Everything You Need to Know About Sun Exposure
June 7, 2023
It’s officially summer and warmer weather has finally arrived! We’re about to dive in (no pool needed) to some hot topics relating to sun, heat and health!
The Sunshine Vitamin and Other Benefits of Sun Exposure
Ever heard of the sunshine vitamin? Vitamin D is a hormone that is synthesized in the skin when exposed to sunlight. UVB rays interact with 7-dehydrocholesterol in the skin which produces vitamin D3. Sunscreen blocks UVB rays which reduces the skin's capacity to produce vitamin D. If you practice good sun safety by reducing sun exposure, covering up, and wearing sunscreen, it may limit the amount of vitamin D synthesized in your skin. Individuals with darker skin will also require longer durations of sun exposure than individuals with fair skin. If you are someone who gets little to no sun exposure during summer, you may want to consider supplementing vitamin D year round.
In addition to the much needed vitamin D boost, exposure to sunlight has actually been linked to improved energy and elevated mood, potentially due to beta endorphins produced in skin cells when exposed to UV radiation. These beta endorphins may induce mood enhancement and relaxation if sufficient concentrations reach the brain. This explains why I feel like a brand new person every time the sun is out!
What is Melanin?
Ever wondered why spending time in the sun makes us tan? Cells called melanocytes are present in our skin and are responsible for melanin production, melanin is important because it absorbs UV radiation and reduces UV-induced damage! Skin color is determined by the ratio of eumelanin and pheomelanin; eumelanin is black or brown pigment and pheomelanin is red or yellow pigment. Eumelanin has better photoprotective properties compared to pheomelanin, and individuals with lighter skin (high in pheomelanin) are therefore at higher risk of developing skin cancer compared to individuals with darker skin.
UV exposure triggers melanin production in melanocytes in order to protect the skin (this makes us tan!), but the UV rays from the sun can cause sunburn when the melanocytes fail to produce melanin quickly enough. This sun damage can accumulate over time and can potentially contribute to the development of skin cancer, so please wear sunscreen and practice sun safety…
Sun safety and Sensible Sun Exposure
Sensible sun exposure involves enough sun exposure to produce sufficient amounts of vitamin D, but not so much sun exposure that sunburn develops, as this can increase the risk of sun damage and developing skin cancer. As mentioned previously, UV exposure is needed to synthesize vitamin D, but high doses of UV radiation can cause sunburn, immunosuppression, DNA damage, photoaging and skin cancer.
In order to practice sun safety, it is useful to become familiar with the UV Index. The UV index indicates how strong UV radiation is, this varies across seasons as well as the hour the of day. The general recommendation is that no protection is needed when the UV index is between 0-2, protection such as sunscreen is recommended when the UV index is 3-7, and extra protection or even avoiding being outside is recommended when the UV index is above 8.
And if you’re planning on traveling somewhere nice and warm, please think twice before you book a trip to your local tanning salon for a base tan. It is commonly thought that a base tan will act as a photoprotectant and prevent sunburn, but this is not entirely true. Although a base tan may provide a sun protection factor (SPF) of 3-4, this only blocks 65% of UV rays, which is not much considering SPF 10 blocks 90% of UV rays and SPF 50 blocks 98% of UV rays. So please stick to sunscreen (or stay in the shade) if you want to prevent sun damage. And don’t forget to reapply your sunscreen regularly, especially if you’re out in the sun, swimming or sweating!
