Don't Get Your Sunlight Through The Window

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Lucas Aoun

Founder @ BYB

January 11, 2021

Sun exposure through windows is not going to assist you to increase your Vitamin D levels. Apart from using the sun through the morning window to “wake you up” and entrain your circadian rhythm (Body clock), it appears that there are some serious dangers to sustained exposure to sunlight behind a window. When you're exposed to sunlight through windows -- in your office, your home or your car -- you get the UVA but virtually none of the beneficial UVB (Wilson et al., 2012).⁣⁣⁣

It's important to remember that vitamin D3 is formed from exposure to UVB rays, whereas UVA radiation actually DESTROYS vitamin D. This helps keep your body in balance; it's one of the protective mechanisms your body has to avoid overdosing on vitamin D when you're outside.⁣⁣⁣

Key Facts


Avoid tanning through a window as it will increase your skin cancer risk. Since the UVA has a longer wavelength, it can penetrate materials more easily, and when the sun is filtered through a window, this effectively filters out the majority of UVB radiation, but only minimally filters out UVAs. What's the significance of that, you ask? This can lead to significant health problems, because in addition to destroying vitamin D3, UVA's also increase oxidative stress. UVA is one of the primary culprits behind skin cancer, and it increases photo aging of your skin (D’Orazio et al., 2013). ⁣⁣⁣




Stop exposing yourself to the sun through windows. It will NOT help you synthesise Vitamin D and can actually cause more harm than good. Best to expose your body to sun OUTSIDE.⁣



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