Depression is a significant health issue in young women with few assessment strategies for early detection. It has been suggested that self-efficacy and vitamin D levels can predict and prevent depression. The authors examined the relationship between vitamin D levels, coping self-efficacy and depression in 77 college age women over three seasons. The results of the repeated measures analysis showed that a strong, inverse relationship existed between self-efficacy and depression but not vitamin D levels. These findings were consistent across the three data collection points. The results implied that strengthening perceived coping self-efficacy may be useful in order to maintain the mental health of young college age women. (c) 2014 Elsevier Inc. All rights reserved.