This summer, the City of Toronto is getting on the case for skin protection and expanding it’s #BeSunSafe program, placing dispensers for free sunscreen in public parks. Last year, this program was piloted with five parks around the waterfront, and this year it will be expanded to 50 locations. This is an important step for the City of Toronto as sunscreen and clothing items (sleeves, hats, cover ups, etc.) have been implemented as the first line of defence against skin malignancies.

While the sun can be dangerous to the skin, it is also instrumental to human survival. The earth, evolution, and humanity have needed sunlight not just to exist, but to thrive. Mood, sleep, and general health are all key functions that are dependant on the sun, vitamin D being the most popular in this relationship.

When sunlight (specifically the UVB rays) hits the skin, it manufactures vitamin D, which then is essential to the body for maintaining levels of calcium, bone growth, muscle weakness and more. Other recent studies also suggest that vitamin D has a role in prevention of diabetes, cancer, inflammatory conditions, and heart problems.

Most recently, some are relating the rise in vitamin D deficiencies to extra diligent sun protection – a concern in Canada, where it’s well known that vitamin D is something Canadians may be missing in the long winter’s darker months. skincancer.org notes that it doesn’t take a lot of time in the sun to produce vitamin D. Even a ten minute walk outside can stimulate production. While on the flip side, a study from 2015 noted that it only takes one minute for UVA rays to begin to cause damage in the sun.

With two opposing schools of thought, how does one find the balance between sun block and sun exposure? The answer is not as difficult as one might think.

Sun protection 101

Sunproof factor (SPF) refers to the length of time that a sunscreen will protect you for. It is possible to get protection against UVA rays, UVB rays, or both, which is known as broad spectrum. UVA rays have a longer wavelength and will penetrate to the middle layer of the skin (the dermis), while UVB rays typically penetrate the outer layer (epidermis). While UVB rays are also strongest in the middle portion of the day, UVA lasts throughout the entire day.

All of these factors are important in choosing protection, as SPF refers only to time, while UVA/UVB/Broadspectrum refer to the intensity of protection. An article from Consumer Reports in 2017 highlights that in the US, there is no test for the level of UVA/UVB protection, it’s simply a pass/fail. For the consumer, this means that the sunscreen only has to prove that it can block both UVA and UVB rays, but does not have to indicate to what depth and extent.

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In 2015, a different article by Consumer Report also notes that no sunscreen blocks 100 per cent of the UVB rays (which, as noted above, are the main rays in producing vitamin D), with SPF 30, blocking about 97 per cent of UVB rays.

Vitamin D 101

Vitamin D is available by dietary sources, supplements, and sun exposure. It is what health professionals call a “fat soluble vitamin”, meaning the body can store it in fat cells for a length of time. This is beneficial to the body as we can consume it through the diet, then store and use it at a later time. Some foods that include vitamin D are: fortified juices/milk, grains, yogurt, eggs (yolks), meat, beef, many forms of fish, including fish oil supplements, some cooking oils, and more.

The balance is more simple than one might think, as the research doesn’t seem to indicate as big a problem as the anecdotal debates. It is always recommended to follow the current medical guidelines: Protecting the skin against growing malignancies should be of primary concern when spending time in the sun. Sunscreen should be used at an appropriate SPF and spectrum, and reapplied as necessary.

Using the research as a guideline, vitamin D deficiencies are able to be managed dietarily and are not showing (according to the evidence) as a concern in the summer months, even with proper and diligent sun protection.