Sunscreen, sunlight, and vitamin D: Everything you need to know
As we move into the summer months and start spending more time outside, vitamin D is often put back of mind. Most people assume once they are being exposed to enough sunlight to synthesize their daily dose of vitamin D.
In reality, it is extremely difficult to rely on the sun for vitamin D, no matter what the time of year. One study showed that pregnant women in even the warmest Mediterranean climates need extra vitamin D through the form of a supplement.
Why is it so difficult to get vitamin D through sunlight?
- UVB rays, which are the rays that give us a sunburn and provide vitamin D, do not significantly penetrate glass. This is something to keep in mind if you work in an office by a window. 
- It takes longer for vitamin D to be made from darker pigmented skin.
- It is more difficult to synthesize vitamin D the farther you live from the equator. 
- Sunscreens block UV rays from penetrating the skin and damaging cells. Sunscreen above SPF 8 will also prevent 98% of vitamin D sun intake. 
Why is it so important to wear sunscreen in the summer?
- The Canadian Dermatology Association and Health Canada advise against direct exposure of sunlight, especially for infants. 
- Direct UV exposure can lead to leathery, wrinkled skin over time. 
- Sunscreen defends the skin from damaging ultraviolet rays by forming a protective barrier. Used properly, sunscreen can help to prevent skin cancer. 
- Prolonged sun exposure can also lead to further health problems. Physicians and scientists agree that people should use sun protection to prevent skin cancer.
- The American Academy of Dermatology warns that there is no scientifically safe way to get enough vitamin D from sunlight without increasing skin cancer risk. 
How should I get my vitamin D?
Sun exposure is not as important for the body’s vitamin D supply as it used to be. Whether you do not receive enough sun exposure in the summer or choose to use sunscreen, increasing your levels of vitamin D through supplementation is a welcome option.