Immune regulatory effects of high dose vitamin D3 supplementation in a randomized controlled trial in relapsing remitting multiple sclerosis patients receiving IFNβ; the SOLARIUM study

Nutritional interventional studies in patients with multiple sclerosis: a scoping review of the current clinical evidence

A good nutritional status appears to slow down disease progression and ameliorate symptoms' intensity in patients with multiple sclerosis (MS). Up to date, there are several interventional studies, which have explored the potential beneficial effects of specific dietary patterns as well as specific bioactive nutrients against disease progression and symptomatology of MS patients. This is a thorough, scoping review, which aims to critically summarize and scrutinize the currently available clinical evidence of the potential beneficial effects of nutritional interventional studies against MS progression and symptomatology. This review was conducted to systematically map the research done in this area, as well as to identify gaps in knowledge. For this purpose, we thoroughly explored the most accurate scientific web databases, e.g., PubMed, Scopus, Web of Science, and Google Scholar to achieve the most relevant clinical human studies applying effective and characteristic keywords. There are currently several dietary patterns and specific bioactive nutrients that show promising results by slowing down disease progression and by improving MS symptoms. However, there are also certain conflicting results, while most of the existing studies enrolled a small number of MS patients. Nutritional interventions may exert substantial protective effects against MS progression and symptomatology. However, large, long-term, randomized, double-blind, controlled clinical trials with a prospective design are strongly recommended to delineate whether such nutritional intervention may attenuate disease progression, and improve symptomatology in MS patients.

Vitamin D Supplementation: Effect on Cytokine Profile in Multiple Sclerosis

Vitamin D is known for its role in modulating calcium and phosphate homeostasis and is implicated both in bone mineralization and immune system regulation. The immune-modulatory role of vitamin D and its impact on multiple sclerosis (MS) courses are still debated. The aim of this review was to check the effect of vitamin D supplementation on cytokine profile regulation in people with MS. A significant increase in serum concentrations of interleukin (IL)-10 and Transforming growth factor (TGF)-β1 after vitamin D supplementation was demonstrated in most studies, with some of them reporting a reduction in disability scores after vitamin D supplementation and an inverse correlation between IL-10 levels and disability. The effect of vitamin D on the serum levels of IL-17 and IL-6 was controversial; different results across studies could be explained by a variability in the treatment duration, route, and frequency of administration, as well as the dosage of vitamin D supplementation, responses to vitamin D treatment and the serum levels reached with supplementation, including the methods used for cytokine analysis and the different cell types investigated, the MS phenotype, the disease phase (active vs. non-active) and duration, and concomitant treatment with disease-modifying therapies. Nevertheless, the significant increase in the serum concentrations of IL-10 and TGF-β1, demonstrated in most studies, suggests an anti-inflammatory effect of vitamin D supplementation.

Regulation of Dendritic Cell Functions by Vitamins as Promising Therapeutic Strategy for Immune System Disorders

A functional immune system is crucial for a healthy life, protecting from infections, tumors, or autoimmune disorders; these are accomplished by the interaction between various immune cells. Nourishment, particularly micronutrients, are very important components in the immune system balance, therefore this review emphasizes the vitamins (D, E, A, C) and Dendritic cells' subsets due to vitamins' roles in immune processes, especially on dendritic cells' functions, maturation, and cytokine production. Current studies reveal significant benefits related to vitamins, including vitamin E, which can contribute to the control of dendritic cells' function and maturation. Furthermore, vitamin D plays an immunoregulatory and anti-inflammatory role in the immune system. Metabolite of vitamin A which is called retinoic acid leads to T cells' differentiation to T helper 1 or T helper 17, so low levels of this vitamin exacerbate the menace of infectious diseases, and vitamin C has anti-oxidant effects on dendritic cells and modulate their activation and differentiation program. Additionally, the correlation between the amount of vitamin and the occurrence or progression of allergic diseases and autoimmunity disorders is discussed according to the results of previous studies.

Low serum 25‑hydroxy-vitamin D levels are associated with cognitive impairment in multiple sclerosis

BACKGROUND

Cognitive impairment frequently affects people with multiple sclerosis (MS). Low vitamin D has been associated with cognitive dysfunction in different neurodegenerative diseases, and, in MS, with motor disability and disease activity. We aim to investigate associations between vitamin D and cognitive status in MS.

METHODS

In this cross-sectional study, we included 181 MS patients, recruited consecutively at the MS Unit of the Policlinico Federico II University Hospital of Naples, Italy, between January and April 2022, with serum 25‑hydroxy (25-OH) vitamin D measurements using Chemiluminescence-ImmunoAssay, and cognitive assessment using the Brief International Cognitive Assessment for MS (BICAMS), which includes Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II) and Brief Visuospatial Memory Test-Revised (BVMT-R). We collected demographics (age, sex, education), and clinical variables (disease duration, disease subtype, expanded disability status scale (EDSS), disease modifying treatment, relapses in previous 12 months, vitamin D supplementation, comorbidities). For a subset of patients (n = 41, 23.2% of the total sample), we collected Beck Depression Inventory-II, Beck Anxiety Inventory, and Modified Fatigue Impact Scale.

RESULTS

At univariable linear regression models, serum 25-OH-vitamin D levels were 0.9 ng/mL higher for each unit increase of SDMT adjusted scores (Coeff=0.93; 95%CI=0.81, 1.04; p<0.01), 0.7 ng/mL higher for each unit increase of CVLT-II adjusted scores (Coeff=0.68; 95%CI=0.53, 0.83; p<0. 01), 0.6 ng/mL higher for each unit increase of BVMT-R adjusted scores (Coeff=0.58; 95%CI=0.43, 0.73; p<0.01), -9.63 ng/mL lower for each impaired BICAMS test (Coeff=-9.63; 95%CI=-11.48, -7.79; p<0.01), and -2.2 ng/mL lower for each unit increase of EDSS (Coeff=-2.16; 95%CI=-3.57, -0.75; p<0.01). At multivariable linear regression models, we confirmed associations between 25-OH-vitamin D and EDSS (Coeff=-2.09; 95%CI=-4.45, -0.43; p<0.01), SDMT (Coeff=0.75; 95%CI=0.60, 0.90; p<0.01), and CVLT-II (Coeff=0.14; 95%CI=0.01, 0.28; p = 0. 04). Results remained unchanged when including depression, anxiety and fatigue scores.

CONCLUSIONS

Lower serum 25-OH-vitamin D was associated with worse cognitive function in MS. Future studies should consider longitudinal variations in cognitive function in relation to vitamin D supplementation.

Co-occurrence of glioma and multiple sclerosis: Prevailing theories and emerging therapies

Though the concurrence of primary brain tumors and multiple sclerosis (MS) is exceedingly rare, instances have been noted in the literature as early as 1949. Given these observations, researchers have proposed various ideas as to how these malignancies may be linked to MS. Due to insufficient data, none have gained traction or been widely accepted amongst neurologists or neuro-oncologists. What is abundantly clear, however, is the mounting uncertainty faced by clinicians when caring for these individuals. Concerns persist about the potential for disease modifying therapies (DMTs) to initiate or promote tumor growth and progression, and to date, there are no approved treatments capable of mitigating both MS disease activity and tumor growth, let alone established guidelines that clinicians may refer to. Collectively, these gaps in the literature impose limitations to optimizing the care and management of this population. As such, our hope is to stimulate further discussion of this topic and prompt future investigations to explore novel treatment options and advance our understanding of these concurrent disease processes. To this end, the chief objective of this article is to evaluate proposed ideas of how the diseases may be linked, outline emerging therapies for both MS and brain tumors, and describe evidence-based approaches to diagnosing and treating this patient population.

Linking Mechanisms of Vitamin D Signaling with Multiple Sclerosis

Environmental triggers often work via signal transduction cascades that modulate the epigenome and transcriptome of cell types involved in the disease process. Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system being characterized by a combination of recurring inflammation, demyelination and progressive loss of axons. The mechanisms of MS onset are not fully understood and genetic variants may explain only some 20% of the disease susceptibility. From the environmental factors being involved in disease development low vitamin D levels have been shown to significantly contribute to MS susceptibility. The pro-hormone vitamin D3 acts via its metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) as a high affinity ligand to the transcription factor VDR (vitamin D receptor) and is a potent modulator of the epigenome at thousands of genomic regions and the transcriptome of hundreds of genes. A major target tissue of the effects of 1,25(OH)2D3 and VDR are cells of innate and adaptive immunity, such as monocytes, dendritic cells as well as B and T cells. Vitamin D induces immunological tolerance in T cells and reduces inflammatory reactions of various types of immune cells, all of which are implicated in MS pathogenesis. The immunomodulatory effects of 1,25(OH)2D3 contribute to the prevention of MS. However, the strength of the responses to vitamin D3 supplementation is highly variegated between individuals. This review will relate mechanisms of individual's vitamin D responsiveness to MS susceptibility and discuss the prospect of vitamin D3 supplementation as a way to extinguish the autoimmunity in MS.

Co-delivery of vitamin D3 and Lkb1 siRNA by cationic lipid-assisted PEG-PLGA nanoparticles to effectively remodel the immune system in vivo

The imbalance of the immune system can lead to the occurrence of autoimmune diseases. Controlling and regulating the proliferation and function of effector T (Teff) cells and regulatory T (Treg) cells becomes the key to treating these diseases. Dendritic cells (DCs), as dedicated antigen-presenting cells, play a key role in inducing the differentiation of naive CD4+ T cells. In this study, we designed a cationic lipid-assisted PEG-PLGA nanoparticle (NPs/VD3/siLkb1) to deliver 1,25-dihydroxyvitamin D3 (VD3) and small interfering RNA (siRNA) to DC cells in the draining lymph nodes. By modulating the phenotypic changes of DC cells, this approach expands Treg cells and reduces the occurrence of autoimmune diseases. Thus, this study provides a novel approach to alleviating the occurrence and development of autoimmune diseases while also minimizing the risk of unwanted complications.

A review of the critical role of vitamin D axis on the immune system

In recent years, the physiological and molecular functions of vitamin D (Vit-D) have been deeply investigated. At first, Vit-D was considered a regulator of mineral and skeletal homeostasis. However, due to the extensive-expression pattern of Vit-D receptor (VDR) in almost every non-skeletal cell, Vit-D is considered mainly a multifunctional agent with broad effects on various tissues, notably the immune system. The expression of VDR in immune cells such as dendritic cells, monocyte/macrophage, neutrophils, B cells and T cells has been well demonstrated. Besides, such immune cells are capable of metabolizing the active form of Vit-D which means that it can module the immune system in both paracrine and autocrine manners. Vit-D binding protein (DBP), that regulates the levels and homeostasis of Vit-D, is another key molecule capable of modulating the immune system. Recent studies indicate that dysregulation of Vit-D axis, variations in the DBP and VDR genes, and Vit-D levels might be risk factors for the development of autoimmune disease. Here, the current evidence regarding the role of Vit-D axis on the immune system, as well as its role in the development of autoimmune disease will be clarified. Further insight will be given to those studies that investigated the association between single nucleotide polymorphisms of DBP and VDR genes with autoimmune disease susceptibility.

Molecular biomarkers and cognitive impairment in multiple sclerosis: State of the field, limitations, and future direction - A systematic review and meta-analysis

OBJECTIVE

Multiple sclerosis (MS) is associated with cognitive impairment (CI) such as slowed information processing speed (IPS). Currently, no immunocellular or molecular markers have been established in cerebrospinal fluid and serum analysis as surrogate biomarkers with diagnostic or predictive value for the development of CI. This systematic review and meta-analysis aims to sum up the evidence regarding currently discussed markers for CI in MS.

METHODS

A literature search was conducted on molecular biomarkers of CI in MS, such as neurofilament light chain, chitinases, and vitamin D.

RESULTS

5543 publications were screened, of which 77 entered the systematic review. 13 studies were included in the meta-analysis. Neurofilament light chain (CSF: r_p = -0.294, p = 0.003; serum: r_p = -0.137, p = 0.001) and serum levels of vitamin D (r_p = 0.190, p = 0.014) were associated with IPS outcomes.

CONCLUSIONS

Neurofilament light chain and vitamin D are promising biomarkers to track impairments in IPS in MS. Further longitudinal research is needed to establish the use of molecular biomarkers to monitor cognitive decline.

Vitamin D Supplementation Practices among Multiple Sclerosis Patients and Professionals

Vitamin D serum level increase is associated with a reduction in clinical relapse rate, gadolinium-enhancing lesions, new or enlarging T2 lesions and new active lesions in the MRI in MS patients. However, current RCTs assessing the vitamin D supplementation therapeutic effect in MS provide inconclusive results. Experts recommend vitamin D measurements and implementations among patients with MS. This article discusses an observational study, performed without any intervention to evaluate the vitamin D status and practices among MS patients and professionals in the clinical setting. A total of 139 patients with MS treated by disease-modifying therapy were recruited and fulfilled the standardized questionnaire assessing the vitamin D supplementation practices and vitamin D level influencing factors such as education, insolation, smoking, obesity and current treatment. The collected data were then compared to the patients' vitamin D serum levels available in medical records at the baseline and after 12 months of observation. Professionals' practices and recommendations were also assessed. A total of 74.1% patients confirmed vitamin D supplementation, and all patients were administered cholecalciferol, taken orally. However, only 43.69% of the patients achieved an optimal vitamin D concentration (30-50 ng/mL). The lack of a doctor's recommendation was the most frequent reason for the absence of vitamin D supplementation. The most often recommended vitamin D daily dose was 4000 IU. There was no adverse effect of supplementation observed. Vitamin D status in patients with MS is currently better than in the general population, but still, a significant percentage of patients do not implement vitamin D.

Vitamin D supplementation and immune-related markers: an update from nutrigenetic and nutrigenomic studies

Vitamin D is both a nutrient and a neurologic hormone that plays a critical role in modulating immune responses. While low levels of vitamin D are associated with increased susceptibility to infections and immune-related disorders, vitamin D supplementation has demonstrated immunomodulatory effects that can be protective against various diseases and infections. Vitamin D receptor is expressed in immune cells that have the ability to synthesise the active vitamin D metabolite. Thus, vitamin D acts in an autocrine manner in a local immunologic milieu in fighting against infections. Nutrigenetics and nutrigenomics are the new disciplines of nutritional science that explore the interaction between nutrients and genes using distinct approaches to decipher the mechanisms by which nutrients can influence disease development. Though molecular and observational studies have proved the immunomodulatory effects of vitamin D, only very few studies have documented the molecular insights of vitamin D supplementation. Until recently, researchers have investigated only a few selected genes involved in the vitamin D metabolic pathway that may influence the response to vitamin D supplementation and possibly disease risk. This review summarises the impact of vitamin D supplementation on immune markers from nutrigenetics and nutrigenomics perspective based on evidence collected through a structured search using PubMed, EMBASE, Science Direct and Web of Science. The research gaps and shortcomings from the existing data and future research direction of vitamin D supplementation on various immune-related disorders are discussed.

Full spectrum of vitamin D immunomodulation in multiple sclerosis: mechanisms and therapeutic implications

Vitamin D deficiency has been associated with the risk of multiple sclerosis, disease activity and progression. Results from in vitro experiments, animal models and analysis of human samples from randomized controlled trials provide comprehensive data illustrating the pleiotropic actions of Vitamin D on the immune system. They globally result in immunomodulation by decreasing differentiation of effector T and B cells while promoting regulatory subsets. Vitamin D also modulates innate immune cells such as macrophages, monocytes and dendritic cells, and acts at the level of the blood–brain barrier reducing immune cell trafficking. Vitamin D exerts additional activity within the central nervous system reducing microglial and astrocytic activation. The immunomodulatory role of Vitamin D detected in animal models of multiple sclerosis has suggested its potential therapeutic use for treating multiple sclerosis. In this review, we focus on recent published data describing the biological effects of Vitamin D in animal models of multiple sclerosis on immune cells, blood–brain barrier function, activation of glial cells and its potential neuroprotective effects. Based on the current knowledge, we also discuss optimization of therapeutic interventions with Vitamin D in patients with multiple sclerosis, as well as new technologies allowing in-depth analysis of immune cell regulations by vitamin D.

Is there a window of opportunity for the therapeutic use of vitamin D in multiple sclerosis?

Multiple sclerosis is an autoimmune treatable but not curable disease. There are a multiplicity of medications for multiple sclerosis therapy, including a class entitled disease-modifying drugs that are mainly indicated to reduce the number and severity of disease relapses. Not all patients respond well to these therapies, and minor to severe adverse effects have been reported. Vitamin D, called sunshine vitamin, is being studied as a possible light at the end of the tunnel. In this review, we recapitulated the similar immunopathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis, the immunomodulatory and neuroprotective potential of vitamin D and the state-of-art concerning its supplementation to multiple sclerosis patients. Finally, based on our and other groups’ experimental findings, we analyzed the need to consider the relevance of the route and the different time-point administration aspects for a more rational indication of this vitamin to multiple sclerosis patients.

Vitamin D related genetic polymorphisms affect serological response to high-dose vitamin D supplementation in multiple sclerosis

Introduction

A poor 25-hydroxyvitamin D (25(OH)D) status is a much replicated risk factor for developing multiple sclerosis (MS), and several vitamin D-associated single nucleotide polymorphisms (SNPs) have been associated with a higher risk of MS. However, studies on the benefit of vitamin D supplementation in MS show inconclusive results. Here, we explore whether vitamin D-associated SNPs and MS risk alleles confound serological response to vitamin D supplementation.

Methods

34 participants from the SOLARIUM study consented to genotyping, of which 26 had vitamin D data available. The SOLARIUM study randomised relapsing-remitting MS patients to placebo or 14,000 IU vitamin D₃ for 48 weeks. Participants were categorised as either ‘carriers’ or ‘non-carriers’ of the risk allele for 4 SNPs: two related to D binding protein (DBP) and associated with lower 25(OH)D levels (rs4588 and rs7041), and two related to vitamin D metabolism enzymes CYP27B1 and CYP24A1 and associated with a higher risk of MS (rs12368653; rs2248359, respectively). 25(OH)D levels were determined at baseline and after 48 weeks.

Results

The DBP-related SNPs showed no difference in 25(OH)D status at baseline, but carriers of the rs7041 risk allele showed lower 25(OH)D-levels compared to non-carriers after 48 weeks of supplementation (median 224.2 vs. 332.0 nmol/L, p = 0.013). For CYP related SNPs, neither showed a difference at baseline, but carriers of the rs12368653 risk allele showed higher 25(OH)D-levels compared to non-carriers after 48 weeks of supplementation (median 304.1 vs. 152.0 nmol/L, p = 0.014).

Discussion

Vitamin D-related SNPs affect the serological response to high-dose vitamin D supplementation. The effects on more common doses of vitamin D, as well as the clinical consequence of this altered response, need to be investigated further.

Serum Vitamin D Level among Multiple Sclerosis Patients in the Tropics: Experience from a Private Clinic in Addis Ababa, Ethiopia

Background

Multiple sclerosis (MS) is an immune mediated disabling neurological disorder. Very little is known about MS in Ethiopia. The objective of this study was to determine the prevalence of hypovitaminosis D and associated factors in cohort of MS patients in Ethiopia.

Method

A cross-sectional observational study was conducted among 25 multiple sclerosis patients at Yehuleshet Specialty Clinic, Addis Ababa, Ethiopia.

Results

The prevalence of vitamin D deficiency was 96% (n=24). The average serum vitamin D was 14.8 (±10.4) ng/mL. The mean age was 35.8 (±10) years. Females accounted for 80% (n=20). Relapsing and remitting MS was the commonest variant. Motor, sensory, and mixed symptoms accounted for 40% (n=10), 20% (n=5), and 24% (n=6), respectively. Cold or hot weather and stress were reported as worsening factors in 24% (n=6). Relapse rate was 44% (n=11). Fatigue and seizure disorder were reported by 80% (n=20) and 16% (n=4) respectively. Steroid is the commonest prescribed medication for the patients. A negative correlation was found between serum vitamin D and age (r = -0.062, p = 0.7). Similarly, a negative association was observed between vitamin D and duration of illness (r = -0.311, p = 0.1). Fatigue was reported by those with moderate hypovitaminosis compared to those having severe hypovitaminosis (p=0.002). Seizure was reported more by those with vitamin D below 10ng/mL compared to those having above 10 ng/mL (p=0.004).

Conclusion

Our study demonstrates a high prevalence of hypovitaminosis D in Ethiopian MS patients. Hypovitaminosis D was associated with increment in age and duration of illness.

Proportions of circulating transitional B cells associate with MRI activity in interferon beta-treated multiple sclerosis patients

B-cells contribute to MS pathogenesis. The association of circulating B-cell phenotypes with combined unique active lesions (CUA) on MRI at 48 weeks follow-up was investigated in 50 interferon beta-treated MS patients. Transitional B-cell proportions were lower in participants with CUA at week 0 and 48 [p = 0.004, p = 0.002]. A decrease in circulating anti-EBNA-1 IgG levels between week 0 and 48 associated with absence of CUA [p = 0.047], but not with B-cell profiles. In a multi-factor model for CUA-risk, transitional B-cell proportions contributed independent from NK/T-cell ratio, change in anti-EBNA-1 IgG, and vitamin D supplementation. Transitional B-cells may predict treatment response in MS.

Low-Dose Vitamin D3 Supplementation Does Not Affect Natural Regulatory T Cell Population but Attenuates Seasonal Changes in T Cell-Produced IFN-γ: Results From the D-SIRe2 Randomized Controlled Trial

Background

Seasonal variations have been reported for immune markers. However, the relative contributions of sunlight and vitamin D variability on such seasonal changes are unknown.

Objective

This double-blind, randomized, placebo-controlled trial tested whether daily 400 IU vitamin D₃ supplementation affected short-term (12 weeks) and long-term (43 weeks) natural regulatory T cell (nTreg) populations in healthy participants.

Design

62 subjects were randomized equally to vitamin D versus placebo in March and assessed at baseline, April (4w), June (12w), September (25w) and January (43w). Circulating nTregs, ex vivo proliferation, IL-10 and IFN-γ productions were measured. Vitamin D metabolites and sunlight exposure were also assessed.

Results

Mean serum 25-hydroxyvitamin D (25(OH)D) increased from 35.8(SD 3.0) to 65.3(2.6) nmol/L in April and remained above 75 nmol/L with vitamin D supplementation, whereas it increased from 36.4(3.2) to 49.8(3.5) nmol/L in June to fall back to 39.6(3.5) nmol/L in January with placebo. Immune markers varied similarly between groups according to the season, but independently of 25(OH)D. For nTregs, the mean (%CD3⁺CD4⁺CD127^lo cells (SEM)) nadir observed in March (2.9(0.1)%) peaked in September at 4.0(0.2)%. Mean T cell proliferation peaked in June (33156(1813) CPM) returning to the nadir in January (17965(978) CPM), while IL-10 peaked in June and reached its nadir in September (median (IQR) of 262(283) to (121(194) pg/ml, respectively). Vitamin D attenuated the seasonal increase in IFN-γ by ~28% with mean ng/ml (SEM) for placebo vs vitamin D, respectively, for April 12.5(1.4) vs 10.0(1.2) (p=0.02); June 13.9(1.3) vs 10.2(1.7) (p=0.02) and January 7.4(1.1) vs 6.0(1.1) (p=0.04).

Conclusions

Daily low dose Vitamin D intake did not affect the nTregs population. There were seasonal variation in nTregs, proliferative response and cytokines, suggesting that environmental changes influence immune response, but the mechanism seems independent of vitamin D status. Vitamin D attenuated the seasonal change in T cell-produced IFN-γ, suggesting a decrease in effector response which could be associated with inflammation.

Clinical Trial Registration

https://www.isrctn.com, identifier (ISRCTN 73114576).

Vitamin D supplementation in multiple sclerosis: an expert opinion based on the review of current evidence

INTRODUCTION

Vitamin D has long been known for its immune-modulating effects, next to its function in calcium metabolism. As a consequence, poor vitamin D status has been associated with many diseases including multiple sclerosis (MS). Epidemiological studies suggest an association between a poor vitamin D status and development of MS and a poor vitamin D status is associated with more relapses and faster progression after patients are diagnosed with MS.

AREA’S COVERED

The aim of the authors was to review the role of vitamin D supplementation in the treatment of MS. Pubmed was used to review literature with a focus of vitamin D supplementation trials and meta-analyses in MS.

EXPERT OPINION

There is no solid evidence to support the application of vitamin D therapy, based on current available supplementation trials, although there are some promising results in the clinically isolated syndrome (CIS) patients and young MS patients early after initial diagnosis. The authors recommend further larger clinical trials with selected patient groups, preferable CIS patients and young patients at the time of diagnosis, using vitamin D₃ supplements to reach a 100 nmol/l level, to further investigate the effects of vitamin D supplementation in MS.

Effects of vitamin D supplementation on blood markers in ulcerative colitis patients: a systematic review and meta-analysis

OBJECTIVE

Observational studies have shown that vitamin D levels are inversely related to ulcerative colitis activity, yet evidence from population interventions remains inconsistent. We conducted a systematic review and meta-analysis of randomized-controlled trials to clarify the effect of vitamin D on blood markers in patients with ulcerative colitis.

METHODS

The PubMed, Cochrane Library, Embase, CNKI, VIP, and Wanfang databases were searched for studies published before June 2020. Information was collected regarding serum vitamin D levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), and Ca (calcium), and parathyroid hormone (PTH), and ulcerative colitis disease activity index (UCDAI) research data.

RESULTS

Seven studies (n = 539) were included in the meta-analysis. Vitamin D supplementation resulted in significant improvements in the serum vitamin D levels (standardized mean difference (SMD) = 0.69, 95% CI (0.36, 1.03), P < 0.001), ESR (weighted mean difference (WMD) = - 1.10, 95% CI (- 1.97, - 0.24), P = 0.01), CRP (SMD = - 0.43, 95% CI (- 0.67, - 0.20), P = 0.0003), and Ca (SMD = 0.92, 95% CI (0.09, 1.74), P = 0.03) but not in other outcomes. According to subgroup analysis, supplementation with vitamin D at a dose of ≥ 300,000 IU/day can improve serum vitamin D levels. Supplementation with a sufficient dose of vitamin D in a short period of time can also improve serum vitamin D levels. According to GRADE method evaluation, the evidence quality was classified as low for the Serum Vitamin D Level and ESR, and very low for the CRP, PTH, Ca, and UCDAI.

CONCLUSIONS

Compared with placebo control interventions, vitamin D supplementation seemed to be an effective intervention for patients with ulcerative colitis. Different doses of vitamin D and durations of intervention produce different effects. However, due to the limitation of the quality of the included studies, the above conclusions still need to be verified by more high-quality studies and weak clinical recommendations.

Oral and Topical Vitamin D, Sunshine, and UVB Phototherapy Safely Control Psoriasis in Patients with Normal Pretreatment Serum 25-Hydroxyvitamin D Concentrations: A Literature Review and Discussion of Health Implications

Vitamin D, sunshine and UVB phototherapy were first reported in the early 1900s to control psoriasis, cure rickets and cure tuberculosis (TB). Vitamin D also controlled asthma and rheumatoid arthritis with intakes ranging from 60,000 to 600,000 International Units (IU)/day. In the 1980s, interest in treating psoriasis with vitamin D rekindled. Since 1985 four different oral forms of vitamin D (D2, D3, 1-hydroxyvitaminD3 (1(OH)D3) and 1,25-dihydroxyvitaminD3 (calcitriol)) and several topical formulations have been reported safe and effective treatments for psoriasis-as has UVB phototherapy and sunshine. In this review we show that many pre-treatment serum 25(OH)D concentrations fall within the current range of normal, while many post-treatment concentrations fall outside the upper limit of this normal (100 ng/mL). Yet, psoriasis patients showed significant clinical improvement without complications using these treatments. Current estimates of vitamin D sufficiency appear to underestimate serum 25(OH)D concentrations required for optimal health in psoriasis patients, while concentrations associated with adverse events appear to be much higher than current estimates of safe serum 25(OH)D concentrations. Based on these observations, the therapeutic index for vitamin D needs to be reexamined in the treatment of psoriasis and other diseases strongly linked to vitamin D deficiency, including COVID-19 infections, which may also improve safely with sufficient vitamin D intake or UVB exposure.

Failed, Interrupted, or Inconclusive Trials on Immunomodulatory Treatment Strategies in Multiple Sclerosis: Update 2015-2020

In the past decades, multiple sclerosis (MS) treatment has experienced vast changes resulting from major advances in disease-modifying therapies (DMT). Looking at the overall number of studies, investigations with therapeutic advantages and encouraging results are exceeded by studies of promising compounds that failed due to either negative or inconclusive results or have been interrupted for other reasons. Importantly, these failed clinical trials are informative experiments that can help us to understand the pathophysiological mechanisms underlying MS. In several trials, concepts taken from experimental models were not translatable to humans, although they did not lack a well-considered pathophysiological rationale. The lessons learned from these discrepancies may benefit future studies and reduce the risks for patients. This review summarizes trials on MS since 2015 that have either failed or have been interrupted for various reasons. We identify potential causes of failure or inconclusiveness, looking at the path from basic animal experiments to clinical trials, and discuss the implications for our current view on MS pathogenesis, clinical practice, and future study designs. We focus on anti-inflammatory treatment strategies, without including studies on already approved and effective DMT. Clinical trials addressing neuroprotective and alternative treatment strategies are presented in a separate article.

NK/T cell ratios associate with interleukin-2 receptor alpha chain expression and shedding in multiple sclerosis

NK/T-cell ratios predict disease activity in relapsing remitting multiple sclerosis (RRMS). We investigated in 50 RRMS patients whether interleukin-2 receptor alpha-chain (IL-2Rα) expression and shedding associates with NK/T-cell balance, as suggested by daclizumab-trials in RRMS. A subsample (N = 31) was genotyped for IL2RA-associated MS risk SNPs. CD56^bright NK-cell/IL-17A⁺CD4⁺ T-cell ratios correlated negatively with plasma and PBMC-culture supernatant sIL-2Rα-levels [R = -0.209; p = 0.038 and R = -0.254; p = 0.012, resp.], and with CD4⁺ T-cell CD25 MFI [R = -0.341; p = 0.001]. Carriers of the rs3118470 risk-allele showed higher sIL-2Rα-levels (P = 0.031) and a lower CD56^bright NK-cell/IL-17A⁺CD4⁺ T-cell ratio (P = 0.038). Therefore, IL-2Rα may be involved in the interplay between NK-cells and T-cells.

Herpesvirus Antibodies, Vitamin D and Short-Chain Fatty Acids: Their Correlation with Cell Subsets in Multiple Sclerosis Patients and Healthy Controls

Although the etiology of multiple sclerosis (MS) is still unknown, it is commonly accepted that environmental factors could contribute to the disease. The objective of this study was to analyze the humoral response to Epstein-Barr virus, human herpesvirus 6A/B and cytomegalovirus, and the levels of 25-hydroxyvitamin D (25(OH)D) and the three main short-chain fatty acids (SCFA), propionate (PA), butyrate (BA) and acetate (AA), in MS patients and healthy controls (HC) to understand how they could contribute to the pathogenesis of the disease. With this purpose, we analyzed the correlations among them and with different clinical variables and a wide panel of cell subsets. We found statistically significant differences for most of the environmental factors analyzed when we compared MS patients and HC, supporting their possible involvement in the disease. The strongest correlations with the clinical variables and the cell subsets analyzed were found for 25(OH)D and SCFAs levels. A correlation was also found between 25(OH)D and PA/AA ratio, and the interaction between these factors negatively correlated with interleukin 17 (IL-17)-producing CD4+ and CD8+ T cells in untreated MS patients. Therapies that simultaneously increase vitamin D levels and modify the proportion of SCFA could be evaluated in the future.

Vitamin D and Immune Regulation: Antibacterial, Antiviral, Anti-Inflammatory

Regulation of immune function continues to be one of the most well-recognized extraskeletal actions of vitamin D. This stemmed initially from the discovery that antigen presenting cells such as macrophages could actively metabolize precursor 25-hydroxyvitamin D (25D) to active 1,25-dihydroxyvitamin D (1,25D). Parallel observation that activated cells from the immune system expressed the intracellular vitamin D receptor (VDR) for 1,25D suggested a potential role for vitamin D as a localized endogenous modulator of immune function. Subsequent studies have expanded our understanding of how vitamin D exerts effects on both the innate and adaptive arms of the immune system. At an innate level, intracrine synthesis of 1,25D by macrophages and dendritic cells stimulates expression of antimicrobial proteins such as cathelicidin, as well as lowering intracellular iron concentrations via suppression of hepcidin. By potently enhancing autophagy, 1,25D may also play an important role in combatting intracellular pathogens such as M. tuberculosis and viral infections. Local synthesis of 1,25D by macrophages and dendritic cells also appears to play a pivotal role in mediating T-cell responses to vitamin D, leading to suppression of inflammatory T helper (Th)1 and Th17 cells, and concomitant induction of immunotolerogenic T-regulatory responses. The aim of this review is to provide an update on our current understanding of these prominent immune actions of vitamin D, as well as highlighting new, less well-recognized immune effects of vitamin D. The review also aims to place this mechanistic basis for the link between vitamin D and immunity with studies in vivo that have explored a role for vitamin D supplementation as a strategy for improved immune health. This has gained prominence in recent months with the global coronavirus disease 2019 health crisis and highlights important new objectives for future studies of vitamin D and immune function. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Prognostic value of natural killer cell/T cell ratios for disease activity in multiple sclerosis

Background and purpose

Natural killer (NK) cells may play a role in multiple sclerosis (MS). Ratios of NK cells to CD4⁺ T cells have been proposed as a biomarker for the therapeutic effect of stem cell transplantation in MS. The objectives here were to explore the relevance of this ratio in MS patients by analysing NK and T cell subsets, as well as their prognostic value for disease activity.

Methods

Baseline peripheral blood mononuclear cells of 50 relapsing–remitting MS patients, participating in our vitamin D supplementation study (SOLARIUM), were analysed with flow cytometry. Disease activity was measured as new magnetic resonance imaging lesions, relapses and mean plasma neurofilament light chain levels after 48 weeks of follow‐up.

Results

The proportion of NK cells correlated negatively with CD4⁺ T cells (R = −0.335, p = 0.001) and interleukin 17A (IL‐17A⁺) CD4⁺ T cells (R = −0.203, p = 0.043). Participants with magnetic resonance imaging activity or relapses displayed lower NK/IL‐17A⁺ CD4⁺ T cell ratios (p =0.025 and p = 0.006, respectively). The NK/IL‐17A⁺ CD4⁺ T cell ratio correlated negatively with neurofilament light chain levels (R = −0.320, p = 0.050). Vitamin D supplementation did not affect these ratios.

Conclusions

Our data suggest a protective role of an expanded NK cell compartment compared to the CD4⁺ T cell subset fractions in relapsing–remitting MS patients. NK/CD4⁺ T cell ratios may be a prognostic biomarker for disease activity in MS.

Vitamin D and IFN-β Modulate the Inflammatory Gene Expression Program of Primary Human T Lymphocytes

IFN-β treatment is a commonly used therapy for relapsing-remitting multiple sclerosis (MS), while vitamin D deficiency correlates with an increased risk of MS and/or its activity. MS is a demyelinating chronic inflammatory disease of the central nervous system, in which activated T lymphocytes play a major role, and may represent direct targets of IFN-β and vitamin D activities. However, the underlying mechanism of action of vitamin D and IFN-β, alone or in combination, remains incompletely understood, especially when considering their direct effects on the ability of T lymphocytes to produce inflammatory cytokines. We profiled the expression of immune-related genes and microRNAs in primary human T lymphocytes in response to vitamin D and IFN-β, and we dissected the impact of these treatments on cytokine production and T cell proliferation. We found that the treatments influenced primarily memory T cell plasticity, rather than polarization toward a stable phenotype. Moreover, our data revealed extensive reprogramming of the transcriptional output of primary T cells in response to vitamin D and IFN-β and provide the bases for further mechanistic insights into these commonly used treatments.

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.

Effect of vitamin D supplementation on N-glycan branching and cellular immunophenotypes in MS

Objective

To investigate the effect of cholecalciferol (vitamin D3) supplementation on peripheral immune cell frequency and N‐glycan branching in patients with relapsing‐remitting multiple sclerosis (RRMS).

Methods

Exploratory analysis of high‐dose (20 400 IU) and low‐dose (400 IU) vitamin D3 supplementation taken every other day of an 18‐month randomized controlled clinical trial including 38 RRMS patients on stable immunomodulatory therapy (NCT01440062). We investigated cholecalciferol treatment effects on N‐glycan branching using L‐PHA stain (phaseolus vulgaris leukoagglutinin) at 6 months and frequencies of T‐, B‐, and NK‐cell subpopulations at 12 months with flow cytometry.

Results

High‐dose supplementation did not change CD3+ T cell subsets, CD19+ B cells subsets, and NK cells frequencies, except for CD8+ T regulatory cells, which were reduced in the low‐dose arm compared to the high‐dose arm at 12 months. High‐dose supplementation decreased N‐glycan branching on T and NK cells, measured as L‐PHA mean fluorescence intensity (MFI). A reduction of N‐glycan branching in B cells was not significant. In contrast, low‐dose supplementation did not affect N‐glycan branching. Changes in N‐glycan branching did not correlate with cell frequencies.

Interpretation

Immunomodulatory effect of vitamin D may involve regulation of N‐glycan branching in vivo. Vitamin D3 supplementation did at large not affect the frequencies of peripheral immune cells.

Immunoregulatory effects and therapeutic potential of vitamin D in multiple sclerosis

Initially recognised as an important factor for bone health, vitamin D is now known to have a range of effects on the immune system. Vitamin D deficiency is associated with an increased risk of multiple sclerosis (MS), a chronic immune-mediated demyelinating disease of the CNS. In this review, we explore the links between vitamin D deficiency, MS risk, and disease activity. We also discuss the known immune effects of vitamin D supplementation and the relevance of these observations to the immunopathology of MS. Finally, we review the existing evidence for vitamin D supplementation as an MS therapy, highlighting several recent clinical studies and trials.

The Potential Immunoregulatory Roles of Vitamin D in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoantibody-mediated disease affecting the central nervous system (CNS). Its pathogenesis involves both innate and acquired immune reactions; specific antibody (Aquaporin-4 antibody) and inflammatory cells cause direct damage on lesion sites, while B cell-T cell interactions facilitate the demyelination. However, its etiology is still not fully understood. Vitamin D deficiency is present in numerous autoimmune diseases, including NMOSD. Evidence suggests that low vitamin D levels mayassociate with disease activity and relapse rate in NMOSD, indicating the participation in the pathogenesis of NMOSD. The immunoregulatory roles of vitamin D in both numerous autoimmune diseases and experimental autoimmune encephalomyelitis (EAE) models are increasingly recognized. Recent studies have revealed vitamin D modulation in cytokine production, immune cell development and differentiation, as well as antibody production. By enhancing an anti-inflammatory environment and suppressing the overactivated autoimmune process, vitamin D shows its potential immunoregulatory roles in NMOSD, which could possibly introduce a new therapy for NMOSD patients.

High dose vitamin D exacerbates central nervous system autoimmunity by raising T-cell excitatory calcium

Poor vitamin D status is associated with a higher relapse rate and earlier disability in multiple sclerosis. Based on these associations, patients with multiple sclerosis are frequently supplemented with the vitamin D precursor cholecalciferol, although it is unclear whether this regimen is of therapeutic benefit. To model consequences of this common practice, mice were fed for more than 3 months with a low, medium or high dose of cholecalciferol, representative of vitamin D deficiency, modest and disproportionally high supplementation, respectively, in patients with multiple sclerosis. Compared to vitamin D-deprived mice, its moderate supplementation reduced the severity of subsequent experimental autoimmune encephalomyelitis, which was associated with an expansion of regulatory T cells. Direct exposure of murine or human T cells to vitamin D metabolites inhibited their activation. In contrast, mice with 25-(OH) vitamin D levels above 200 nmol/l developed fulminant experimental autoimmune encephalomyelitis with massive CNS infiltration of activated myeloid cells, Th1 and Th17 cells. When dissecting this unexpected outcome, we observed that high, but not medium dose vitamin D had caused mild hypercalcaemia, which rendered T cells more prone to pro-inflammatory activation. Exposing murine or human T cells to equivalent calcium concentrations in vitro enhanced its influx, triggering activation, upregulation of pro-inflammatory gene products and enhanced transmigration across a blood-brain barrier model. These findings suggest that vitamin D at moderate levels may exert a direct regulatory effect, while continuous high dose vitamin D treatment could trigger multiple sclerosis disease activity by raising mean levels of T-cell excitatory calcium.

Vitamin D as a Potential Therapy for Multiple Sclerosis: Where Are We?

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system and is caused by an aberrant immune response to myelin sheath. Disease-modifying medications, which mainly aim to suppress such aberrant immune response, have significantly improved MS treatment. However, the disease severity continues to worsen. In contrast, progressively more data suggest that 1,25-dihydroxyvitamin D or 1,25(OH)₂D, i.e., the active vitamin D, suppresses the differentiation of potentially pathogenic T cells associated with MS, enhances the differentiation of regulatory T cells that suppress the pathogenic T cells, and promotes remyelination. These novel 1,25(OH)₂D functions have encouraged investigators to develop vitamin D as a potential therapy for MS. However, because of the hypercalcemia that is associated with high 1,25(OH)₂D concentrations, supplementation of native vitamin D has been a major focus in clinical trials for the treatment of MS, but such trials have produced mixed data. In this article, we will review current progress in the supplementation of different vitamin D forms for the treatment of experimental autoimmune encephalomyelitis (i.e., an MS animal model) as well as MS. Furthermore, we will review alternative strategies that our laboratory and others are pursuing in an attempt to circumvent the hurdles that are hampering the effective use of vitamin D as a potential therapy for MS.

Vitamin D's Effect on Immune Function. Nutrients. 2020;12. [PMID: 32353972 PMCID: PMC7281985 DOI: 10.3390/nu12051248]

Ever since its discovery by Windhaus, the importance of the active metabolite of vitamin D (1,25-dihydroxyvitamin D₃; 1,25-(OH)2D₃) has been ever expanding. In this review, the attention is shifted towards the importance of the extra-skeletal effects of vitamin D, with special emphasis on the immune system. The first hint of the significant role of vitamin D on the immune system was made by the discovery of the presence of the vitamin D receptor on almost all cells of the immune system. In vitro, the overwhelming effect of supra-physiological doses of vitamin D on the individual components of the immune system is very clear. Despite these promising pre-clinical results, the translation of the in vitro observations to solid clinical effects has mostly failed. Nevertheless, the evidence of a link between vitamin D deficiency and adverse outcomes is overwhelming and clearly points towards avoidance of vitamin D deficiency especially in early life.

Vitamin D, smoking, EBV, and long-term cognitive performance in MS: 11-year follow-up of BENEFIT

OBJECTIVE

To investigate whether vitamin D, smoking, and anti-Epstein-Barr virus (EBV) antibody concentrations predict long-term cognitive status and neuroaxonal injury in multiple sclerosis (MS).

METHODS

This study was conducted among 278 patients with clinically isolated syndrome who participated in the clinical trial BENEFIT (Betaferon/Betaseron in Newly Emerging Multiple Sclerosis for Initial Treatment) and completed the 11-year assessment (BENEFIT-11). We measured serum 25-hydroxyvitamin-D (25(OH)D), cotinine (smoking biomarker), and anti-Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG) at baseline and at months 6, 12, and 24 and examined whether these biomarkers contributed to predict Paced Auditory Serial Addition Test (PASAT)-3 scores and serum neurofilament light chain (NfL) concentrations at 11 years. Linear and logistic regression models were adjusted for sex, baseline age, treatment allocation, steroid treatment, multifocal symptoms, T2 lesions, and body mass index.

RESULTS

Higher vitamin D predicted better, whereas smoking predicted worse cognitive performance. A 50-nmol/L higher mean 25(OH)D in the first 2 years was related to 65% lower odds of poorer PASAT performance at year 11 (95% confidence intervals [95% CIs]: 0.14-0.89). Standardized PASAT scores were lower in smokers and heavy smokers than nonsmokers (p _trend = 0.026). Baseline anti-EBNA-1 IgG levels did not predict cognitive performance (p _trend = 0.88). Associations with NfL concentrations at year 11 corroborated these findings-a 50-nmol/L higher mean 25(OH)D in the first 2 years was associated with 20% lower NfL (95% CI: -36% to 0%), whereas smokers had 20% higher NfL levels than nonsmokers (95% CI: 2%-40%). Anti-EBNA-1 antibodies were not associated with NfL.

CONCLUSIONS

Lower vitamin D and smoking after clinical onset predicted worse long-term cognitive function and neuronal integrity in patients with MS.

Is there any link between vitamin D deficiency and vasovagal syncope?

BACKGROUND

This study aimed to investigate serum 25[OH]D levels between patients with vasovagal syncope (VVS) diagnosed with head-up tilt table test (HUTT) and age-matched healthy people.

METHODS

The study included 75 consecutive patients (32.3 ± 10.7 years), who presented with syncope and underwent HUTT and 52 healthy controls (32.9 ± 14.1 years). HUTT patients were divided into two groups according to whether there was syncope response to the test. Patients underwent cardiac, psychiatric, and neurological investigation. Serum 25[OH]D levels were measured by chemiluminescent microparticle immunoassay method.

RESULTS

There was no difference between the two groups in terms of age, gender, body mass index (BMI), echocardiographic findings (P > .05). Mean serum 25[OH]D (24.5 ± 6.3 vs 20.1 ± 8.8 ng/mL, P = .003) and vitamin B12 levels (436.4 ± 199.2 vs 363.1 ± 107.6 pg/mL, P = .009) was lower in syncope patients when compared to the control group. In correlation analyses, syncope was shown as correlated with the vitamin D (r = -264, P = .003) and vitamin B12 levels (r = -233, P = .009). But, multivariate regression analyses showed that only vitamin D increased risk of syncope [OR: 0.946, 95% CI (0.901-0.994)]. There was no difference in terms of age, gender, BMI, echocardiographic findings between the in HUTT positive (n = 45) and negative groups (n = 29). Only vitamin D level was significantly lower in HUTT positive group (17.5 ± 7.7 vs 24.4 ± 9.1 ng/mL, P = .002). There was no difference among in the vasovagal subgroups in terms of vitamin D level and other features.

CONCLUSION

Vitamin D and B12 levels were reasonably low in syncope patients, but especially low Vitamin D levels were associated with VVS diagnosed in HUTT.

Effects of Vitamin D Supplements on IL-10 and INFγ Levels in Patients with Multiple Sclerosis: a Systematic Review and Meta-Analysis

Background:Vitamin D is one of the considerable environmental factors exhibiting immunomodulatory and anti-inflammatory effects. Objective: To conduct a systematic review and meta-analysis to estimate the effect of vitamin D supplements on IL-10 and INFγ levels in patients with multiple sclerosis. Methods: We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Ovid, The Cochrane Library and gray literature, including references of selected studies, conference abstracts which were published up to May 2019. We included single- or double-blinded RCTs or open-label trials in which one of the main outcomes was INFγ and/ or IL-10 levels after vitamin D supplementation. Only articles that had been published in English were included. Results: The literature search yielded 369 articles, that were monitored by us. After eliminating duplicates, 128 studies remained; from these, we excluded observational studies, reviews, case reports and non-randomized trials, and 33 studies remained. Finally, only three articles were included. The mean difference for INFγ was 268.4 and 95 % CI 200.6-336.1. There was no significant heterogeneity (I ² = 0 %, Chi ² = 0.1, p = 0.7). The mean difference for IL-10 was 398.3 and 95% CI -528.05-1324.8). There was significant heterogeneity (I2 = 94 %, Chi2 = 31.1 p < 0.001). Conclusion: The results of this systematic review were not satisfactory. More clinical trials are further needed to evaluate the effects of vitamin D supplements on IL-10 and INFγ levels in patients with multiple sclerosis.

Vitamin D3 supplementation and neurofilament light chain in multiple sclerosis

OBJECTIVES

Low circulating vitamin D levels are associated with an increased risk of active MRI lesions and relapses in several cohorts with relapsing remitting multiple sclerosis (RRMS). Randomized controlled supplementation trials are, however, negative on their primary endpoints, while secondary MRI endpoints suggest anti-inflammatory effects. Circulating levels of neurofilament light chain (NfL) are a biomarker of disease activity in RRMS. We explored whether 48-week high-dose vitamin D₃ supplements were associated with lower circulating NfL levels.

MATERIALS & METHODS

Of N = 40 Dutch interferon beta-treated participants with RRMS of the SOLAR trial, plasma samples at baseline and 48-week follow-up were available. Of these participants, N = 24 were supplemented with 14 000 IU/d vitamin D₃ and N = 16 with placebo. Twenty-five hydroxyvitamin D₃ (25(OH)D₃ ) levels were measured with LC-MS/MS, and NfL levels were measured in duplicate with Simoa.

RESULTS

Serum 25(OH)D₃ levels at 48 weeks were increased in the vitamin D₃ when compared to placebo group (median level 281 [IQR 205-330] vs 72 [39-88] nmol/L; P < .01). NfL levels at 48 weeks did not differ between the treatment groups (median level 25.4 [IQR 19.6-32.2] vs 25.3 [17.9-30.1] pg/mL; P = .74). Higher week 48 NfL level showed a trend toward association with a higher risk of combined unique active lesions on the week 48 MRI scan (OR 2.39 [95% CI 0.93-6.12] for each 10 pg/mL increase; P = .07).

CONCLUSIONS

Supplementation of high-dose vitamin D₃ for 48 weeks was not associated with lower NfL levels. This study does not support an effect of vitamin D₃ on this biomarker of neuro-axonal injury.

An Update on Vitamin D and Disease Activity in Multiple Sclerosis

Vitamin D and its main active metabolite 1,25-dihydroxyvitamin D serve a crucial role in maintenance of a healthy calcium metabolism, yet have additional roles in immune and central nervous system cell homeostasis. Serum levels of 25-hydroxyvitamin D are a biomarker of future disease activity in patients with early relapsing-remitting multiple sclerosis (RRMS), and vitamin D supplementation in patients with low circulating 25-dihydroxyvitamin D levels has been anticipated as a potential efficacious treatment strategy. The results of the first large randomized clinical trials (RCTs), the SOLAR and CHOLINE studies, have now been published. The SOLAR study compared 14,000 IU of vitamin D3 (cholecalciferol) per day with placebo for 48 weeks in 232 randomized patients, whereas CHOLINE compared vitamin D3 100,000 IU every other week with placebo for 96 weeks in 129 randomized patients. All patients in both studies also used interferon-β-1a. None of the studies met their primary endpoints, which were no evidence of disease activity (NEDA-3) at 48 weeks in SOLAR and annualized relapse rate at 96 weeks in CHOLINE. Both studies did, however, suggest modest effects on secondary endpoints. Thus, vitamin D reduced the number of new or enlarging lesions and new T2 lesions in SOLAR, and the annualized relapse rate and number of new T1 lesions, volume of hypointense T1 lesions, and disability progression in the 90 patients who completed 96 weeks' follow-up in CHOLINE. We conclude that none of the RCTs on vitamin supplementation in MS have met their primary clinical endpoint in the intention to treat cohorts. This contrasts the observation studies, where each 25 nmol/l increase in 25-hydroxyvitamin D levels were associated with 14-34% reduced relapse risk and 15-50% reduced risk of new lesions on magnetic resonnance imaging. This discrepancy may have several explanations, including confounding and reverse causality in the observational studies. The power calculations of the RCTs have been based on the observational studies, and the RCTs may have been underpowered to detect less prominent yet important effects of vitamin D supplementation. Although the effect of vitamin D supplementation is uncertain and less pronounced than suggested by observational studies, current evidence still support that people with MS should avoid vitamin D insufficiency, and preferentially aim for vitamin D levels around 100 nmol/L or somewhat higher.

Vitamin D rise enhances blood perfusion in patients with multiple sclerosis

The chemical structure of vitamin D resembles steroids and anabolics. Following activation by enzymatic hydroxylation, vitamin D enhances numerous body functions. We determined 25-hydroxy-vitamin D, number of erythrocytes, haematocrit, mean corpuscular haemoglobin and mean corpuscular volume in 97 patients with multiple sclerosis initially and 6 months later. Patients with deficient levels of 25-hydroxyvitamin D (< 30 ng/mL) were advised to perform vitamin D supplementation and received a prescription of a vitamin D formulation. Six months later we observed a rise of 25-OH-vitamin D, as to be expected, and a modified constellation of blood parameters such as elevation of mean corpuscular haemoglobin concentration and fall of mean corpuscular volume. Mean corpuscular haemoglobin and number of erythrocytes remained stable. The haematocrit went down. We suggest that vitamin D elevation may be beneficial in disorders characterised by chronic neuroinflammation and neurodegeneration, since changes of blood perfusion parameters may enhance cellular tissue oxygenation.

The role of vitamin D in increasing circulating T regulatory cell numbers and modulating T regulatory cell phenotypes in patients with inflammatory disease or in healthy volunteers: A systematic review

Background

The evidence for vitamin D and other agents that experimentally modulate T regulatory cells (Tregs) for the treatment of patients with autoimmune or allergic diseases has not been established.

Objective

We have undertaken a systematic review of randomised controlled trials to assess the efficacy of vitamin D, vitamin A, niacin and short-chain fatty acids in enhancing absolute Treg numbers and phenotypes in patients with inflammatory or autoimmune disease.

Methods

This systematic review was conducted using a predefined protocol (PROSPERO International prospective register of systematic reviews, ID = CRD42016048648/ CRD42016048646). Randomised controlled trials of patients with inflammatory or autoimmune disease or healthy participants which compared either oral vitamin D or vitamin A or short-chain fatty acids with control or placebo and measured the absolute concentration of proportion of Tregs were eligible for inclusion. Searches of electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PUBMED and Web of Science) identified eight eligible independent trials (seven autoimmune disease trials, one trial of healthy subjects). Data were extracted by two reviewers and the risk of study bias was assessed using Cochrane Collaboration methodology.

Results

Planned meta-analysis was not possible due to the heterogeneous nature of the studies. Nevertheless, in five trials of autoimmune disorders which measured the proportion of Tregs, a higher proportion was observed in the vitamin D group compared to controls at 12 months in all but one trial. In the trial of healthy subjects, a significant difference was reported, with a higher percentage of Tregs observed in the vitamin D group (at 12 weeks, mean 6.4% (SD 0.8%) (vitamin D) vs 5.5% (1.0%) (placebo). There were no trials to assess the efficacy of vitamin A, niacin and short-chain fatty acids in enhancing absolute Treg numbers.

Conclusions

Vitamin D supplementation may increase Treg/CD3 ratios in both healthy individuals and patients with autoimmune disorders and may increase Treg function. There remains a need for further suitably powered clinical studies aimed at enhancing Treg numbers and/or function.

Dietary Supplements on Controlling Multiple Sclerosis Symptoms and Relapses: Current Clinical Evidence and Future Perspectives

Background: Multiple sclerosis (MS) constitutes a chronic progressive demyelinating disease which negatively affects the central nervous system. MS symptoms detrimentally affect the quality of life, as well as the life expectancy of MS patients. In this aspect, the present study aims to critically summarize and evaluate the currently available clinical studies focusing on the potential beneficial effects of dietary supplements on controlling MS symptomatology and relapse. Methods: PubMed database was comprehensively searched, using relative keywords to identify clinical trials that investigated the beneficial effects of dietary supplementation against MS symptomatology and progression. 40 clinical trials were found, which were divided into categories. Results: Nutritional status of MS patients, as well as supplementation have been suggested as potential factors affecting progression. Several substantial studies have documented a systematically high prevalence of vitamin A, B12 and D3 deficiency amongst MS patients. At present, clinical data have suggested that most of the dietary supplements under study may exert antioxidant and anti-inflammatory properties, improving depression symptomatology and quality of life overall. However, malnutrition risk in MS patients has not been adequately explored in order for more precise conclusions to be drawn. The supplements that may have a positive effect on MS are vitamins, fatty acids, antioxidants, phytochemicals and melatonin. Conclusions: Several dietary supplements may decrease inflammation and fatigue, also increasing also autoimmunity tolerance in MS patients, and thus improving quality of life and life expectancy. Currently, there is no effective clinical indication for applying dietary supplementation as complementary treatment against MS symptomatology.

Emerging role of vitamin D in autoimmune diseases: An update on evidence and therapeutic implications

Vitamin D plays a key role in in calcium homeostasis and, thus, provides an important support in bone growth by aiding in the mineralization of the collagen matrix. However, vitamin D performs various immunomodulatory, anti-inflammatory, antioxidant and anti-fibrotic actions. Autoimmune diseases result from an aberrant activation of the immune system, whereby the immune response is directed against harmless self-antigens. Does vitamin D play a role in the pathophysiology of autoimmune diseases? And, if so, what is its role? In the last decade, researchers' interest in vitamin D and its correlations with autoimmune diseases has considerably increased. We conducted a literature review, covering the period January 1, 2009 through March 30, 2019, in PubMed. We analyzed more than 130 studies in order to find a correlation between vitamin D levels and its effect upon several autoimmune diseases. The analysis demonstrated an inverse association between vitamin D and the development of several autoimmune diseases, such as SLE, thyrotoxicosis, type 1 DM, MS, iridocyclitis, Crohn's disease, ulcerative colitis, psoriasis vulgaris, seropositive RA, polymyalgia rheumatica. International multicenter study could allow us to confirm the data already present in the literature in the single clinical studies and to evaluate when to effectively supplement vitamin D in patients who do not take corticosteroids.

Adverse events from large dose vitamin D supplementation taken for one year or longer

In recent years, clinical trials increasingly have given large doses of vitamin D supplements to investigate possible health benefits beyond bone at high 25-hydroxyvitamin D levels. However, there are few publications on the safety of high-dose vitamin D given long term. The study objective was to investigate the cumulative relative risk (RR) of total adverse events, kidney stones, hypercalcemia and hypercalciuria from ≥2800 IU/d vitamin D₂ or D₃ supplementation, followed for one year or more in randomized controlled trials (RCTs). A systematic review was conducted in Medline Ovid, EMBASE and Cochrane in March 2018 to update results of studies published since a previous review in October 2015. RCTs were included if they gave vitamin D₂ or D₃ at ≥2800 IU/d for at least one year and reported on total adverse events or at least one calcium-related adverse event. There were a total of 32 studies that met the inclusion criteria. Of these, only 15 studies (3150 participants) reported one or more event of the outcomes of interest. Long-term high-dose vitamin D supplementation did not increase total adverse events compared to placebo in 1731 participants from 10 studies (RR = 1.05; 95% CI = 0.88, 1.24; p = 0.61), nor kidney stones in 1336 participants from 5 studies (RR = 1.26; 95% CI = 0.35, 4.58; p = 0.72). However, there was a trend for vitamin D to increase risk of hypercalcemia in 2598 participants from 10 studies (RR = 1.93; 95% CI = 1.00, 3.73; p = 0.05); while its effect on hypercalciuria in only 276 participants from 3 studies was inconclusive (RR = 1.93; 95% CI = 0.83, 4.46; p = 0.12). In conclusion, one year or longer supplementation with a large daily, weekly or monthly dose of vitamin D₂ /D₃ did not significantly increase a risk of total adverse events or kidney stones, although there was a trend towards increased hypercalcemia, and possibly for hypercalciuria.

Effectiveness of Vitamin D Supplementation in the Management of Multiple Sclerosis: A Systematic Review

Objective: to examine the extent of effect vitamin D in Multiple Sclerosis (MS) on pathology and symptoms. Methods: A literature search was performed in November 2018 (CRD42018103615). Eligibility criteria: randomised control trials in English from 2012 to 2018; a clinical diagnosis of MS; interventions containing vitamin D supplementation (vitamin D3 or calcitriol) in disease activity compared to a control/placebo; improvement in: serum 25(OH)D, relapse rates, disability status by Expanded Disability Status Scale (EDSS) scores, cytokine profile, quality of life, mobility, T2 lesion load and new T2 or T1 Gd enhancing lesions, safety and adverse effects. Risk of bias was evaluated. Results: Ten studies were selected. The study size ranged from 40 to 94 people. All studies evaluated the use of vitamin D supplementation (ranging from 10 to 98,000 IU), comparing to a placebo or low dose vitamin D. The duration of the intervention ranged from 12 to 96 weeks. One trial found a significant effect on EDSS score, three demonstrated a significant change in serum cytokines level, one found benefits to current enhancing lesions and three studies evaluating the safety and tolerability of vitamin D reported no serious adverse events. Disease measures improved to a greater extent overall in those with lower baseline serum 25(OH)D levels. Conclusions: As shown in 3 out of 10 studies, improvement in disease measures may be more apparent in those with lower baseline vitamin D levels.

The role of vitamin D and P2X7R in multiple sclerosis

Multiple sclerosis (MS) is characterized by neuroinflammatory infiltrates and central nervous system demyelination. In the neuroinflammatory foci of MS there is increased expression of a purinergic receptor, P2X7R. Although implicated in the neuroinflammation, the exact role of P2X7R in the context of MS is unclear and forms the basis of this review. In this review, we also introduce the immunopathologies and inflammatory processes in MS, with a focus on P2X7R and the possible immunomodulatory role of vitamin D deficiency in this setting.

Vitamin D Supplementation in Central Nervous System Demyelinating Disease-Enough Is Enough

The exact cause of multiple sclerosis (MS) remains elusive. Various factors, however, have been identified that increase an individual's risk of developing this central nervous system (CNS) demyelinating disease and are associated with an acceleration in disease severity. Besides genetic determinants, environmental factors are now established that influence MS, which is of enormous interest, as some of these contributing factors are relatively easy to change. In this regard, a low vitamin D status is associated with an elevated relapse frequency and worsened disease course in patients with MS. The most important question, however, is whether this association is causal or related. That supplementing vitamin D in MS is of direct therapeutic benefit, is still a matter of debate. In this manuscript, we first review the potentially immune modulating mechanisms of vitamin D, followed by a summary of current and ongoing clinical trials intended to assess whether vitamin D supplementation positively influences the outcome of MS. Furthermore, we provide emerging evidence that excessive vitamin D treatment via the T cell-stimulating effect of secondary hypercalcemia, could have negative effects in CNS demyelinating disease. This jointly merges into the balancing concept of a therapeutic window of vitamin D in MS.

Vitamin D, Inflammation and Immunity: Review of Literature and Considerations on Recent Translational and Clinical Research Developments

The most relevant and recent literature findings linking exposure to sunlight, Vitamin D (VD), inflammation and immune system in health and disease, are reviewed.

Reduced sunlight exposure determined hypo-vitaminosis D to be common among patients or even healthy subjects, especially at higher latitudes. Numerous studies support the hypothesis that VD insufficiency could contribute to the higher autoimmune diseases incidence in the same geographic areas.

In the present review, the ways in which VD was reported to influence immune system, contributing to organism homeostasis or disease development are addressed. In fact, some of the hormone activities were recognised to determine stimulation or inhibition of immune system components.

Several diseases, where an association with VD deficiency was studied, are summarised. Finally, the rationale for optimization of substitutive/additive therapy with VD analogues and the last innovations regarding these drugs are mentioned.