With winter approaching and dark days ahead in many parts of the country, it’s a good time to re-examine to the role of the sun in our lives, specifically in how lack of sunshine can affect our sleeping patterns.
Sunshine and darkness are the triggers to producing melatonin, the sleep hormone that is essential to our getting a good night’s rest. Together, light and darkness work through our eyes on our pineal gland to control our body’s circadian rhythm, which is the vehicle that triggers melatonin production when the blue light from the sun (or artificial sources) fades, i.e., when night falls and the lights are turned out.
It’s said that, to fine-tune and sustain our natural circadian rhythm, we need to spend at least 10 minutes in the sun each day. For those who live in winter climes that block the sun, this can be a bit challenging. Moreover, there’s growing evidence that exposure to sunlight, especially in the morning, improves not only sleep but overall health and well-being.
“There is increasing evidence that exposure to light during the day, particularly in the morning, is beneficial to your health via its effects on mood, alertness and metabolism,” expalins Phyllis Zee, M.D., a Northwestern Medicine neurologist and sleep specialist.
Using an actigraph, researchers studied 49 workers for two weeks to determine the effect of light on both their sleep and overall quality of life. Half the group worked in a windowless environment, the other half in a well-sunlit office space. The first group proved more likely to complain of physical problems and fatigue during the day. More tellingly, the windowless workers scored shorter sleep durations on the actigraph, which is a motion detector that differentiates sleep from wakefulness.
If you do live in a dark, wintry northern clime, you should try to spend some time outside to get whatever rays of sunshine you can. Failing that, you can use a tanning salon (believe it or not) or even take vitamin D3 supplements. The best source of vitamin D is the sun, but if the sun is hiding, supplements and tanning salons are alternatives. And remember, low vitamin D has been linked to a variety of physical ills, as well as being an impediment to good sleep. (Vitamin D deficiency has also been linked to obesity.)
One thing about vitamin D3 supplements, though, is that your body is not able to regulate your intake and absorption of the vitamin. In contrast, when you’re in the sun, your body naturally shuts off vitamin D production when it reaches the proper level. Therefore, seek the advice of your health care professional before undertaking any supplemental regimen.
Remember, not only do you need sunlight to regulate your circadian rhythm, but you also need total darkness when sleeping. Turn off any source of light in your sleeping area and make sure your windows are covered sufficiently to prevent any outside light from keeping you awake. And always be ready to seek professional advice when facing chronic sleep-deprivation issues.