Abstract
Depression in students is a major public health problem. Although several risk factors associated with depression have been identified, the cause of depression is still not clear. Several studies have demonstrated that physical activity and nutrient intake, such as increased levels of B vitamins in serum, decrease symptoms of depression. The aim of this study was to investigate the association between physical activity and dietary intake of vitamins B₆, B₉, and B₁₂ and symptoms of depression among postgraduate students. The results of this study suggest that intake of vitamin B9 may modulate the total score of Center for Epidemiological Studies Depression Scale (CES-D) and two subscales of the CES-D including depressive affect and interpersonal difficulties. This study also showed that moderate/high levels of physical activity were inversely and significantly associated with symptoms of depression (total scores) and three subscales of the CES-D including depressive affect, positive affect, and somatic complaints.