Why our bodies need those blue-sky days

By Nikki Bauman

The contrast of fresh powdered snow amplified by a background of cerulean vastness is one of nature’s finest vistas.  Fellow outdoor enthusiasts refer to these conditions as “bluebird” days, a term routinely followed with hooting, hollering, and high-fiving between friends and strangers gathering on the ski hill to worship the good weather.

Why do we have more fun in the sun?  It isn’t the scenery; it’s chemistry.  As living organisms, harvesting energy from the sun is crucial for regulating homeostasis. Our bodies literally crave sunshine, especially in the winter when it’s harder to come by as days are shortened, offsetting our mood as a result.

Serotonin is a neurotransmitter, sending signals from neurons to target cells.  It is one of the oldest components of the nervous system found in the Animal Kingdom, derived over a billion years ago from a line of molecules releasing energy derived from the sun.  In sea urchins, it controls appetite.  In higher order mammals, it regulates sleep patterns. In humans, it functions as an anti-depressant to regulate the brain’s emotional state.

There’s no better cure to mid-winter blues than a bluebird day.  You may not realize it, but these are the days your mood swings back to its peek.  This may be due to the supporting benefits of another familiar product of the sun, Vitamin D.  Vitamin D is produced in the skin in response to UVB rays.  It encourages and stabilizes serotonin production, formulating a natural balance to keep us happy.  A Vitamin D deficiency will not just result in brittle bones, it will cause serotonin levels to dramatically fluctuate (aka “mood swing”).

Low levels of serotonin instigate classic winter habits of seasonal depression, craving comfort food, and repeatedly hitting the snooze button in the morning.  Like many other species, humans respond to circadian rhythms with periods of lightness and darkness. As the day shifts into night, your body stops producing Vitamin D and serotonin levels drop.  This doesn’t mean night equals sadness, but the body definitely reacts by slowing down both physically and mentally.

If you’re indoors, pause for a moment and look up.  Are you now marveling at a glowing fluorescent bulb illuminating the room to what you think is an intense source of light?  You’re actually deprived of slices of the spectrum.  Light bulbs lack UV rays, which are exactly the rays that stimulate Vitamin D production.  In fact, too much time spent bunkered down under fluorescent lighting may actually decrease serotonin, leaving you grumpy and fatigued.

Seasonal affective disorder (SAD) runs rampant during winter months with extended periods of gray, overcast skies to compliment frigid, short days.  If you find yourself routinely depressed, fatigued, and unable to concentrate, perhaps it’s time to ditch the Zoloft and get outside.