Serum vitamin D and hippocampal gray matter volume in schizophrenia

Blood-brain barrier dysfunction and folate and vitamin B12 levels in first-episode schizophrenia-spectrum psychosis: a retrospective chart review

Vitamin deficiency syndromes and blood-brain barrier (BBB) dysfunction are frequent phenomena in psychiatric conditions. We analysed the largest available first-episode schizophrenia-spectrum psychosis (FEP) cohort to date regarding routine cerebrospinal fluid (CSF) and blood parameters to investigate the association between vitamin deficiencies (vitamin B12 and folate) and BBB impairments in FEP. We report a retrospective analysis of clinical data from all inpatients that were admitted to our tertiary care hospital with an ICD-10 diagnosis of a first-episode F2x (schizophrenia-spectrum) between January 1, 2008 and August 1, 2018 and underwent a lumbar puncture, blood-based vitamin status diagnostics and neuroimaging within the clinical routine. 222 FEP patients were included in our analyses. We report an increased CSF/serum albumin quotient (Qalb) as a sign of BBB dysfunction in 17.1% (38/222) of patients. White matter lesions (WML) were present in 29.3% of patients (62/212). 17.6% of patients (39/222) showed either decreased vitamin B12 levels or decreased folate levels. No statistically significant association was found between vitamin deficiencies and altered Qalb. This retrospective analysis contributes to the discussion on the impact of vitamin deficiency syndromes in FEP. Although decreased vitamin B12 or folate levels were found in approximately 17% of our cohort, we found no evidence for significant associations between BBB dysfunction and vitamin deficiencies. To strengthen the evidence regarding the clinical implications of vitamin deficiencies in FEP, prospective studies with standardized measurements of vitamin levels together with follow-up measurements and assessment of symptom severity in addition to CSF diagnostics are needed.

Brain changes in neuroimaging of adult patients with vitamin D deficiency: systematic review protocol

INTRODUCTION

Brain abnormalities detected through neuroimaging are described in patients with vitamin D deficiency, however, it is still not clear which cerebral alterations are more frequent and characteristic in this population. Thus, this review aims to identify and classify which are the main and most frequent brain changes found by neuroimaging in patients with vitamin D deficiency.

METHODS AND ANALYSIS

The study protocol was constructed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the leading research question was formulated through Population, Intervention, Comparator, Outcome, Setting. The evidence will be researched at the following electronic databases: PubMed, PsycINFO, Scopus, Web of Science and EMBASE. Two researchers will work in the selection, analysis and inclusion phases of the articles. In the case of divergence, a third-party reviewer will be contacted. The following studies will be included: (1) cohort studies, case-control studies and cross-sectional studies; (2) studies carried out on patients with serum 25-hydroxyvitamin D levels below 30 ng/mL; (3) studies conducted with an adult population; (4) studies using neuroimaging methods. Articles considered eligible will be analysed by the Newcastle-Ottawa Quality Assessment Scale/cross-section studies to evaluate study quality. The survey will be conducted from June to December 2022.

ETHICS AND DISSEMINATION

The identification of the main and most frequent brain alterations found through neuroimaging in patients with vitamin D deficiency can guide professionals as to the identification which of the main cerebral pathologies detected through neuroimaging are related to vitamin D deficiency, in choosing more sensitive and specific neuroimaging tests to detect these brain changes, in addition to emphasising the importance of monitoring and maintaining adequate serum levels of vitamin D, in order to reduce possible cognitive sequelae. Results will be announced at national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018100074.

Taurine, an essential β-amino acid insulates against ketamine-induced experimental psychosis by enhancement of cholinergic neurotransmission, inhibition of oxidative/nitrergic imbalances, and suppression of COX-2/iNOS immunoreactions in mice

Cholinergic, oxidative, nitrergic alterations, and neuroinflammation are some key neuropathological features common in schizophrenia disease. They involve complex biological processes that alter normal behavior. The present treatments used in the management of the disorder remain ineffective together with some serious side effects as one of their setbacks. Taurine is a naturally occurring essential β-amino acid reported to elicit antipsychotic property in first episode psychosis in clinical setting, thus require preclinical investigation. Hence, we set out to investigate the effects of taurine in the prevention and reversal of ketamine-induced psychotic-like behaviors and the associated putative neurobiological mechanisms underlying its effects. Adult male Swiss mice were sheared into three separate cohorts of experiments (n = 7): drug alone, preventive and reversal studies. Treatments consisted of saline (10 mL/kg/p.o./day), taurine (50 and 100 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) with concomitant ketamine (20 mg/kg/i.p./day) injections between days 8-14, or 14 days entirely. Behavioral hyperactivity, despair, cognitive impairment, and catalepsy were measured. Brain oxidative/nitrergic imbalance, immunoreactivity (COX-2 and iNOS), and cholinergic markers were determined in the striatum, prefrontal-cortex, and hippocampus. Taurine abates ketamine-mediated psychotic-like episodes without cataleptogenic potential. Taurine attenuated ketamine-induced decrease in glutathione, superoxide-dismutase and catalase levels in the striatum, prefrontal-cortex and hippocampus. Also, taurine prevented and reversed ketamine-mediated elevation of malondialdehyde, nitrite contents, acetylcholinesterase activity, and suppressed COX-2 and iNOS expressions in a brain-region dependent manner. Conclusively, taurine insulates against ketamine-mediated psychotic phenotype by normalizing brain central cholinergic neurotransmissions, oxidative, nitrergic and suppression of immunoreactive proteins in mice brains.

Impaired spatial memory in adult vitamin D deficient BALB/c mice is associated with reductions in spine density, nitric oxide, and neural nitric oxide synthase in the hippocampus

Vitamin D deficiency is prevalent in adults and is associated with cognitive impairment. However, the mechanism by which adult vitamin D (AVD) deficiency affects cognitive function remains unclear. We examined spatial memory impairment in AVD-deficient BALB/c mice and its underlying mechanism by measuring spine density, long term potentiation (LTP), nitric oxide (NO), neuronal nitric oxide synthase (nNOS), and endothelial NOS (eNOS) in the hippocampus. Adult male BALB/c mice were fed a control or vitamin D deficient diet for 20 weeks. Spatial memory performance was measured using an active place avoidance (APA) task, where AVD-deficient mice had reduced latency entering the shock zone compared to controls. We characterised hippocampal spine morphology in the CA1 and dentate gyrus (DG) and made electrophysiological recordings in the hippocampus of behaviourally naïve mice to measure LTP. We next measured NO, as well as glutathione, lipid peroxidation and oxidation of protein products and quantified hippocampal immunoreactivity for nNOS and eNOS. Spine morphology analysis revealed a significant reduction in the number of mushroom spines in the CA1 dendrites but not in the DG. There was no effect of diet on LTP. However, hippocampal NO levels were depleted whereas other oxidation markers were unaltered by AVD deficiency. We also showed a reduced nNOS, but not eNOS, immunoreactivity. Finally, vitamin D supplementation for 10 weeks to AVD-deficient mice restored nNOS immunoreactivity to that seen in in control mice. Our results suggest that lower levels of NO and reduced nNOS immunostaining contribute to hippocampal-dependent spatial learning deficits in AVD-deficient mice.

The association between vitamin D and symptom domains in psychotic disorders: A systematic review

BACKGROUND

Vitamin D deficiency is prevalent among people with psychosis and may play a role in the aetiology of psychotic disorders. However, its impact on clinical symptom severity has not been independently reviewed.

METHODS

We conducted a systematic search of randomized trials and observational studies that assessed the relationship between vitamin D and symptom domains (positive and negative psychotic symptoms, total and general psychopathology, cognitive and depressive) in people with a psychotic disorder.

RESULTS

1040 articles were identified, of which 29 were eligible for inclusion: 26 observational studies and 3 randomized trials. Five studies included people with First-Episode Psychosis (FEP) and 24 included people with enduring psychosis. Most observational studies found that vitamin D was inversely associated with negative symptoms (57%; 13/23), positively associated with cognitive performance (63%; 5/8), and bore no association with positive symptoms (68%; 15/22), total psychopathology (64%; 7/11), general psychopathology (57%; 4/7) or depressive symptoms (64%; 9/14). Randomized controlled trials indicated that vitamin D supplementation improved cognitive performance (100%; 1/1) and, in some cases, reduced total psychopathology (50%; 1/2), general psychopathology (50%; 1/2) and negative symptoms (30%; 1/3), but had no effect on positive (100%; 3/3) or depressive (100%; 3/3) symptoms. Some positive associations were attenuated when controlled for potential confounders.

CONCLUSION

Low vitamin D was found to be inversely associated with more severe clinical symptoms in some, but not all symptom domains in people with psychosis. These preliminary findings warrant further exploration, particularly in regard to cognitive performance and negative symptoms.

The psychotropic effect of vitamin D supplementation on schizophrenia symptoms

BACKGROUND

Schizophrenia is a multifactorial disease involving interactions between genetic and environmental factors. Vitamin D has recently been linked to many metabolic diseases and schizophrenia. Vitamin D plays essential roles in the brain in the context of neuroplasticity, neurotransmitter biosynthesis, neuroprotection, and neurotransmission. Vitamin D receptors are demonstrated in most brain regions that are related to schizophrenia. However, very few studies in the literature examine the effects of 25-hydroxyvitamin D (25OHD) on schizophrenia symptoms.

METHODS

This study aimed to examine the effects of vitamin D replacement on positive, negative, and cognitive symptoms of schizophrenia. Serum 25OHD levels of 52 schizophrenia patients were measured. SANS and SAPS were used to evaluate the severity of schizophrenia symptoms, and the Wisconsin Card Sorting Test: CV4 was used for cognitive assessment. The study was completed with 40 patients for various reasons. The patients whose serum 25OHD reached optimal levels after vitamin D replacement were reevaluated with the same scales in terms of symptom severity. The SPSS 25 package program was used for statistical analysis. The Independent-Samples t-test was used to examine the relationship between the variables that may affect vitamin D levels and the vitamin D level and to examine whether vitamin D levels had an initial effect on the scale scores.

RESULTS

The mean plasma 25OHD levels of the patients was 17.87 ± 5.54. A statistically significant relationship was found only between the duration of sunlight exposure and 25 OHD level (p < 0.05). The mean SANS and SAPS scores of the participants after 25OHD replacement (23.60 ± 15.51 and 7.78 ± 8.84, respectively) were statistically significantly lower than mean SANS and SAPS scores before replacement (51.45 ± 17.96 and 18.58 ± 15.59, respectively) (p < 0.001 for all). Only the total attention score was significantly improved after replacement (p < 0.05).

CONCLUSION

The data obtained from our study suggest that eliminating the 25OHD deficiency together with antipsychotic treatment can improve the total attention span and positive and negative symptoms in schizophrenia. The 25OHD levels should be regularly measured, replacement should be started when necessary, and the patients should be encouraged to get sunlight exposure to keep optimal 25OHD levels.

Neuroimaging changes associated with vitamin D Deficiency - a narrative review

ABSTRACTEmerging evidence suggests the role of vitamin D in brain health and its implication in the pathogenesis of cognitive impairment. The Aim of this review is to summarize current evidence on neuroimaging changes seen in vitamin D deficient individuals. Cross-sectional and longitudinal studies have consistently found an association between low serum 25 hydroxyvitamin D and cognitive impairment. Furthermore, investigating the association between serum 25 hydroxyvitamin D and neuroimaging abnormalities could provide an insight into the potential mechanisms underlying the association with cognitive impairment. Animal studies have demonstrated structural changes in the cerebral cortex and hippocampus of vitamin D deficient mice. Neuroimaging studies of the brain have shown increased white matter hyperintensities in periventricular, cortical, and juxtacortical areas and grey matter atrophy of the hippocampus, anterior cingulate cortex, and left calcarine sulcus in elderly with vitamin D deficiency.

Serum Vitamin D and Cingulate Cortex Thickness in Older Adults: Quantitative MRI of the Brain

Background:

Vitamin D insufficiency is associated with brain changes, and cognitive and mobility declines in older adults.

Method:

Two hundred and fifteen Caucasian older community-dwellers (mean±SD, 72.1±5.5years; 40% female) received a blood test and brain MRI. The thickness of perigenual anterior cingulate cortex, midcingulate cortex and posterior cingulate cortex was measured using FreeSurfer from T1-weighted MR images. Age, gender, education, BMI, mean arterial pressure, comorbidities, use of vitamin D supplements or anti-vascular drugs, MMSE, GDS, IADL, serum calcium and vitamin B9 concentrations, creatinine clearance were used as covariables.

Results:

Participants with vitamin D insufficiency (n=80) had thinner total cingulate thickness than the others (24.6±1.9mm versus 25.3±1.4mm, P=0.001); a significant difference found for all 3 regions. Vitamin D insufficiency was cross-sectionally associated with a decreased total cingulate thickness (β=- 0.49, P=0.028). Serum 25OHD concentration correlated positively with the thickness of perigenual anterior (P=0.011), midcingulate (P=0.013) and posterior cingulate cortex (P=0.021).

Conclusion:

Vitamin D insufficiency was associated with thinner cingulate cortex in the studied sample of older adults. These findings provide insight into the pathophysiology of cognitive and mobility declines in older adults with vitamin D insufficiency.

Hypovitaminosis D is associated with negative symptoms, suicide risk, agoraphobia, impaired functional remission, and antidepressant consumption in schizophrenia

Hypovitaminosis D has been associated with, respectively, major depressive disorder, schizophrenia (SZ), and cognitive disorders in the general population, and with positive and negative symptoms and metabolic syndrome in schizophrenia. The objective was to determine the prevalence of hypovitaminosis D and associated factors in a non-selected multicentric sample of SZ subjects in day hospital. Hypovitaminosis D was defined by blood vitamin D level < 25 nM. Depressive symptoms were assessed by the Calgary Depression Rating Scale Score and Positive and Negative Syndrome Scale Score. Anxiety disorders and suicide risk were evaluated by the Structured Clinical Interview for Mental Disorders. Functioning was evaluated with the Functional Remission of General Schizophrenia Scale. Hypovitaminosis D has been found in 27.5% of the subjects. In multivariate analysis, hypovitaminosis D has been significantly associated with, respectively, higher suicide risk (aOR = 2.67 [1.31-5.46], p = 0.01), agoraphobia (aOR = 3.37 [1.66-6.85], p < 0.0001), antidepressant consumption (aOR = 2.52 [1.37-4.64], p < 0.001), negative symptoms (aOR = 1.04 [1.01-1.07], p = 0.04), decreased functioning (aOR = 0.97[0.95-0.99], p = 0.01), and increased leucocytosis (aOR = 1.17 [1.04-1.32], p = 0.01) independently of age and gender. No association with alcohol use disorder, metabolic syndrome, peripheral inflammation, insulin resistance, or thyroid disturbances has been found (all p > 0.05). Despite some slight abnormalities, no major cognitive impairment has been associated with hypovitaminosis D in the present sample (all p > 0.05 except for WAIS similarities score). Hypovitaminosis D is frequent and associated with suicide risk, agoraphobia and antidepressant consumption in schizophrenia, and more slightly with negative symptoms. Patients with agoraphobia, suicide risk and antidepressant consumption may, therefore, benefit in priority from vitamin D supplementation, given the benefit/risk profile of vitamin D. Further studies should evaluate the impact of vitamin D supplementation on clinical outcomes of SZ subjects.

Inflammatory biomarkers in psychosis and clinical high risk populations

BACKGROUND

Immunological, nutritional, and microbial factors have been implicated in the pathophysiology of schizophrenia, but the interrelationship among measures is understudied. In particular, an increase in the levels of the pro-inflammatory cytokine interleukin-6 (IL-6) is associated with all phases of the illness, and may be associated with other inflammatory markers. Vitamin D is a modulator of the immune system, and LPS antibodies are an indirect measure of gut barrier function. In this study we investigated potential contributing inflammatory mechanisms for IL-6 elevation.

METHODS

We compared the levels of vitamin D, C-reactive protein (CRP), antibodies to lipopolysaccharide (LPS), and IL-6 in children, adolescents and young adults with psychosis (n = 47), individuals at clinical high risk for psychosis (n = 17) and unaffected comparison controls (n = 33). Participants were diagnosed by a psychiatrist, using a structured interview, the MINI-Neuropsychiatric Interview. 25(OH)D was measured in serum using chemiluminescent micro particle immunoassay, and anti-LPS antibodies, CRP and IL-6 levels were measured by ELISA.

RESULTS

IL-6 and C-reactive protein levels were significantly elevated in the psychosis group relative to the unaffected control subjects. In the psychosis group, levels of IL-6 correlated positively with IgA anti-LPS antibodies and negatively correlated with vitamin D.

CONCLUSIONS

Our findings show a significant correlation between IL-6, anti-LPS antibodies and vitamin D deficiency in psychosis, suggesting the existence of multiple potential pathways related to IL-6 elevation in psychosis, and therefore multiple potential strategies for risk mitigation. Collectively these findings support hypotheses regarding interrelated inflammatory contributions to the pathophysiology of psychosis.

Adult vitamin D deficiency disrupts hippocampal-dependent learning and structural brain connectivity in BALB/c mice

Converging evidence from human and animal studies support an association between vitamin D deficiency and cognitive impairment. Previous studies have shown that hippocampal volume is reduced in adults with vitamin D deficiency as well as in a range of disorders, such as schizophrenia. The aim of the current study was to examine the effect of adult vitamin D (AVD) deficiency on hippocampal-dependent spatial learning, and hippocampal volume and connectivity in healthy adult mice. Ten-week-old male BALB/c mice were fed a control (vitamin D 1500 IU/kg) or vitamin D-depleted (vitamin D 0 IU/kg) diet for a minimum of 10 weeks. The mice were then tested for hippocampal-dependent spatial learning using active place avoidance (APA) and on tests of muscle and motor coordination (rotarod and grip strength). The mice were perfused and brains collected to acquire ex vivo structural and diffusion-weighted images using a 16.4 T MRI scanner. We also performed immunohistochemistry to quantify perineuronal nets (PNNs) and parvalbumin (PV) interneurons in various brain regions. AVD-deficient mice had a lower latency to enter the shock zone on APA, compared to control mice, suggesting impaired hippocampal-dependent spatial learning. There were no differences in rotarod or grip strength, indicating that AVD deficiency did not have an impact on muscle or motor coordination. AVD deficiency did not have an impact on hippocampal volume. However, AVD-deficient mice displayed a disrupted network centred on the right hippocampus with abnormal connectomes among 29 nodes. We found a reduction in PNN positive cells, but no change in PV, centred on the hippocampus. Our results provide compelling evidence to show that AVD deficiency in otherwise healthy adult mice may play a key role in hippocampal-dependent learning and memory formation. We suggest that the spatial learning deficits could be due to the disruption of right hippocampal structural connectivity.

Hypovitaminosis D is associated with depression and anxiety in schizophrenia: Results from the national FACE-SZ cohort

OBJECTIVE

Hypovitaminosis D has been associated with respectively major depressive disorder, schizophrenia (SZ) and cognitive disorders in the general population, and with positive and negative symptoms and metabolic syndrome in schizophrenia. The objectives were (i) to determine the prevalence of hypovitaminosis D and associated factors (with a focus on depression and cognition) in a national non-selected multicentric sample of community-dwelling SZ subjects (ii) to determine the rate of SZ patients being administered vitamin D supplementation and associated factors.

METHODS

A comprehensive 2 daylong clinical and neuropsychological battery was administered in 140 SZ subjects included between 2015 and 2017 in the national FondaMental Expert Center (FACE-SZ) Cohort. Hypovitaminosis D was defined by blood vitamin D level <25 nM. Depressive symptoms were assessed by the Positive and Negative Syndrome Scale depressive subscore and current anxiety disorder by the Structured Clinical Interview for Mental Disorders.

RESULTS

Hypovitaminosis D has been found in 21.4% of the subjects and none of them had received vitamin D supplementation in the previous 12 months. In multivariate analysis, hypovitaminosis D has been significantly associated with respectively higher depressive symptoms (aOR = 1.18 [1.03-1.35], p = 0.02) and current anxiety disorder (aOR = 6.18 [2.15-17.75], p = 0.001), independently of age and gender. No association of hypovitaminosis D with respectively positive and negative symptoms, cognitive scores or other biological variables has been found (all p > 0.05), however, a trend toward significance has been found for metabolic syndrome (p = 0.06). Vitamin D supplementation has been administered during the previous 12 months in only 8.5% of the subjects but was associated with lower depressive symptoms (aOR = 0.67 [0.46-0.98], p = 0.04) and lower rate of current anxiety disorder (aOR = 0.06 [0.01-0.66], p = 0.02) compared to patients with hypovitaminosis D.

CONCLUSION

Hypovitaminosis D is frequent and associated with depressive symptoms and anxiety disorders in schizophrenia. Vitamin D supplementation is associated with lower depressive and anxiety symptoms, however patients with hypovitaminosis D remain insufficiently treated.

Nutritional Deficiencies and Clinical Correlates in First-Episode Psychosis: A Systematic Review and Meta-analysis

Objective

Diet is increasingly recognized as a potentially modifiable factor influencing the onset and outcomes of psychiatric disorders. Whereas, previous research has shown long-term schizophrenia is associated with various nutritional deficiencies, this meta-analysis aimed to determine the prevalence and extent of nutritional deficits in first-episode psychosis (FEP).

Method

A search of electronic databases conducted in July 2017 identified 28 eligible studies, examining blood levels of 6 vitamins and 10 minerals across 2612 individuals: 1221 individuals with FEP and 1391 control subjects. Meta-analyses compared nutrient levels in FEP to nonpsychiatric controls. Clinical correlates of nutritional status in patient samples were systematically reviewed.

Results

Significantly lower blood levels of folate (N = 6, n = 827, g = -0.624, 95% confidence interval [CI] = -1.176 to -0.072, P = .027) and vitamin D (N = 7, n = 906, g = -1.055, 95% CI = -1.99 to -0.119, P = .027) were found in FEP compared to healthy controls. Synthesis of clinical correlates found both folate and vitamin D held significant inverse relationships with psychiatric symptoms in FEP. There was also limited evidence for serum level reductions of vitamin C (N = 2, n = 96, g = -2.207, 95% CI = -3.71 to -0.71, P = .004). No differences were found for other vitamins or minerals.

Conclusions

Deficits in vitamin D and folate previously observed in long-term schizophrenia appear to exist from illness onset, and are associated with worse symptomology. Further research must examine the direction and nature of these relationships (ie, mediator, moderator, or marker) with clinical status in FEP. Future trials assessing efficacy of nutrient supplementation in FEP samples should consider targeting and stratifying for baseline deficiency.

Adjunctive nutrients in first-episode psychosis: A systematic review of efficacy, tolerability and neurobiological mechanisms

AIM

The effects of nutrient-based treatments, including adjunctive vitamin or antioxidant supplementation, have been explored extensively in long-term schizophrenia. However, no systematic evaluation of trials in "first-episode psychosis" (FEP) has been conducted, despite the potential benefits of using these treatments during the early stages of illness. Therefore, we aimed to review all studies examining efficacy, tolerability and the biological mechanisms of action, of nutrient supplementation in FEP.

METHODS

A systematic review of electronic databases was conducted from inception to July 2017. All information on feasibility, clinical outcomes and mechanistic findings from nutrient supplementation clinical trials was extracted and systematically synthesized.

RESULTS

Eleven studies with a total of 451 patients with FEP (from 8 independent randomized controlled trials) were eligible for inclusion. Six studies examined omega-3 fatty acids, with inconsistent effects on psychiatric symptoms. However, mechanistic studies found significant improvements in hippocampal neuronal health and brain glutathione. Antioxidants "n-acetyl cysteine" (n = 1) and vitamin C (n = 2) also improved oxidative status in FEP, which was associated with reduced psychiatric symptoms. No benefits were found for vitamin E (n = 1). Finally, one study trialling the amino acid taurine, showed significant improvements in positive symptoms and psychosocial functioning.

CONCLUSION

There is preliminary evidence that taurine improves outcomes in FEP, whereas effects of omega-3 and antioxidant vitamins/amino-acids are inconsistent; perhaps mainly benefitting patients with high levels of oxidative stress. Future studies should evaluate multifaceted dietary and supplementation interventions in FEP; targeting-specific nutritional deficits and the range of aberrant biological processes implicated in the disorder.

Vitamin D deficiency is associated with reduced hippocampal volume and disrupted structural connectivity in patients with mild cognitive impairment

Vitamin D deficiency may exacerbate adverse neurocognitive outcomes in the progression of diseases such as Parkinson's, Alzheimer's, and other dementias. Mild cognitive impairment (MCI) is prodromal for these neurocognitive disorders and neuroimaging studies suggest that, in the elderly, this cognitive impairment is associated with a reduction in hippocampal volume and white matter structural integrity. To test whether vitamin D is associated with neuroanatomical correlates of MCI, we analyzed an existing structural and diffusion MRI dataset of elderly patients with MCI. Based on serum 25-OHD levels, patients were categorized into serum 25-OHD deficient (<12 ng/mL, n = 27) or not-deficient (>12 ng/mL, n = 29). Freesurfer 6.0 was used to parcellate the whole brain into 164 structures and segment the hippocampal subfields. Whole-brain structural connectomes were generated using probabilistic tractography with MRtrix. The network-based statistic (NBS) was used to identify subnetworks of connections that significantly differed between the groups. We found a significant reduction in total hippocampal volume in the serum 25-OHD deficient group especially in the CA1, molecular layer, dentate gyrus, and fimbria. We observed a connection deficit in 13 regions with the right hippocampus at the center of the disrupted network. Our results demonstrate that low vitamin D is associated with reduced volumes of hippocampal subfields and connection deficits in elderly people with MCI, which may exacerbate neurocognitive outcomes. Longitudinal studies are now required to determine if vitamin D can serve as a biomarker for Alzheimer's disease and if intervention can prevent the progression from MCI to major cognitive disorders.

Vitamin D levels, brain volume, and genetic architecture in patients with psychosis

BACKGROUND

Lower vitamin D levels are found in people with schizophrenia and depressive disorders, and also associated with neuroimaging abnormalities such as reduced brain volume in both animals and humans. Reduced whole brain and increased ventricular volume are also systematically reported in schizophrenia. Even though vitamin D deficiency has been proposed as a risk mechanism for schizophrenia there exist no studies to date of the association between vitamin D levels and brain volume in this population. Therefore, we investigated the relationship between vitamin D levels and brain phenotypes in psychotic disorders, and assessed possible interactions with genetic variants in vitamin D receptor (VDR) and other genetic variants that play a role in vitamin D levels in the body.

METHODS

Our sample consisted of 83 psychosis patients and 101 healthy controls. We measured vitamin D levels as serum 25-hydroxyvitamin D. All participants were genotyped and neuroimaging conducted by structural magnetic resonance imaging.

RESULTS

Vitamin D levels were significantly positively associated with peripheral grey matter volume in patients (β 860.6; 95% confidence interval (CI) 333.4-1466, p < .003). A significant interaction effect of BSML marker (rs1544410) was observed to mediate the association between patient status and both white matter volume (β 23603.3; 95% CI 2732.8-48708.6, p < .05) and whole brain volume (β 46670.6, 95% CI 8817.8-93888.3, p < .04). Vitamin D did not predict ventricular volume, which rather was associated with patient status (β 4423.3, 95% CI 1583.2-7267.8p < .002) and CYP24A1 marker (rs6013897) (β 2491.5, 95% CI 269.7-4978.5, p < .04).

CONCLUSIONS

This is the first study of the association between vitamin D levels and brain volume in patients with psychotic disorders that takes into account possible interaction with genetic polymorphisms. The present findings warrant replication in independent samples.

Vitamin D deficiency: infertility and neurodevelopmental diseases (attention deficit hyperactivity disorder, autism, and schizophrenia)

The process of development depends on a number of signaling systems that regulates the progressive sequence of developmental events. Infertility and neurodevelopmental diseases, such as attention deficit hyperactivity disorder, autism spectrum disorders, and schizophrenia, are caused by specific alterations in these signaling processes. Calcium signaling plays a prominent role throughout development beginning at fertilization and continuing through early development, implantation, and organ differentiation such as heart and brain development. Vitamin D plays a major role in regulating these signaling processes that control development. There is an increase in infertility and an onset of neurodevelopmental diseases when vitamin D is deficient. The way in which vitamin D deficiency acts to alter development is a major feature of this review. One of the primary functions of vitamin D is to maintain the phenotypic stability of both the Ca²⁺ and redox signaling pathways that play such a key role throughout development.

Systematic Review on Vitamin D Level in Apparently Healthy Indian Population and Analysis of Its Associated Factors

BACKGROUND

Vitamin D which is involved in the maintenance of bone mineral homeostasis has been found to portray various pleiotropic effects. Although it has been widely accepted that serum 25-hydroxy Vitamin D level above 30 ng/ml is considered optimal for the biological actions of Vitamin D, there is a need to explore the levels of Vitamin D reported among Indians from various regions of the country. Hence, this systematic review aims to appraise the status of Vitamin D levels reported from apparently healthy Indians across various parts of India.

METHODOLOGY

A comprehensive literature search was carried out to identify the range of Vitamin D levels among apparently healthy individuals from various parts of India, with the search term "Vitamin D and India" in the search portals of PubMed, Google Scholar, Indmed, and ScienceDirect. A total of 2998 articles were retrieved by the above search strategy, of which only forty studies fulfilled the criteria to be included in the systematic review. Studies done in various states were compiled under the respective zones based on the classification of Indian zones as specified in Zonal maps of India.

RESULTS

The level of Vitamin D from all the forty included studies ranged from 3.15 ± 1.4 to 52.9 ± 33.7 ng/ml. The effect size of Vitamin D level was higher in the South Zone compared to other zones.

CONCLUSION

The present study shows that Vitamin D deficiency is prevalent among apparently healthy Indians living in different regions of India, irrespective of their exposure to sunlight.

The effects of vitamin and mineral supplementation on symptoms of schizophrenia: a systematic review and meta-analysis

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.

METHOD

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.

Correlates of vitamin D in psychotic disorders: A comprehensive systematic review

People with psychosis have high prevalence of low vitamin D levels but the correlates and relevance of this deficiency are unclear. A systematic search of major databases from inception to 03/2016 was undertaken investigating correlates of vitamin D in people with psychosis. Data was summarised with a best evidence synthesis. Across 23 included studies (n=1770 psychosis, n=8171 controls) a mean difference in vitamin D levels between both groups of -11.14ng/ml±0.59 was found. 53 unique correlations between vitamin D and outcomes in people with psychosis were identified. The evidence base was broadly equivocal although season of blood sampling (67% of studies found a positive correlation with warmer seasons) and parathyroid hormone (100% of studies found a negative correlation) were associated with vitamin D levels. The most commonly non-correlated variables were: BMI (83% found no correlation), age (73%), gender (86%), smoking (100%), duration of illness (100%) and general assessment of functioning score (100%). In conclusion, whilst many unique correlates have been investigated, there is weak and inconclusive evidence regarding the consistency and meaning of the correlates of vitamin D levels in people with psychosis. Future longitudinal studies should consider the correlates of vitamin D in people with psychosis.

Vitamin D deficiency, behavioral atypicality, anxiety and depression in children with chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a complex developmental disorder with serious medical, cognitive and emotional symptoms across the lifespan. This genetic deletion also imparts a lifetime risk for developing schizophrenia that is 25-30 times that of the general population. The origin of this risk is multifactorial and may include dysregulation of the stress response and immunological systems in relation to brain development. Vitamin D is involved in brain development and neuroprotection, gene transcription, immunological regulation and influences neuronal signal transduction. Low levels of vitamin D are associated with schizophrenia, depression and anxiety in the general population. Yet, little is known about how vitamin D levels in children with 22q11.2DS could mediate risk of psychosis in adulthood. Blood plasma levels of vitamin D were measured in children aged 7-16 years with (n=11) and without (n=16) 22q11.2DS in relation to parent reports of children's anxiety and atypicality. Anxiety and atypicality in childhood are risk indicators for the development of schizophrenia in those with 22q11.2DS and the general population. Children with 22q11.2DS had lower vitamin D levels, as well as elevated anxiety and atypicality compared with typical peers. Higher levels of anxiety, depression and internalizing problems but not atypicality were associated with lower levels of vitamin D. Vitamin D insufficiency may relate to higher levels of anxiety and depression, in turn contributing to the elevated risk of psychosis in this population. Further study is required to determine casual linkages between anxiety, stress, mood and vitamin D in children with 22q11.2DS.