By: Marc Sorenson, Sunlight Institute–
Research from Belgium has shown that there is a high rate vitamin D deficiency in elderly nursing-home residents. In fact, almost every resident was deficient. Also, the research showed that as vitamin D deficiency was compared with the likelihood of depression among those residents, there was a consistent tendency toward increasing depressive symptoms with increasing D deficiency. In other words, those who were most D deficient were most likely to be depressed.
This research simply confirms the results of other investigations, most notably a study showing that Those whose vitamin D levels were deficient—defined as less than 20 ng/ml—had 11.7 times the incidence of depression when compared to those whose vitamin D levels were higher. Usually an association is considered impressive when a measured factor correlates to a 50% increase or decrease. In this case, the correlation between vitamin D deficiency and risk of depression was a staggering 1,169 percent! Still other related research showed that elderly persons whose serum vitamin D levels were in the deficient category had three-and-one-half times the risk of being admitted to a nursing home as those whose levels were in the highest category.
Interestingly, the first phrase of the title of the research from Belgium was “Walk on the sunny side of life.” Ninety percent of the vitamin D in the serum of Americans is produced by the skin in response to sunlight exposure, so research like that mentioned above is really a measure of sunlight exposure and depression. Obviously, what these depressed elderly persons really need is to get out of the care facility and into the sunlight!
 Verhoeven V, Vanpuyenbroeck K, Lopez-Hartmann M, Wens J, Remmen R. Walk on the sunny side of life–epidemiology of hypovitaminosis D and mental health in elderly nursing home residents. J Nutr Health Aging 2012 Apr;16(4):417-20
 Wilkins C. et al. Vitamin D Deficiency Is Associated With Low Mood and Worse Cognitive Performance in Older Adults. Am J Geriatr Psychiatry 2006;14:1032–1040).
 Visser, M. et al. Low serum vitamin concentrations of 25 hydroxyvitamin D in older persons and the risk of nursing home admission. Am J Clin Nutr 2006;84:616-22.