(HealthDay)—Vitamin D supplementation has no overall effect on depressive symptoms, but may have a significant effect for those with clinically significant depression, according to a review published online March 14 in Psychosomatic Medicine.
Jonathan A. Shaffer, Ph.D., from the Columbia University Medical Center in New York City, and colleagues conducted a systematic review to identify randomized trials that compared the effect of vitamin D supplementation with a control condition on depression or depressive symptoms. Seven trials, involving 3,191 participants, were included in the analyses.
The researchers found that despite considerable heterogeneity there was no overall effect for vitamin D supplementation on depressive symptoms (standardized mean difference [SMD], −0.14; P = 0.16). For participants with clinically significant depressive symptoms or depressive disorder, vitamin D supplementation had a moderate, statistically significant effect (two studies: SMD, −0.60; P = 0.046), while the effect was small and nonsignificant for those without clinically significant depression (five studies: SMD, −0.04; P = 0.61). The risk of bias was unclear or high in most trials.
"Vitamin D supplementation may be effective for reducing depressive symptoms in patients with clinically significant depression; however, further high quality research is needed," the authors write.
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