“The best way to start your day? The science backs naked cartwheels in the sun” [Nature]. A review of In Defense of Sunlight: The Surprising Science of Sun Exposure. by Rowan Jacobsen.
On Vitamin D:
What is more, people’s over-reliance on vitamin-D tablets is debated. It’s true that rickets, a childhood condition that causes bones to weaken, was suppressed with the help of vitamin-D-fortified foods. However, the disease has risen again among children who spend a lot of time indoors and don’t get enough exposure to sunlight. For people with less than 20 nanograms per millilitre of vitamin D in their blood, taking a supplement won’t do them harm. But sunshine on skin produces vitamin D naturally, in the form of a hormone that helps calcium to get into our bones.
For natural vitamin-D production, skin-cancer specialist Rachel Neale advocates regular short exposures to sunlight, with as much skin bared as possible. Jacobsen therefore proposes that “ten minutes of naked cartwheels in the backyard might not be a terrible idea”.
And morning light and mitochrondia:
Furthermore, he asks us to “look more deeply into what a body is and how it navigates the flux of daily existence”. Consider, for example, the impact of near-infrared light on mitochondria, the bacteria-like structures in cells that convert nutrients into energy. Mitochondria contain an enzyme that absorbs near-infrared wavelengths, and infrared light makes up half of the solar radiation that reaches us.
If you step out into sunlight in the morning, your mitochondria generate more energy, according to physicist Bob Fosbury. And remarkably, his investigations have found that tiny nanostructures in brain cells resemble solar panels. The nanostructures have “exactly the same kind of structure and spacing that we put on solar cells to enhance their absorption characteristics”, Fosbury’s colleague Scott Zimmerman says. “Optically, it’s one of the most beautiful things I’ve ever seen.” Fosbury thinks that these nanostructures evolved to trap infrared photons.
Truly, we are “wonderfully made” ( 139:14), if not “fearfully”; I don’t know why beautiful and functionality complexity should be a thing to fear, unless we fear ignorance, instead of seeking to allay it.