What was once thought of as simply one of many factors in the development of Seasonal Affective Disorder, vitamin D has now been identified by researchers to have a direct link to seasonal depression. An international research study conducted in tandem by the University of Georgia, University of Pittsburgh, and the Queensland University of Technology in Australia, revealed the importance of vitamin D on physical and mental health.
 

Physical Health Impact

It has already been established that vitamin D plays a large role in bone health. In fact, adequate levels are essential in preventing diseases such as osteomalacia and rickets, a softening of the bones in both adults and children. But, by analyzing over 100 studies done on the subject, researchers have found a series of links regarding the influence of vitamin D on mental health. 
 

Mental Health Impact

For one, we know the amount of sunlight available varies seasonally, especially depending on the geographic region. As the amount of the available sunlight fluctuates, the amount of vitamin D levels in the body fluctuate along with it. Vitamin D is also involved with the synthesis of serotonin and dopamine, two neurotransmitters in the brain— low levels of these chemicals are directly linked to depression. Therefore, a deficit in vitamin D might lead to a deficit in these chemicals. In fact, a number of studies have found that depressed subjects often have low levels of vitamin D. 
 
With sunlight being the ultimate source of vitamin D, the low levels that accompany the winter months lead to this seasonal affective disorder that plagues up to 10% of our population. Experts stress that this new research is of international importance because of the number of health concerns there are associated with vitamin D deficiency. Regardless of geographical location, it is still possible to be lacking in this essential vitamin. They state that only a few minutes in the sun each day should be enough to maintain adequate levels of the vitamin.