Researchers from the University Georgia College of Education in a collaborative international partnership have released a new study linking vitamin D deficiency to seasonal affective disorder. The study is based on a review of over 100 articles which has found a relationship between vitamin D and seasonal depression.
“Seasonal affective disorder is believed to affect up to 10 percent of the population, depending upon geographical location, and is a type of depression related to changes in season,” said Alan Stewart, an associate professor in the department of counseling and human development services. “People with SAD have the same symptoms every year, starting in fall and continuing through the winter months.”
“We believe there are several reasons for this, including that vitamin D levels fluctuate in the body seasonally, in direct relation to seasonally available sunlight,” Stewart said. “For example, studies show there is a lag of about eight weeks between the peak in intensity of ultraviolet radiation and the onset of SAD, and this correlates with the time it takes for UV radiation to be processed by the body into vitamin D.
Vitamin D plays a role in regulating neurotransmitters in the brain as it assists in producing serotonin and dopamine within the brain, both chemicals linked to depression, according to the researchers.
“Evidence exists that low levels of dopamine and serotonin are linked to depression, therefore it is logical that there may be a relationship between low levels of vitamin D and depressive symptoms,” said Kimlin, a Cancer Council Queensland Professor of Cancer Prevention Research. “Studies have also found depressed patients commonly had lower levels of vitamin D.”
The researchers recommend maintaining adequate levels of vitamin D for good mental health.
Alan E. Stewart, Kathryn A. Roecklein, Susan Tanner, Michael G. Kimlin. Possible contributions of skin pigmentation and vitamin D in a polyfactorial model of seasonal affective disorder. Medical Hypotheses, 2014; 83 (5): 517 DOI: 10.1016/j.mehy.2014.09.010