Vitamin D deficiency depression linked in international study

Vitamin D deficiency is not just harmful to physical health--it also might impact mental health, according to a team of Australian and US researchers that has found a link between seasonal affective disorder, or SAD, and a lack of sunlight. "Rather than being one of many factors, vitamin D could have a regulative role in the development of SAD," says one of the team, Alan Stewart of the University of Georgia College of Education.