The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trials.

Neurosteroid and immunological actions of vitamin D may regulate depression-linked physiology. Meta-analyses investigating the effect of vitamin D on depression have been inconsistent. This meta-analysis investigated the efficacy of vitamin D in reducing depressive symptoms among adults in randomized placebo-controlled trials (RCT). General and clinical populations, and studies of ill individuals with systemic diseases were included. Light therapy, co-supplementation (except calcium) and bipolar disorder were exclusionary. Databases Medline, PsycINFO, CINAHL and The Cochrane Library were searched to identify relevant articles in English published before April 2022. Cochrane risk-of-bias tool (RoB 2) and GRADE were used to appraise studies. Forty-one RCTs (n = 53,235) were included. Analyses based on random-effects models were performed with the Comprehensive Meta-analysis Software. Results for main outcome (n = 53,235) revealed a positive effect of vitamin D on depressive symptoms (Hedges' g = -0.317, 95% CI [-0.405, -0.230], p < 0.001, I2 = 88.16%; GRADE: very low certainty). RoB assessment was concerning in most studies. Notwithstanding high heterogeneity, vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression. PROSPERO registration number: CRD42020149760. Funding: Finnish Medical Foundation, grant 4120 and Juho Vainio Foundation, grant 202100353.

The effect of emerging nutraceutical interventions for clinical and biological outcomes in multiple sclerosis: A systematic review.

BACKGROUND: Due to the considerable burden of multiple sclerosis (MS)-related symptoms and the need to identify effective interventions to prevent disease progression, various nutraceutical interventions have been trialed as adjunctive treatments. The aim of this review was to investigate the efficacy and safety of nutraceutical interventions for clinical and biological outcomes in people with MS. METHODS: In accordance with PRISMA reporting guidelines, a systematic literature search was conducted using three electronic literature databases. Risk of bias was assessed using the Jadad scale. RESULTS: Thirty-seven randomized controlled trials, investigating fourteen nutraceuticals, were included in the review. Trials that investigated alpha lipoic acid (n = 4/6), ginkgo biloba (n = 3/5), vitamin A (n = 2/2), biotin (n = 1/2), carnitine (n = 1/2), green tea (n = 1/2), coenzyme Q10 (n = 1/1), probiotics (n = 1/1), curcumin (n = 1/1), Andrographis paniculata (n = 1/1), ginseng (n = 1/1), and lemon verbena (n = 1/1) were reported to improve biological (e.g. MRI brain volume change, antioxidant capacity) and/or clinical (e.g. fatigue, depression, Expanded Disability Status Scale) outcomes in multiple sclerosis compared to control. However, most trials were relatively small (average study sample size across included studies, n = 55) and there were few replicate studies per nutraceutical to validate the reported results. Furthermore, some nutraceuticals (e.g. green tea and inosine) should be used with caution due to reported adverse events. Risk of bias across most studies was low, with 31 studies receiving a score between 4 and 5 (out of 5) on the Jadad Scale. CONCLUSION: The existing literature provides preliminary support for the use of a number of nutraceutical interventions in MS. However, sufficiently powered long-term trials are required to expand the currently limited literature and to investigate unexplored nutraceuticals that may target relevant pathways involved in MS such as the gut microbiome and mitochondrial dysfunction. Prospero ID: CRD42018111736.

Effect of saffron supplementation on symptoms of depression and anxiety: a systematic review and meta-analysis.

CONTEXT: Saffron (Crocus sativus L.) has gained interest as a potential treatment in psychiatry. OBJECTIVE: This systematic review and meta-analysis sought to investigate the effect of saffron supplementation, as both an adjunctive therapy and monotherapy, on symptoms of depression and anxiety in clinical and general populations compared with pharmacotherapy or placebo. DATA SOURCES: Using the PRISMA guidelines, a systematic literature review of randomized controlled trials was conducted. DATA EXTRACTION: A meta-analysis was conducted to determine treatment effect. Risk of bias was assessed using the Jadad scale. RESULTS: Twenty-three studies were included. Saffron had a large positive effect size when compared with placebo for depressive symptoms (g = 0.99, P < 0.001) and anxiety symptoms (g = 0.95, P < 0.006). Saffron also had a large positive effect size when used as an adjunct to antidepressants for depressive symptoms (g = 1.23, P = 0.028). Egger's regression test found evidence of publication bias. CONCLUSIONS: Saffron could be an effective intervention for symptoms of depression and anxiety; however, due to evidence of publication bias and lack of regional diversity, further trials are required. PROSPERO registration CRD42017070060.