Vitamin D Deficiency Causes Depression and SAD

Dave Edwards

Vitamin D has long been touted as a miracle nutrient responsible for maintaining physical health. But new research by the University of Georgia College of Education now suggests that it may significantly impact mental health.

The team of researchers have found a link between a deficiency in vitamin D, caused by lack of sunlight, and seasonal affective disorder, or SAD.

"Rather than being one of many factors, vitamin D could have a regulative role in the development of SAD."

Seasonal affective disorder is believed to affect up to 10 percent of the population and is a type of depression related to changes in season. According to Alan Stewart of UGA, "people with SAD have the same symptoms every year, starting in fall and continuing through the winter months."

Stewart believes there are several reasons that vitamin D contributes to seasonal depression, including that vitamin D levels fluctuate in the body depending on seasonally available sunlight.

"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."

Kimlin stated that depressed patients are commonly found to have lower levels of vitamin D and that levels of the vitamin vary according to the pigmentation of the skin. The implications of this mean that not only do those with greater skin pigmentation experience higher vitamin D deficiency, but are also "at greater risk of psychological and psychiatric conditions."

Kimlin also said that adequate vitamin D levels were essential in maintaining bone health with deficiencies causing osteomalacia in adults and rickets in children.

The new research substantiates previous links between vitamin D and mental health, with Kimlin adding that there are now "strong indications that maintaining adequate levels of vitamin D are also important for good mental health."

Current recommendations by the U.S. Institute of Medicine are that vitamin D levels should exceed 50 nanomoles per liter and Kimlin believes that a few minutes of daily sunlight exposure should be enough to maintain adequate levels.

"This research is of international importance because no matter where you live, low levels of vitamin D can be a health concern."