Trial reportEBioMedicine2017
Vitamin D Supplementation in Chronic Schizophrenia Patients Treated with Clozapine: A Randomized, Double-Blind, Placebo-controlled Clinical Trial.
Trial report in EBioMedicine, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 37 papers, 6 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
37 citing papers in PubMed, 6 syntheses or guidelines pooled it, 82 citations in OpenAlex.
- Vitamin D as a Modifiable Risk Factor in Schizophrenia a Systematic Review.Biomolecules · 2025Pooled it
- Nutraceuticals and phytoceuticals in the treatment of schizophrenia: a systematic review and network meta-analysis "Nutra NMA SCZ".Molecular psychiatry · 2025Pooled it
- Severe Vitamin D Deficiency-A Possible Cause of Resistance to Treatment in Psychiatric Pathology.Medicina (Kaunas, Lithuania) · 2023Pooled it
- Effect of vitamin D supplementation on the incidence and prognosis of depression: An updated meta-analysis based on randomized controlled trials.Frontiers in public health · 2022Pooled it
- Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries.The Cochrane database of systematic reviews · 2021 · on this mapPooled it
- Pharmacological Interventions to Treat Antipsychotic-Induced Dyslipidemia in Schizophrenia Patients: A Systematic Review and Meta Analysis.Frontiers in psychiatry · 2021Pooled it
- Effect of Vitamin D Supplementation on Outcomes in People With Early Psychosis: The DFEND Randomized Clinical Trial.JAMA network open · 2021Trial
- Clinical and metabolic response to vitamin D plus probiotic in schizophrenia patients.BMC psychiatry · 2019Trial
- Clinical outcomes of mitochondrial-enhancing nutraceutical supplementation in psychiatric disorders: A systematic review.General psychiatry · 2026Article
- Vitamin D and Vitamin BDiseases (Basel, Switzerland) · 2026Review
- Pharmacological and Mechanistic Interventions for Cognitive Impairment Associated With Schizophrenia: A Review of Registered Clinical Trials.Acta psychiatrica Scandinavica · 2026Review
- Nutritional Management of Schizophrenia: Gut-Brain Axis Mechanisms and Dietary Interventions.Molecular neurobiology · 2026Review
- Clinical practice guidelines for management of schizophrenia in India: A comprehensive overview.Indian journal of psychiatry · 2026Article
- The Etiological Role of Impaired Neurogenesis in Schizophrenia: Interactions with Inflammatory, Microbiome and Hormonal Signaling.International journal of molecular sciences · 2025Review
- Refining antipsychotic treatment strategies in schizophrenia: discovery of genetic biomarkers for enhanced drug response prediction.Molecular psychiatry · 2025Article
- Unlocking the Potential of Vitamin D: A Comprehensive Exploration of Its Role in Neurological Health and Diseases.Biology · 2025Review
- Analysis of clinical studies on clozapine from 2012-2022.Naunyn-Schmiedeberg's archives of pharmacology · 2024Review
- Investigating the Impacts of Diet, Supplementation, Microbiota, Gut-Brain Axis on Schizophrenia: A Narrative Review.Nutrients · 2024Review
- Effectiveness of Vitamin D on Neurological and Mental Disorders.Diseases (Basel, Switzerland) · 2024Review
- The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?Nutrients · 2024Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
16 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundWhile accumulating evidence suggests that vitamin D deficiency may be involved in the risk to develop schizophrenia and its outcome, there are no studies on vitamin D supplementation in this context. We sought to assess the effect of vitamin D supplementation on psychiatric, cognitive and metabolic parameters in chronic clozapine-treated schizophrenia patients.
methodsThis eight-week, randomized, double-blind, placebo-controlled clinical trial, recruited schizophrenia patients who had been maintained on clozapine treatment for at least 18weeks and had low levels of vitamin D (<75nmol/l) and total PANSS scores >70 (to ascertain the presence of residual symptoms). Patients were randomly allocated to either weekly oral drops of vitamin D (14,000IU) or placebo and subsequently assessed at two-week intervals for psychosis severity, mood, cognition and metabolic profile.
resultsTwenty four patients were randomly assigned to vitamin D (aged 39.4±9.6years, 75% males) and the other 23 patients to the placebo arm (aged 42.5±11.2years, 60.9% males). After eight weeks, the vitamin D group exhibited a significant increase in vitamin D levels (31.4 vs -0.4nmol/l, p<0.0001). There was no significant effect of vitamin D on psychotic, depressive or metabolic parameters. However, in the vitamin D group, there was a trend towards improved cognition (effect size=0.17, significance lost following Bonferroni correction).
conclusionsVitamin D supplementation was associated with a trend towards improved cognition, but did not affect psychosis, mood or metabolic status. It is possible that the robust decrease in the PANSS scores in both groups may have obscured an effect of vitamin D supplementation.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.