Vitamin D and neurocognitive dysfunction: preventing "D"ecline?

Maternal Vitamin D and its Role in Determining Fetal Origins of Mental Health

There is evidence that mental health disorders may have roots in fetal life and are associated with deficiencies in various micronutrients, including vitamin D. During pregnancy, vitamin D balance is influenced by an increase in maternal calcitriol and a substantial increase in maternal Vitamin D Binding Protein concentrations. In the early stages of life, vitamin D is necessary to mediate numerous brain processes such as proliferation, apoptosis, and neurotransmission. Furthermore, Vitamin D has a recognized anti-inflammatory activity that normally suppresses inflammation. Increased activation of hypothalamo-pituitary-adrenal axis (HPA) and inflammation during gestation may influence maternal health and fetal neurodevelopment during and beyond pregnancy. A deficit of Vitamin D and maternal stressful events during gestation, such as perinatal depression, could influence the efficacy of the immune system altering its activity. Vitamin D deficiency during gestation associated with a reduction in fetal brain development has been widely described and correlated with alteration in the production of the brain-derived neurotrophic factor. To this regard, many studies highlights that low maternal vitamin D dosage during gestation has been related to a significantly greater risk to develop schizophrenia and other severe mental illnesses in later life. The objective of this paper is a comprehensive overview of maternal vitamin D balance in determining the fetal origins of mental health with some references to the link between vitamin D levels, inflammatory responses to stress and mental disorders in adult life.

Effects of a Nutritional Formulation Containing Caprylic and Capric Acid, Phosphatidylserine, and Docosahexaenoic Acid in Streptozotocin-Lesioned Rats

Background

It has been studied that nutrition can influence Alzheimer's disease (AD) onset and progression. Some studies on rodents using intraventricular streptozotocin (STZ) injection showed that this toxin changes cerebral glucose metabolism and insulin signaling pathways.

Objective

The aim of the present study was to evaluate whether a nutritional formulation could reduce cognitive impairment in STZ-induced animals.

Methods

The rats were randomly divided into two groups: sham and STZ. The STZ group received a single bilateral STZ-ICV injection (1 mg/kg). The sham group received a bilateral ICV injection of 0.9% saline solution. The animals were treated with AZ1 formulation (Instanth^® NEO, Prodiet Medical Nutrition) (1 g/kg, PO) or its vehicle (saline solution) for 30 days, once a day starting one day after the stereotaxic surgery (n = 6-10). The rats were evaluated using the open field test to evaluate locomotor activity at day 27 after surgery. Cognitive performance was evaluated at day 28 using the object recognition test and the spatial version of the Y-maze test. At day 30, the rats were anesthetized with chloral hydrate (400 mg/kg, i.p) and euthanized in order to evaluate IBA1 in the hippocampus. The differences were analyzed using one-way ANOVA with Bonferroni's or Kruskal Wallis with Dunn's post-hoc test.

Results/Conclusion

STZ-lesioned rats present memory impairment besides the increased microglial activation. The treatment with AZ1 formulation reversed the memory impairment observed in the object recognition test and Y-maze and also reduced IBA1 in CA1 and DG.

Clinical Severity and Calcium Metabolism in Patients with Bipolar Disorder

Parathyroid hormone (PTH), vitamin D and serum calcium play a key role in several physiological and pathological conditions. Vitamin D and PTH receptors are largely expressed in the central nervous system and are involved in the modulation of inflammatory responses. Few studies investigated the association between calcium homeostasis imbalance and psychiatric disorders. This study aims to assess calcium homeostasis imbalance in patients with bipolar disorder (BD) and its impact on clinical outcome. We recruited 199 patients with BD, who were administered with validated assessment instruments to investigate depressive, manic and anxiety symptoms, affective temperaments, childhood trauma and global functioning. Serum calcium, vitamin D and PTH levels were assessed in all patients. Levels of PTH correlated with several clinical characteristics, including the diagnosis of bipolar disorder type I (BD-I), the presence of psychotic symptoms, lithium treatment, suicidality, total number of acute episodes and of hospitalizations (p < 0.0001) and seasonality (p < 0.05). At the regression analyses, higher levels of PTH were predicted by early age at onset, number of hospitalizations, aggressive behaviors (p < 0.05), higher Childhood Trauma Questionnaire total score (CTQ) (p < 0.001) and treatment with lithium (p = 0.01). Our findings suggest that the calcium homeostasis could play a role in BD patients, and that PTH levels are correlated with the clinical severity of the disorder.

1,25(OH)2D3 Alleviates Aβ(25-35)-Induced Tau Hyperphosphorylation, Excessive Reactive Oxygen Species, and Apoptosis Through Interplay with Glial Cell Line-Derived Neurotrophic Factor Signaling in SH-SY5Y Cells

Amyloid beta (Aβ) accumulation in the brain is one of the major pathological features of Alzheimer's disease. The active form of vitamin D (1,25(OH)₂D₃), which acts via its nuclear hormone receptor, vitamin D receptor (VDR), has been implicated in the treatment of Aβ pathology, and is thus considered as a neuroprotective agent. However, its underlying molecular mechanisms of action are not yet fully understood. Here, we aim to investigate whether the molecular mechanisms of 1,25(OH)₂D₃ in ameliorating Aβ toxicity involve an interplay of glial cell line-derived neurotrophic factor (GDNF)-signaling in SH-SY5Y cells. Cells were treated with Aβ(25-35) as the source of toxicity, followed by the addition of 1,25(OH)₂D₃ with or without the GDNF inhibitor, heparinase III. The results show that 1,25(OH)₂D₃ modulated Aβ-induced reactive oxygen species, apoptosis, and tau protein hyperphosphorylation in SH-SY5Y cells. Additionally, 1,25(OH)₂D₃ restored the decreasing GDNF and the inhibited phosphorylation of the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) protein expressions. In the presence of heparinase III, these damaging effects evoked by Aβ were not abolished by 1,25(OH)₂D_3. It appears 1,25(OH)₂D₃ is beneficial for the alleviation of Aβ neurotoxicity, and it might elicit its neuroprotection against Aβ neurotoxicity through an interplay with GDNF-signaling.

Serum vitamin D level is associated with speed of processing in multiple sclerosis patients

Multiple Sclerosis (MS) is often associated with low serum 25(OH)D levels, as well as cognitive dysfunctions. The relationship between 25(OH)D and the most commonly affected cognitive domain in MS; processing speed, is poorly explored. The purpose of this study is to: (1) assess the effect of serum 25(OH)D change on processing speed in MS, and (2) explore the relationship between serum 25(OH)D and brain volume changes in MS. A retrospective chart review was conducted, data from 299 patients were extracted (baseline), of whom 163 had follow-up measurements (after at least a 9-month interval). The Symbol Digits Modalities Test (SDMT) was used as a measure of processing speed. MRI data was available from 78 individuals at baseline, and 70 at follow-up. SDMT scores and brain volumes (Cerebellum (total, grey, and white), intracranial, Grey Matter (GM), and White Matter (WM)) were compared based on 25(OH)D levels and their changes towards follow-up. Results indicated that patients with deficient 25(OH)D levels had lower SDMT scores when compared to those with sufficient levels, and SDMT scores improved as a function of 25(OH)D. For MRI measures, only patients with sufficient 25(OH)D levels during both assessment periods had significant changes in intracranial and total cerebellum volumes. We conclude that 25(OH)D levels seem to have an effect on processing speed in MS, thus the importance of clinical monitoring and supplementation in this regard is reinforced.

Potential Preventive Strategies for Amyotrophic Lateral Sclerosis

It may seem useless to propose preventive measures for a disease without established pathogenesis and successful therapy, such as amyotrophic lateral sclerosis (ALS). However, we will show that ALS shares essential molecular mechanisms with aging and that established anti-aging strategies, such as healthy diet or individually adjusted exercise, may be successfully applied to ameliorate the condition of ALS patients. These strategies might be applied for prevention if persons at ALS risk could be identified early enough. Recent research advances indicate that this may happen soon.

Vitamin D, Folate, and Cobalamin Serum Concentrations Are Related to Brain Volume and White Matter Integrity in Urban Adults

Background and objectives: Lower vitamin status has been linked to cognitive deficits, pending mechanistic elucidation. Serum 25-hydroxyvitamin D [25(OH)D], folate and cobalamin were explored against brain volumes and white matter integrity (WMI).

Methods: Two prospective waves from Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study were primarily used [Baltimore, City, MD, 2004–2015, N = 183–240 urban adults (Age_v1: 30–64 years)]. Serum vitamin 25-hydroxyvitamin D [25(OH)D], folate and cobalamin concentrations were measured at visits 1 (v₁: 2004–2009), while structural and diffusion Magnetic Resonance Imaging (sMRI/dMRI) outcomes were measured at vscan: 2011–2015. Top 10 ranked adjusted associations were corrected for multiple testing using familywise Bonferroni (FWER < 0.05) and false discovery rates (FDR, q-value < 0.10).

Results: We found statistically significant (FWER < 0.05; β±SE) direct associations of 25(OH)D(v₁) with WM volumes [overall: +910 ± 336/males: +2,054 ± 599], occipital WM; [overall: +140 ± 40, males: +261 ± 67 and Age_v1 > 50 years: +205 ± 54]; parietal WM; [overall: +251 ± 77, males: +486 ± 129 and Age_v1 > 50 years: +393 ± 108] and left occipital pole volume [overall: +15.70 ± 3.83 and above poverty: 19.0 ± 4.3]. Only trends were detected for cobalamin exposures (q < 0.10), while serum folate (v₁) was associated with lower mean diffusivity (MD) in the Anterior Limb of the Internal Capsule (ALIC), reflecting greater WMI, overall, while regional FA (e.g., cingulum gyrus) was associated with greater 25(OH)D concentration.

Conclusions: Among urban adults, serum 25(OH)D status was consistently linked to larger occipital and parietal WM volumes and greater region-specific WMI. Pending longitudinal replication of our findings, randomized controlled trials of vitamin D supplementation should be conducted against brain marker outcomes.

Vitamin D Status and Related Factors among Korean Stroke Survivors: A Nationwide Population-Based Study

The aim of this study was to investigate the vitamin D status and related factors in community-dwelling Korean stroke survivors. Data of 23,872 individuals ≥20 y who participated in the Korea National Health and Nutrition Examination Surveys (KNHANES) were analyzed. Participants who had ever been diagnosed with stroke by a doctor were defined as stroke survivors (n=431). The serum 25-hydroxyvitamin D (25(OH)D) level was measured by radioimmunoassay, and vitamin D deficiency was defined as 25(OH)D<20 ng/mL. The association between vitamin D and stroke status was analyzed using multivariable general linear models and logistic regression models adjusted for sociodemographic and clinical covariates. The adjusted mean 25(OH)D level of stroke survivors was significantly lower than that of nonstroke controls; however, after adjustment for systolic blood pressure level and use of antihypertensive medication, the difference was no longer statistically significant. The burden of 25(OH)D deficiency was not higher in stroke survivors than in nonstroke controls (adjusted OR=1.14; 95% CI, 0.81-1.62). Current smoking was independently associated with 25(OH)D deficiency among stroke survivors (adjusted OR=3.17; 95% CI, 1.33-7.55). These findings indicated that treatment of high blood pressure and smoking cessation may be important measures to control vitamin D levels in stroke survivors.

Serum 25-hydroxyvitamin D level in patients with chronic liver disease and its correlation with hepatic encephalopathy: A cross-sectional study

Background

Hepatic encephalopathy (HE) is an established clinical manifestation in chronic liver disease (CLD). It is associated with various factors including gastrointestinal bleed, constipation, and dyselectrolemia. Recently 25-hydroxyvitamin D (25-OHD) deficiency has been identified as one of the factors associated with the development of HE. The current study was aimed to assess the level of 25-OHD in patients with CLD and hepatic encephalopathy and the relationship between 25-OHD deficiency and hepatic encephalopathy.

Materials and Methods

This cross-sectional study included 100 subjects of either sex between 18 and 60 years of age, diagnosed as CLD on the basis of ultrasonography with hepatic encephalopathy and 50 age, sex-matched CLD subjects without encephalopathy. Hemogram, hepatic and renal functions, serum electrolytes, coagulation profile, and serum 25-hydroxyvitamin D levels were recorded.

Results

The baseline variables were matched for age, sex, hepatic and kidney function, and coagulation profiles. The hemoglobin (P = 0.002) and platelet count (P = 0.0003) were significantly lower in subjects with HE. The mean level of 25-OHD was significantly lower in subjects with HE as compared to the control group (25.62 ± 21.94 nmol/L vs 37.44 ± 18.61 nmol/L, P < 0.001). The mean 25-OHD level was 30.64 ± 21.64 nmol/L in grade 1 HE, 12.03 ± 11.05 nmol/L in grade 3 with P < 0.0001, and 18.8 ± 16.88 nmol/L in grade 4 with P < 0.0001 when compared to grade 1. Moderate and severe deficiency of 25-OHD level was significantly associated with higher grades of HE, i.e. grades 3 and 4 (P < 0.0001). There was a significant negative correlation between 25-OHD levels and worsening grades of hepatic encephalopathy (person's correlation coefficient r = -0.354; P = 0.0003).

Conclusion

In this cohort of North Indian population, serum 25-OHD level was significantly lower in patients with CLD and HE. The levels of 25-OHD showed a significant negative correlation with hepatic encephalopathy.

Role of Vitamin D in Preventing and Treating Selected Extraskeletal Diseases-An Umbrella Review

Evidence is accumulating that vitamin D may have beneficial effects on respiratory tract, autoimmune, neuro-degenerative, and mental diseases. The present umbrella review of systematic reviews (SRs) of cohort studies and randomised controlled trials (RCTs), plus single Mendelian randomisation studies aims to update current knowledge on the potential role of vitamin D in preventing and treating these extraskeletal diseases. Altogether, 73 SRs were identified. Observational data on primary prevention suggest an inverse association between vitamin D status and the risk of acute respiratory tract infections (ARI), dementia and cognitive decline, and depression, whereas studies regarding asthma, multiple sclerosis (MS), and type 1 diabetes mellitus (T1DM) are scarce. SRs of RCTs support observational data only for the risk of ARI. No respective RCTs are available for the prevention of chronic obstructive pulmonary disease (COPD), MS, and T1DM. SRs of RCTs indicate beneficial therapeutic effects in vitamin D-deficient patients with asthma and COPD, while effects on major depression and T1DM need to be further elucidated. Mendelian randomisation studies do not consistently support the results of SRs. Since several limitations of the included SRs and existing RCTs do not permit definitive conclusions regarding vitamin D and the selected diseases, further high-quality RCTs are warranted.

The Influence of Vitamin D on Neurodegeneration and Neurological Disorders: A Rationale for its Physio-pathological Actions

Vitamin D is a steroid hormone implicated in the regulation of neuronal integrity and many brain functions. Its influence, as a nutrient and a hormone, on the physiopathology of the most common neurodegenerative diseases is continuously emphasized by new studies. This review addresses what is currently known about the action of vitamin D on the nervous system and neurodegenerative diseases such as Multiple Sclerosis, Alzheimer's disease, Parkinson's disease and Amyotrophic Lateral Sclerosis. Further vitamin D research is necessary to understand how the action of this "neuroactive" steroid can help to optimize the prevention and treatment of several neurological diseases.

Genetic, environmental and biomarker considerations delineating the regulatory effects of vitamin D on central nervous system function

Studies show that vitamin D (vit-D) (25(OH)D), the bioactive metabolite (1,25(OH)2D3) and vit-D receptors (vit-D receptor; protein disulphide isomerase, family A member 3) are expressed throughout the brain, particularly in regions pivotal to learning and memory. This has led to the paradigm that avoiding vit-D deficiency is important to preserve cognitive function. However, presently, it is not clear if the common clinical measure of serum 25(OH)D serves as a robust surrogate marker for central nervous system (CNS) homeostasis or function. Indeed, recent studies report CNS biosynthesis of endogenous 25(OH)D, the CNS expression of the CYP group of enzymes which catalyse conversion to 1,25(OH)2D3 and thereafter, deactivation. Moreover, in the periphery, there is significant ethnic/genetic heterogeneity in vit-D conversion to 1,25(OH)2D3 and there is a paucity of studies which have actually investigated vit-D kinetics across the cerebrovasculature. Compared with peripheral organs, the CNS also has differential expression of receptors that trigger cellular response to 1,25(OH)2D3 metabolites. To holistically consider the putative association of peripheral (blood) abundance of 25(OH)D on cognitive function, herein, we have reviewed population and genetic studies, pre-clinical and clinical intervention studies and moreover have considered potential confounders of vit-D analysis.

Vitamin D and Depression: A Critical Appraisal of the Evidence and Future Directions

BACKGROUND

Growing evidence points to the role of vitamin D in the pathobiology and treatment of depression. However, the evidence is inconsistent in many aspects. The objectives of this narrative review were to evaluate the state of the evidence, synthesize the knowledge gaps, and formulate recommendations for more enhanced research in this growing area.

METHODS

Electronic searches of MEDLINE via PubMed, Cochrane Library, and Google Scholar databases were carried out from inception till February 2019 to identify relevant English language peer-reviewed articles. Abstracts generated were systematically screened for eligibility. Included articles were grouped under three broad themes: The association between vitamin D and depression, its biological underpinnings, and trials evaluating the efficacy of vitamin D supplementation in depression. Relevant data were extracted as per a structured proforma.

RESULTS

A total of 61 articles were included in the present review. Overall findings were that there is a relationship between vitamin D and depression, though the directionality of this association remains unclear. The association appears to be driven by the homeostatic, trophic, and immunomodulatory effects of vitamin D. Evidence from supplementation trials suggest a more robust therapeutic effect on subjects with major depression and concurrent vitamin D deficiency.

CONCLUSION

Serum vitamin D levels inversely correlate with clinical depression, but the evidence is not strong enough to recommend universal supplementation in depression. Enriching depression treatment trials with subjects having concurrent vitamin D deficiency appears to be a potential step forward in identifying subgroups who may maximally benefit from this approach.

Reduced Vitamin D Levels are Associated with Stroke-Associated Pneumonia in Patients with Acute Ischemic Stroke

Background and aim

Stroke-associated pneumonia (SAP) is a common complication in patients with acute ischemic stroke (AIS). This study explored the potential relationship between serum vitamin D levels and SAP.

Methods

This study recruited 863 consecutive AIS patients. In-hospital SAP was defined as a complication that occurred after stroke, during hospitalization, that was confirmed radiographically. Serum vitamin D levels were measured within 24 hrs of admission and the patients were divided into vitamin D sufficient (>50 nmol/L), insufficient (25–50 nmol/L), and deficient (<25 nmol/L) groups.

Results

In this study, 102 (11.8%) patients were diagnosed with SAP. Compared to the patients without SAP, patients with SAP had significantly lower vitamin D levels (P = 0.023). The incidence of SAP was significantly higher in patients with vitamin D deficiency than in those with vitamin D insufficiency or sufficiency (21.2% vs 16.2% & 9.5%, P = 0.006). After adjusting for confounders, vitamin D deficiency and insufficiency were independently associated with SAP (OR = 3.034, 95% CI = 1.207–7.625, P = 0.018; OR = 1.921, 95% CI = 1.204–3.066, P = 0.006, respectively). In multiple-adjusted spline regression, vitamin D levels showed a linear association with the risk of SAP (P < 0.001 for linearity).

Conclusion

Reduced vitamin D is a potential risk factor of in-hospital SAP, which can help clinicians identify high-risk SAP patients.

Prevalence of 25-hydroxyvitamin D deficiency in the acute rehabilitation population following traumatic brain injury

OBJECTIVE

To determine the prevalence of vitamin D deficiency among individuals with traumatic brain injury (TBI) undergoing acute inpatient rehabilitation.

SETTING

Inpatient rehabilitation.

PARTICIPANTS

Participants were admitted from November 1st, 2010 through June 30th, 2015 with diagnosis of mild-severe TBI and had serum 25 OH vitamin D levels checked upon admission. 369 out of 845 met inclusion.

DESIGN

Retrospective cohort.

MAIN MEASURES

25 OH vitamin D, vitamin D treatment.

RESULTS

The majority of patients were male (67%), Caucasian (89%) with private insurance (61%) and a mean age of 43.5±21.0 years. 25 OH vitamin D levels were categorized: deficient (<20 ng/mL), insufficient (20-29.9 ng/mL), and sufficient (≥30 ng/mL). There were 95 (26%) patients that were deficient, 131 (36%) that were insufficient, and 143 (39%) that were sufficient. Race/ethnicity was found to be significant (p = 0.0145) with the largest percentage of Hispanics found in the insufficient and deficient categories, and the largest percentage of Blacks in the deficient category. Most patients with deficient or insufficient vitamin D levels were prescribed vitamin D replacement during their rehab stay (p < 0.0001).

CONCLUSION

The majority of patients undergoing acute inpatient rehabilitation were found to have insufficient or deficient vitamin D levels, therefore it should be routinely screened and treated as indicated.

The effect of vitamin D on cognitive functions in young female patients: a prospective controlled study using the Montreal Cognitive Assessment

AIM

Our aim was to determine whether there is a relationship between vitamin D [25(OH)D] and cognitive functioning in women with low 25(OH)D levels.

METHODS

Ninety female patients, 25-45 years of age, who attended our outpatient clinic and had 25(OH)D levels < 30 ng/mL, were included. The Montreal Cognitive Assessment (MoCA) scale was used to determine cognitive functioning; the scale is divided into seven subgroups. Patients were divided into three subgroups according to their 25(OH)D levels. After a three-month period of 25(OH) D replacement, the patients underwent a re-evaluation using the MoCA scale.

RESULTS

The total MoCA score before treatment was significantly different from the score after treatment (p < 0.05). Language and delayed recall functions were significantly different before and after treatment (p < 0.05).

CONCLUSION

Vitamin D levels were related to cognitive functioning in our study group.

Protection of cholinergic and antioxidant system contributes to the effect of Vitamin D3 ameliorating memory dysfunction in sporadic dementia of Alzheimer's type

OBJECTIVE

Investigate Vitamin D3 (VD3) effect on the Acetylcholinesterase (AChE), oxidative damage and behavioral tests in animals subjected to Intracerebroventicular injection of Streptozotocin (ICV-STZ) simulating a Sporadic Dementia of Alzheimer's Type (SDAT) and treated with VD3 (21 days).

METHODS

Animals were divided into eight groups: Vehicle, VD12.5 μg/kg, VD42 μg/kg, VD125 μg/kg, STZ, STZ+VD12.5 μg/kg, STZ+VD42 μg/kg, STZ+VD125 μg/kg.

RESULTS

VD3 prevented the increase in AChE in groups of VD42 µg/kg and VD125 µg/kg; in AChE of synaptossomes and TBARS levels prevented the increase in group VD125 µg/kg; in ROS levels there was not a significant difference; for the Carbonyl Content all doses prevented the increase. Total Thiols prevent the decrease in VD42 µg/kg and VD125 µg/kg, and Reduced Glutathione prevented the decrease in VD125 µg/kg, Oxidized Glutathione prevented the increase in VD125 µg/kg. In relation to behavioral tests, the VD3 prevented the increase in time to find (days 2 and 3), in the time to find the platform (day 3) and in time spent in the quadrant (day 2). However, in relation to crossings there was not difference in groups. These results indicated the therapeutic effect of the VD3 in model of STZ in rats.

Co-treatment of vitamin D supplementation and aerobic training improves memory deficit in ovariectomized rat

Objective: Metabolic syndrome (MetS) and insufficient vitamin D levels are globally increasing phenomena which are correlated with cognitive impairment. This study investigated the interactive effect of aerobic training with vitamin D supplementation on memory deficit in rats with metabolic syndrome induced by ovariectomy.Methods: A total of forty Wistar rats weighing 240-255 gr were randomly matched on their body weight and divided into ovariectomy (OVX, n = 32) and sham-operated (SHAM; n = 8) groups. OV group was then divided into vitamin D supplementation (OVX + Vit D; 10000 IU/kg/week, for 8 weeks, n = 8), aerobic training (OVX + AT; n = 8), aerobic training and vitamin D supplementation (OVX + AT + Vit D; 10000 IU/kg/week, for 8 weeks, n = 8), and vehicle control group receiving sesame oil (OVX + Ses Oil; n = 8). After the end of intervention, passive avoidance learning and memory were assessed in step through passive avoidance paradigm. Obtained data were analyzed by ANOVA and post hoc Tukey test.Results: After 8 weeks of aerobic training and vitamin D supplementation, step through dark compartment latency (STL) was significantly higher and total time spent in that compartment (TSD) was lower in OVX + AT + Vit D compared to the other counterpart groups.Conclusion: Vitamin D supplementation combined with 8-week aerobic training alleviates cognitive impairment metabolic syndrome induced by ovariectomy.

Mid-life serum Vitamin D concentrations were associated with incident dementia but not late-life neuropsychological performance in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Activated Vitamin D has anti-inflammatory properties and adequate 25-hydroxyvitamin D [25(OH)D] concentrations may be important for neurocognitive function and protection against neurologic injury. We examined whether mid-life 25(OH) D concentrations were associated with later-life performance on neuropsychological testing, functional ability, depressive symptoms, and incident dementia.

METHODS

We studied 13,039 white and black ARIC participants who had serum 25(OH) D measured mid-life at visit 2 (1990-1992). Over the next ~ 20 years through visit 5 (2011-2013), participants underwent 3 additional in-person visits, annual telephone calls, and hospitalization surveillance. An extensive battery of neuropsychological outcomes were assessed at visit 5 using standardized protocols. Incident dementia was ascertained through a formal algorithm that included data from in-person cognitive testing, telephone interviews, hospital discharge codes, and death certificate codes. Diagnoses of dementia were adjudicated by expert clinician committee. For the primary cognitive analyses, we imputed for missing covariates and outcomes and used linear regression to evaluate non-concurrent cross-sectional associations of mid-life 25(OH) D (visit 2) with late-life neuropsychological outcomes (visit 5). We also used Cox regression models to examine associations of mid-life 25(OH) D and incident dementia.

RESULTS

In mid-life, the mean (SD) age of participants was 57 (6) years, 57% were women, and 24% black. Mean (SD) 25(OH) D was 24.3 (8.6) ng/mL; 33% had deficient (< 20 ng/mL), 44% intermediate (20- < 30 ng/mL), and 23% sufficient (≥30 ng/mL) 25(OH) D concentrations. Association between mid-life 25(OH) D and late-life performance on neuropsychological testing were mostly null. There was no significant association with functional ability or depressive symptoms. Results were similar in a sensitivity analysis using complete-case data (no imputation). However, after a median follow-up of 20 years, low 25(OH) D concentrations were associated with increased risk for incident dementia (p = 0.01 for trend across categories), with HR of 1.26 (95% CI 1.06, 1.49) for participants with deficient 25(OH) D, compared to sufficient concentrations.

CONCLUSION

In this community cohort, mid-life serum 25(OH) D concentrations were associated with incident dementia but not with performance on neuropsychological testing, functional ability, or depressive symptoms, 20 years later. Whether serum 25(OH) D concentrations are causally related to dementia or confounded by poorer health status remains uncertain.

TRIAL REGISTRATION

Registered on clinicaltrials.gov NCT00005131 .

Depressed Serum 25-Hydroxyvitamin D Levels Increase Hospital Stay and Alter Glucose Homeostasis in First-ever Ischemic Stroke

BACKGROUND AND OBJECTIVE

Vitamin D deficiency is internationally recognized among the potentially modifiable risk factors for ischemic cardio-cerebrovascular diseases. However, the association between vitamin D deficiency and stroke morbidity or mortality remains insufficiently known. Our aim is to investigate their relevance to 25-hydroxyvitamin D [25(OH) D] levels and clinical severity and outcome after 3 months in first-ever ischemic stroke.

METHODS

Retrospective analysis of 356 consecutive patients in first-ever ischemic stroke between 2013 and 2015. Serum 25(OH) D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome after 3 months of onset was evaluated using the modified Rankin scale (mRS).

RESULTS

Among the 356 enrolled patients, HbA1c was higher in insufficiency/deficiency group than that in the sufficiency group (6.3 ± 1.7 vs. 5.9 ± 1.1, p =0.015). The hospital stay was longer in insufficiency/deficiency group than that in the sufficiency group (11 (8-17) vs. 9.5 (7-13), p = 0.035). There was a significant inversed trend between serum 25(OH) D levels and hospital stay (OR 0.960, P = 0.031), using logistic regression.

CONCLUSION

25(OH)D levels are associated with glucose homeostasis, 25(OH) D contributes to increase the length of hospital stay. Low serum 25-OHD level is an independent predictor for hospital stay in first-ever ischemic stroke. Vitamin D deficiency did not predict functional outcome in the span of 3 months.

The potential role of serum vitamin D level in migraine headache: a case-control study

PURPOSE

Much concern was directed toward exploring the relationship between vitamin D and migraine. There is strong evidence that vitamin D supplementation can decrease frequency, severity, and duration of migraine headache attacks. The aim of this work was to investigate the difference in serum levels of 25 (OH)-vitamin D between patients with migraine and healthy controls, to determine the differences in headache characteristics according to vitamin D status, and to correlate serum 25 (OH)-vitamin D level with duration, frequency, and severity of migraine headache attacks.

PATIENTS AND METHODS

This is a case-control study conducted on 40 patients diagnosed with migraine and 40 healthy controls. History was taken from patients with migraine regarding headache characteristics. Migraine severity scale (MIGSEV) and Headache Impact Test-6 (HIT-6) were used for migraine assessment. Serum 25(OH)-vitamin D was measured for all patients and controls using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Patients with migraine had significantly lower 25(OH)-vitamin D serum level in comparison to controls (P-value=0.019). The incidence of aura, phonophobia/photophobia, autonomic manifestations, allodynia, and resistance to medications were significantly higher in migraineurs with vitamin D deficiency than those with normal vitamin D. There was a statistically significant negative correlation between 25(OH)-vitamin D serum level and attack duration in hours (P-value˂0.001), frequency of the attacks/month (P-value˂0.001), MIGSEV scale (P-value=0.001), and HIT-6 scale (P-value=0.001).

CONCLUSION

Patients with migraine had significant vitamin D deficiency compared to healthy controls. Such deficiency significantly affects headache characteristics, duration, frequency, and severity of headache attacks.

Vitamin D concentration and risk of Alzheimer disease: A meta-analysis of prospective cohort studies

BACKGROUND

Considerable controversy exists on the association between serum vitamin D concentrations and Alzheimer disease (AD) risk. This study aimed to synthesize the association of serum vitamin D concentrations with AD in adults.

METHODS

PubMed, Embase, and Cochrane library databases were searched for prospective cohort studies with data on serum vitamin D concentrations and AD risk.

RESULT

The studies that reported the adjusted relative risks (RRs) with 95% confidence intervals (CIs) of AD associated with serum vitamin D concentrations were included and subjected to subgroup analyses. Six prospective cohort studies with 1607 AD cases and 21,692 individuals were included in the meta-analysis. In 4 cohort studies with information about serum vitamin D concentrations <25 and 25 to 50 nmol/L, the random effects summary estimate did not show an increased risk of AD after adjustment for the established risk factors, while 3 cohort studies reported the RRs for incident AD per standard deviation (SD) decrease in serum vitamin D concentration and the random effects summary estimate did not show an increased risk of AD after adjustment for the established risk factors.

CONCLUSIONS

The current meta-analysis indicated that serum vitamin D deficiency (<25 nmol/L) or insufficiency (25-50 nmol/L) was not statistically significant and associated with the risk of AD.

The combined presence of hypertension and vitamin D deficiency increased the probability of the occurrence of small vessel disease in China

BACKGROUND

The exact relationship between 25-hydroxyvitamin D [25(OH) D] levels and small vessel disease (SVD) are not clear in China. The aim of this study was to determine such the association between 25(OH) D and SVD in China.

METHODS

We retrospectively enrolled 106 patients with SVD and 115 controls between Jan 2017 and Dec 2017. All the subjects were categorized into three subgroups according to the level of 25 (OH) D: vitamin D deficiency (< 12 ng/ml), insufficiency (12-20 ng/ml) and sufficiency (> 20 ng/ml).

RESULTS

Among 106 SVD patients, 80 (75.5%) were men and the mean age was 61.6 ± 13.2 years. The deficiency of 25(OH) D was observed in 76 (71.7%) of SVD patients and 47 (40.9%) of controls (P = 0.001). Compared with controls, patients with SVD were more likely to be male, a stroke history, smokers, with hyperlipidemia, higher systolic and diastolic blood pressure and low-density lipoprotein, and lower of 25(OH)D level (P < 0.05). Logistic regression analysis revealed the level of 25 (OH) D as an independent predictor of SVD (OR 0.772, 95% CI 0.691-0.862, P = 0.001). Compared with the sufficient 25 (OH) D group, the ORs of SVD in deficient and insufficient 25(OH)D group were 5.609 (95% CI 2.006-15.683) and 1.077 (95% CI: 0.338-3.428) after adjusting for potential confounders, respectively. In hypertensives with vitamin D deficient and insufficient group compared with sufficient group, the ORs of SVD increased to 9.738 (95% CI 2.398-39.540) and 1.108 (95% CI 0.232-5.280), respectively (Pinteraction = 0.001).

CONCLUSION

We found significant associations between SVD and 25(OH)D deficiency. The combined presence of hypertension and vitamin D deficiency increased the probability of developing SVD. Our findings will warrant further prospective studies in the future.

Non-Skeletal Activities of Vitamin D: From Physiology to Brain Pathology

Vitamin D is a secosteroid hormone regulating the expression of almost 900 genes, and it is involved in the regulation of calcium and phosphate metabolism, immune response, and brain development. Low blood vitamin D levels have been reported in patients affected by various diseases. Despite a large amount of literature data, there is uncertainty surrounding the role of vitamin D as a serum biomarker in Alzheimer’s disease (AD) and Parkinson’s disease (PD). Indeed, the lack of internationally recognized 25(OH)D₃ reference measurement procedures and standard materials in the past led to unstandardized serum total 25(OH)D₃ results among research and clinical care laboratories. Thus, most of the literature studies reported unstandardized data, which are of little use and make it difficult to draw conclusions of the role of vitamin D in AD and PD. This review summarizes the extra-skeletal actions of vitamin D, focusing its role in immunomodulation and brain function, and reports the issue of lacking standardized literature data concerning the usefulness of vitamin D as a biomarker in AD and PD.

Comparing the effectiveness of vitamin D plus iron vs vitamin D on depression scores in anemic females: Randomized triple-masked trial

Background: Low levels of 25-hydroxyvitamin D (25(OH)D) have been related to depression and anxiety. It seems that anemia is associated with vitamin D deficiency. We aimed to evaluate the effects of iron-vitamin D co-supplementation versus vitamin D alone on depression scores in anemic females with low levels of serum 25-hydroxyvitamin D. Methods: This randomized controlled trial was conducted on eighty premenopausal females who were recruited between May 2015 and October 2015 from primary health care centers. Women with anemia and low concentrations of 25(OH)D were randomized to either 1000 IU/d vitamin D plus 27 mg/d iron (D-Fe) or vitamin D plus placebo supplements (D-P) for 12 weeks. Depressive and anxious symptoms were evaluated with the Beck Depression Inventory (BDI) with subscales 1-13 and 14-21 and Beck Anxiety Inventory (BAI). To compare the groups, Mann-Whitney or chi-squared tests were used and within groups comparison was performed using Wilcoxon signed ranks test. The study was registered on www.clinicaltrial.org as NC 01876563. Results: The serum concentrations of 25(OH)D were increased significantly in both groups at the end of the study. In both groups, there was a significant improvement in total BDI, the BDI subscale, and the BAI scores (p<0.001). No differences were found between groups (p>0.05). Conclusion: Although the potential positive effect of vitamin D on mental health was evident, iron plus vitamin D co-supplementation did not demonstrate any significant benefits over vitamin D alone, neither in depression score reduction nor anxiety symptoms.

Impact of environmental pollution, dietary factors and diabetes mellitus on Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is complex neurodevelopmental condition described by impairments in three main behavioral areas: social deficits, impaired communication, and repetitive behaviors. Despite many years of vast study, the causes of ASD are still unknown. Various risk factors including genetic, infectious, metabolic and immunological have been investigated however, environmental, nutritional and diabetes related risk factors have not received sufficient attention. This study has provided an insight into the comprehensive interaction between environmental pollution, dietary factors and diabetes mellitus that could lead to the advancement of this debilitating neurodevelopment disorder. The literature search was done using PubMed and Google Scholar databases up to October 2018. Key words "Environmental Pollution", "Nutritional Factors", "Diabetes Mellitus", "Autism Spectrum Disorder" were selected.

Vitamin D and the nervous system

Objective: to summarise the activities that Vitamin D (VD) carries out in the brain and to clarify the potential role of VD in neurological diseases. Methods: a literature research has been performed in Pubmed using the following keywords: 'Vitamin D', 'nervous system', 'brain'. Results: the studies reviewed show that VD contributes to cerebral activity in both embryonic and adult brain, helping the connectivity of neural circuits responsible for locomotor, emotional and reward-dependent behavior. Low VD serum levels have been found in patients affected by Alzheimer Disease, Parkinson Disease, Multiple Sclerosis, Autism Spectrum Disorders, Sleep Disorders and Schizophrenia. Discussion: findings are controversial and should be interpreted with caution, since most of the studies performed have observational study set and few interventional studies are available, producing conflicting results. Overall, it can be stated that the potential role of Vitamin D in neurological diseases is mostly unclear and further randomised controlled trials are needed to understand better whether Vitamin D supplementation treatment can be useful in brain disorders.

Vitamin D Deficiency in the Gulf Cooperation Council: Exploring the Triad of Genetic Predisposition, the Gut Microbiome and the Immune System

Vitamin D is a fat soluble secosteroid that is primarily synthesized in the skin upon exposure to Ultraviolet B (UVB) sun rays. Vitamin D is essential for the growth and development of bones and helps in reducing inflammation by strengthening muscles and the immune system. Despite the endless supply of sunlight in the Gulf Cooperation Council (GCC) countries which includes United Arab Emirates, Qatar, Kuwait, Bahrain, Saudi Arabia, and Oman, Vitamin D deficiency in the (GCC) general population at various age groups remains alarmingly high. In parallel runs the increasing prevalence of acute and chronic illnesses including, autoimmune diseases, cancer, type 1 diabetes mellitus, cardiovascular disease and Inflammatory bowel disease in the adult as well as the pediatric population of these countries. The exact association between Vitamin D deficiency and chronic disease conditions remains unclear; however, studies have focused on the mechanism of Vitamin D regulation by assessing the role of the Vitamin D associated genes/proteins such as VDR (Vitamin D receptor), VDBP (Vitamin D Binding protein), CYP27B1 as these are integral parts of the Vitamin D signaling pathway. VDR is known to regulate the expression of more than 200 genes across a wide array of tissues in the human body and may play a role in controlling the Vitamin D levels. Moreover, reduced Vitamin D level and downregulation of VDR have been linked to gut dysbiosis, highlighting an intriguing role for the gut microbiome in the Vitamin D metabolism. However, this role is not fully described yet. In this review, we aim to expand our understanding of the causes of Vitamin D deficiency in the GCC countries and explore the potential relationship between the genetic predisposition, Vitamin D levels, immune system and the gut microbiome composition. Trying to unravel this complex interaction may aid in understanding the mechanism by which Vitamin D contributes to various disease conditions and will pave the way toward new therapeutics treatments for Vitamin D deficiency and its associated outcomes.

Severity of Vitamin D Deficiency Predicts Mortality in Ischemic Stroke Patients

Background

Vitamin D (VD) deficiency is considered an independent risk factor for death due to cardiovascular events including ischemic stroke (IS). We assessed the hypothesis that decreased levels of 25-hydroxyvitamin D (25-OH-D) are associated with increased risk of mortality in patients with IS.

Methods

Serum 25-OH-D, intact parathyroid hormone (iPTH), and intact fibroblast growth factor 23 (iFGF23) levels were assessed in serum of 240 consecutive patients admitted within the 24 hours after the onset of IS. Mortality data was obtained from the local registry office.

Results

Only three subjects (1.3%) had an optimal 25-OH-D level (30-80 ng/mL), 25 (10.4%) had a mildly reduced (insufficient) level, 61 (25.4%) had moderate deficiency, and 151 (62.9%) had a severe VD deficiency. 20% subjects had secondary hyperparathyroidism. The serum 25-OH-D level was significantly lower than that in 480 matched subjects (9.9 ± 7.1 vs. 21.0 ± 8.7 ng/mL). Of all the patients, 79 (32.9%) died during follow-up observation (44.9 months). The mortality rates (per year) were 4.81 and 1.89 in a group with and without severe VD deficiency, respectively (incidence rate ratio: 2.52; 95% CI: 1.44–4.68). There was no effect of secondary hyperparathyroidism and iFGF23 levels on mortality rates. Age, 25 − OH − D < 10 ng/mL, and functional status (modified Rankin scale) were significant factors increasing the risk of death in multivariable Cox proportional hazard regression test.

Conclusions

Severe VD deficiency is an emerging, strong negative predictor for survival after IS, independent of age and functional status. VD supplementation in IS survivals may be considered due to high prevalence of its deficiency. However, it is uncertain whether it will improve their survival.

Serum vitamin D and cognition in a cohort of Boston-area Puerto Ricans

Background: Vitamin D has been suggested as a protective factor for cognitive health, however results of prior studies have been mixed. To examine whether serum 25(OH)D concentration is related to cognition and cognitive decline in a study of Boston Area Puerto Ricans. Methods: We examined the association between serum 25(OH)D, cognitive function and cognitive decline in a longitudinal study of 967 Boston Area Puerto Rican adults. Results: In analyses adjusted for potential confounders, participants in the bottom quintile of 25(OH)D had similar cognitive function at baseline, as measured by a global cognitive score (mean difference: 0.09 (95% CI: -0.02, 0.19); p-trend: 0.18), and similar 2-year rates of cognitive decline (mean difference: -0.01 (95% CI: -0.09, 0.07), p-trend: 0.61) as those in the top 25(OH)D quintile. No significant associations were observed between baseline serum 25(OH)D concentration and 2-year change in individual cognitive test scores or change in executive function or memory domains. Conclusions: We observed no significant association between serum 25(OH)D and cognition in this cohort of Boston Area Puerto Ricans.

Effect of Vitamin D on Cognitive Functions in Older Adults: 24-Week Follow-Up Study

The purpose of this study is to assess the effect of vitamin D replacement on cognitive function in older adults. A total of 560 patients who underwent comprehensive geriatric assessment including Global cognitive assessment, Basic Activities of Daily Living (BADL), and Instrumental Activities of Daily Living (IADL) twice in 6-month period were retrospectively reviewed. Oral cholecalciferol was replaced to patients with vitamin D deficiency routinely. In baseline cognitive scores, BADL-IADL scores were lower in the severe deficiency group than in the deficiency and adequate groups (P < .05). With regard to the relation between changes in cognitive functions, BADL-IADL scores on the 6-month versus baseline, no difference was determined in patients with and without dementia (P > .05). Vitamin D replacement may not improve cognitive performance in older adults, even if vitamin D is raised to adequate level, suggesting that longer term replacement therapy may be needed to improve cognitive function.

Decreasing serum 25-hydroxyvitamin D levels and risk of early neurological deterioration in patients with ischemic stroke

BACKGROUND AND AIMS

Vitamin D deficiency has been linked to a higher risk of ischemic stroke. We therefore explored the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and early neurological deterioration (END) after acute ischemic stroke in a hospital-based prospective study.

METHODS

From June 2016 to June 2018, patients with ischemic stroke within 48 hr from symptom onset were consecutively recruited. Serum 25(OH)D levels were measured at admission. END was defined as an increase of ≥1 point in motor power or ≥2 points in the total National Institute of Health Stroke Scale score within 7 days after admission. Multiple logistic regression models were performed to calculate the odds ratio (OR) and confidence intervals (CI) of 25(OH)D levels in predicting END.

RESULTS

A total of 478 subjects were enrolled, of which 136 (28.5%) patients developed END. The mean 25(OH)D levels were 49.5 ± 15.8 nmol/L. Univariate logistic regression analysis showed that advanced age, white matter lesions, high level of body mass index, diastolic blood pressure, fasting blood glucose and homocysteine, and low 25(OH)D levels were associated with END. Furthermore, multivariate regression analysis demonstrated that the first quartile of 25(OH)D concentrations [OR, 2.628; 95% CI,1.223-5.644; p = 0.013] was independently risk factor for END.

CONCLUSIONS

This study illustrated that lower 25(OH)D levels might be associated with an increasing risk of END in acute ischemic stroke patients.

The Association Between Vitamin D Status, Vitamin D Supplementation, Sunlight Exposure, and Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND This literature review and meta-analysis aimed to determine the association between deficiency of vitamin D, or 25-hydroxyvitamin D, and Parkinson's disease, and whether vitamin D from supplements and sunlight improves the symptoms of Parkinson's disease. MATERIAL AND METHODS A literature review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Systematic literature review was performed using databases that included the Web of Science, PubMed, the Cochrane Library, and Embase. The Jadad scale (the Oxford quality scoring system) and the Newcastle-Ottawa scale (NOS) were used to evaluate the quality of the studies. RESULTS Eight studies were included in the meta-analysis. Both 25-hydroxyvitamin D insufficiency (<30 ng/mL) (OR, 1.77; 95% CI, 1.29-2.43; P<0.001) and deficiency (<20 ng/mL) (OR, 2.55; 95% CI, 1.98-3.27; P<0.001) were significantly associated with an increased risk of Parkinson's disease when compared with normal controls Sunlight exposure (³15 min/week) was significantly associated with a reduced risk of Parkinson's disease (OR, 0.02; 95% CI, 0.00-0.10; P<0.001). The use of vitamin D supplements was effective in increasing 25-hydroxyvitamin D levels (SMD, 1.79; 95% CI, 1.40-2.18; P<0.001), but had no significant effect on motor function (MD, -1.82; 95% CI, -5.10-1.45; P=0.275) in patients with Parkinson's disease. CONCLUSIONS Insufficiency and deficiency of 25-hydroxyvitamin D and reduced exposure to sunlight were significantly associated with an increased risk of Parkinson's disease. However, vitamin D supplements resulted in no significant benefits in improving motor function for patients with Parkinson's disease.

Serum 25-hydroxyvitamin D3 level may be associated with olfactory dysfunction in de novo Parkinson's disease

The purpose of our study was to investigate the association between olfactory function in Parkinson's disease (PD) and serum vitamin D status. Thirty-nine patients with de novo PD were enrolled in this study. Olfactory function was assessed by an odor identification test, as a part of the KVSS (Korean version of sniffin' sticks) II test. All patients were also assessed with the NMSS (Non-Motor Symptoms Scale for PD) to check the subjective change in ability to smell. Vitamin D status was determined by measuring the level of serum 25-hydroxyvitamin D3 (25-OHD3). Multiple linear regression tests and correlation analysis were applied to verify the association between serum 25-OHD3 level and patients' subjective and objective olfactory dysfunction. The serum 25-OHD3 level was independently associated with odor identification score in patients with PD (β = 0.38, p < 0.01). Another statistically significant variable was clinical subtype of PD (Intermediate subtype: β = -0.33, p < 0.05; Akinetic rigid type: β = -0.55, p < 0.01). The serum 25-OHD3 level was also negatively correlated with the score for item number 28 in NMSS (Spearman's rho = -0.32, p < 0.05). Our results showed that vitamin D status might be an independent factor for olfactory dysfunction in PD. Although the underlying mechanism has not been clearly identified, we postulate that vitamin D plays a role in the pathogenesis of olfactory dysfunction in PD. Further investigation to elucidate the precise relationship of vitamin D to PD is essential.

Vitamin D in Neurological Diseases: A Rationale for a Pathogenic Impact

It is widely known that vitamin D receptors have been found in neurons and glial cells, and their highest expression is in the hippocampus, hypothalamus, thalamus and subcortical grey nuclei, and substantia nigra. Vitamin D helps the regulation of neurotrophin, neural differentiation, and maturation, through the control operation of growing factors synthesis (i.e., neural growth factor [NGF] and glial cell line-derived growth factor (GDNF), the trafficking of the septohippocampal pathway, and the control of the synthesis process of different neuromodulators (such as acetylcholine [Ach], dopamine [DA], and gamma-aminobutyric [GABA]). Based on these assumptions, we have written this review to summarize the potential role of vitamin D in neurological pathologies. This work could be titanic and the results might have been very fuzzy and even incoherent had we not conjectured to taper our first intentions and devoted our interests towards three mainstreams, demyelinating pathologies, vascular syndromes, and neurodegeneration. As a result of the lack of useful therapeutic options, apart from the disease-modifying strategies, the role of different risk factors should be investigated in neurology, as their correction may lead to the improvement of the cerebral conditions. We have explored the relationships between the gene-environmental influence and long-term vitamin D deficiency, as a risk factor for the development of different types of neurological disorders, along with the role and the rationale of therapeutic trials with vitamin D implementation.

Еffects of fortified milk on cognitive abilities in school-aged children: results from a randomized-controlled trial

BACKGROUND

Micronutrients such as vitamins and minerals and long-chain polyunsaturated omega-3 fatty acids (PUFAs) are essential for children's brain development and cognitive functions. The current study investigated whether milk fortified with micronutrients and PUFA can result in improved cognitive function in mainstream school children.

METHODS

One-hundred-and-nineteen children (age 8-14, 58 boys) were randomly allocated to a fortified milk group or a regular full milk control group. Participants consumed 0.6L/day of the milk for 5 months. We recorded relevant biochemical, anthropometric, and cognitive measures (working memory and processing speed) at the start of the study and at follow-up after 5 months.

RESULTS

The fortified milk significantly increased docosahexaenoic acid (DHA) (change from baseline of 28% [95% CI 17-39%] vs. -6% [95% CI - 13 to 0%] in the control group) and serum 25OH-vitamin D concentrations (41% [95% CI 30-52%] vs. 21% [95% CI 11-30%] in the control group). The fortified milk improved working memory on one of two tests (32% [95% CI 17-47%] vs. 13% [95% CI 6-19%] in the control group). The fortified milk also indirectly increased processing speed on one of two tests; this effect was small and completely mediated by increases in 25OH-vitamin D concentrations.

CONCLUSIONS

These results suggest that fortifying milk with micronutrients and PUFA could be an effective and practical way to aid children's cognitive development.

Serum 25-hydroxyvitamin D deficiency predicts poor outcome among acute ischemic stroke patients without hypertension

25-Hydroxyvitamin D (25(OH)D) deficiency is a frequent condition in patients who suffer acute ischemic stroke (AIS), and several studies suggested that it may be associated with a poorer prognosis. Whether this association is affected by hypertension is unclear. Our aim was to investigate the association between 25(OH)D levels and both clinical severity and outcome after 3 months in AIS patients stratified by the history of hypertension. Consecutive first-ever AIS patients admitted to the Third Affiliated Hospital of Sun Yat-sen University, China were identified. Clinical information was collected. Serum 25(OH)D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome was evaluated after 3 months of onset using the modified Rankin Scale (mRS). Multivariate analyses were performed using logistic regression models. During the study period, 377 patients were diagnosed as AIS and were included in the analysis. 25(OH)D deficiency was not associated with the risk of NIHSS at admission and 3 months mRS both in total patients and the hypertension subgroup. Among AIS without hypertension, 25(OH)D deficiency subjects had a significantly higher of NIHSS at admission and 3 months mRS compared with those with 25(OH)D ≥ 50 nmol/L. The odds ratios (95% confidence interval) were 5.51(1.83-16.60) and 4.63(1.53-14.05) in the multivariable adjusted model (P for linear trend < 0.05). Serum lower 25(OH)D levels can be seen as an independent prognostic factor of functional outcome in AIS without hypertension. Additional studies about improving prognosis of AIS by vitamin D supplementation could be first applied to these patients.

Prenatal co-exposure to neurotoxic metals and neurodevelopment in preschool children: The Environment and Childhood (INMA) Project

We sought to determine whether prenatal co-exposure to As, Cd, Hg, Mn, and Pb was associated with impaired neurodevelopment in preschool children from the Spanish Environment and Childhood (INMA) Project, using the placenta as exposure matrix. We measured metal levels in placenta tissue samples randomly selected from five of the seven population-based birth cohorts participating in the INMA Project, collected between 2000 and 2008. Neuropsychological assessment of cognitive and motor function was carried through the use of the McCarthy Scales of Children's Abilities (MSCA) at the age of 4-5years. Data on placental metal levels, MSCA scores, and relevant covariates was available for 302 children. Mn was detected in all placental samples, Cd in nearly all placentas (99%) and As, Hg, and Pb in 22%, 58%, and 17% of the placentas, respectively. After adjusting for potential confounders, detectable As levels were associated with decrements in global and verbal executive functions and quantitative abilities; detectable Hg was associated with lower scores on the verbal function of posterior cortex in a dose-response manner, and non-linearly related to poorer motor function and gross motor skills; and Mn levels were associated with decrement in perceptual-performance skills in a dose-response manner but with better memory span and quantitative skills. A synergistic interactive effect was found between As and Pb with respect to the general cognitive score, whereas an antagonistic interaction was found between Mn and Hg. Prenatal exposure to As and Hg may be a risk factor for cognitive and motor impairment in children, while the effects of Cd and Mn on neurodevelopment are less clear. Future studies should examine combined and interactive effects of exposure to multiple metals during vulnerable periods of brain development prospectively.

Vitamin D Status and Intakes and Their Association With Cognitive Trajectory in a Longitudinal Study of Urban Adults

CONTEXT

Serum 25-hydroxyvitamin D [25(OH)D], and dietary and supplemental vitamin D may influence cognitive outcomes.

OBJECTIVES

Sex-, age-, and race-specific associations of vitamin D status and intake with longitudinal change in various cognitive domains were examined in a large sample of ethnically and socioeconomically diverse US urban adults.

DESIGN

Two prospective waves of data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study were used.

PARTICIPANTS

Adults in Baltimore, Maryland, aged 30 to 64 years at baseline (n = 1231 to 1803), were followed for a mean (± standard deviation) of 4.64 ± 0.93 years. Visit 1 occurred between 2004 and 2009; visit 2, between 2009 and 2013; there were 1.5 to 2.0 visits per participant.

MAIN OUTCOME AND EXPOSURE MEASURES

Cognitive performance was assessed using 11 test scores covering domains of global cognition, attention, learning/memory, executive function, visuospatial/visuoconstruction ability, psychomotor speed, and language/verbal. Serum 25(OH)D, vitamin D intake, and use of supplements containing vitamin D were the key exposures.

RESULTS

A consistent relationship was found between vitamin D status (overall) and supplemental intake (older women and black adults), with a slower rate of decline in the domain of verbal fluency. Higher dietary intake of vitamin D was linked to slower rate of decline in verbal memory among younger women, and a slower rate of decline in visual memory/visuoconstructive abilities among white adults. All other associations were inconsistent.

CONCLUSIONS

Vitamin D status and intakes were inversely related to domain-specific cognitive decline in US urban adults.