By Marc Sorenson, EdD, Sunlight Institute…
A recent press release from the Vitamin D Society of Canada discusses the need for vitamin D in the winter, in order to reduce the risk and intensity of seasonal affective disorder, or SAD. SAD is a feeling of low motivation, depressed mood, decreased concentration, anxiety and despair.
Dr. Samantha Kimball, the scientific advisor for the Society, has found that increasing vitamin D intake can help reduce the symptoms of SAD. She mentions that vitamin D, which is generated in the body by sunlight exposure, can modulate the immune system and reduce inflammation, thereby reducing the risk of depression.
Dr. Kimball is correct; the change can be absolutely dramatic based on serum vitamin D levels. One remarkable piece of research showed that those persons who had the lowest levels of D had almost 12 times as likely to be depressed as those who had the highest levels.
Although I fully agree with Dr. Kimball, I can’t help but wish she had mentioned more on the benefits of the sunlight or even sunlamps, which are the most natural ways to increase vitamin D, but are also marvelously effective in improving mood beyond vitamin D.
In addition to vitamin D, there is a chemical produced by the brain in response to sunlight exposure to the eyes. It is called serotonin and is a natural “upper” or mood enhancer. It is also a neurotransmitter and is available to us from bright light entering the eyes. Even is Canada in winter, when there is no vitamin-D stimulating potential in sunlight, just being outdoors when there is sunshine will work to improve or prevent SAD. Sunlight can dramatically increase serotonin levels in the brain.
Dr. Gavin Lambert and his colleagues in Australia measured serotonin levels in response to varying degrees of bright light. To do this, they drew blood samples from the internal jugular veins of 101 men and compared the serotonin concentration of the blood to weather conditions and seasons. The results were remarkable: Men who were measured on a very bright day produced eight times more serotonin than those who were measured on a cloudy, dismal day. They also observed that the effect of bright light was immediate, and that there was no holdover from day to day. Serotonin levels were also seven times higher in summer than winter. There we have another answer to SAD. When the sun is shining, wherever you are, take advantage of it. It will elevate your mood and make you feel more alive. And remember that tanning beds and other types of sunlight do a great job of increasing your vitamin D when the sun doesn’t shine. Finally, bright, full-spectrum lighting will also enhance your mood. Merry Christmas and HAPPY Holidays!
Click this link to read the Vitamin D Society press release: http://www.vitamindsociety.org/press_release.php?id=39
 Wilkins CH, Sheline YI, Roe CM, Birge SJ, Morris JC. Vitamin D Deficiency Is Associated With Low Mood and Worse Cognitive Performance in Older Adults. Am J Geriatr Psychiatry 2006;14:1032–1040).
 Lambert GW, Reid C, Kaye DM, Jennings GL, Esler MD. Effect of sunlight and season on serotonin turnover in the brain. Lancet. 2002 Dec 7;360(9348):1840-2.