Researchers have suggested that Vitamin D supplements may not be able to decrease depression.
The review, by Jonathan A. Shaffer, PhD, assistant professor of medical sciences at Columbia University Medical Center (CUMC), and team at CUMC's Center for Cardiovascular Behavioral Health, found that only seven trials with a total of approximately 3200 participants compared the effect of vitamin D supplementation on depression with no vitamin D supplementation.
Nearly all of these trials were characterized by methodological limitations, and all but two involved participants without clinically significant depression at the start of the study. The overall improvement in depression across all trials was small and not clinically meaningful.
However, additional analyses of the clinical data by Dr. Schaffer hinted that vitamin D supplements may help patients with clinically significant depression, particularly when combined with traditional antidepressant medication. New well-designed trials that test the effect of vitamin D supplements in these patients are needed to determine if there is any clinical benefit.
The authors note that supplementation with vitamin D also may be effective only for those with vitamin D deficiency. They also recommend that future studies consider how vitamin D dosing and mode of delivery contribute to its effects on depression.
The study has been published online in the journal Psychosomatic Medicine.