HealthDay News — Vitamin D supplementation may help reduce symptoms of depression, according to a systematic review and meta-analysis published online July 11 in Critical Reviews in Food Science and Nutrition.
Tuomas Mikola, from the Institute of Clinical Medicine at the University of Eastern Finland in Kuopio, and colleagues conducted a systematic literature review to identify studies investigating the efficacy of vitamin D in reducing depressive symptoms. Studies assessing light therapy, cosupplementation (except calcium), and bipolar disorder were excluded.
Based upon 41 randomized placebo-controlled trials (53,235 participants), the researchers found that vitamin D had a positive effect on depressive symptoms (GRADE: very low certainty). Vitamin D supplementation ≥2,000 IU per day appears to reduce depressive symptoms, even considering the heterogeneity of dosing in the included studies.
“Despite the broad scope of this meta-analysis, the certainty of evidence remains low due to the heterogeneity of the populations studied and due to the risk of bias associated with a large number of studies,” Mikola said in a statement. “These findings will encourage new, high-level clinical trials in patients with depression in order to shed more light on the possible role of vitamin D supplementation in the treatment of depression.”