Vitamin D supplementation in bipolar depression: A double blind placebo controlled trial

Vitamin D in Central Nervous System: Implications for Neurological Disorders

Vitamin D, obtained from diet or synthesized internally as cholecalciferol and ergocalciferol, influences bodily functions through its most active metabolite and the vitamin D receptor. Recent research has uncovered multiple roles for vitamin D in the central nervous system, impacting neural development and maturation, regulating the dopaminergic system, and controlling the synthesis of neural growth factors. This review thoroughly examines these connections and investigates the consequences of vitamin D deficiency in neurological disorders, particularly neurodegenerative diseases. The potential benefits of vitamin D supplementation in alleviating symptoms of these diseases are evaluated alongside a discussion of the controversial findings from previous intervention studies. The importance of interpreting these results cautiously is emphasised. Furthermore, the article proposes that additional randomised and well-designed trials are essential for gaining a deeper understanding of the potential therapeutic advantages of vitamin D supplementation for neurological disorders. Ultimately, this review highlights the critical role of vitamin D in neurological well-being and highlights the need for further research to enhance our understanding of its function in the brain.

Effectiveness of Vitamin D on Neurological and Mental Disorders

(1) Background: Mental disorders are conditions that affect a person's cognition, mood, and behaviour, such as depression, anxiety, bipolar disorder, and schizophrenia. In contrast, neurological disorders are diseases of the brain, spinal cord, and nerves. Such disorders include strokes, epilepsy, Alzheimer's, and Parkinson's. Both mental and neurological disorders pose significant global health challenges, impacting hundreds of millions worldwide. Research suggests that certain vitamins, including vitamin D, may influence the incidence and severity of these disorders; (2) Methods: This systematic review examined the potential effects of vitamin D supplementation on various mental and neurological disorders. Evidence was gathered from databases like PubMed, Cochrane, and Google Scholar, including multiple randomized controlled trials comparing vitamin D supplementation to placebo or no treatment for conditions like depression, bipolar disorder, epilepsy, schizophrenia, and neuroinflammation; (3) Results: The findings strongly indicate that vitamin D supplementation may benefit a range of mental health and neurological disorders. The magnitude of the beneficial impact varied by specific disorder, but the overall pattern strongly supports the therapeutic potential of vitamin D on these disorders; (4) Conclusions: This review provides valuable insight into the role vitamin D may play in the management of critical brain-related health issues.

Nutraceuticals in Psychiatric Disorders: A Systematic Review

Correct nutrition and diet are directly correlated with mental health, functions of the immune system, and gut microbiota composition. Diets with a high content of some nutrients, such as fibers, phytochemicals, and short-chain fatty acids (omega-3 fatty acids), seem to have an anti-inflammatory and protective action on the nervous system. Among nutraceuticals, supplementation of probiotics and omega-3 fatty acids plays a role in improving symptoms of several mental disorders. In this review, we collect data on the efficacy of nutraceuticals in patients with schizophrenia, autism spectrum disorders, major depression, bipolar disorder, and personality disorders. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out the direction for future research.

The effect of vitamin D supplementation on primary depression: A meta-analysis

BACKGROUND

Previous meta-analyses reported inconsistent results on the effect of vitamin D on depression because of different baseline concentrations of 25-hydroxyvitamin D [25(OH)D], highlighting the need for a more accurate subgroup analysis of previously published findings. The goal of the present study was to evaluate the effect of vitamin D supplementation on depression in adults.

METHODS

A systematic search in numerous databases including PubMed, Embase, and Web of Science was performed. Randomized-controlled trials comparing the effect of vitamin D on depression in adults were selected.

RESULTS

Eighteen studies met the inclusion criteria in the retrieved citations. The meta-analysis showed that vitamin D supplementation had a significant effect on overall reduction in depression symptom scores (SMD = -0.15, 95 % CI [-0.26, -0.04]). Sub-group analysis showed that vitamin D supplementation significantly reduced depressive symptom scores in patients with serum 25(OH)D levels higher than 50 nmol/L (SMD = -0.38, 95 % CI [-0.68, -0.08]).

CONCLUSIONS

Vitamin D supplementation has a benefit on improving depressive symptoms in adults with primary depression and 25(OH)D levels higher than 50 nmol/L but has no effect on improving depressive symptoms in adults with primary depression and 25(OH)D levels lower than 50 nmol/L. Relatively high levels of 25(OH)D maybe required for alleviating depression.

LIMITATIONS

The randomized studies included in this study were designed and completed at different times and countries, the variability in duration and dose of vitamin D supplementation may have introduced significant heterogeneity and have militated against observation of the effects of vitamin D supplementation on depression.

Severe Vitamin D Deficiency-A Possible Cause of Resistance to Treatment in Psychiatric Pathology

In the last few years, vitamin D functions have been studied progressively, and along with their main role in regulating calcium homeostasis, the potential function in the nervous system and the link between different psychiatric disorders and vitamin D deficiency have been revealed. The discovery of vitamin D receptors in multiple brain structures, like the hippocampus, led to the hypothesis that vitamin D deficiency could be responsible for treatment resistance in psychiatric diseases. The aim of this study was to analyze the current knowledge in the literature regarding vitamin D deficiency among individuals afflicted with psychiatric disorders and assess the potential therapeutic benefits of vitamin D supplementation. A systematic search was conducted on the PubMed database for articles published in the last five years (2016-2022) in English, focusing on human subjects. Results show that vitamin D deficiency has implications for numerous psychiatric disorders, affecting mood and behavior through its influence on neurotransmitter release, neurotrophic factors, and neuroprotection. It also plays a role in modulating inflammation, which is often elevated in psychiatric disorders. In conclusion, vitamin D deficiency is prevalent and has far-reaching implications for mental health. This review underscores the importance of exploring the therapeutic potential of vitamin D supplementation in individuals with psychiatric disorders and highlights the need for further research in this complex field.

Vitamin D Status in Bipolar Disorder

Vitamin D status may impact acute affective symptomatology and the severity of symptoms in patients with bipolar disorder (BD). Therefore, this cross-sectional study analyzed 25(OH)D, 24,25(OH)2D, and the vitamin D metabolite ratio (VMR) in BD and correlated the results with clinical affective symptomatology and functionality. The inactive precursor 25(OH)D, and its principal catabolite 24,25(OH)2D, were measured simultaneously with a validated liquid chromatography-tandem mass spectrometry method in 170 BD outpatients and 138 healthy controls. VMR was calculated as follows: VMR = 100×(24,25(OH)2D/25(OH)D). The psychometric assessment comprised: Beck Depression Inventory-II, Hamilton Depression Rating Scale, Young Mania Rating Scale, Global Assessment of Functioning, and number of suicide attempts. We did not find a significant difference between patients and controls in the concentrations of 25(OH)D and 24,25(OH)2D. Additionally, the VMR was comparable in both groups. The calculations for the clinical parameters showed a negative correlation between the Young Mania Rating Scale and 24,25(OH)2D (r = -0.154, p = 0.040), as well as the Young Mania Rating Scale and the VMR (r = -0.238, p = 0.015). Based on the small effect size and the predominantly euthymic sample, further exploration in individuals with manic symptoms would be needed to confirm this association. In addition, long-term clinical markers and an assessment in different phases of the disease may provide additional insights.

Non-canonical pathways in the pathophysiology and therapeutics of bipolar disorder

Bipolar disorder (BD) is characterized by extreme mood swings ranging from manic/hypomanic to depressive episodes. The severity, duration, and frequency of these episodes can vary widely between individuals, significantly impacting quality of life. Individuals with BD spend almost half their lives experiencing mood symptoms, especially depression, as well as associated clinical dimensions such as anhedonia, fatigue, suicidality, anxiety, and neurovegetative symptoms. Persistent mood symptoms have been associated with premature mortality, accelerated aging, and elevated prevalence of treatment-resistant depression. Recent efforts have expanded our understanding of the neurobiology of BD and the downstream targets that may help track clinical outcomes and drug development. However, as a polygenic disorder, the neurobiology of BD is complex and involves biological changes in several organelles and downstream targets (pre-, post-, and extra-synaptic), including mitochondrial dysfunction, oxidative stress, altered monoaminergic and glutamatergic systems, lower neurotrophic factor levels, and changes in immune-inflammatory systems. The field has thus moved toward identifying more precise neurobiological targets that, in turn, may help develop personalized approaches and more reliable biomarkers for treatment prediction. Diverse pharmacological and non-pharmacological approaches targeting neurobiological pathways other than neurotransmission have also been tested in mood disorders. This article reviews different neurobiological targets and pathophysiological findings in non-canonical pathways in BD that may offer opportunities to support drug development and identify new, clinically relevant biological mechanisms. These include: neuroinflammation; mitochondrial function; calcium channels; oxidative stress; the glycogen synthase kinase-3 (GSK3) pathway; protein kinase C (PKC); brain-derived neurotrophic factor (BDNF); histone deacetylase (HDAC); and the purinergic signaling pathway.

Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder

BACKGROUND

Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.

METHODS

Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001.

RESULTS

The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.

CONCLUSION

UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.

Identifying potential risk genes and pathways for neuropsychiatric and substance use disorders using intermediate molecular mediator information

Neuropsychiatric and substance use disorders (NPSUDs) have a complex etiology that includes environmental and polygenic risk factors with significant cross-trait genetic correlations. Genome-wide association studies (GWAS) of NPSUDs yield numerous association signals. However, for most of these regions, we do not yet have a firm understanding of either the specific risk variants or the effects of these variants. Post-GWAS methods allow researchers to use GWAS summary statistics and molecular mediators (transcript, protein, and methylation abundances) infer the effect of these mediators on risk for disorders. One group of post-GWAS approaches is commonly referred to as transcriptome/proteome/methylome-wide association studies, which are abbreviated as T/P/MWAS (or collectively as XWAS). Since these approaches use biological mediators, the multiple testing burden is reduced to the number of genes (∼20,000) instead of millions of GWAS SNPs, which leads to increased signal detection. In this work, our aim is to uncover likely risk genes for NPSUDs by performing XWAS analyses in two tissues-blood and brain. First, to identify putative causal risk genes, we performed an XWAS using the Summary-data-based Mendelian randomization, which uses GWAS summary statistics, reference xQTL data, and a reference LD panel. Second, given the large comorbidities among NPSUDs and the shared cis-xQTLs between blood and the brain, we improved XWAS signal detection for underpowered analyses by performing joint concordance analyses between XWAS results i) across the two tissues and ii) across NPSUDs. All XWAS signals i) were adjusted for heterogeneity in dependent instruments (HEIDI) (non-causality) p-values and ii) used to test for pathway enrichment. The results suggest that there were widely shared gene/protein signals within the major histocompatibility complex region on chromosome 6 (BTN3A2 and C4A) and elsewhere in the genome (FURIN, NEK4, RERE, and ZDHHC5). The identification of putative molecular genes and pathways underlying risk may offer new targets for therapeutic development. Our study revealed an enrichment of XWAS signals in vitamin D and omega-3 gene sets. So, including vitamin D and omega-3 in treatment plans may have a modest but beneficial effect on patients with bipolar disorder.

Decreased Levels of Vitamin D in Bipolar Patients

Recently, vitamin D is considered a pleiotropic hormone, and as such, it has also become a topic of renewed interest in neuropsychiatry for its proposed role in the aetiology and pathophysiology of different psychiatric conditions, including mood disorders (MDs). This seems particularly crucial while considering the relatively high and often neglected prevalence of hypovitaminosis D in the general population and in specific groups, such as patients suffering from the most common type of MDs, which are major depression (MDD) and bipolar disorders (BDs). Therefore, in view of the controversial literature and findings on this topic and its potential therapeutic implications, the present study aimed at evaluating vitamin D levels in the plasma of a sample of inpatients fulfilling the DSM-5 criteria for mood episodes within BDs. The clinical picture was assessed by means of specific rating scales. The results showed that the vitamin D levels (mean ± SD, nM/L) of the bipolar patients of our sample were significantly lower (14.58 ± 11.27 nmol/L) than the normative values (>30 nmol/L). Eleven patients had sufficient values and only 4 had optimal, while 19 showed insufficient, 18 critical, and 17 severely critical levels. No differences emerged according to different socio-demographic or clinical features. In our opinion, the present findings strengthen previous research highlighting decreased vitamin D levels in bipolar patients and support the role of this pleiotropic hormone in BDs. Nevertheless, further studies should follow to corroborate the data of this preliminary study and to address the potential benefits of vitamin D supplementation in the treatment of MDs.

The Role of Diet as a Modulator of the Inflammatory Process in the Neurological Diseases

Neurological diseases are recognized as major causes of disability and mortality worldwide. Due to the dynamic progress of diseases such as Alzheimer’s disease (AD), Parkinson’s Disease (PD), Schizophrenia, Depression, and Multiple Sclerosis (MD), scientists are mobilized to look for new and more effective methods of interventions. A growing body of evidence suggests that inflammatory processes and an imbalance in the composition and function of the gut microbiome, which play a critical role in the pathogenesis of various neurological diseases and dietary interventions, such as the Mediterranean diet the DASH diet, or the ketogenic diet can have beneficial effects on their course. The aim of this review was to take a closer look at the role of diet and its ingredients in modulating inflammation associated with the development and/or progression of central nervous system diseases. Presented data shows that consuming a diet abundant in fruits, vegetables, nuts, herbs, spices, and legumes that are sources of anti-inflammatory elements such as omega-3 fatty acids, polyphenols, vitamins, essential minerals, and probiotics while avoiding foods that promote inflammation, create a positive brain environment and is associated with a reduced risk of neurological diseases. Personalized nutritional interventions may constitute a non-invasive and effective strategy in combating neurological disorders.

Alternations of vitamin D and cognitive function in first-diagnosed and drug-naïve BD patients: Physical activity as a moderator

BACKGROUND

The pathophysiological mechanism of cognitive impairments of bipolar disorder (BD) has not yet been completely revealed. It is well known that Vitamin D and physical activity (PA) are associated with BD. However, specific links between Vitamin D and cognitive deficits in BD are still unclear.

METHOD

The serum levels of vitamin D were measured. The cognitive performances of 102 first-diagnosed and drug-naïve BD patients were evaluated for analysis. The repeatable battery for the assessment of neuropsychological status (RBANS) and the Stroop Color-Word test was used in this study. PA was collected by international physical activity questionnaire.

RESULT

Patients with BD had high levels of serum vitamin D. Furthermore, immediate and delayed memory was negatively associated with vitamin D levels in patients' group. The serum levels of vitamin D in patients with low PA were positively associated with memory. However, increased PA attenuated the protective effect of vitamin D on executive cognition.

CONCLUSION

It is concluded that the increased levels of vitamin D were observed in the serum of patients with BD. Thus, it is found that more PA is less beneficial to cognition of patients with BD than longer resting.

Effect of Vitamin D Supplementation on Depression in Adults: A Systematic Review of Randomized Controlled Trials (RCTs)

Vitamin D is a nutrient potentially beneficial in the treatment of depression. The study aimed to carry out a systematic review of the studies assessing the influence of vitamin D supplementation on depression within Randomized Controlled Trials (RCTs). The systematic review was prepared on the basis of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020155779). The peer-reviewed studies available within PubMed or Web of Science databases until September 2021 were taken into account. The number of screened records was 8514, and 8 records were included. Two independent researchers conducted screening, including, reporting, and risk of bias assessment using the revised Cochrane risk-of-bias tool for randomized trials. The included studies presented a population of patients with major depressive disorders or general depression, as well as bipolar depression or postpartum depression. The majority of included studies were conducted for 8 weeks or 12 weeks, while one study was conducted for 6 months. Within the large number of included studies, a daily dose of 1500 IU, 1600 IU, or 2800 IU was applied, while within some studies, a vitamin D dose of 50,000 IU was applied weekly or biweekly. Among applied psychological measures of depression, there were various tools. In spite of the fact that the majority of included studies (five studies) supported the positive effect of vitamin D supplementation for the psychological measure of depression, for three studies the positive influence was not supported. A medium risk of bias was indicated for six studies, while a high risk of bias was defined for only two studies, due to deviations from the intended interventions and in measurement of the outcome, as well as for one study, also arising from the randomization process and due to missing outcome data. Based on conducted assessment, it should be emphasized that there are only four studies supporting the positive influence of vitamin D supplementation for the psychological measure of depression of the medium risk of bias, while two studies of a medium risk of bias did not support it. Taking this into account, the conducted systematic review is not a strong confirmation of the effectiveness of vitamin D supplementation in the treatment of depression.

A preliminary investigation of the clinical and cognitive correlates of circulating vitamin D in bipolar disorder

The role that vitamin D plays in the cognitive and clinical characteristics of bipolar disorder (BD) is unclear. We examined differences in the levels and deficiency status of vitamin D in an Australian sample of BD patients compared to healthy controls; and determined the extent to which vitamin D is associated with clinical variables and cognitive function in the sample. 22 healthy controls and 55 stable outpatients with a diagnosis of BD and low-grade mood symptomatology provided a sample of blood and completed cognitive tests and clinical measures. Plasma concentrations of 25-hydroxyvitamin D (vitamin D) were assayed and used to segregate participants into subgroups with sufficient or deficient levels of vitamin D. Subgroups were then compared in terms of global cognition and a range of sociodemographic and clinical factors (number of past mood episodes, illness duration, seasonal mood pattern, mood symptom severity), while mean levels of vitamin D were compared between patients and controls. Although almost 27% of the current sample were vitamin D deficient, no significant differences in mean vitamin D levels or the prevalence of vitamin D deficiency were evident between BD patients and controls. Vitamin D was not associated with global cognition in either patients or controls, nor any of the clinical measures assessed in the study. In conclusion, we observed no difference in the vitamin D levels and deficiency status of an Australian sample of healthy individuals and BD patients with low grade mood symptomatology compared to controls. Clinical symptoms and global cognition also appear to be independent of vitamin D levels in BD.

The association between vitamin D serum levels, supplementation, and suicide attempts and intentional self-harm

OBJECTIVES

The purpose of this study is to determine the associations between Vitamin D supplementation, 25(OH) blood serum levels, suicide attempts, and intentional self-harm in a population of veterans in the Department of Veterans Affairs (VA).

METHODS

A retrospective cohort study of US Veterans supplemented with Vitamin D. Veterans with any Vitamin D3 (cholecalciferol) or Vitamin D2 (ergocalciferol) fill between 2010 and 2018 were matched 1:1 to untreated control veterans having similar demographics and medical histories. Cox proportional hazards regression was used to estimate the time from the first Vitamin D3 (cholecalciferol) or Vitamin D2 (ergocalciferol) prescription fill to the first suicide attempt or intentional self-harm. Analyses were repeated in stratified samples to measure associations by race (Black or White), gender (male or female), blood levels (0-19 ng/ml, 20-39 ng/ml, and 40+ ng/ml), and average daily dosage.

RESULTS

Vitamin D3 and D2 supplementation were associated with a 45% and 48% lower risk of suicide attempt and self-harm ((D2 Hazard Ratio (HR) = 0.512, [95% CI, 0.457, 0.574]; D3 HR = 0.552, [95% CI, 0.511, 0.597])). Supplemented black veterans and veterans with 0-19 ng/ml vitamin D serum levels were at ~64% lower risk relative to controls (Black Veteran HR: 0.362 [95% CI: 0.298,0.440]; 0-19 ng/ml HR: 0.359 [95% CI: 0.215,0.598]). Supplementation with higher vitamin D dosages was associated with greater risk reductions than lower dosages (Log Average Dosage HR: 0.837 [95% CI: 0.779,0.900]).

CONCLUSIONS

Vitamin D supplementation was associated with a reduced risk of suicide attempt and self-harm in Veterans, especially in veterans with low blood serum levels and Black veterans.

The interactions between vitamin D and neurofilament light chain levels on cognitive domains in bipolar disorder

BACKGROUND

Bipolar disorder is a chronic mental disorder related to cognitive deficits. Low serum vitamin D levels are significantly associated with compromised cognition in neuropsychiatric disorders. Although patients with bipolar disorder frequently exhibit hypovitaminosis D, the association between vitamin D and cognition in bipolar disorder, and their neuroaxonal integrity, is unclear.

AIMS

To investigate the interaction effects between vitamin D and neurofilament light chain (NfL) levels on cognitive domains in bipolar disorder.

METHOD

Serum vitamin D and NfL levels were determined in 100 euthymic patients with bipolar disorder in a cross-sectional study. Cognitive function was measured with the Brief Assessment of Cognition in Affective Disorders. We stratified by age groups and used general linear models to identify associations between vitamin D and NfL levels and their interaction effects on cognitive domains.

RESULTS

The mean vitamin D and NfL levels were 16.46 ng/nL and 11.10 pg/mL, respectively; 72% of patients were vitamin D deficient. In the older group, more frequent hospital admissions and lower physical activity were identified in the group with versus without vitamin D deficiency. The age-modified interaction effect of vitamin D and NfL was associated with composite neurocognitive scores and verbal fluency in both age groups, and with processing speed domain in the younger group.

CONCLUSIONS

We observed a high vitamin D deficiency prevalence in bipolar disorder. We identified the interaction of vitamin D and NfL on cognitive domains, and the effect was modified by age. Longitudinal or randomised controlled studies enrolling patients with various illness durations and mood statuses are required to validate our findings.

Effect of vitamin D supplementation on the incidence and prognosis of depression: An updated meta-analysis based on randomized controlled trials

Background

There have been several controversies about the correlation between vitamin D and depression. This study aimed to investigate the relationship between vitamin D supplementation and the incidence and prognosis of depression and to analyze the latent effects of subgroups including population and supplement strategy.

Methods

A systematic search for articles before July 2021 in databases (PubMed, EMBASE, Web of Science, and the Cochrane Library) was conducted to investigate the effect of vitamin D supplementation on the incidence and prognosis of depression.

Results

This meta-analysis included 29 studies with 4,504 participants, indicating that the use of vitamin D was beneficial to a decline in the incidence of depression (SMD: −0.23) and improvement of depression treatment (SMD: −0.92). Subgroup analysis revealed that people with low vitamin D levels (<50 nmol/L) and females could notably benefit from vitamin D in both prevention and treatment of depression. The effects of vitamin D with a daily supplementary dose of >2,800 IU and intervention duration of ≥8 weeks were considered significant in both prevention and treatment analyses. Intervention duration ≤8 weeks was recognized as effective in the treatment group.

Conclusion

Our results demonstrate that vitamin D has a beneficial impact on both the incidence and the prognosis of depression. Whether suffering from depression or not, individuals with low vitamin D levels, dose >2,800 IU, intervention duration ≥8 weeks, and all females are most likely to benefit from vitamin D supplementation.

Nutrition and bipolar disorder: a systematic review

INTRODUCTION

Individuals with bipolar disorder (BD) have higher rates of unhealthy lifestyles and risk for medical comorbidities Research currently suggests that dietary factors may play a role in the development of depression and anxiety. Therefore, nutritional approaches are potential strategies for the treatment of BD. The aim of this review is to summarize the available evidence on nutrition and BD.

MATERIALS AND METHODS

The paper was developed based on PRISMA 2020 guidelines. The search was conducted in Sep-2021 using PubMed and Cochrane Library, augmented by manually checked references lists. The search found 986 studies, of which 47 were included, combined with 13 from reference lists, totaling 60 studies.

RESULTS

There were 33 observational trials, of which 15 focused on fatty acids, 9 on micronutrients, 5 on specific foods, 4 on macro and micronutrients. The 27 interventional studies mainly focused on fatty acids, micronutrients and N-acetylcysteine (NAC).

DISCUSSION

Dietary intake or supplementation of unsaturated fatty acids, mainly Omega-3 seems to be associated with improved BD symptoms, along with seafood, folic acid and zinc. Studies found variable, mainly non-significant impacts of creatine, carnitine, vitamin D, inositol or NAC supplementation on BD. There are promising results associated with Coenzyme Q10 (Coq10) and probiotics. Taken together, these preliminary findings suggest that dietetic approaches might be included as part of BD treatment. Also considering the high risk of metabolic disorders in individuals with BD, they should be encouraged to choose healthy dietary lifestyles, including daily intake of fruits, vegetables, seafood and whole grains.

Therapeutic Interventions to Mitigate Mitochondrial Dysfunction and Oxidative Stress–Induced Damage in Patients with Bipolar Disorder

Bipolar disorder (BD) is characterized by mood changes, including recurrent manic, hypomanic, and depressive episodes, which may involve mixed symptoms. Despite the progress in neurobiological research, the pathophysiology of BD has not been extensively described to date. Progress in the understanding of the neurobiology driving BD could help facilitate the discovery of therapeutic targets and biomarkers for its early detection. Oxidative stress (OS), which damages biomolecules and causes mitochondrial and dopamine system dysfunctions, is a persistent finding in patients with BD. Inflammation and immune dysfunction might also play a role in BD pathophysiology. Specific nutrient supplements (nutraceuticals) may target neurobiological pathways suggested to be perturbed in BD, such as inflammation, mitochondrial dysfunction, and OS. Consequently, nutraceuticals may be used in the adjunctive treatment of BD. This paper summarizes the possible roles of OS, mitochondrial dysfunction, and immune system dysregulation in the onset of BD. It then discusses OS-mitigating strategies that may serve as therapeutic interventions for BD. It also analyzes the relationship between diet and BD as well as the use of nutritional interventions in the treatment of BD. In addition, it addresses the use of lithium therapy; novel antipsychotic agents, including clozapine, olanzapine, risperidone, cariprazine, and quetiapine; and anti-inflammatory agents to treat BD. Furthermore, it reviews the efficacy of the most used therapies for BD, such as cognitive–behavioral therapy, bright light therapy, imagery-focused cognitive therapy, and electroconvulsive therapy. A better understanding of the roles of OS, mitochondrial dysfunction, and inflammation in the pathogenesis of bipolar disorder, along with a stronger elucidation of the therapeutic functions of antioxidants, antipsychotics, anti-inflammatory agents, lithium therapy, and light therapies, may lead to improved strategies for the treatment and prevention of bipolar disorder.

Mitochondrial modulators in the treatment of bipolar depression: a systematic review and meta-analysis

Mitochondrial dysfunction has been implicated in the risk, pathophysiology, and progression of mood disorders, especially bipolar disorder (BD). Thus, the objective of this meta-analysis was to determine the overall antidepressant effect of mitochondrial modulators in the treatment of bipolar depression. Outcomes included improvement in depression scale scores, Young Mania Rating Scale (YMRS) and Clinical Global Impression-Severity Scale (CGI-S) score. Data from randomized controlled trials (RCTs) assessing the antidepressant effect of diverse mitochondrial modulators were pooled to determine standard mean differences (SMDs) compared with placebo.13 RCTs were identified for qualitative review. The overall effect size of mitochondrial modulators on depressive symptoms was -0.48 (95% CI: -0.83 to -0.14, p = 0.007, I² = 75%), indicative of a statistically significant moderate antidepressant effect. In the subgroup analysis, NAC improved depressive symptoms compared with placebo (-0.88, 95% CI: -1.48 to -0.27, I² = 81%). In addition, there was no statistical difference between mitochondrial modulators and placebo in YMRS. Although mitochondrial modulators were superior to placebo in CGI-S score (-0.44, 95% CI: -0.83 to -0.06, I² = 71%), only EPA was superior to placebo in subgroup analysis. Overall, a moderate antidepressant effect was observed for mitochondrial modulators compared with placebo in the treatment of bipolar depression. The small number of studies, diversity of agents, and small sample sizes limited interpretation of the current analysis.

Comparative efficacy of mitochondrial agents for bipolar disorder during depressive episodes: a network meta-analysis using frequentist and Bayesian approaches

RATIONALE

Mitochondrial dysfunctions have emerged as new biological hypothesis and therapeutic target for bipolar disorder. This network meta-analysis has been done to evaluate the comparative efficacy of mitochondrial agents in bipolar depression.

METHODS

After a comprehensive literature search on PubMed/MEDLINE, Cochrane databases, and International Trials Registry Platform, efficacy data were extracted from 15 randomized controlled trials. Random-effects meta-analysis was done following both frequentist and Bayesian approaches to pool the effects across the interventions. A network graph was built, relative effects of interventions in respect to one another and placebo were calculated, and treatments were ranked as per P- and SUCRA scores. Change in depression rating score was the primary outcome. Data was entered in contrast level and arm level for frequentist and Bayesian approaches, respectively.

RESULTS

Amongst mitochondrial agents, N-acetylcysteine (NAC) was shown to have the highest probability of being the best treatment, followed by coenzyme Q10 and combination therapy of alpha-lipoic acid (ALA) and acetyl-L-carnitine (ALCAR) as depicted by P- and SUCRA scores. In the Bayesian approach, none of the treatments had better efficacy than placebo, but in the frequentist approach, NAC (effect estimate: - 1.18 (95% CI: - 2.05; - 0.31)) was significantly better than placebo.

CONCLUSION

Methodically, there may be a difference of magnitude in frequentist and Bayesian approaches, but the direction of effect and ranking probabilities do not differ. We conclude that none of the existing mitochondrial agents showed better efficacy than placebo in bipolar depression regarding depression rating scores.

Effect of omega-3 and vitamin D co-supplementation on psychological distress in reproductive-aged women with pre-diabetes and hypovitaminosis D: A randomized controlled trial

PURPOSE

Psychological distresses and pre-diabetes are among the risk factors of developing type-II diabetes. The present study was conducted to determine the effectiveness of omega-3 and vitamin D co-supplementation on psychological distresses in women of reproductive age with pre-diabetes and hypovitaminosis D.

METHODS

The present factorial clinical trial was conducted on 168 women of reproductive age with pre-diabetes and hypovitaminosis D. These participants were selected by stratified random sampling and were assigned to four groups for 8 weeks: group 1 (placebo group), group 2 (omega-3 group), group 3 (vitamin D group), and group 4 (co-supplement group). The medication and placebo doses being two 1000-mg tablets each day for omega-3 and 50,000-IU pearls every 2 weeks for vitamin D. Fasting blood glucose and vitamin D were measured at the beginning of the study. The Depression Anxiety Stress Scale-21 and the Pittsburgh Sleep Quality Index were completed by the participants at the start and end of the intervention.

RESULTS

A significant difference was observed in terms of reduction in anxiety and improvement in sleep quality in the co-supplementation compared to the other three groups (p < .05). There was also a significant difference between the group receiving both supplements and the group receiving only placebos in terms of reduction in depression and stress (p < .05).

CONCLUSION

Vitamin D and omega-3 co-supplementation improved depression, anxiety, and sleep quality in women of reproductive age with pre-diabetes and hypovitaminosis D. Therefore, these two supplements can be recommended for improving the mental health of this group of women.

CLINICAL TRIAL REGISTRY

Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on February 9, 2019.

Adverse health outcomes in vitamin D supplementation trials for depression: A systematic review

BACKGROUND

Vitamin D deficiency is a universal risk factor for adverse health outcomes. Since depression is consistently associated with low vitamin D levels as well as several adverse health outcomes, vitamin D supplementation may be especially relevant for depressed persons. This review examines the potential benefits of vitamin D for (somatic) health outcomes in randomised controlled supplementation trials for depression.

METHOD

Systematic literature search to assess whether adverse health outcomes, such as frailty, falls, or cognitive functioning, were included in vitamin D supplementation trials for depression, and whether these outcomes were affected by supplementation. The revised Cochrane tool for assessing risk of bias in randomised trials was used.

RESULTS

Thirty-one trials were included. Adverse health outcomes were considered in five studies. Two studies reported some beneficial effect on an adverse health outcome.

CONCLUSIONS AND IMPLICATIONS

While depressed persons are at increased risk of vitamin D deficiency, supplementation trials hardly addressed the common negative health consequences of low vitamin D levels as secondary outcome measures. Well-designed trials of the effects of vitamin D supplementation in late-life depression should explore whether adverse health outcomes can be prevented or stabilised, and whether depression benefits from this improvement.

Vitamin D: A Pleiotropic Hormone with Possible Psychotropic Activities

BACKGROUND

After the recognition of the efficacy of cod-liver oil in rickets at the end of the eighteenth century, and the isolation and synthesis of the liposoluble vitamin D in 1931, its mode of actions and functions were deeply explored. Biochemical studies permitted to identify five forms of vitamin D, called D1, D2, D3, D4 and D5, differing in ultrastructural conformation and origin, with vitamin D2 (ergocalciferol) and D3 (cholecalciferol) representing the active forms. In the last decades especially, a constantly increasing bulk of data highlighted how vitamin D could regulate several activities and processes.

AIMS

The aim of the present paper was to review and comment on the literature on vitamin D, with a focus on its possible role in the pathophysiology of neuropsychiatric disorders.

DISCUSSION

Available literature indicates that vitamin D regulates a variety of processes in humans and in the central nervous system. Vitamin D deficiency is associated with an enhanced pro-inflammatory state, and formation of Aβ oligomers that might contribute to the cognitive decline typical of the elderly age and, perhaps, dementia. More in general, vitamin D is supposed to play a crucial role in neuroinflammation processes that are currently hypothesized to be involved in the pathophysiology of different psychiatric disorders, such as major depression, bipolar disorders, obsessive-compulsive disorders and psychosis.

CONCLUSION

It is conceivable that vitamin D supplementation might pave the way towards "natural" treatments of a broad range of neuropsychiatric disorders, or at least be useful to boost response to psychotropic drugs in resistant cases.

Advances in the psychopharmacotherapy of bipolar disorder type I

INTRODUCTION

Research into the pharmacologic management of bipolar type I illness continues to progress.

AREAS COVERED

Randomized clinical trials performed with type I bipolar disorder in the years 2015 to August 2020 are reviewed. There are new indications for the use of cariprazine, for bipolar mania and depression, and a long-acting injectable formulation of aripiprazole has also been approved for relapse prevention in bipolar illness. Most of the randomized clinical trials are effectiveness studies.

EXPERT OPINION

Over the 20 years from 1997 through 2016, the use of lithium and other mood stabilizers has declined by 50%, while the use of both second-generation antipsychotics (SGAs) and antidepressants has increased considerably. Over the same time period (1990-2017), disability-adjusted life years (DALYs) increased by 54.4%, from 6.02 million in 1990 to 9.29 million in 2017 which is greater than the 47.74% increase in incidence of the disease, suggesting that the changes in prescribing patterns have not been helpful for our patients. Furthermore, recent effectiveness studies continue to confirm the superiority of lithium and other mood stabilizers in the management of bipolar illness for both psychiatric and medical outcomes, reaffirming their role as foundational treatments in the management of type I bipolar disorder. Clinicians need to reassess their prescribing habits.

A Systematic Review of Nutraceuticals for the Treatment of Bipolar Disorder

BACKGROUND

Certain nutrient supplements (nutraceuticals) may target neurobiological pathways perturbed in bipolar disorder (BD) such as inflammation, oxidative stress, and mitochondrial dysfunction. Nutraceuticals thus may have a potential role as adjunctive treatments for BD.

METHODS

A search of Embase via embase.com, PubMed via PubMed, Cumulated index to nursing and allied health literature (CINAHL) Complete via EBSCO, and Cochrane Central Register of Controlled Clinical Trials via cochranelibrary.com was conducted to identify published randomized controlled trials assessing the efficacy of nutraceuticals on mood symptomatology in adults with BD. Search terms for BD, nutraceuticals, and clinical trials (total search terms = 75) were used to search from inception to February 20, 2020. The Cochrane Collaboration's tool for assessing the risk of bias in randomized trials was used to assess the risk of bias.

RESULTS

A total of 1,712 studies were identified through the search. After rigorous screening, 22 studies were included in the review. There was large variability across the studies with 15 different nutraceutical agents assessed and as such insufficient homogeneity for a meta-analysis to be conducted (I² > 50%). Studies revealed promising, albeit conflicting, evidence for omega-3 fatty acids and N-acetylcysteine. Isolated positive results were reported for coenzyme Q10.

CONCLUSION

Given nutraceuticals are tolerable and accessible, they may be useful as potential adjunctive treatments for BD. Nutraceuticals targeting neuroinflammation or mitochondrial activity may have the most potential for the depressive phase. However, further studies are required to determine efficacy.

The role of vitamin D in bipolar disorder: Epidemiology and influence on disease activity

BACKGROUND

Although many studies found an association between psychiatric disorders, especially major depressive disorder, and vitamin D deficiency, little is still known about the association between vitamin D and bipolar disorder (BD). Therefore, the present review aims at providing an overview of the available literature exploring the role of vitamin D in BD patients in different phases of the disease.

METHODS

From a bibliographic research in PubMed until April 2020, we collected ten original studies that fulfilled our inclusion criteria.

RESULTS

No significant differences in vitamin D levels between BD patients and other psychiatric disorders were found by most of the studies. In the majority of the studies, the average values of vitamin D in BD population were sub-threshold for vitamin D deficiency. Moreover, although an association between vitamin D levels and clinical symptomatology was observed in BD patients, it cannot be considered a specific marker of this disorder but a common characteristic shared with other psychiatric disorders, including schizophrenia and major depressive disorder. Finally, vitamin D supplementation was associated with a reduction in both depressive and manic symptoms.

LIMITATIONS

Few studies with small and heterogeneous populations. Methodological heterogeneity in terms of vitamin D measurement and threshold.

CONCLUSIONS

The results showed that vitamin D status does not differ between BD and other psychiatric conditions. However, given the correlation between vitamin D levels and depressive or manic symptoms, we could hypothesize that an adequate vitamin D status could positively affect the mood balance thanks to its immunomodulatory activity.

Depression, Metabolic Syndrome, Serum TSH, and Vitamin D Concentrations in Rural and Urban Postmenopausal Women

Background and objectives: Depression is a serious problem affecting people worldwide, however it more commonly concerns women. Depression reduces the quality of life and, in many cases, leads to suicide. Numerous new biological factors have been demonstrated to have an impact on the pathogenesis of depression, including vitamin D, thyroid hormones, as well as factors related to heart disease. The aim of the study was to assess the impact of serum thyroid stimulating hormone (TSH) and vitamin D concentrations as well as metabolic syndrome on the severity of depression in Polish postmenopausal women from urban and rural areas. Materials and Methods: The study was conducted in 2018–2019 in the Lublin region, Poland, and comprised 396 postmenopausal women (239 living in rural areas and 157 living in urban areas). Metabolic syndrome criteria according to the International Diabetes Federation and Beck Depression Inventory were used, and laboratory blood tests were performed. Results: A significantly higher percentage of the examined rural residents had moderate or severe depression in comparison to the urban ones (p = 0.049). The examined women from rural areas had a significantly higher serum vitamin D concentration in comparison to the urban ones (p < 0.001). The rural residents more commonly had below-normal levels of serum TSH and less commonly had normal levels in comparison to the urban residents. Metabolic syndrome was found in 70% of the rural residents, and that number was significantly lower in the urban ones (22%, p < 0.001). Conclusions: The severity of depression in postmenopausal Polish women was correlated negatively with the serum TSH concentration in women from rural areas. The severity of depression was increased in urban postmenopausal women with hypertension. No correlation of the depression severity with the serum vitamin D concentration or other criteria of metabolic syndrome was found.

Nutrition interventions in populations with mental health conditions: a scoping review

Nutrition is a modifiable factor for intervention in mental disorders. This scoping review characterized nutrition intervention research in mental disorders. A 3-category framework characterized nutrition interventions: Guide (e.g., counselling), Provide (e.g., food provisions), and Add (e.g., supplementation). Nutrition interventions were classified as single-component (e.g., Guide) or complex (e.g., Guide-Provide). Sixty-nine trials met inclusion criteria, 96% were randomized controlled trials. Most commonly diagnosed mental disorders were depressive disorder (i.e., persistent) or major depressive disorder (n = 39), schizophrenia (n = 17), and other psychotic disorders (n = 13). Few trials included patients with anxiety disorders (n = 2) or bipolar disorders (n = 3). Several trials (n = 15, 22%) assessed and implemented nutrition interventions to improve dietary patterns, of which 11 (73%) reported statistically significant and clinically important positive effects of nutrition interventions on mental disorders. The majority of the trials (n = 61, 90%) investigated supplementation, most commonly adding essential fatty acids, vitamins, or minerals. The majority (n = 48, 70%) reported either statistically significant or clinically important effect and 31 (51%) reported both. Though most interventions led to statistically significant improvements, trials were heterogeneous for targeted mental disorders, nutrition interventions, and outcomes assessed. Given considerable heterogeneity, further research from robust and clinically relevant trials is required to support high-quality health care with effective nutrition interventions. Novelty Future research on whole-diet interventions powered to detect changes in mental health outcomes as primary objectives is needed. Dietitians may be an opportunity to improve feasibility and efficacy of nutrition interventions for mental disorder patients. Dietitians may be of value to educate mental health practitioners on the importance of nutrition.

The effect of vitamin D supplement on negative emotions: A systematic review and meta-analysis

BACKGROUND

The several meta-analyses of the effect of vitamin D on depression have produced inconsistent results and studies dealing with anxiety were not incorporated. There has been no comprehensive analysis of how results are affected by the nature of the sample or the dosage and duration of supplementation. The study is aimed to investigate whether vitamin D supplementation reduces negative emotions and to analyze the possible influence of sample and regimen.

METHOD

We conducted a systematic review and meta-analysis of randomized controlled trials comparing the effect of vitamin D and placebo on negative emotion. Databases were searched for relevant articles published before February 2019.

RESULTS

The analysis covered 25 trials with a total of 7,534 participants and revealed an effect of vitamin D on negative emotion (Hedges' g = -0.4990, 95% CI [-0.8453, -0.1528], p = .0047, I²  = 97.7%). Subgroup analysis showed that vitamin D had an effect on patients with major depressive disorder and on subjects with serum 25(OH)D levels ≤50 nmol/L. The pooled data from trials of vitamin D supplementation lasting ≥8 weeks and dosage ≤4,000 IU/day indicated that vitamin D had an effect.

CONCLUSIONS

Our results support the hypothesis that vitamin D supplementation can reduce negative emotions. Patients with major depressive disorder and individuals with vitamin D deficiency are most likely to benefit from supplementation. But to interpret the results with high heterogeneity should still be cautious.

Targeting Mitochondrial Dysfunction for Bipolar Disorder

People with bipolar disorder (BD) all too often have suboptimal long-term outcomes with existing treatment options. They experience relapsing episodes of depression and mania and also have interepisodic mood and anxiety symptoms. We need to have a better understanding of the pathophysiology of BD if we are to make progress in improving these outcomes. This chapter will focus on the critical role of mitochondria in human functioning, oxidative stress, and the biological mechanisms of mitochondria in BD. Additionally, this chapter will present the evidence that, at least for some people, BD is a product of mitochondrial dysregulation. We review the modulators of mitochondria, the connection between current BD medication treatments and mitochondria, and additional medications that have theoretical potential to treat BD.

Nutrient and genetic biomarkers of nutraceutical treatment response in mood and psychotic disorders: a systematic review

Objective: Nutrient and genetic biomarkers in nutraceutical trials may allow for the personalisation of nutraceutical treatment and assist in predicting treatment response. We aimed to synthesise the findings of trials which have included these biomarkers to determine which may be most useful for predicting nutraceutical response in mood and psychotic disorders.Methods: A systematic review was conducted assessing available literature concerning nutraceutical clinical trials in mood and psychotic disorders (major depression, bipolar disorder, schizophrenia) with baseline and endpoint blood nutrient markers or genetic data available.Results: We identified 35 eligible studies (total n = 3836 participants) examining baseline and endpoint nutrient biomarkers and/or genetic polymorphisms. The key result, as reported in 10 out of 11 omega-3 studies, was a strong association between polyunsaturated fatty acid concentrations (mostly EPA and DHA) and psychiatric outcomes, although the exact nature of the association varied between studies and diagnoses. There was no consistent evidence for levels of other nutrients (including Vitamin D, SAM/SAH ratios, carnitine, folate and vitamin B12) relating to treatment response. The evidence for associations between one-carbon cycle genotypes (e.g. MTHFR C677 T, MTR and FOLH1) and treatment response was also inconsistent.Discussion: The available data tentatively supports omega-3 indices as biomarkers of response to omega-3 treatments in mood disorders. Further research with larger samples examining combinations of polymorphisms is required to determine if any genetic factors influence nutraceutical response in mood and psychotic disorders.

The effect of adjunctive nutraceuticals in bipolar disorder: A systematic review of randomized placebo-controlled trials

BACKGROUND

Nutraceuticals are a group of compounds of growing interest for mental health professionals. Given the implication of certain nutrients in the onset of bipolar disorder, it has been hypothesized that nutraceuticals might be effective in improving symptoms of the condition (i.e. mania or depression). Our systematic review aimed to evaluate the effectiveness of adjunctive nutraceuticals compared to placebo.

METHODS

We searched the following databases from inception to February 2019: Web of Science, CINAHL, Embase, and PsycINFO. We included only original randomized controlled trials written in English, testing the efficacy of nutraceuticals in add-on to standard care, compared to placebo, in patients with bipolar disorder.

RESULTS

After identifying 6584 potentially relevant publications, we finally included 25 studies, among which six used fatty acids, seven micronutrients, seven amino acids. One study tested probiotics, while in four trials a combination of different types of nutraceuticals was used. Even if some compounds have shown promising results (i.e. fatty acids and N-acetyl cysteine for depression, amino acid drinks and folic acid for mania), the majority of nutraceuticals did not cause significant improvements in comparison to placebo.

LIMITATIONS

We could not perform a meta-analysis due to the high heterogeneity of trials, which were also affected by some methodological caveats.

CONCLUSIONS

Evidence regarding the efficacy of adjunctive nutraceuticals in bipolar disorder is inconsistent. Nevertheless, they appear generally free from relevant side effects. Well-designed trials are needed to further explore the potential role of nutraceuticals in different mood episodes.

Vitamin D in schizophrenia and depression: a clinical review

Evidence from preclinical and clinical studies supports a role for vitamin D deficiency in many mental disorders. In this review, we discuss the role of vitamin D in the aetiology and treatment of schizophrenia and depression and their physical health comorbidities. Although observational studies support a potential association between vitamin D and schizophrenia and depression, sufficient high-quality evidence from clinical trials does not yet exist to establish a place for vitamin D supplementation in optimising clinical response or promoting physical health. Completed randomised controlled trials are needed to provide insights into the efficacy and safety of vitamin D in the management of mental disorders.

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DECLARATION OF INTEREST

F.G. has received support or honoraria for CME, advisory work and lectures from Bristol-Myers Squibb, Janssen, Lundbeck, Otsuka, Roche and Sunovion, and has a family member with professional links to Lilly and GSK, including shares. She is in part funded by the National Institute for Health Research's (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London and the South London Collaboration for Leadership in Applied Health Research & Care Funding scheme, and by the Maudsley Charity. The views expressed in this article are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Efficacy of vitamin D supplementation in major depression: A meta-analysis of randomized controlled trials

Background

There is a need to develop and periodically evaluate new treatment strategies in major depression due to the high burden of nonresponse and inadequate response to antidepressants.

Aim

We aimed to assess the effect of vitamin D supplementation on depression symptom scores among individuals with clinically diagnosed major depression.

Materials and Methods

Electronic search of databases was carried out for published randomized controlled trials in English language, peer-reviewed journals from inception till August 2017. Outcome measure used for effect size calculation was depression symptom scores. Effect sizes for the trials were computed using standardized mean difference (Cohen's d), and I2 test was used to assess sample heterogeneity. Pooled mean effect sizes were derived using both fixed and random-effects model. Critical appraisal of studies was done using the Cochrane risk of bias assessment tool.

Results

A total of four trials involving 948 participants were included in the study. In three trials, the intervention group received oral vitamin D supplementation whereas in one parenteral vitamin D was given. Pooled mean effect size for vitamin D supplementation on depressive symptom ratings in major depression was 0.58 (95% confidence interval, 0.45-0.72). The I2 value for heterogeneity was 0 suggesting low heterogeneity among studies. Egger plot intercept indicated minimal publication bias.

Conclusion

Vitamin D supplementation favorably impacted depression ratings in major depression with a moderate effect size. These findings must be considered tentative owing to the limited number of trials available and inherent methodological bias noted in few of them.

Are plasma 25-hydroxyvitamin D and retinol levels and one-carbon metabolism related to metabolic syndrome in patients with a severe mental disorder?

There is a scarcity of studies assessing the influence of biomarkers in metabolic syndrome in psychiatric patients. Our aim was to correlate serum or plasma levels of 25-hydroxyvitamin D (25-OH-VD), retinol, vitamin B12 (VB12), folate and homocysteine (Hcy), with the metabolic status, in a sample of 289 outpatients with Schizophrenia or Bipolar Disorder. Logistic regression and multiple linear regressions were performed to assess the ability of biomarkers to predict the presence of MetS, the number of risk factors for MetS, and insulin resistance indexes (HOMA and QUICKI). Regarding the association between biomarkers and the QUICKI index, the model explained 6.8% of the variance, with folate and 25-OH-VD levels contributing significantly to the model. The model predicting the number of MetS risk factors was significant and explained 21.7% of the variance, being 25-OH-VD and retinol the statistically significant factors. As for the impact of biomarkers on MetS, the model was statistically significant, being 25-OH-VD and retinol levels the significant factors.  We report for the first time an association between MetS and both low 25-OH-VD and high retinol concentrations. Inflammation-related biomarkers may help identify patients with a high risk of MetS who might benefit from healthy lifestyle counselling and early intervention.