy sunscreen that is waterproof. There is no such thing as waterproof sunscreen, only water-resistant sunscreen. What’s the difference? Water-resistant sunscreen can only resist a certain time of being wet before it loses effectiveness. For most water-resistant sunscreen this is between 40 and 80 minutes. Which means that most likely you will still need to reapply your sunscreen after you get out of the water.
On a related note, no sunscreen is sweat proof, and if you are planning on sweating while outside make sure to reapply liberally as sweat will break down even water-resistant sunscreen.
You don’t need to use sunscreen if you have darker skin
Melanin is a pigment produced in the skin that gives our bodies their colour. People with darker skin have more melanin while those with lighter have less. It is true that melanin provides some natural protection against UV rays, so that people with darker skin are less susceptible to sunburn and sun damage. However, dark skin still allows some UV radiation through and is still susceptible to burning. It should also be noted that sun damage is harder to see on dark skin, so it can be more easily overlooked until it is too late. This means that sunscreen is still required to give darker skin full protection from the sun’s rays.
You don’t need to use sunscreen on cloudy days
This is one of those persistent myths that a lot of people now understand is just not true. While it might look like clouds give fantastic protection from the sun’s rays, they actually only block out around 25% of the UVA and UVB rays that are harmful to the skin. This means that on cloudy days you are exposed to pretty much the same about of cancer causing radiation as on sunny ones.