title: The effects of vitamin and mineral supplementation on symptoms of schizophrenia: a systematic review and meta-analysis.
abstract: BACKGROUND
  When used as an adjunctive with antipsychotics, certain vitamins and minerals may be effective for improving symptomatic outcomes of schizophrenia, by restoring nutritional deficits, reducing oxidative stress, or modulating neurological pathways.
  
  
  METHODS
  We conducted a systematic review of all randomized controlled trials (RCTs) reporting effects of vitamin and/or mineral supplements on psychiatric symptoms in people with schizophrenia. Random-effects meta-analyses were used to calculate the standardized mean difference between nutrient and placebo treatments.
  
  
  RESULTS
  An electronic database search in July 2016 identified 18 eligible RCTs, with outcome data for 832 patients. Pooled effects showed that vitamin B supplementation (including B6, B8 and B12) reduced psychiatric symptoms significantly more than control conditions [g = 0.508, 95% confidence interval (CI) 0.01-1.01, p = 0.047, I 2 = 72.3%]. Similar effects were observed among vitamin B RCTs which used intention-to-treat analyses (g = 0.734, 95% CI 0.00-1.49, p = 0.051). However, no effects of B vitamins were observed in individual domains of positive and negative symptoms (both p > 0.1). Meta-regression analyses showed that shorter illness duration was associated with greater vitamin B effectiveness (p = 0.001). There were no overall effects from antioxidant vitamins, inositol or dietary minerals on psychiatric symptoms.
  
  
  CONCLUSIONS
  There is preliminary evidence that certain vitamin and mineral supplements may reduce psychiatric symptoms in some people with schizophrenia. Further research is needed to examine how the benefits of supplementation relate to nutrient deficits and the impact upon underlying neurobiological pathways, in order to establish optimal nutrient formulations for improving clinical outcomes in this population. Future studies should also explore the effects of combining beneficial nutrients within multi-nutrient formulas.
authors.affiliation: Division of Psychology and Mental Health,University of Manchester,Manchester,UK.
authors.forename: J
authors.initials: J
authors.lastname: Firth
authors.affiliation: Physiotherapy Department,South London and Maudsley NHS Foundation Trust, London,UK.
authors.forename: B
authors.initials: B
authors.lastname: Stubbs
authors.affiliation: Department of Psychiatry,University of Melbourne, The Melbourne Clinic,Melbourne,Australia.
authors.forename: J
authors.initials: J
authors.lastname: Sarris
authors.affiliation: Department of Exercise Physiology,School of Medical Sciences,Faculty of Medicine,University of New South Wales,Sydney,Australia.
authors.forename: S
authors.initials: S
authors.lastname: Rosenbaum
authors.affiliation: Keeping the Body in Mind Program,South Eastern Sydney Local Health District,Sydney,Australia.
authors.forename: S
authors.initials: S
authors.lastname: Teasdale
authors.affiliation: Deakin University, IMPACT Strategic Research Centre, School of Medicine,Victoria,Australia.
authors.forename: M
authors.initials: M
authors.lastname: Berk
authors.affiliation: Division of Psychology and Mental Health,University of Manchester,Manchester,UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Yung
mesh_terms: D019587:Dietary Supplements; D006801:Humans; D012559:Schizophrenia / Q000188:drug therapy*; D014803:Vitamin B Complex / Q000494:pharmacology*
chemical_list: D014803:Vitamin B Complex
keywords: Adjunctive; diet; food; nutrition; psychosis