Vitamin D deficiency and its role in neurological conditions: A review

Association of vitamin D deficiency with post-exercise hypotension and arterial stiffness following prolonged endurance exercise in healthy young men

BACKGROUND

Vitamin D is associated with vascular function; however, the impact of different vitamin D levels on vascular elasticity following prolonged exercise remains uncertain. The primary objective of this study was to investigate the association of vitamin D levels with changes in peripheral pulse wave velocity (pPWV) and the magnitude of acute post-exercise hypotension (PEH) following prolonged endurance exercise in healthy young men.

METHODS

All the participants were divided into two groups: the 25-hydroxyvitamin D (25(OH)D) sufficiency group (25(OH)D ≧50 nmol/L) and the deficiency group (25(OH)D < 50 nmol/L). A cardiopulmonary exercise test for maximal oxygen uptake (V . O2max) was performed on the graded cycling. The prolonged exercise was set at 60% V . O2max for 120 min of continuous riding on a stationary bicycle. The pPWV and blood pressure were measured at baseline and 0, 15, 30, 45, 60 min after prolonged endurance exercise.

RESULTS

Post hoc analysis revealed that the vitamin D sufficient group had a greater magnitude of PEH than the deficiency group at post-45 min. Multiple linear regression analyses showed a significant correlation between 25(OH)D and both pPWV (p = 0.036) and PEH (p = 0.007), after adjusting for V . O2max, weight, height, and physical activity. In addition, the 25(OH)D deficiency group also had higher pPWV at post-15 min (5.41 ± 0.93 vs 4.84 ± 0.75 m/s), post-30 min (5.30 ± 0.77 vs 4.87 ± 0.50 m/s), post-45 min (5.56 ± 0.93 vs 5.05 ± 0.68 m/s) than the sufficiency group.

CONCLUSIONS

There was a positive correlation between 25(OH)D levels and systolic PEH following prolonged endurance exercise. Individuals with sufficient 25(OH)D status may have better vascular elasticity and more efficient blood pressure regulation during exercise.

Causal associations between modifiable risk factors and isolated REM sleep behavior disorder: a mendelian randomization study

Objectives

This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).

Methods

Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses.

Results

Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], p = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], p = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], p = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], p = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], p = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated.

Conclusion

Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.

Interaction between vitamin D level, antiseizure medications (ASM) and seizure control in epilepsy adult patients

OBJECTIVE

To investigate vitamin D levels and factors associated with seizure control in adult patients with epilepsy (APE).

METHOD

Cross-sectional study with APE in routine outpatient follow-up at a neurology clinic. Clinical variables, antiseizure medications (ASM) and vitamin D were investigated. Data were analyzed using the Chi2 or Fisher's exact tests, Mann-Whitney, Spearman's correlation coefficient, ROC curve and univariate and multiple logistic regression analysis.

RESULTS

Mean age was 46.5±15.1 years and disease duration was 27.5±17.0 years; 52.7% (n=49) of patients used one ASM and 47.3% (n=44) used≥2 ASM. There was a significant difference in the level of vitamin D according to the number of ASM and it was higher in patients who used a single ASM (26.02±10.22 versus 22.50±8.69; P=0.048). In the logistic regression, when vitamin D level was set at 20ng/mL, the chance of seizure control for patients using a single ASM was 6.99 times greater than for those using≥2 ASM. When vitamin D level was set at 40ng/mL, the number of ASM did not modify seizure control. There was no correlation between vitamin D and disease duration, patient age and age at the time of the first seizure. In the logistic regression, it was observed that satisfactory levels of vitamin D did not modify potential seizure control.

CONCLUSION

Thirty-three percent (33%) of patients presented with vitamin D deficiency (values below 20ng/mL) and 80% had vitamin D levels below what is recommended (30ng/mL). The use of ASM, when associated with different levels of vitamin D, modified the probability of seizure control in APE. Vitamin D levels and intrinsic epilepsy factors are associated with failure to effectively control seizures.

Middle-term nitrogen dioxide exposure and electrocardiogram abnormalities: A nationwide longitudinal study

BACKGROUND

Recently, professionals, such as those from the World Health Organization, have recommended a rigorous standard for nitrogen dioxide (NO2), a typical urban air pollutant affected by regular traffic emissions, based on its short-term and long-term cardiorespiratory effects. However, the association between middle-term NO2 exposure and cardiovascular disorders remains unknown.

OBJECTIVES

This study was conducted to examine the relationship between NO2 exposure and its middle-term cardiovascular risks indicated by electrocardiogram (ECG) abnormalities.

METHOD

We included 61,094 subjects (132,249 visits) with repeated ECG observations based on longitudinal data from the China National Stroke Screening Survey (CNSSS). The NO2 exposure concentration was derived from a predictive model, measured as the monthly average concentration in the 6 months of preceding the ECG measurement. We used the generalized estimation equation to assess the association between NO2 exposure and ECG abnormalities.

RESULT

For each 10 µg/m3 increase in monthly average NO2 concentration, the odds ratio of ECG abnormalities was 1.10 (95% confidence interval [CI] 1.09-1.12) after multiple adjustments. Stratified regression analyses of urban and rural residents showed associations between middle-term NO2 exposure and ECG abnormalities in urban (OR 1.09 [95% CI 1.08-1.11]) and rural residents (OR 1.14 [95% CI 1.10-1.19]). The association was robust within different subpopulations. Associations generally remained statistically significant (OR 1.03 [95% CI 1.02-1.05]) after extra adjustment for PM2.5. Exposure-response relationship analysis revealed a nearly linear relationship between NO2 exposure and the risk for ECG abnormalities.

CONCLUSION

Using the variation in ECG signals as a potentially reversible indicator for subclinical risk in cardiovascular systems, our study provides additional evidence on the increased risk posed by middle-term NO2 exposure. Our study showed that policies controlling for NO2 concentrations are beneficial to prevent cardiovascular diseases among Chinese adults.

Targeting Glutamate Neurotoxicity through Dietary Manipulation: Potential Treatment for Migraine

Glutamate, the main excitatory neurotransmitter in the central nervous system, is implicated in both the initiation of migraine as well as central sensitization, which increases the frequency of migraine attacks. Excessive levels of glutamate can lead to excitotoxicity in the nervous system which can disrupt normal neurotransmission and contribute to neuronal injury or death. Glutamate-mediated excitotoxicity also leads to neuroinflammation, oxidative stress, blood-brain barrier permeability, and cerebral vasodilation, all of which are associated with migraine pathophysiology. Experimental evidence has shown the protective effects of several nutrients against excitotoxicity. The current review focuses on the mechanisms behind glutamate's involvement in migraines as well as a discussion on how specific nutrients are able to work towards restoring glutamate homeostasis. Understanding glutamate's role in migraine is of vital importance for understanding why migraine is commonly comorbid with widespread pain conditions and for informing future research directions.

Neuroimmunological Effect of Vitamin D on Neuropsychiatric Long COVID Syndrome: A Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19). COVID-19 is now recognized as a multiorgan disease with a broad spectrum of manifestations. A substantial proportion of individuals who have recovered from COVID-19 are experiencing persistent, prolonged, and often incapacitating sequelae, collectively referred to as long COVID. To date, definitive diagnostic criteria for long COVID diagnosis remain elusive. An emerging public health threat is neuropsychiatric long COVID, encompassing a broad range of manifestations, such as sleep disturbance, anxiety, depression, brain fog, and fatigue. Although the precise mechanisms underlying the neuropsychiatric complications of long COVID are presently not fully elucidated, neural cytolytic effects, neuroinflammation, cerebral microvascular compromise, breakdown of the blood-brain barrier (BBB), thrombosis, hypoxia, neurotransmitter dysregulation, and provoked neurodegeneration are pathophysiologically linked to long-term neuropsychiatric consequences, in addition to systemic hyperinflammation and maladaptation of the renin-angiotensin-aldosterone system. Vitamin D, a fat-soluble secosteroid, is a potent immunomodulatory hormone with potential beneficial effects on anti-inflammatory responses, neuroprotection, monoamine neurotransmission, BBB integrity, vasculometabolic functions, gut microbiota, and telomere stability in different phases of SARS-CoV-2 infection, acting through both genomic and nongenomic pathways. Here, we provide an up-to-date review of the potential mechanisms and pathophysiology of neuropsychiatric long COVID syndrome and the plausible neurological contributions of vitamin D in mitigating the effects of long COVID.

Effects of Vitamin D on Migraine: A Meta-Analysis

OBJECTIVE

The aim of this study was to evaluate the difference in mean serum 25-hydroxy vitamin D level between migraineurs and nonmigraineurs, the association between hypovitaminosis D and migraine, and the effects of oral vitamin D supplementation on migraine-related symptoms as compared to placebo.

METHODS

Relevant databases were searched for observational studies and randomized-controlled trials (RCTs) which evaluated the difference in mean serum 25-hydroxy vitamin D level between migraineurs and nonmigraineurs; the association between hypovitaminosis D and migraine; and the effects of vitamin D supplementation on migraine-frequency, duration, and severity. Pooled mean difference and odds ratio were calculated (random-effects model, RevMan version 5.3).

RESULTS

Ten observational studies and two RCTs were included. The serum 25-hydroxy vitamin D level in the migraineurs was significantly lower than that in the nonmigraineurs [mean difference - 4.44 ng/mL (95% CI: -6.11, -2.77)] (low-GRADE evidence). Hypovitaminosis D was found to be significantly associated with migraine [OR: 1.95 (95% CI: 1.07, 3.58)] (low-GRADE evidence). As compared to placebo, oral vitamin D supplementation significantly reduced the monthly migraine-frequency [mean difference: -2.20 (95% CI: -3.04, -1.36)].

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although it did not reduce the migraine-duration [mean difference: -16.00 hours per month (95% CI: -42.77, 10.76)] and migraine-severity score [standardized mean difference: -0.23 (95% CI: -0.79, 0.32)] (moderate-GRADE evidence).

CONCLUSION

Serum 25-hydroxy vitamin D level was significantly lower in the migraineurs than that in the nonmigraineurs, and hypovitaminosis D was significantly associated with migraine. Oral vitamin D supplementation significantly reduced migraine-frequency, but not its duration and severity.

Molecular insights into the pathogenic impact of vitamin D deficiency in neurological disorders

Neurological disorders are the major cause of disability, leading to a decrease in quality of life by impairing cognitive, sensorimotor, and motor functioning. Several factors have been proposed in the pathogenesis of neurobehavioral changes, including nutritional, environmental, and genetic predisposition. Vitamin D (VD) is an environmental and nutritional factor that is widely distributed in the central nervous system's subcortical grey matter, neurons of the substantia nigra, hippocampus, thalamus, and hypothalamus. It is implicated in the regulation of several brain functions by preserving neuronal structures. It is a hormone rather than a nutritional vitamin that exerts a regulatory role in the pathophysiology of several neurological disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and multiple sclerosis. A growing body of epidemiological evidence suggests that VD is critical in neuronal development and shows neuroprotective effects by influencing the production and release of neurotrophins, antioxidants, immunomodulatory, regulation of intracellular calcium balance, and direct effect on the growth and differentiation of nerve cells. This review provides up-to-date and comprehensive information on vitamin D deficiency, risk factors, and clinical and preclinical evidence on its relationship with neurological disorders. Furthermore, this review provides mechanistic insight into the implications of vitamin D and its deficiency on the pathogenesis of neurological disorders. Thus, an understanding of the crucial role of vitamin D in the neurobiology of neurodegenerative disorders can assist in the better management of vitamin D-deficient individuals.

Neuroprotective effects of combined therapy with memantine, donepezil, and vitamin D in ovariectomized female mice subjected to dementia model

Women older than 60 have a higher risk of dementia, aging-related cognitive decline, and Alzheimer's Disease (AD) than the rest of the population. The main reason is hormonal senescence after menopause, a period characterized by a decline in estrogen levels. Since the effectiveness of drugs currently approved for the treatment of AD is limited, it is necessary to seek the development of new therapeutic strategies. Vitamin D deficiency is prevalent in AD patients and individuals with dementia in general. The supplementation of this vitamin in dementia patients might be an interesting approach for increasing the effectiveness of pre-existing medications for dementia treatment. Thus, the present study aims to investigate the effect of vitamin D treatment associated with memantine and donepezil in female mice submitted to ovariectomy (OVX) for five months and subjected to a dementia animal model induced by intracerebroventricular injection of aggregated amyloid βeta (Aβ_1-42). For this purpose, Balb/c mice were divided into five experimental groups, which received 17 days of combined therapy with vitamin D, donepezil, and memantine. Then, animals were subjected to behavioral tests. OVX groups exhibited reduced levels of estradiol (E2) in serum, which was not altered by the combined therapy. Higher levels of vitamin D3 were found in the OVX animals submitted to the triple-association treatment. Mice exposed to both OVX and the dementia animal model presented impairment in short and long-term spatial and habituation memories. Also, female mice exposed to Aβ and OVX exhibited a reduction in brain-derived neurotrophic factor (BDNF) and interleukin-4 (IL-4) levels, and an increase in tumor necrose factor-α (TNFα) levels in the hippocampus. Besides, increased levels of IL-1β in the hippocampus and cerebral cortex were observed, as well as a significant increase in immunoreactivity for glial fibrillary acidic protein (GFAP), an astrocytes marker, in the hippocampus. Notably, triple-association treatment reversed the effects of the exposition of mice to Aβ and OVX in the long-term spatial and habituation memories impairment, as well as reversed changes in TNFα, IL-1β, IL-4, and GFAP immunoreactivity levels in the hippocampus of treated animals. Our results indicate that the therapeutic association of vitamin D, memantine, and donepezil has beneficial effects on memory performance and attenuated the neuroinflammatory response in female mice subjected to OVX associated with a dementia animal model.

Impact of vitamin D on the prognosis after spinal cord injury: A systematic review

Vitamin D (VitD) insufficiency is a worldwide health problem and affects billions of people. Spinal cord injury (SCI) patients seem more susceptible to developing suboptimal levels of VitD. However, the literature regarding its impact on the prognosis of SCI is limited. Thus, in this review, we systematically investigated the published studies via a combination of keywords associated with SCI and VitD in four medical databases (Medline, Embase, Scopus, and Web of Science). All included studies were analyzed, and selected clinical data on the prevalence of VitD insufficiency (serum 25-hydroxyvitamin D < 30 ng/ml) and deficiency (serum 25-hydroxyvitamin D < 20 ng/ml) were collected for further meta-analysis via random effects. Through literature review, a total of 35 studies were eligible and included. The meta-analysis of VitD status (13 studies, 1,962 patients) indicated high prevalence of insufficiency (81.6% [75.7, 87.5]) and deficiency (52.5% [38.1, 66.9]) after SCI. Besides, low levels of VitD were reported to be associated with a higher risk of skeletal diseases, venous thromboembolism, psychoneurological syndromes, and chest illness after injury. Existing literature suggested that supplemental therapy might act as an adjuvant treatment to facilitate post-injury rehabilitation. Non-human experimental studies highlighted the neuroprotective effect of VitD, which was associated with enhancing axonal and neuronal survival, suppressing neuroinflammation, and modulating autophagy. Therefore, the current evidence suggests that the prevalence of VitD insufficiency is high in the SCI population, and low-level VitD may impair functional restoration after SCI. VitD supplemental treatment may have potential benefits to accelerate rehabilitation in mechanistically related processes after SCI. However, due to the limitation of the available evidence, more well-designed randomized controlled trials and mechanism experimental research are still needed to validate its therapeutic effect, elucidate its neuroprotective mechanism, and develop novel treatments.

Vitamin D3 Promotes Structural and Functional Recovery After Vincristine-Induced Peripheral Neuropathy in Rats: An Experimental Study

Background Vincristine-induced peripheral neuropathy (VIPN) is a distal axonopathy characterized by the loss of distal myelinated axons. This study aimed to assess the potential neuroregenerative roles of vitamin D3 using functional and electron microscopic analyses in a rat model of VIPN. Methodology A total of 40 female Wistar rats were randomly divided into four main groups: Group 1 (control, n = 10), Group 2 (vincristine, n = 10), Group 3 (vincristine + vitamin D3, n = 10), and Group 4 (vincristine + vehicle, n = 10). Vincristine was administered intraperitoneally at a dose of 0.15 mg/kg, for two weeks, to induce peripheral neuropathy. Following successful induction, vitamin D3 (500 IU/kg/day) and vehicle treatments were applied weekly over four weeks. Structural (electron microscopic analysis) and functional analysis (von Frey test, pinch test, and electrophysiological analysis) were performed to assess functional recovery after peripheral nerve impairment. Results Withdrawal responses to mechanical allodynia and pinch tests were significantly higher in the vitamin D3-treated group (P < 0.05). The electrophysiological analysis also supported these results. Electron microscopic evaluation revealed that the remyelinated nerve fibers in the vitamin D3-treated group (Group 3) had thick myelin sheaths and normal axonal morphology. Conclusions Our study demonstrated that vitamin D3 could promote functional and structural recovery in a rat model of VIPN. Further studies should be conducted to elucidate the underlying mechanisms by which vitamin D3 exerts its regenerative effects in VIPN, using alternative administration protocols.

Is vitamin D supplementation of potential benefit for community-living people with Alzheimer's disease?

BACKGROUND

Vitamin D is associated not only with effects on calcium and bone metabolisms but also with many chronic diseases. Low vitamin D levels in patients with Alzheimer's disease have been widely reported in the literature.

AIM

The purpose of this study was to critically review the potential benefit of vitamin D supplementation in individuals with Alzheimer's disease living in the community.

METHODS

A systematic literature search was conducted in PubMed, CINAHL, EMBASE and the Cochrane Library for papers published 2011-2018.

RESULTS

Seven papers were selected, consisting of one clinical trial, five cohort studies and one systematic review. Studies showed an association only between vitamin D deficiency and lower attention in older people. None of the reviewed studies provided evidence of a positive impact of vitamin D supplementation on cognitive function in older people with Alzheimer's disease.

CONCLUSION

There was no evidence that vitamin D supplementation has a direct benefit for Alzheimer's disease. The review synthesised the existing body of knowledge and concluded that optimum levels of vitamin D (neither too low nor too high) do appear to have positive effects on patient outcomes and quality of life. It is still unclear why vitamin D intake is inadequate as people age. Further research is needed to clarify vitamin-D-related aspects of Alzheimer's disease.

Determinants of Dietary Vitamin D Intake in Population-Based Cohort Sample of Polish Female Adolescents

Vitamin D has a pleiotropic effect and its deficiency is a risk factor for many diseases. The purpose of this study was to analyze the dietary intake of vitamin D and the factors determining this intake by female post-primary school students in Poland. The study was conducted on a nationwide sample of 4469 female Polish adolescents (aged 14-20) recruited from all regions across Poland. The vitamin D intake was assessed using VIDEO-FFQ (Vitamin D Estimation Only-Food Frequency Questionnaire). The median dietary vitamin D intake was 2.33 μg per day and it was lower than the 15 μg recommended in Poland for more than 98% of the group. The highest vitamin D intake per day was noted for fish (0.52 μg), whereas the lowest was noted for fats (0.04 μg). Factors that influenced the dietary vitamin D intake were the amount and species of fish consumed, region of residence, use of vitamin D supplements, and vegetarian or vegan diets. In contrast, vitamin D intake did not depend on body mass index and age. Based on the results of the survey, it can be concluded that the alarmingly low intake of vitamin D by Polish female adolescents is a result of the limited supply of vitamin D primarily from fish and fish products. This may be due to insufficient nutritional knowledge, indicating an urgent need to educate the surveyed population in this area.

Long-Term Exposure to Ozone Increases Neurological Disability after Stroke: Findings from a Nationwide Longitudinal Study in China

Simple Summary

In China, ozone is a major air pollutant that has been linked to stroke incidence and mortality. However, how long-term exposure to ozone affects the life quality among stroke survivors is unknown. This study presents a longitudinal analysis of nationwide data of Chinese adults, and shows that exposure to ozone can increase the risk of post-stroke disability. Taking ambient O₃ under control can delay the progression of neurological disability among stroke survivors.

Abstract

Exposure to ozone (O₃) is associated with stroke incidence and mortality. However, whether long-term exposure to O₃ is associated with post-stroke neurological disability remains unknown. This study investigated the relationship based on the longitudinal analysis of China National Stroke Screening Survey (CNSSS), which included 65,778 records of stroke patients. All of the analyzed patients were followed-up at least twice. Stroke disability was assessed using the modified Rankin scale (mRS). Long-term exposure was assessed by the peak-season or annual mean of maximum 8-h O₃ concentrations for 365 days before the mRS measurement. We used fixed-effect models to evaluate the associations between O₃ and mRS score, with adjustment for multiple confounders, and found a 10 µg/m³ increase in peak-season O₃ concentration was associated with a 0.0186 (95% confidence interval [CI] 0.0115–0.0256) increment in the mRS score. The association was robust in various subpopulations. For secondary outcomes, for each 10 µg/m³ increment in peak-season O₃, the odds ratio of an increased mRS score (vs. unchanged or decreased mRS score) increased by 23% (95% CI 9–37%). A nonlinear analysis showed a sublinear association between O₃ exposure and risk for post-stroke disability. A saturation effect was observed at an O₃ concentration of more than ~120 μg/m³. Our study adds to evidence that long-term exposure to O₃ increases the risk of neurological disability after stroke.

Vitamin D Deficiency and Prognosis after Traumatic Brain Injury with Intracranial Injury: A Multi-Center Observational Study

Vitamin D may be important for neuroprotection after traumatic brain injury (TBI) by modifying the inflammatory response. The objective of this study was to evaluate the association between vitamin D deficiency and functional and survival outcomes in patients with TBI and intracranial injury. This study was a prospective multi-center cohort study conducted on adult TBI patients, with intracranial hemorrhage or diffuse axonal injury confirmed by radiological examination, admitted to five participating emergency departments (EDs) from December 2018 to June 2020. The study outcomes were good functional recovery at hospital discharge and survival at 6-months after injury. The primary exposure was serum vitamin D deficiency (0-10 ng/mL). Multi-level logistic regression analysis was performed to estimate the association between vitamin D deficiency and the study outcomes. Among 606 patients, 101 (16.7%) patients had vitamin D deficiency at the time of ED arrival. Good functional recovery was observed in 65.2% (395/606) of total population, and this proportion was significantly lower in the vitamin D deficiency group than the non-deficiency group (56.4 vs. 66.9%, p = 0.04, adjusted odds ratio (OR; 95% confidence interval [CI]): 0.56 (0.36-0.88)). Overall survival rate at 6 months after injury was 79.5% (434/546), and patients with vitamin D deficiency had significantly lower likelihood of survival at 6 months than patients without deficiency [75.0 vs. 80.3%, adjusted OR (95% CI): 0.59 (0.39-0.89)]. Vitamin D deficiency is associated with poor functional outcomes at hospital discharge and mortality at 6-months after injury in TBI patients with intracranial hemorrhage or diffuse axonal injury.

Amyotrophic Lateral Sclerosis as an Adverse Drug Reaction: A Disproportionality Analysis of the Food and Drug Administration Adverse Event Reporting System

INTRODUCTION

Amyotrophic lateral sclerosis is a fatal progressive disease with a still unclear multi-factorial etiology. This study focused on the potential relationship between drug exposure and the development of amyotrophic lateral sclerosis by performing a detailed analysis of events reported in the FDA Adverse Event Reporting System database.

METHODS

The FDA Adverse Event Reporting System quarterly data (January 2004-June 2020) were downloaded and deduplicated. The reporting odds ratios and their 95% confidence intervals were calculated as a disproportionality measure. The robustness of the disproportion was assessed accounting for major confounders (i.e., using a broader query, restricting to suspect drugs, and excluding reports with amyotrophic lateral sclerosis as an indication). Disproportionality signals were prioritized based on their consistency across analyses (reporting odds ratio stability).

RESULTS

We retained 1188 amyotrophic lateral sclerosis cases. Sixty-two drugs showed significant disproportionality for amyotrophic lateral sclerosis onset in at least one analysis, and 31 had consistent reporting odds ratio stability, including tumor necrosis factor-alpha inhibitors and statins. Disproportionality signals from ustekinumab, an immunomodulator against interleukins 12-23 used in autoimmune diseases, and the anti-IgE omalizumab were consistent among analyses and unexpected.

CONCLUSIONS

For each drug emerging as possibly associated with amyotrophic lateral sclerosis onset, biological plausibility, underlying disease, and reverse causality could be argued. Our findings strengthened the plausibility of a precipitating role of drugs primarily through immunomodulation (e.g., tumor necrosis factor-alpha, ustekinumab, and omalizumab), but also by impacting metabolism and the musculoskeletal integrity (e.g., statins and bisphosphonates). Complement and NF-kB dysregulation could represent interesting topics for planning translational mechanistic studies on amyotrophic lateral sclerosis as an adverse drug effect.

Vitamin D and Nerve Conduction In Pediatric Type-1 Diabetes Mellitus

INTRODUCTION

The aim of this study is to investigate a possible association between vitamin D deficiency and diabetic peripheral neuropathy in pediatric patients with type 1 diabetes mellitus.

MATERIALS-METHODS

Twenty-nine patients with type 1 diabetes mellitus and 19 healthy controls were included to the study. All individuals were evaluated for diabetic peripheral neuropathy with nerve conduction studies. Complete blood cell count, biochemical investigations, serum vitamin D levels, hemoglobin A1c levels were recorded.

RESULTS

No statistically significant differences between the diabetes and control groups in terms of gender, age, body weight, height, body mass index, systolic and diastolic blood pressures, laboratory investigations, serum vitamin D levels and nerve conduction studies was found. Patients with diabetes were grouped as patients with normal serum vitamin D levels and patients with vitamin D deficiency. Sensory nerve action potential of sural nerve and motor peroneal nerve velocity were statistically significantly lower in diabetic patients with vitamin D deficiency compared to diabetic patients with normal vitamin D levels (p 0.009 and 0.005 respectively).

CONCLUSION

Our results suggested that hypovitaminosis D might lead to development of neuropathic changes particularly on the lower limb nerves even in the early stages of the disease. It should be kept in mind that patients with hypovitaminosis D should be elaborately examined and closely followed up for the development of diabetic neuropathic changes, even if glucose control is achieved.

Calcifediol (25OH Vitamin D3) Deficiency: A Risk Factor from Early to Old Age

Vitamin D deficiency is the main cause of nutritional rickets in children and osteomalacia in adults. There is consensus that nutritional access to vitamin D can be estimated by measuring serum concentrations of 25OHD and vitamin D deficiency can thus be considered as calcifediol deficiency. However, the threshold for vitamin D/calcifediol sufficiency remains a matter of debate. Vitamin D/calcifediol deficiency has been associated with musculoskeletal effects but also multiple adverse extra-skeletal consequences. If these consequences improve or if they can be treated with vitamin D supplementation is still unclear. Observational studies suggest a higher infection risk in people with low calcifediol levels. There is also a consistent association between serum calcifediol and cardiovascular events and deaths, but large-scale, long-term intervention studies did not show any benefit on cardiovascular outcomes from supplementation, at least not in subjects without clear vitamin D deficiency. Cancer risk also did not change with vitamin D treatment, although there are some data that higher serum calcifediol is associated with longer survival in cancer patients. In pregnant women, vitamin D supplementation decreases the risk of pre-eclampsia, gestational diabetes mellitus, and low birth weight. Although preclinical studies showed that the vitamin D endocrine system plays a role in certain neural cells as well as brain structure and function, there is no evidence to support a beneficial effect of vitamin D in neurodegenerative diseases. Vitamin D supplementation may marginally affect overall mortality risk especially in elderly subjects with low serum calcifediol concentrations.

ERp57/PDIA3: new insight

The ERp57/PDIA3 protein is a pleiotropic member of the PDIs family and, although predominantly located in the endoplasmic reticulum (ER), has indeed been found in other cellular compartments, such as the nucleus or the cell membrane. ERp57/PDIA3 is an important research target considering it can be found in various subcellular locations. This protein is involved in many different physiological and pathological processes, and our review describes new data on its functions and summarizes some ligands identified as PDIA3-specific inhibitors.

Vitamin D and its' role in Parkinson's disease patients with SARS-CoV-2 infection. A review article

A novel coronavirus reportedly called 2019-nCoV started to spread around the world at the end of 2019. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was later renamed after links with SARS were observed. Multiple studies have reported possible connections between the COVID-19 virus and neurodegenerative diseases, including Parkinson's disease. Theories support that vitamin D deficiency plays a part in the pathogenicity of Parkinson's disease or the credibility of the associated dopamine system. Administration of vitamin D3 was shown to significantly enhance the motor and non-motor manifestations of Parkinson's disease and enhance the quality of life. Also, multiple recent reviews have shown specific ways in which vitamin D reduces the risk of pathogenic infections. Recent studies supported the potential role of vitamin D in reducing the risk of COVID-19 infections and mortality. On the immunological level, immune response regulation remains one of the well-recognized actions of vitamin D. Vitamin D deficiency has been linked to complications in patients with SARS-CoV-2 infection and Parkinson's disease. Whereas more studies are required, Vitamin D supplementation with a moderate and well-calculated dosage of vitamin D3 in patients with Parkinson's disease can help minimize the risk and burden of COVID-19 complications.

Vitamin D deficiency in benign paroxysmal positional vertigo

Aim. To assess the level of vitamin D (D3) in patients with benign paroxysmal positional vertigo (BPPV). Materials and methods. The study included 25 patients. The control group consisted of 30 people, comparable in age with the main group, without BPPV. All patients included in the study underwent a standard examination of the vestibular sphere, which compised the Head impulse test, the Fukuda test, the Shaking test, the DixHolpike and MacluraPagnini test. Hydroxyvitamin D levels were analyzed by enzyme immunoassay. In the study of the psychological sphere, the following questionnaires were used: Dizziness Handicap Inventory, Beck Depression Scale, SpielbergerKhanin Anxiety Scale, TAS-26 alexithymia scale. Results. The average level of hydroxyvitamin D among patients was 19.658.6 ng/ml, which corresponds to a deficiency of vitamin D, in the control group, vitamin D3 was within the reference values (30100 ng/ml) and amounted to 33.7810.7 ng/ml (p0.001). There is a negative correlation between the level of hydroxyvitamin D and the age of the patients. There is a correlation (Spearman's criterion -0.463254, p0.001) between the frequency of recurrence of BPPV and a decrease in the level of hydroxyvitamin D. Conclusion. Vitamin D deficiency prevails among patients with BPPV.

1,25(OH)2 D3 attenuates sleep disturbance in mouse models of Lewis lung cancer, in silico and in vivo

Many clinical studies have reported that patients diagnosed with cancer will suffer from sleep disturbance during their clinical process, especially among lung cancer patients, and this effect will not easily subside. 1,25-dihydroxy-vitamin-D3 [1,25(OH)2 D3 ], the activated form of vitamin D, can participate in neuronal differentiation and prevent damage to the nervous system. However, little is known about the potential therapeutic effects of cancer-related psychiatric symptoms. In light of this, we hypothesized that a low circulating level of vitamin D was related to sleep quality in the presence of a tumor, 1,25(OH)2 D3 may be an effective way to ameliorate sleep disturbance and neurochemical alterations along with the cancer progress. Male C57BL/6 mice were implanted with intracranial transmitters to monitor electroencephalogram and were subcutaneously inoculated with Lewis lung cancer cells. The results demonstrated that on Days 19-20, tumor-bearing mice displayed fragmented sleep, shortened wake phase, prolonged sleep in the non-rapid eye movement phase, and the levels of vitamin D-associated genes in the brain had changed a lot compared to control mice. Importantly, 1,25(OH)2 D3 treatment really effectively saved the sleep quality of tumor-bearing mice. We further explored and confirmed that 1,25(OH)2 D3 repressed tumor-induced neuroinflammation (IL-1β, TNF-α, IL-6, IL-10, IFN-γ, and IL-2), enhanced neurotrophic factors (brain-derived neurotrophic factor [BDNF], glialcellline-derived neurotrophic factor) and 5-HT system in the hippocampus, hypothalamus or cortex. A molecular docking approah manifested the ability of 1,25(OH)2 D3 to affect the activity of tryptophan hydroxylase 2 and BDNF. Together, our results suggested that 1,25(OH)2 D3 treatment may attenuate sleep disturbance in Lewis lung cancer-bearing mice, and become a promising strategy for treating cancer symptom clusters to ameliorate the quality of life of patients with cancer.

Vitamin D: A Pleiotropic Hormone with Possible Psychotropic Activities

BACKGROUND

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

AIMS

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

DISCUSSION

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

CONCLUSION

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

Interferon alpha serum level association with low vitamin D levels in Chinese patients with primary Sjögren’s syndrome

The purpose of this retrospective cross-sectional study was to explore the clinical and pathogenic significance of vitamin D and its relationship with interferon-α (IFN-α) in Chinese patients with primary Sjögren’s syndrome (pSS). In our study, 32 pSS patients and 50 healthy controls were included. Serum vitamin D and IFN-α concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and analyzed with the correlations of EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI). The multiple linear regression analysis of 25-OH vitamin D3 level with ESSDAI scores in pSS patients was also investigated. Serum 25-OH vitamin D3 significantly correlated in an inverse manner with ESSDAI scores ( p < 0.001, r = −0.781) and IgG ( p < 0.001, r = −0.64). Serum 25-OH vitamin D3 were only related to peripheral nervous system (PNS) domain deficiency. Further, serum IFN-α was positively correlated with ESSDAI, but negatively correlated with serum 25-OH vitamin D3. These results suggest an important role of vitamin D regulating disease activity in pSS patients and value of supplement vitamin D in pSS treatment.

Nutraceuticals and Behavioral Therapy for Headache

PURPOSE OF REVIEW

Headache affects and disables at least 1 billion people worldwide. Patients and providers seek new therapies to relieve headache without the side effects and financial burden of current treatments. This narrative review highlights recent treatment advances in integrative headache medicine: nutraceuticals and behavioral therapies.

RECENT FINDINGS

Growing use of complementary and alternative medicine (CAM) therapies for headache (riboflavin, coenzyme Q10, magnesium, vitamin D, melatonin) alongside mainstream treatments is increasing with improving evidence of quality, safety, and tolerability. Increasing interest in medical cannabis is tempered by lack of evidence regarding safety and efficacy. Behavioral therapies including cognitive behavioral therapy (CBT), biofeedback, mindfulness-based stress reduction (MBSR), and acceptance and commitment therapy (ACT) improve patient resiliency and self-efficacy outcomes and reduce disability. The body of evidence for nutraceutical and behavioral CAM interventions for headache continues to grow and improve in quality. Providers and patients should educate themselves regarding CAM therapies as part of integrative headache management. Future studies should examine combinatorial trials of CAM therapies against current standards of headache care.

The effects of vitamin D3 supplementation on TGF-β and IL-17 serum levels in migraineurs: post hoc analysis of a randomized clinical trial

BACKGROUND

Although the exact mechanism involved in migraine pathogenesis remained uncertain, and different researches have been developed to address the role of neuroinflammation and immune dysfunction. Therefore, considering the immune protective functions of vitamin D3, we aimed to investigate the effects of daily administration of 2000 IU D3 supplements on serum status of immune markers in migraine patients.

METHODS AND MATERIALS

Eighty episodic migraineurs who randomly assigned into two equal groups to receive either vitamin D3 2000 IU/d or placebo for 12-week were enrolled in this placebo-controlled double-blind trial included. Serum concentrations of transforming growth factor-beta (TGF-β) and interleukin (IL)-17 were evaluated at baseline and after the trial via the ELISA method.

RESULTS

Applying ANCOVA adjusted for baseline levels and confounding variables, it was found that the serum level of TGF-β was significantly higher in vitamin D group (adjusted mean:1665.50 ng/L) than the placebo group (1361.90 ng/L) after the experiment (P-value = 0.012); on the other hand, vitamin D prevented the increment in IL-17 serum level in the intervention group after the trial (adjusted mean:37.84 ng/L) comparing to the controls (adjusted mean:70.09 ng/L; P-value = 0.039). The Pearson correlation analysis revealed a significant positive correlation between changes in serum 25-hydroxy-vitamin D (25(OH)D) and TGF-β (r = - 0.306, P-value = 0.008). In contrast, no significant correlations were noted between serum 25(OH) D and IL-17 changes throughout the study.

CONCLUSION

Based on the results of this study, it was revealed that 12-week vitamin D3 supplementation (2000 IU/day) could enhance the Th17/Treg related cytokines balance in episodic migraineurs. Although these findings are promising, it is needed to be extended.

TRIAL REGISTRATION

The trial is registered in the Iranian registry of clinical trials (IRCT) at 11 July 2018, with IRCT code: IRCT20151128025267N6 ( https://www.irct.ir/trial/31246 ).

Vitamin D and the athlete-patient: state of the art

Vitamin D deficiency is common in athletes. The conventional measurement of vitamin D levels provides a general indicator of body stores. However, there are nuances in its interpretation as values of 25(OH)D do not correlate absolutely with the amount of 'bioavailable' vitamin to the cells. Vitamin D should be regarded as a hormone and influences between 5% and 10% of our total genome. Determining the precise effect of the vitamin, isolated from the actions of other cofactors, is not straightforward and restricts our complete understanding of all of its actions. Deficiency has harmful effects on not only bone and muscle but also wider areas, including immunity and respiratory and neurological activities. More caution should be applied regarding the ability of supranormal vitamin D levels to elevate athletic performance. Hopefully, future research will shed more light on optimal levels of vitamin D and supplementation regimes, and improved understanding of its intracellular control of our genetic mechanisms and how extrinsic influences modify its activity.

Sexual function and depressive symptoms in primary infertile women with vitamin D deficiency undergoing IVF treatment

OBJECTIVE

To investigate the prevalence of female sexual dysfunction (FSD) and depression in primary infertile women with 25-Hydroxyvitamin D3 (25-OH VD) deficiency undergoing in-vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) treatment.

MATERIALS AND METHODS

A total of 80 women with 25-OH VD3 deficiency (<20 ng/mL = group 1), 80 women with 25-OH VD3 insufficiency (20-29.9 ng/mL = group 2), and 80 women with a normal 25-OH VD3 level (30-60 ng/mL = group 3) were included the study. Female sexual function and depression were measured using the Female Sexual Function Index (FSFI) and Beck Depression Inventory (BDI).

RESULTS

No statistically significant differences were found among the groups in terms of demographic characteristics, baseline and laboratory parameters. Statistically significant differences were observed among the groups with regard to FSD and depression. The FSFI (group 1 = 22.46 ± 2.13, group 2 = 25.82 ± 2.13 and group 3 = 28.66 ± 2.13, respectively) and sexual domain scores were low in women with 25-OH VD deficiency, and the number of women with depression (BDI score ≥ 17) was high (p < 0.05). Correlation analysis showed that the sexual domain scores were positively correlated with the 25-OH VD level, and the BDI score showed a significant negative correlation with the total FSFI score and 25-OH VD levels.

CONCLUSION

The 25-OH VD status was associated with FSD and depression and that the degree of sexual dysfunction could depend on the severity of 25-OH VD levels. Further studies are needed to elucidate this issue.

Vitamin D assessment and precision of clinical referrals: Insights gained from a teaching hospital in southern India

Objective:

Vitamin D deficiency is widely prevalent worldwide. This has led to a significant surge in referrals for vitamin D assessment in recent years. The cost-effectiveness and rationalization of this practice is uncertain. This study aimed to evaluate the referral pattern for vitamin D testing from a tertiary center in southern India.

Materials and Methods:

This was a cross-sectional study done over a period of one year (2017). A total of 95,750 individuals, referred for vitamin D screening were included in this study. Details regarding referring departments and indications for referral were obtained from the computerized hospital information processing system (CHIPS).

Results:

The study population exhibited a female preponderance (54.1%) with mean (SD) age of 40.3 (18.5) years. Overall, 44% were found to have vitamin D deficiency. Most of the referrals were from nephrology (15.4%), neurology (10.1%), and orthopedics (9.1%). Nevertheless, dermatology, the staff-clinic, and hematology which contributed to 3.3%, 1.7%, and 1.7% of referrals, had a higher proportion of vitamin D deficiency of 59.1%, 57.7%, and 64.6%, respectively. Although the most common indications for referral were generalized body aches (20.5%) and degenerative bone disorders (20.1%), the proportion of subjects with vitamin D deficiency referred for these indications were 46.1% and 41.6%, respectively. In contrast, chronic steroid use that accounted for 3.3% of the referrals had 59.1% of subjects who were deficient in vitamin D.

Conclusion:

To ensure a rational approach to vitamin D testing, clinicians ought to use their discretion to screen those truly at risk for vitamin D deficiency on a case to case basis and avoid indiscriminate testing of the same.

Implications of Vitamin D in Multiple Sclerosis and Other Neurodegenerative Processes: Bibliometric Analysis and Systematic Review

In recent years, numerous investigations focused on the pleiotropic actions of vitamin D have been carried out. These actions include the participation of this molecule in neurophysiological and neuropathological processes. As a consequence, abundant scientific literature on the role of this vitamin in neurodegenerative entities has emerged, even concerning clinical studies. To identify the level of scientific evidence concerning the relation between vitamin D and neurodegenerative diseases, from a quantitative and qualitative perspective. To describe, by means of a bibliometric analysis, the scientific production and its evolution through time in quantitative terms, regarding the implications of vitamin D in neurodegeneration. To analyse and present the degree of evidence in the aforementioned field of study, a systematic review of the literature focused on the most prevalent neurodegenerative diseases was carried out. We retrieved 848 articles in the bibliometric analysis, the majority of which were dated between the years 2010-2017. The most studied metabolite was the 25(OH)D3 and the most cited disease was multiple sclerosis. In the systematic review, we found studies about Alzheimer's and Parkinson's diseases and again, about multiple sclerosis prominently (in number and quality), with 12 randomised double-blind clinical trials. The research about vitamin D and its relations with neurodegenerative diseases shows a growing evolution over the last decade. More studies are needed to find correlations between the clinical severity of these diseases and the specific status of vitamin D and the genotypes related with them, which seems to be a future trend.

Electrophysiological evaluation of carpal tunnel syndrome female patients after vitamin D replacement

OBJECTIVE

The effects of vitamin D on the central and peripheral nervous system continue to be investigated today. In the present study, we aimed to evaluate pain and electrophysiologic response in patients with carpal tunnel syndrome (CTS) who have undergone replacement therapy due to vitamin D deficiency.

METHODS

Fifty female patients diagnosed with mild and moderate CTS and accompanied by vitamin D deficiency were included in this study. Nerve conduction study (NCS) was performed before and after vitamin D replacement, and the patient's pain was evaluated with Visual Analogue Scale (VAS).

RESULTS

When NCS were compared before and after treatment, there was a statistically significant improvement in the median distal sensory onset latency (DSOL) and sensory conduction velocity (CV) and motor distal latencies (DML) values (p=0.001; p<0.001; p=0.001, respectively). At the same time, there was a decrease in the VAS values in patients (p<0.001). When the two groups were compared there was an improvement in DSOL and sensory CV in both groups, but in DML only in moderate CTS group.

CONCLUSION

In this study, it was shown that mild and moderate CTS patients had an improvement in pain and electrophysiological parameters after vitamin D replacement. Replacing vitamin D in early stages of CTS may be beneficial.

Role of Vitamin D in Athletes and Their Performance: Current Concepts and New Trends

We are currently experiencing a vitamin D (VITD) deficiency pandemic across the world. Athletes have the same predisposition to low levels of vitamin D, the majority of its concentrations being below 20 ng/mL in a wide range of sports, especially in the winter months. Vitamin D is important in bone health, but recent research also points out its essential role in extraskeletal functions, including skeletal muscle growth, immune and cardiopulmonary functions and inflammatory modulation, which influence athletic performance. Vitamin D can also interact with extraskeletal tissues to modulate injury recovery and also influence the risk of infection. The data presented in this paper has triggered investigations in relation to the importance of maintaining adequate levels of vitamin D and to the possible positive influence supplementation has on immune and musculoskeletal functions in athletes, benefiting their performance and preventing future injuries. The objective of this review is to describe the latest research conducted on the epidemiology of vitamin D deficiency and its effects on sports performance and musculoskeletal health.

Vitamin D status of untreated children and adolescent Egyptian patients with genetic generalized epilepsy: A case-control study

PURPOSE

Antiepileptic drugs (AEDs) are commonly incriminated for vitamin D deficiency in children with epilepsy. The aim of this study was to examine 25(OH) vitamin D status among children and adolescents with genetic generalized epilepsy (GGE) who had never received AEDs and its relation to seizure frequency and epilepsy duration.

METHODS

This case-control study was conducted on 42 recently diagnosed patients with GGE, aged ≤18 years and 40 age- and gender-matched controls. Serum 25(OH) vitamin D level was performed for all participants.

RESULTS

Serum 25(OH) vitamin D level was significantly lower in patients (median = 22 ng/ml, interquartile range (IQR) = 16.6-28.6) compared with controls (median = 58.4 ng/ml, IQR = 53-68), (P-value < 0.001). Patients with ≥4 seizures per month had a significantly lower level of serum 25(OH) vitamin D (median = 17.7 ng/ml, IQR = 16-24) than patients with lower seizure frequency (median = 28.3 ng/ml, IQR = 24.2-40.2), (P-value = 0.004). Also, there was a statistically significant negative correlation between the duration of epilepsy and serum 25(OH) vitamin D level (r = -0.309, P-value = 0.046). The receiver operating characteristic curve analysis showed that serum 25(OH) vitamin D level with a cutoff value of 23.9 distinguished patients with low seizure frequency (five or less per year) from patients with higher seizure frequency with a sensitivity and specificity of 80% and 74%, respectively (area under the curve (AUC) = 0.798).

CONCLUSION

Vitamin D deficiency is found in treatment-naive children with epilepsy and adolescents with GGE, and it is associated with higher seizure frequency, longer disease duration, and younger age at onset.

Antioxidants and Nanotechnology: Promises and Limits of Potentially Disruptive Approaches in the Treatment of Central Nervous System Diseases

Many central nervous system (CNS) diseases are still incurable and only symptomatic treatments are available. Oxidative stress is suggested to be a common hallmark, being able to cause and exacerbate the neuronal cell dysfunctions at the basis of these pathologies, such as mitochondrial impairments, accumulation of misfolded proteins, cell membrane damages, and apoptosis induction. Several antioxidant compounds are tested as potential countermeasures for CNS disorders, but their efficacy is often hindered by the loss of antioxidant properties due to enzymatic degradation, low bioavailability, poor water solubility, and insufficient blood-brain barrier crossing efficiency. To overcome the limitations of antioxidant molecules, exploitation of nanostructures, either for their delivery or with inherent antioxidant properties, is proposed. In this review, after a brief discussion concerning the role of the blood-brain barrier in the CNS and the involvement of oxidative stress in some neurodegenerative diseases, the most interesting research concerning the use of nano-antioxidants is introduced and discussed, focusing on the synthesis procedures, functionalization strategies, in vitro and in vivo tests, and on recent clinical trials.

Vitamin D in migraine headache: a comprehensive review on literature

INTRODUCTION

As a primary headache, migraine has been established as the first leading disability cause worldwide in the subjects who aged less than 50 years. A variety of dietary supplements have been introduced for migraine complementary treatment. As an anti-inflammatory and antioxidant agent, vitamin D is one of these agents which has been of interest in recent years. Although higher prevalence of vitamin D deficiency/insufficiency has been highlighted among migraineurs compared to controls, there is not any consensus in prescribing vitamin D in clinical practice. Therefore, in the current review, in addition to observational and case-control studies, we also included clinical trials concerning the effects of vitamin D supplementation on migraine/headache.

METHODS

Based on a PubMed/MEDLINE and ScienceDirect database search, this review study includes published articles up to June 2019 concerning the association between migraine/headache and vitamin D status or supplementation.

RESULTS

The percentage of subjects with vitamin D deficiency and insufficiency among migraineurs and headache patients has been reported to vary between 45 and 100%. In a number of studies, vitamin D level was negatively correlated with frequency of headaches. The present findings show that supplementation with this vitamin in a dose of 1000-4000 IU/d could reduce the frequency of attacks in migraineurs.

CONCLUSION

It seems a high proportion of migraine patients might suffer from vitamin D deficiency/insufficiency. Further, the current evidence shows that in addition to routine drug therapy, vitamin D administration might reduce the frequency of attacks in migraineurs. However, these results have yet to be confirmed.

Effects of cholecalciferol on behavior and production of reactive oxygen species in female mice subjected to corticosterone-induced model of depression

Major depressive disorder (or depression) is one of the most frequent psychiatric illnesses in the population, with chronic stress being one of the main etiological factors. Studies have shown that cholecalciferol supplementation can lead to attenuation of the depressive state; however, the biochemical mechanisms involved in the relationship between cholecalciferol and depression are not very well known. The objective of this study was to investigate the effects of the administration of cholecalciferol on behavioral parameters (tail suspension test (TST), open field test (OFT), splash test (ST)) and redox state (dichlorofluorescein (DCF)) in adult female Swiss mice subjected to a model of depression induced by chronic corticosterone treatment. Corticosterone (20 mg/kg, p.o.) was administered once a day for 21 days. For investigation of the antidepressant-like effect, cholecalciferol (100 IU/kg) or fluoxetine (10 mg/kg, positive control) was administered p.o. within the last 7 days of corticosterone administration. After the treatments, the behavioral tests and biochemical analyses in the hippocampus and prefrontal cortex of the rodent samples were performed. Animals submitted to repeated corticosterone administration showed a depressive-like behavior, evidenced by a significant increase in the immobility time in the TST, which was significantly reduced by the administration of cholecalciferol or fluoxetine. In addition, the groups treated with cholecalciferol and fluoxetine showed a significant decrease in the production of reactive oxygen species (ROS) in the hippocampus. These results show that cholecalciferol, similar to fluoxetine, has a potential antidepressant-like effect, which may be related to the lower ROS production.

A preliminary transcriptome analysis suggests a transitory effect of vitamin D on mitochondrial function in obese young Finnish subjects

OBJECTIVE

The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation.

DESIGN AND METHODS

We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (±s.d.) age 20.4 (±2.5) years and BMIs 36 (±10) and 23 (±4) kg/m2, respectively. The supplemental daily vitamin D dose was 50 µg (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects.

RESULTS

Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 × 10-14). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects.

CONCLUSIONS

Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.

Focus on 1,25-Dihydroxyvitamin D3 in the Peripheral Nervous System

In this review, we draw attention to the roles of calcitriol (1,25-dihydroxyvitamin D3) in the trophicity of the peripheral nervous system. Calcitriol has long been known to be crucial in phosphocalcium homeostasis. However, recent discoveries concerning its involvement in the immune system, anti-cancer defenses, and central nervous system development suggest a more pleiotropic role than previously thought. Several studies have highlighted the impact of calcitriol deficiency as a promoting factor of various central neurological diseases, such as multiple sclerosis, amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. Based on these findings and recent publications, a greater role for calcitriol may be envisioned in the peripheral nervous system. Indeed, calcitriol is involved in myelination, axonal homogeneity of peripheral nerves, and neuronal-cell differentiation. This may have useful clinical consequences, as calcitriol supplementation may be a simple means to avoid the onset and/or development of peripheral nervous-system disorders.

Vitamin D Status and Seasonal Variation among Danish Children and Adults: A Descriptive Study

The aim of the present study was to describe vitamin D status and seasonal variation in the general Danish population. In this study, 3092 persons aged 2 to 69 years (2565 adults, 527 children) had blood drawn twice (spring and autumn) between 2012 and 2014. A sub-sample of participants had blood samples taken monthly over a year. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by liquid chromatography mass spectrometry, and information on supplement use was assessed from questionnaires. Seasonal variations in 25(OH)D concentrations were evaluated graphically and descriptively, and status according to age, sex, and supplement use was described. It was found that 86% of both adults and children were vitamin D-sufficient in either spring and or/autumn; however, many had a spring concentration below 50 nmol/L. A wide range of 25(OH)D concentrations were found in spring and autumn, with very low and very high values in both seasons. Among adults, women in general had higher median 25(OH)D concentrations than men. Furthermore, vitamin D supplement use was substantial and affected the median concentrations markedly, more so during spring than autumn. Seasonal variation was thus found to be substantial, and bi-seasonal measurements are vital in order to capture the sizable fluctuations in vitamin D status in this Nordic population.

Vitamin D Status and Analysis of Specific Correlates in Preschool Children: A Cross-Sectional Study in Southern Croatia

Vitamin D deficiency is a globally important problem, particularly in children, but there is a lack of information regarding this deficiency in preschool children from southeastern Europe. This study aimed to establish the levels of 25-hydroxyvitamin D (25(OH)D) and associations of gender, time spent outdoors, physical activity (PA), and body mass index (as predictors) with the 25(OH)D level (outcome) in healthy preschool children. The participants were preschoolers (all 5⁻6 years of age) from southern Croatia. All the participants were tested during their mandatory medical examination 6⁻7 months prior to school enrollment. The PA was obtained using the preschool-age physical activity questionnaire (Pre-PAQ), which categorizes PA into five levels (from sedentary to vigorous PA). The prevalence of 25(OH)D deficiency was high: 58% of the children had 25(OH)D levels of <50 nmol/L (deficiency), and an additional 29% had an insufficient level of 25(OH)D (50⁻75 nmol/L). Boys had higher levels of 25(OH)D than girls. A multinomial regression using 25(OH)D categories as the outcome and a sufficient level (>75 nmol/L) as the reference value identified gender as the only significant predictor of 25(OH)D status, with boys being at lower risk for 25(OH)D deficiency than girls. These results showed a high prevalence of 25(OH)D deficiency in preschoolers from the southern part of Croatia, which is additionally alarming based on the geographical position of the studied region (42° N) and its high number of sunshine hours (>2600 h per year). Future studies examining other potential correlates of 25(OH)D in the region are warranted.

Serum Vitamin D Status in a Group of Migraine Patients Compared With Healthy Controls: A Case-Control Study

OBJECTIVE

The association between serum vitamin D and migraine is investigated in this research.s BACKGROUND: Although the pathogenesis of migraine headache is not fully understood, the possible role of inflammation and disturbed immune system has been proposed; thus, higher levels of vitamin D might reduce the risk of migraine. However, the results of related studies have been inconclusive.

METHODS

Seventy healthy individuals and 70 age- and sex-matched migraineurs (34 chronic and 36 episodic migraineurs), diagnosed according to the International Headache Society criteria (ICHD-IIIβ), were recruited. After obtaining baseline data and assessing migraine disability, a 30-day headache diary was given to the participants. Blood samples were obtained and 25(OH)D serum concentrations were determined using ELISA techniques. Serum 25(OH)D under 20, 20-29, and 30-100 ng/mL were considered deficient, insufficient, and sufficient, respectively. The applied statistical tests for between-group comparisons include independent-sample t-test, chi-square, and analysis of variance. Multiple regression analysis was also performed to identify the possible risk factors of migraine headache.

RESULTS

Migraine patients had significantly lower mean (SD) of serum VitD (30 (16) ng/mL) than healthy subjects (43 (19) ng/mL) (P < .001). The number (%) of subjects with VitD deficiency and insufficiency was significantly higher among the migraineurs (36 (53.7%)) than the controls (18 (26.1%)) (P < .0001). A significant negative association between migraine headache and serum VitD was detected in the fully adjusted multiple regression models when comparing the third and the highest serum 25(OH)D quartiles with the lowest (OR = 0.20; 95% CI = 0.05-0.77; OR = 0.17; 95% CI = 0.04-0.64, respectively, P for trend = .009). For each 5 ng/mL increase in serum 25(OH)D, there was a 22% odds decrease in the odds of migraine (OR = 0.78; 95% CI = 0.68-0.90; P = .001).

CONCLUSION

We have found that a higher level of serum VitD (between 50 to less than 100 ng/mL) among a sample of the Iranian population is associated with 80-83% lower odds of migraine headache than those with serum 25(OH)D levels below 20 ng/mL. However, there is a need for well-designed clinical trials to investigate beneficial effects of increased serum 25(OH)D on lower risk of migraine.

Serum vitamin D deficiency in subjects with severe acquired brain injury and relationship with functional severity

BACKGROUND

Vitamin D may be important for the development and function of the nervous system. Low serum vitamin D levels have been detected in several neurological diseases.

OBJECTIVE

To ascertain the relationship between 25(OH)D serum level and disability in subjects with severe acquired brain injury (sABI).

DESIGN

Prospective cross-sectional study Methods: Consecutive subjects with sABI admitted to neuro-rehabilitation were enrolled. A sample of subjects from the neurological ward was considered the control group. Vitamin D serum levels and blood parameters were measured at admission. Disability Rating Scale (DRS), Glasgow Outcome Scale (GOS), and Level of Cognitive Functioning (LCF) were used in assessing disability.

RESULTS

A total of 104 subjects (34 F, 70 M; mean age 53.9 ± 15.2 years) were enrolled: 54 (19 F, 35 M) with sABI and 50 (15 F, 35 M) subjects as control group. Deficient mean serum levels of vitamin D (19.2 ± 9.4 ng/mL) were detected in the subjects with sABI and a significant inverse correlation between vitamin D serum levels and DRS score was detected (p = 0.04).

CONCLUSION

Subjects with sABI showed vitamin D deficiency that might correlate to disability severity. The reason is unclear and might represent a secondary phenomenon resulting from the inflammatory process.

The association between serum vitamin d level and cognitive function in older adults: Cooper Center Longitudinal Study

Low blood level of vitamin D and low physical activity have been linked to the development of cognitive impairment in older adults. The purpose of the present study was to examine the relationship between serum vitamin D and cognition as measured via the Montreal Cognitive Assessment (MoCA) in a healthy, older population. The study sample consisted of 4358 patients from the Cooper Clinic in Dallas, TX. All participants underwent a maximal graded exercise test to determine cardiorespiratory fitness (CRF). Cognitive impairment was defined as a MoCA score <25. Low vitamin D status was defined as serum 25-hydroxyvitamin D <30 ng/mL. Multivariable logistic regression analysis was employed to evaluate the association between vitamin D blood level and MoCA score. A low MoCA score was directly associated with higher age (OR: 1.75, 95% CI: 1.53, 1.99), and inversely associated with female sex (OR: 0.63, 95% CI: 0.51, 0.77), and years of education (OR: 0.87, 95% CI: 0.84, 0.91). When controlling for significant predictors (age, sex, and education), the low vitamin D group had a significantly greater likelihood of having a low MoCA score (OR: 1.26, 95% CI: 1.04, 1.51). The vitamin D effect remained significant when CRF was added to the model (OR: 1.23, 95% CI: 1.02, 1.48). In conclusion, low vitamin D was shown to be associated with cognitive impairment. Therefore, preventive measures such as vitamin D supplementation may play a protective role in memory loss and/or age-associated cognitive decline.