This time of year, sunshine is hard to find in the Northern Hemisphere. Days are shorter, and the sun shines at a lower angle. Lack of sun is thought to be a cause of seasonal affective disorder, or SAD. SAD is rough on people with diabetes, because it increases carbohydrate cravings and fosters weight gain. But how does lack of sun make us SAD?
Psychologists have often prescribed sunshine for depression. To me, it’s one of the big three depression treatments, along with exercise and social contact. Sunshine is as effective as or more effective than Prozac without the side effects or the withdrawal symptoms. Now there is new understanding of the biological benefits of sun.
A recent study by University of Utah doctors found that people with low vitamin D have more depression and more heart disease. According to Michael F. Holick, MD, PhD, a professor of medicine, physiology, and biophysics at Boston University School of Medicine, “many of the genes that regulate cardiovascular health are directly or indirectly regulated by vitamin D. We know that vitamin D regulates blood pressure, and it is very important for maintaining good heart health.”
Apparently, brain cells also have receptor for vitamin D. “Vitamin D is also essential to the brain,” says Holick. “New research is confirming previous observations that vitamin D deficiency increases the risk of depression.”
Sunshine is the main source of vitamin D, but many of us don’t get enough sun any time of year. When we live and work inside most of the time, it doesn’t matter how clear the skies are. We’re still not feeling sun on our skin. But there are other ways of getting vitamin D. It occurs naturally in fish and is added to milk and vitamin pills.
How much does vitamin D help SAD? For my wife, it’s been tremendous. She used to get desperate every winter (or sometimes in summer with the San Francisco fog.) She would drive or take the train for hours just to find some sun. Since she started taking 2,000 units of vitamin D a day, she doesn’t need that anymore.
Vitamin D isn’t the only biological benefit of sunshine, though. Sunshine also improves sleep. It may do this by stimulating the body to produce melatonin. According to Gila Lindsley, PhD, ACP, melatonin is a natural hormone produced in the pineal gland in the brain. The amount of melatonin produced depends on the amount of light our eyes pick up during the day.
Melatonin is normally released into the bloodstream when it gets dark. The raised after-dark melatonin level causes our body temperatures to drop and prepares us for sleep. This is why many blind people have insomnia. Their bodies can’t tell when to make melatonin and when to secrete it into the bloodstream. Their rhythm is off.
So it could be that taking melatonin a few hours before bed could help you sleep. It certainly helps me. I take 3 milligrams of melatonin every evening and it really helps. I don’t get much sun, what with working inside and being disabled and all. I find it difficult to sleep without the melatonin, although it also helps to actually be tired.
My question is: Can we obtain our sunshine from pills? If we take vitamin D and melatonin, will we be protected from depression, insomnia, heart disease, and other problems associated with lack of sunshine?
Personally, I doubt it. I’m sure there are a dozen other biochemicals that we need sun to regulate. They just haven’t been discovered yet. We evolved to live by cycles of light and darkness, and I doubt we can make up for all that with supplements or medicine. We need that nature time.
I will keep taking vitamin D and melatonin. Right now, though, I think I’ll go out and get some sun! Enjoy your week, and if you have any thoughts on depression, sleep, and sun, please let us know.
By the way, Aisha and I have a new Web address for our couples’ work. Check out our programs at http://coupleswellness.sitesvp.com.