Effects of vitamin D3 on expression of tumor necrosis factor-alpha and chemokines by monocytes

The role of regulatory T cells in vitiligo and therapeutic advances: a mini-review

BACKGROUND

Regulatory T cells (Tregs) play vital roles in controlling immune reactions and maintaining immune tolerance in the body. The targeted destruction of epidermal melanocytes by activated CD8+T cells is a key event in the development of vitiligo. However, Tregs may exert immunosuppressive effects on CD8+T cells, which could be beneficial in treating vitiligo.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to gather information on Tregs and vitiligo.

RESULTS

In vitiligo, there is a decrease in Treg numbers and impaired Treg functions, along with potential damage to Treg-related signaling pathways. Increasing Treg numbers and enhancing Treg function could lead to immunosuppressive effects on CD8+T cells. Recent research progress on Tregs in vitiligo has been summarized, highlighting various Treg-related therapies being investigated for clinical use. The current status of Treg-related therapeutic strategies and potential future directions for vitiligo treatment are also discussed.

CONCLUSIONS

A deeper understanding of Tregs will be crucial for advancing Treg-related drug discovery and treatment development in vitiligo.

Influence of sunlight on the association between 25-hydroxyvitamin D levels and sleep quality in Brazilian adults: A population-based study

OBJECTIVES

This study aimed to evaluate the association of vitamin D with sleep quality during the COVID-19 pandemic and the influence of daily sunlight on this association.

METHODS

This cross-sectional, population-based study among adults stratified by multistage probability cluster sampling was conducted from October to December 2020 in the Iron Quadrangle region of Brazil. The outcome was sleep quality, evaluated by the Pittsburgh Sleep Quality Index. Vitamin D (25-hydroxyvitamin D) concentrations were determined by indirect electrochemiluminescence and a deficiency was classified as 25(OH)D < 20 ng/mL. To assess sunlight, the average daily sunlight exposure was calculated and was classified as insufficient when less than 30 min/d. Multivariate logistic analysis was used to estimate the association between vitamin D and sleep quality. A directed acyclic graph was used to select minimal and sufficient sets of adjustment variables for confounding from the backdoor criterion.

RESULTS

In a total of 1709 individuals evaluated, the prevalence of vitamin D deficiency was 19.8% (95% CI, 15.5-24.9%), and the prevalence of poor sleep quality was 52.5% (95% CI, 48.6-56.4%). In multivariate analysis, vitamin D was not associated with poor sleep quality in individuals with sufficient sunlight. Moreover, in individuals with insufficient sunlight, vitamin D deficiency was associated with poor sleep quality (odds ratio [OR], 2.02; 95% CI, 1.10-3.71). Furthermore, each 1-ng/mL increase in vitamin D levels reduced the chance of poor sleep quality by 4.2% (OR, 0.96; 95% CI, 0.92-0.99).

CONCLUSIONS

Vitamin D deficiency was associated with poor sleep quality in individuals with insufficient exposure to sunlight.

Evaluation of IGF-1, TNF-α, and TGF-β Gene Expression after Oral Vitamin D Supplementation in School-Aged Children with Chronic Bronchial Asthma

BACKGROUND: Airway remodeling in children with bronchial asthma is due to the effect of inflammatory mediators and growth factors on the bronchial epithelium. Vitamin D (VitD) has immunomodulatory effect in many inflammatory diseases as bronchial asthma. The ant-inflammatory and anti-fibrotic role of VitD could prevent or improve air way remodeling in asthmatic patients. AIM: The study investigated the effect of VitD supplementation on the expression of transforming growth factor-beta (TGF-β), tumor necrosis factor-alpha (TNF-α), and insulin growth factor 1(IGF-1) and to correlate them with asthma severity and level of control. METHODS: The serum level of VitD and the mRNA expression of IGF-1, TGF-β, and TNF-α were estimated in 50 patients and 20 healthy controls control subjects using quantitative PCR in real-time. Asthmatic patients with VitD deficiency received VitD supplementation for 2 months followed by remeasurement of serum VitD and the genes expression TGF-β, TNF-α, and IGF-1. RESULT: Pre-intake of VitD and serum level of VitD were lower in all patients than control subjects (p = 0.005). VitD level was directly correlated with IGF-1 mRNA expression, which was indirectly correlated with TGF-β, r = 0.5 and −0.57; p = 0.0001 and 0.002, respectively. After VitD supplementation, the expression of the TGF-β mRNA gene was the only gene that decreased significantly (p = 0.04) together with improved asthma control and spirometric parameters. CONCLUSIONS: VitD supplementation down regulated the gene expression of TGF-β and improved asthma control level, but it did not significantly affect the gene expression of TNF-α and IGF-1.

Impact of Etanercept on Vitamin D Status and Vitamin D-binding Protein in Bio-naïve Patients with Psoriasis

High levels of serum vitamin D-binding protein have been shown previously in patients with psoriasis compared with healthy controls; a possible role in inflammation is implied. The primary objective of this study was to investigate the impact of 24-week etanercept treatment on vitamin D status and vitamin D-binding protein in patients with psoriasis. The secondary aim was to explore whether pre-treatment vitamin D levels could predict the treatment effect. A prospective observational study was performed, including 20 patients with psoriasis and 15 controls. Serum samples were analyzed for, among others, vitamin D metabolites, vitamin D-binding protein and highly sensitive Creactive protein. Baseline levels of vitamin D-binding protein were higher in patients with self-reported arthropathy than in those without. After 24 weeks’ treatment, an improvement in psoriasis was noted, as was a decrease in highly sensitive C-reactive protein. Vitamin D-binding protein decreased in those with self-reported arthropathy. Higher baseline levels of vitamin D were associated with faster and greater improvement in psoriasis. Vitamin D-binding protein may have an inflammatory biomarker role.

Advances in treatment of acute sulfur mustard poisoning - a critical review

Sulfur mustard (SM) is a blistering chemical warfare agent that was used during the World War I and in the Iraq-Iran conflict. The aim of this paper is to discuss and critically review the published results of experiments on the treatment of SM poisoning based on our clinical and research experience. The victims must remove from the contaminated zone immediately. The best solution for decontamination is large amounts of water, using neutral soap and 0.5% sodium hypochlorite. Severely intoxicated patients should be treated according to advanced life support protocols and intensive care therapy for respiratory disorders and the chemical burn. Sodium thiosulfate infusion (100-500 mg/kg/min) should be started up to 60 min after SM exposure. However, N-acetyle cysteine (NAC) is recommended, none of them acts as specific or effective antidote. The important protective and conservative treatment of SM-induced pulmonary injuries include humidified oxygen, bronchodilators, NAC as muculytic, rehydration, mechanical ventilation, appropriate antibiotics and respiratory physiotherapy as clinically indicated. Treatment of acute SM ocular lesions start with topical antibiotics; preferably sulfacetamide eye drop, continue with lubricants, and artificial tears. Treatment for cutaneous injuries include: moist dressing; preferably with silver sulfadiazine cream, analgesic, anti-pruritic, physically debridement, debridase, Laser debridement, followed by skin autologous split-thickness therapy as clinically indicated. The new suggested medications and therapeutic approaches include: anti-inflammatory agents, Niacinamide, Silibinin, Calmodulin antagonists, Clobetasol, full-thickness skin grafting for skin injuries; Doxycycline; Bevacizumab, and Colchicine for ocular injuries. Recommended compounds based on animal studies include Niacinamide, Aprotinin, des-aspartate-angiotensin-I, Gamma-glutamyltransferase, vitamin E, and vitamin D. In vitro studies revealed that Dimethylthiourea, L-nitroarginine, Methyl-ester, Sodium pyruvate, Butylated hydroxyanisole, ethacrynic acid, and macrolide antibiotics are effective. However, none of them, except macrolide antibiotics have been proved clinically. Avoidance of inappropriate polypharmacy is advisable.

The Role of Vitamin D and Omega-3 PUFAs in Islet Transplantation

Recurrence of autoimmunity and allograft rejection represent major challenges that impact the success of islet transplantation. Despite the remarkable improvements achieved in immunosuppression strategies after the publication of the Edmonton protocol, long-term data of intra-hepatic islet transplantation show a gradual decline in beta-cell function. Therefore, there is a growing interest in the investigation of novel, safe and effective anti-inflammatory and immunomodulatory strategies able to promote long-term islet graft survival and notable improvements in clinical outcomes of islet transplant recipients. Vitamin D has been shown to exert anti-inflammatory and immunomodulatory effects. Pre-clinical studies investigating the use of vitamin D and its analogs (alone or in combination with immunosuppressive agents and/or other anti-inflammatory agents, such as omega-3 polyunsaturated fatty acids) showed beneficial results in terms of islet graft survival and prevention of recurrence of autoimmunity/allograft rejection in animal models of syngeneic and allogeneic islet transplantation. Moreover, epidemiologic studies demonstrated that vitamin D deficiency is highly prevalent after solid organ transplantation (e.g., heart, liver or kidney transplantation). However, studies that critically assess the prevalence of vitamin D deficiency among islet transplant recipients have yet to be conducted. In addition, prospective studies aimed to address the safety and efficacy of vitamin D supplementation as an adjuvant immunomodulatory strategy in islet transplant recipients are lacking and are therefore awaited in the future.

Effect of single-dose injection of vitamin D on immune cytokines in ulcerative colitis patients: a randomized placebo-controlled trial

Ulcerative colitis (UC) is a chronic recurrent inflammation of the colon. It has been proposed that the UC pathogenesis may be related to vitamin D deficiency and/or vitamin D administration in UC patients may have an ameliorating effect on the intestinal inflammation. The aim of this study was to assess the effect of vitamin D on the serum levels of immune cytokines in UC patients. In this double-blind randomized controlled trial, 90 mild-to-moderate UC patients were assigned to get either a single muscular injection of 7.5 mg vitamin D3 or 1 mL normal saline as placebo. Three months later serum levels of IL-4, IL-10, IL-12p70, IFN-γ, and TNF-α were measured. Two group variables were compared using independent t-test and analysis of covariance (ANCOVA). There was a significant increase in vitamin D only in the vitamin D group. Compared to placebo, vitamin D had significant decreasing effects on serum TNF-α, IFN-γ, and IL12p70 levels, but it had no significant effect on serum levels of IL4 and IL10. Vitamin D seems to inhibit Th1 immune responses and have no effect on Th2 responses. The findings of this study support several in vitro studies, which suggest a therapeutic immunomodulatory potential of vitamin D.

Vitamin D for secondary prevention of acute wheeze attacks in preschool and school-age children

INTRODUCTION

Vitamin D is best known for its role in bone health; however, the discovery of the vitamin D receptor and the expression of the gene encoding the vitamin D 1α-hydroxylase (CYP27B1) enzyme in a wide variety of tissues including immune cells and respiratory epithelium has led to the discovery of potential roles for vitamin D in the prevention of acute wheeze.

METHODS

We review here the literature concerning the relationships between circulating 25-hydroxyvitamin D (25(OH)D) concentration and secondary prevention of acute wheeze attacks in preschool and school-age children.

RESULTS

Epidemiological data suggest that vitamin D insufficiency (25(OH)D <75 nmol/L) is highly prevalent in preschool and school-age children with wheeze. Preschool age children with a history of wheeze attacks and circulating 25(OH)D <75 nmol/L are at increased risk and frequency of future acute wheeze. However, no consistent association between low vitamin D status and risk of acute wheeze is reported in school-age children. Seven randomised controlled trials (RCTs) with relatively small sample sizes (30-430) and variable quality showed inconsistent results regarding the effect of oral vitamin D supplementation during childhood on the risk of asthma attacks, asthma symptom control, inhaled corticosteroid requirements, spirometry and unscheduled healthcare attendances for wheeze. A RCT showed that vitamin D supplementation had no effect on the frequency of unplanned healthcare attendances due to acute wheeze in 22 preschool children.

DISCUSSION

An evidence-based recommendation for the use of vitamin D as a preventive therapy for wheeze attacks cannot be made until results of further trials are available. The assessment of circulating 25(OH)D concentration and the optimisation of vitamin D status to prevent acute respiratory tract infections, and to maintain skeletal and general health in preschool and school-age children with acute wheeze is worthwhile in its own right, but whether this will reduce the risk of acute wheeze attacks is unclear.

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 deficiency in hepatitis C virus infection: what is old? what is new?

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Vitamin D deficiency and hepatitis viruses-associated liver diseases: A literature review

The secosteroid hormone vitamin D has, in addition to its effects in bone metabolism also functions in the modulation of immune responses against infectious agents and in inhibiting tumorigenesis. Thus, deficiency of vitamin D is associated with several malignancies, but also with a plethora of infectious diseases. Among other communicable diseases, vitamin D deficiency is involved in the pathogenesis of chronic liver diseases caused by hepatitis B and C viruses (HBV, HCV) and high prevalence of vitamin D deficiency with serum levels below 20 mg/mL in patients with HBV and HCV infection are found worldwide. Several studies have assessed the effects of vitamin D supplementation on the sustained virological response (SVR) to interferon (IFN) plus ribavirin (RBV) therapy in HBV and HCV infection. In these studies, inconsistent results were reported. This review addresses general aspects of vitamin D deficiency and, in particular, the significance of vitamin D hypovitaminosis in the outcome of HBV- and HCV-related chronic liver diseases. Furthermore, current literature was reviewed in order to understand the effects of vitamin D supplementation in combination with IFN-based therapy on the virological response in HBV and HCV infected patients.

Effects of 1α,25 Dihydroxyvitamin D3 on Pro-inflammatory Cytokines of Palmitic Acid Treated Thp-1 Cells

The level of saturated fatty acids, such as palmitic acid (PA), correlates with chronic inflammation in obese and metabolic syndrome patients. However, low level of vitamin D₃ is observed in those conditions. The aim of this study is to investigate effects of 1α,25(OH)₂ D₃ on PA-treated THP-1 cells. Using quantitative real-time polymerase chain reaction, we measure mRNA expression of pro-inflammatory cytokines: TNF-α, Interleukin (IL)-1β, IL-6, and chemokine IL-8 under PA and 1α,25(OH)₂ D₃ influence. PA, at all concentrations (25-100 μM), enhanced LPS stimulatory effect on those mRNA expression compared to LPS-treated and -untreated cells. Combination with 1α,25(OH)₂ D₃ increased cytokine expression at high (10^-6 M) and high-normal (10^-8 M) concentrations compared to PA + LPS and LPS alone, both for 2 and 24 h. However, low-normal (10^-10 M) and low (10^-12 M) levels of 1α,25(OH)₂ D₃ could not enhance PA effect, but mRNA expression of pro-inflammatory cytokine was higher than LPS-treated cells. Upstream pathway of 1α,25(OH)₂ D₃ , which is cholecalciferol, also gave the similar result. Further, inhibition of calcium pathway does not play a role in this mechanism. Thus, these findings support pro-inflammatory effect of PA and vitamin D₃ on innate immune response, especially on fat-induced inflammation.

PRACTICAL APPLICATION

The effect of vitamin D₃ on chronic inflammation in obesity is uncertain. This study shows an in vitro possibility that vitamin D₃ could exaggerate inflammation when combined with high SFAs. The idea of using vitamin D₃ supplement to modulate inflammation in fat-related inflammation needs further refined experiments before its clinical application.

Correction of vitamin D deficiency facilitated suppression of IP-10 and DPP IV levels in patients with chronic hepatitis C: A randomised double-blinded, placebo-control trial

Vitamin D deficiency was common among patients with chronic hepatitis C (CHC) and had negative influence on treatment outcome. Correction of vitamin D deficiency improved treatment response. Interferon gamma-induced protein 10 (IP-10) and enzyme dipeptidyl peptidase-4 (DPP IV) involved in inflammatory responses in CHC. Their higher levels at pretreatment of CHC could predict poorer responses. Vitamin D suppressed expression of IP-10 from monocytes in vitro. In CHC patients, DPP IV involved in IP-10 regulation. We hypothesized that correction of vitamin D insufficiency or deficiency in CHC patients might restore immune dysregulation through a pathway linked to the TH1/Th2 cytokines, IP-10 or DPP IV. We conducted a double-blind, placebo-controlled trial. 80 CHC patients with vitamin D levels less than 30 ng/mL were assigned to receive vitamin D (40) or placebo (40) supplements for 6 weeks. The levels of 25-hydroxyvitamin D [25(OH)D], Th1/Th2 cytokines, IP-10 and DPP IV were measured at baseline and at the 6th week. At the end of study, the mean 25(OH)D level in vitamin D group was significantly increased and normalised. There were no changes in the level of Th1/Th2 cytokines. Our important finding revealed that upon correction of vitamin D insufficiency or deficiency, the serum IP-10 and DPP IV levels were decreased significantly as compare to the placebo group (delta changes; 83.27 vs -133.80; 95% CI [-326.910, -40.758], p = 0.0125, and 271.04 vs -518.69; 95% CI [-1179,15, -59.781], p = 0.0305, respectively. As previous evidences suggested that each factor individually influenced and predicted outcome of CHC treatment. Our results offer a new insight and help to piece the puzzle of vitamin D deficiency, IP-10 and DPP IV together in CHC.

TRIAL REGISTRATION

Thai Clinical Trials Registry TCTR20160429001.

The relation of innate and adaptive immunity with viral-induced acute asthma attacks: Focusing on IP-10 and cathelicidin

BACKGROUND

Despite growing evidence suggesting potential association between innate and adaptive immunity in viral-induced acute asthma, there is paucity of data in this area.

OBJECTIVE

This study aimed to investigate the association of innate and adaptive immunity with acute asthma attacks by analysing the role of IFN-γ-inducible protein 10 (IP-10), TLR2, cathelicidin, vitamin D and cytokines.

MATERIAL AND METHODS

This prospective study included 33 patients with viral-induced acute asthma and 30 children with controlled asthma. Nasopharyngeal swab samples were collected for virus identification and asthma attack scores assessed in acute asthma group. Blood sampling for IP-10, TLR2, cathelicidin, vitamin D levels, and spirometric indices were employed.

RESULTS

Serum IP-10 and cathelicidin levels of acute asthma group were significantly higher and vitamin D levels were lower than controlled asthma group (IP-10; p=0.006, cathelicidin; p=0.002, vitamin D; p<0.001). Serum IP-10 levels showed a significant negative correlation with age (p=0.009), TLR2 (p=0.05) and spirometric indices (p=0.002) in all asthmatics and a significant positive correlation with parameters of asthma attack severity (p=0.03) in acute asthma group. Higher cathelicidin values showed significant positive relation to IP-10 (beta coefficient: 33, p=0.02). Serum IP-10 levels higher than 38.9pg/ml (sensitivity: 85%, specificity: 47%, p=0.002) were predictive of virus-induced asthma. Serum IP-10 and vitamin D levels were found to be significantly related to viral-asthma attacks (IP-10; aOR: 8.93, p=0.03 and vitamin D; aOR: 0.82, p=0.001).

CONCLUSIONS

Innate immunity biomarkers such as serum IP-10 and cathelicidin can be used to predict viral-induced acute asthma. These biomarkers may provide potential new treatment targets for acute asthma.

Vitamin D Deficiency Does Not Result in a Breach of Host Defense in Murine Models of Pneumonia

Vitamin D (VitD) has a role in the regulation of calcium and phosphate metabolism and in addition impacts the activity of the immune system. VitD deficiency might be linked to increased susceptibility to respiratory tract infection. The aim of the present study was to characterize the impact of VitD deficiency on the susceptibility to bacterial infection in murine models. C57BL/6N mice were fed a diet with or without VitD for 10 weeks. The VitD-deficient or -sufficient mice were infected with Pseudomonas aeruginosa or Streptococcus pneumoniae The colonization and inflammatory response in the lung were analyzed at defined time points. The serum 25-hydroxy-VitD concentration was significantly lower in mice on the VitD-deficient diet. In infection experiments with Pseudomonas aeruginosa or Streptococcus pneumoniae, no differences could be observed in the numbers of viable bacteria or in differential cell counts in the bronchoalveolar lavage fluids. Measurements of inflammatory cytokines (KC and interleukin-1β [IL-1β]) did not show significant differences between the groups. In conclusion, VitD-deficient animals did not show significantly increased susceptibility to infection or an altered course of infection. The immune systems of humans and mice likely respond differently to VitD. Murine models are likely not appropriate for drawing conclusions on the role of VitD in human pulmonary host defense.

Decreased expression of the vitamin D receptor in women with recurrent pregnancy loss

The multiple functions of vitamin D3 have stimulated interest in the role that this vitamin may play during pregnancy. The present study investigated the expression of the vitamin D receptor (VDR) in women during the first trimester of pregnancy in order to determine whether VDR is associated with recurrent pregnancy loss (RPL). Forty women at 7-10 weeks gestation with RPL and 40 women of similar gestational age with a healthy pregnancy were recruited. VDR mRNA and protein in chorionic villi and decidua were evaluated by immunohistochemistry, confocal laser scanning microscopy (CLSM), western blot, and quantitative real-time polymerase chain reaction. The serum levels of VDR were measured by an enzyme-linked immunosorbent assay. Women with RPL had a significantly weaker expression of VDR mRNA in villi and decidual tissues compared with the control women (both p < 0.0001). Western blot analysis showed an approximately 46% decrease in VDR expression in villi and a 52% decrease in decidua in the RPL vs. the controls. Serum VDR levels were also significantly lower in the RPL group than in the control group (p = 0.003). Compared with the controls, immunohistochemical and CLSM analysis revealed significantly lower VDR expression in villous cytotrophoblasts and stromal cells, as well as in decidual glandular epithelial and stromal cells (all p < 0.05). In conclusion, these observations show that women with RPL have lower levels of VDR expression in chorionic villi, decidua and serum compared with normal pregnant women, suggesting that decreased VDR expression in the first trimester pregnancy may be associated with RPL.

Vitamin D3 for uncontrolled childhood asthma: A pilot study

BACKGROUND

Observational and mechanistic data suggest a role for vitamin D in childhood asthma. However, subsequent interventional trials have been inconsistent. We aimed to assess the effect of 15 weeks of vitamin D3 supplementation compared with placebo (PL) in Irish children with asthma.

METHODS

We conducted a double-blind, randomized, PL-controlled trial of vitamin D supplementation (2000 IU/day) in 44 urban, Caucasian children at high latitude. Assessments were completed at baseline and after 15 weeks of supplementation. Outcome measures were lung function, subjective asthma control and biochemical parameters of total vitamin D, allergy, immunity, airway inflammation, and systemic inflammation. Finally, parents/guardians completed a weekly diary during the trial.

RESULTS

There was no significant difference in baseline 25(OH)D levels, but there was a significant increase in median 25(OH)D in the vitamin D3 group (57.5-105 nmol/l) compared with the PL group (52.5-57.5 nmol/l) (p < 0.0001). There was no significant difference between groups regarding subjective asthma control. Compared with PL, there was a significant decrease in school days missed due to asthma (1 vs. 5 days, p = 0.04) and alkaline phosphatase (-3.4 vs. +16; p = 0.037) in the vitamin D3 group, but there were no beneficial effects regarding several other secondary end-points. However, there were non-significant, advantageous changes in the PL group compared with the vitamin D3 group in subjective asthma control and lung function, particularly percentage of predicted forced expiratory volume in 1 s (+2.5 vs. -4; p = 0.06).

CONCLUSION

Vitamin D3 supplementation led to a significant increase in serum 25(OH)D and decreased school days missed (p = 0.04), but no other advantageous changes in asthma parameters compared with PL. The potential adverse effect of vitamin D deficiency on growth and the potential negative effect of high serum 25(OH)D on pulmonary function warrant further investigation.

Can Vitamin D Supplementation in Addition to Asthma Controllers Improve Clinical Outcomes in Patients With Asthma?: A Meta-Analysis

Effects of vitamin D on acute exacerbation, lung function, and fraction of exhaled nitric oxide (FeNO) in patients with asthma are controversial. We aim to further evaluate the roles of vitamin D supplementation in addition to asthma controllers in asthmatics. From 1946 to July 2015, we searched the PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials, and ISI Web of Science using "Vitamin D," "Vit D," or "VitD" and "asthma," and manually reviewed the references listed in the identified articles. Randomized controlled trials which reported rate of asthma exacerbations and adverse events, forced expiratory volume in 1 s (FEV1, % of predicted value), FeNO, asthma control test (ACT), and serum 25-hydroxyvitamin D levels were eligible. We conducted the heterogeneities test and sensitivity analysis of the enrolled studies, and random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference for dichotomous and continuous data, respectively. Cochrane systematic review software Review Manager (RevMan) was used to test the hypothesis by Mann-Whitney U test, which were displayed in Forest plots. Seven trials with a total of 903 patients with asthma were pooled in our final studies. Except for asthma exacerbations (I2 = 81%, χ2 = 10.28, P = 0.006), we did not find statistical heterogeneity in outcome measures. The pooled RR of asthma exacerbation was 0.66 (95% confidence interval: 0.32-1.37), but without significant difference (z = 1.12, P = 0.26), neither was in FEV1 (z = 0.30, P = 0.77), FeNO (z = 0.28, P = 0.78), or ACT (z = 0.92, P = 0.36), although serum 25-hydroxyvitamin D was significantly increased (z = 6.16, P < 0.001). Vitamin D supplementation in addition to asthma controllers cannot decrease asthma exacerbation and FeNO, nor improve lung function and asthma symptoms, although it can be safely applied to increase serum 25-hydroxyvitamin D levels.

Role of vitamin D in cytotoxic T lymphocyte immunity to pathogens and cancer

The discovery of vitamin D receptor (VDR) expression in immune cells has opened up a new area of research into immunoregulation by vitamin D, a niche that is distinct from its classical role in skeletal health. Today, about three decades since this discovery, numerous cellular and molecular targets of vitamin D in the immune system have been delineated. Moreover, strong clinical associations between vitamin D status and the incidence/severity of many immune-regulated disorders (e.g. infectious diseases, cancers and autoimmunity) have prompted the idea of using vitamin D supplementation to manipulate disease outcome. While much is known about the effects of vitamin D on innate immune responses and helper T (T(H)) cell immunity, there has been relatively limited progress on the frontier of cytotoxic T lymphocyte (CTL) immunity--an arm of host cellular adaptive immunity that is crucial for the control of such intracellular pathogens as human immunodeficiency virus (HIV), tuberculosis (TB), malaria, and hepatitis C virus (HCV). In this review, we discuss the strong historical and clinical link between vitamin D and infectious diseases that involves cytotoxic T lymphocyte (CTL) immunity, present our current understanding as well as critical knowledge gaps in the realm of vitamin D regulation of host CTL responses, and highlight potential regulatory connections between vitamin D and effector and memory CD8 T cell differentiation events during infections.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

Isolated vitamin D deficiency is not associated with nonthyroidal illness syndrome, but with thyroid autoimmunity

AIM

This study aimed to compare thyroid functions, thyroid autoantibodies, and the existence of nonthyroidal illness syndrome (NTIS) according to vitamin D level.

MATERIALS AND METHODS

The study included age- and BMI-matched healthy volunteers with and without vitamin D deficiency. In addition, the nonthyroidal illness syndrome status was evaluated.

RESULTS

Anti-TPO positivity was significantly more common in those with severe and moderate vitamin D deficiency, as compared to those with a normal 25(OH)D level. Furthermore, TSH levels were significantly lower in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. In addition, there was a significant weak inverse correlation between anti-TPO positivity and the 25(OH)D level and a positive correlation between the TSH level and 25(OH)D level. Only 1 thyroid function test result was compatible with NTIS among the participants with moderate vitamin D deficiency; therefore the difference was not significant.

CONCLUSIONS

The prevalence of thyroid autoantibody positivity was higher in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. Additional large-scale studies must be conducted to determine if vitamin D deficiency plays a causal role in the pathogenesis of Hashimoto's thyroiditis and NTIS.

CCL22 to Activate Treg Migration and Suppress Depigmentation in Vitiligo

In vitiligo, gradual cutaneous depigmentation and cytotoxic T cell activity against melanocytes is accompanied by a paucity of regulatory T cells (Tregs) in vitiligo patient skin, indicating that autoimmune responses are not adequately held in check. Thus we sought a means to repopulate patient skin with Tregs. We hypothesized that enhanced expression of CCL22 can promote Treg skin homing to suppress depigmentation. The mouse Ccl22 gene was cloned into an expression vector and resulting DNA was used for gene gun treatment. Two spontaneous depigmentation models with different kinetics of melanocyte loss were utilized, expressing tyrosinase-reactive and gp100-reactive T cell receptor transgenes. Mice were subjected to 5 gene gun treatments 6 days apart, scanned for depigmentation weekly thereafter and monitored for activation and proliferation of relevant T cells and for Treg infiltration to the skin. Significantly reduced depigmentation 2 weeks after treatment was accompanied by a markedly increased abundance of Tregs in the skin at the expense of melanocyte reactive, TCR transgenic T cells as well as by reduced proliferation and reduced IFN-γ production in response to cognate peptide. Continued treatment may be necessary for sustained, local immunosuppression. These findings suggest that topical CCL22 may be used for the treatment of vitiligo.

Role of vitamin D3 in treatment of lumbar disc herniation--pain and sensory aspects: study protocol for a randomized controlled trial

BACKGROUND

Vitamin D receptors have been identified in the spinal cord, nerve roots, dorsal root ganglia and glial cells, and its genetic polymorphism association with the development of lumbar disc degeneration and herniation has been documented. Metabolic effects of active vitamin D metabolites in the nucleus pulposus and annulus fibrosus cells have been studied. Lumbar disc herniation is a process that involves immune and inflammatory cells and processes that are targets for immune regulatory actions of vitamin D as a neurosteroid hormone. In addition to vitamin D's immune modulatory properties, its receptors have been identified in skeletal muscles. It also affects sensory neurons to modulate pain. In this study, we aim to study the role of vitamin D3 in discogenic pain and related sensory deficits. Additionally, we will address how post-treatment 25-hydroxy vitamin D3 level influences pain and sensory deficits severity. The cut-off value for serum 25-hydroxy vitamin D3 that would be efficacious in improving pain and sensory deficits in lumbar disc herniation will also be studied.

METHODS/DESIGN

We will conduct a randomized, placebo-controlled, double-blind clinical trial. Our study population will include 380 cases with one-level and unilateral lumbar disc herniation with duration of discogenic pain less than 8 weeks. Individuals who do not have any contraindications, will be divided into three groups based on serum 25-hydroxy vitamin D3 level, and each group will be randomized to receive either a single-dose 300,000-IU intramuscular injection of vitamin D3 or placebo. All patients will be under conservative treatment. Pre-treatment and post-treatment assessments will be performed with the McGill Pain Questionnaire and a visual analogue scale. For the 15-day duration of this study, questionnaires will be filled out during telephone interviews every 3 days (a total of five times). The initial and final interviews will be scheduled at our clinic. After 15 days, serum 25-hydroxy vitamin D3 levels will be measured for those who have received vitamin D3 (190 individuals).

TRIAL REGISTRATION

Iranian Registry for Clinical Trials ID: IRCT2014050317534N1 (trial registration: 5 June 2014).

The effect of calcium and vitamin D supplementation on osteoporotic rabbit bones studied by vibrational spectroscopy

Fourier transform infrared spectroscopy is utilized to examine the effects of increased calcium, vitamin D, and combined calcium-vitamin D supplementation on osteoporotic rabbit bones with induced inflammation. The study includes different bone sites (femur, tibia, humerus, vertebral rib) in an effort to explore possible differences among the sites. We evaluate the following parameters: mineral-to-matrix ratio, carbonate content, and non-apatitic species (labile acid phosphate and labile carbonate) contribution to bone mineral. Results show that a relatively high dose of calcium or calcium with vitamin D supplementation increases the bone mineralization index significantly. On the other hand, vitamin D alone is not as effective in promoting mineralization even with high intake. Mature B-type apatite was detected for the group with calcium supplementation similar to that of aged bone. High vitamin D intake led to increased labile species concentration revealing bone formation. This is directly associated with the suppression of pro-inflammatory cytokines linked to induced inflammation. The latter is known to adversely alter bone metabolism, contributing to the aetiopathogenesis of osteoporosis. Thus, a high intake of vitamin D under inflammation-induced osteoporosis does not promote mineralization but suppresses bone resorption and restores metabolic balance.

Vitamin D in inflammatory diseases

Changes in vitamin D serum levels have been associated with inflammatory diseases, such as inflammatory bowel disease (IBD), rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis (MS), atherosclerosis, or asthma. Genome- and transcriptome-wide studies indicate that vitamin D signaling modulates many inflammatory responses on several levels. This includes (i) the regulation of the expression of genes which generate pro-inflammatory mediators, such as cyclooxygenases or 5-lipoxygenase, (ii) the interference with transcription factors, such as NF-κB, which regulate the expression of inflammatory genes and (iii) the activation of signaling cascades, such as MAP kinases which mediate inflammatory responses. Vitamin D targets various tissues and cell types, a number of which belong to the immune system, such as monocytes/macrophages, dendritic cells (DCs) as well as B- and T cells, leading to individual responses of each cell type. One hallmark of these specific vitamin D effects is the cell-type specific regulation of genes involved in the regulation of inflammatory processes and the interplay between vitamin D signaling and other signaling cascades involved in inflammation. An important task in the near future will be the elucidation of the regulatory mechanisms that are involved in the regulation of inflammatory responses by vitamin D on the molecular level by the use of techniques such as chromatin immunoprecipitation (ChIP), ChIP-seq, and FAIRE-seq.

The role of vitamin D in human fracture healing: a systematic review of the literature

INTRODUCTION

Vitamin D is essential for bone mineralization and for the subsequent maintenance of bone quality. Mineralization is part of hard callus formation and bone remodelling, processes, which are part of fracture healing. We provide a comprehensive review of the literature to summarize and clarify if possible, the cellular effects of vitamin D and its clinical involvement in the process of fracture healing in human.

MATERIAL AND METHODS

We conducted a literature search in PubMed, Embase (OVID version), and Web of Science.

RESULTS

A total of 75 in vitro and 30 in vivo studies were found with inconsistent results about the cellular effect of vitamin D on fracture involved inflammatory cells, cytokines, growth factors, osteoblasts, osteoclasts and on the process of mineralization. With only five in vitro studies performed on material derived from a fracture site and one in vivo study in fracture patients, the exact cellular role remains unclear. Seven studies investigated the circulating vitamin D metabolites in fracture healing. Although it appears that 25(OH)D and 24,25(OH)2D3 are not affected by the occurrence of a fracture, this might not be the case with serum concentrations of 1,25(OH)2D3. The potential clinical effect of vitamin D deficiency is only described in one case series and three case controlled studies, where the results tend to show no effect of a vitamin D deficiency. No clinical studies were found investigating solely vitamin D supplementation. Two clinical studies found a positive effect of vitamin D supplementation and calcium, of increased bone mineral density or respectively increased fracture callus area at the fracture site. One study found indirect evidence that vitamin D and calcium promoted fracture healing.

CONCLUSION

Despite these results, and the presumed beneficial effect of vitamin D supplementation in deficient patients, clinical studies that address the effects of vitamin D deficiency or supplementation on fracture healing are scarce and remain inconclusive. We conclude that vitamin D has a role in fracture healing, but the available data are too inconsistent to elucidate how and in what manner.

Should vitamin D supplementation be a regular part of asthma care?

Vitamin D (vitD3) deficiency occurs frequently and has profound effects on health, especially asthma. This article examines how current knowledge of vitD3 actions and the worldwide distribution of vitD3 deficiency influences everyday clinical allergy practice. Within the limits of current knowledge, the article concisely explains the molecular nature of vitD3 actions, reviews key vitD3 research as it applies to clinical care, answers questions about the potential clinical impact of low vitD3 levels, and discusses use and safety of vitD3 supplements.

Vitamin D for your patients with chronic hepatitis C?

Vitamin D is increasingly becoming recognized as an important physiological regulator with pleiotropic functions outside of its classical role in skeletal homeostasis. A growing body of clinical evidence highlights the prevalence and risks of vitamin D deficiency in patients suffering from chronic hepatitis C infection, and vitamin D supplementation has been proposed as an adjunct to current standards of care. This review considers the experimental evidence for the anti-inflammatory, antifibrotic and antiviral effects of vitamin D, and discusses the therapeutic potential of vitamin D supplementation to protect against liver disease progression and improve responses to treatment.

Lipopolysaccharide-induced lung injury is independent of serum vitamin D concentration

Vitamin D deficiency is increasing in incidence around the world. Vitamin D, a fat-soluble vitamin, has documented effects on the innate and adaptive immune system, including macrophage and T regulatory (Treg) cell function. Since Treg cells are important in acute lung injury resolution, we hypothesized that vitamin D deficiency increases the severity of injury and delays injury resolution in lipopolysaccharide (LPS) induced acute lung injury. Vitamin D deficient mice were generated, using C57BL/6 mice, through diet modification and limited exposure to ultraviolet light. At 8 weeks of age, vitamin D deficient and sufficient mice received 2.5 g/kg of LPS or saline intratracheal. At 1 day, 3 days and 10 days, mice were anesthetized and lung elastance measured. Mice were euthanized and bronchoalveolar lavage fluid, lungs and serum were collected. Ex vivo neutrophil chemotaxis was evaluated, using neutrophils from vitamin D sufficient and deficient mice exposed to the chemoattractants, KC/CXCL1 and C5a, and to bronchoalveolar lavage fluid from LPS-exposed mice. We found no difference in the degree of lung injury. Leukocytes were mildly decreased in the bronchoalveolar fluid of vitamin D deficient mice at 1 day. Ex-vivo, neutrophils from vitamin D deficient mice showed impaired chemotaxis to KC but not to C5a. Vitamin D deficiency modestly impairs neutrophil chemotaxis; however, it does not affect lung injury or its resolution in an LPS model of acute lung injury.

Common genetic variation in vitamin D metabolism is associated with liver stiffness

Recently, genome-wide studies identified genetic variants that affect serum 25-hydroxyvitamin D levels in healthy populations (rs12785878, near dehydrocholesterol reductase, DHCR7; rs10741657, at CYP2R1; and rs7041, at vitamin D binding protein, GC). Because vitamin D deficiency is associated with advanced liver disease, we hypothesized that these variants are associated with 25(OH)-vitamin D levels and liver fibrosis. Overall, 712 Caucasian patients with chronic liver diseases were included. Liver fibrosis was assessed by transient elastography (TE) and/or histology. Serum levels of 25(OH)-vitamin D were correlated with TE and fibrosis stages. Genotypes were determined using TaqMan assays and tested for association with vitamin D and liver stiffness. Serum 25(OH)-vitamin D levels were inversely correlated with liver stiffness and histology (P < 0.001). Homozygous carriers of the rare DHCR7 allele or the common CYP2R1 allele presented with reduced 25(OH)-vitamin D levels (P < 0.05). The variant rs12785878 in the DHCR7 locus was associated with liver stiffness in both patients with TE <7.0 kPa and TE between 7.0 and 9.5 kPa. 25(OH)-vitamin D levels correlated with sunshine hours at the time of inclusion (P < 0.001).

CONCLUSION

Common variation in 25(OH)-vitamin D metabolism is associated with liver stiffness in patients presenting with low to moderately increased elasticity. Although the susceptible DHCR7 genotype confers small risk, we speculate that the observed stiffness differences indicate a stronger influence of 25(OH)-vitamin D on initiation rather than progression of hepatic fibrosis.

Vitamin D deficiency, smoking, and lung function in the Normative Aging Study

RATIONALE

Vitamin D has immunomodulatory and antiinflammatory effects that may be modified by cigarette smoke and may affect lung function.

OBJECTIVES

To examine the effect of vitamin D deficiency and smoking on lung function and lung function decline.

METHODS

A total of 626 men from the Normative Aging Study had 25-hydroxyvitamin D levels measured at three different times between 1984 and 2003 with concurrent spirometry. Vitamin D deficiency was defined as serum level ≤ 20 ng/ml. Statistical analysis was performed using multivariable linear regression and mixed effects models.

MEASUREMENTS AND MAIN RESULTS

In the overall cohort, there was no significant effect of vitamin D deficiency on lung function or on lung function decline. In both cross-sectional and longitudinal multivariable models, there was effect modification by vitamin D status on the association between smoking and lung function. Cross-sectional analysis revealed lower lung function in current smokers with vitamin D deficiency (FEV(1), FVC, and FEV(1)/FVC; P ≤ 0.0002), and longitudinal analysis showed more rapid rates of decline in FEV(1) (P = 0.023) per pack-year of smoking in subjects with vitamin D deficiency as compared with subjects who were vitamin D sufficient.

CONCLUSIONS

Vitamin D deficiency was associated with lower lung function and more rapid lung function decline in smokers over 20 years in this longitudinal cohort of elderly men. This suggests that vitamin D sufficiency may have a protective effect against the damaging effects of smoking on lung function. Future studies should seek to confirm this finding in the context of smoking and other exposures that affect lung function.

Vitamin D deficiency is associated with poor outcomes and increased mortality in severely ill patients

BACKGROUND

Vitamin D plays a seminal role in many homeostatic mechanisms. In this study, we assessed the correlation between circulating vitamin D levels and mortality rates in critically ill patients.

METHODS

All patients admitted to the intensive care units (ICUs) and internal medicine wards in a university-based hospital that required mechanical ventilation were admitted. Data collected included the underlying disease, basic hematological and biochemical blood test results, APACHE II scores and serum 25-hydroxyvitamin D [25(OH)D] levels. The primary end point was defined as all-cause mortality within 60 days from admission or from acute deterioration.

RESULTS

Between December 2008 and June 2009, 130 patients were enrolled. Average vitamin D concentration was 14.04 ± 6.9 ng/ml; 107 patients were vitamin D deficient (< 20 ng/ml). Total mortality rate after 60 days was 44.3%. Vitamin D levels were correlated with white blood cell (WBC) count, but with no other measured variable. Among the deceased patients, survival curves indicated that survival of patients with vitamin D deficiency was significantly shorter than those whose vitamin D concentration was >20 ng/ml (P < 0.05); the average survival time was 15.3 ± 12.4 days for vitamin D deficient patients compared with 24.2 ± 16.5 days among those with normal vitamin D levels.

CONCLUSION

This study demonstrated that low vitamin D levels are common among patients admitted to ICU. We observed longer survival times among vitamin D sufficient patients. Our results indicate that vitamin D concentration may be either a biomarker of survival or a co-factor. We recommend assessing the effects of vitamin D supplementation in critically ill patients.

Effects of vitamin D3 on the expression of growth-related oncogene-α in THP-1 cells and human primary monocytes

Asthma and many autoimmune diseases, such as systemic lupus erythematosus, have been reported to associate with vitamin D deficiency recently. Growth-related oncogene-α (GRO-α)/CXCL1, a neutrophil-related chemokine, have an important influence on the chronic inflammation of these diseases. It is unknown whether vitamin D has regulatory effects on GRO-α expression in human monocytes. To this end, the human monocytic leukemia cell line, THP-1, and human primary monocytes were pretreated with 1α, 25-(OH)(2)D(3), and was stimulated with lipopolysaccharide (LPS). Supernatants were collected to determine GRO-α level by ELISA. The intracellular signaling was investigated by nuclear factor (NF)-κB inhibitor, the mitogen-activated protein kinase (MAPK) inhibitors, and Western blot. In our studies, LPS-induced GRO-α was significantly enhanced in THP-1 cells, but suppressed in human primary monocytes by 1α, 25-(OH)(2)D(3). Western blotting revealed that 1α, 25-(OH)(2)D(3) increased LPS-stimulated pp38 expression in THP-1 cells, but suppressed LPS-stimulated pMEK1/2-pERK and pJNK in human primary monocytes. In conclusion, the opposite effects of 1α, 25-(OH)(2)D(3) on GRO-α expression in THP-1 cells and human primary monocytes indicated that the data from THP-1 cells should be further confirmed by human primary monocytes. Moreover, vitamin D3 may have potentiality in treating GRO-α-related chronic inflammatory diseases, like asthma and autoimmune diseases.

Effects of vitamin D on the peripheral adaptive immune system: a review

Epidemiological studies have shown that a poor vitamin D status is associated with an increased risk of several diseases, including autoimmune diseases. The immune regulatory function of vitamin D is thought to have an important role in these associations. Cells of the adaptive immune system have shown to be direct targets of the vitamin D metabolites. Besides being direct targets, cells of the adaptive immune system express the enzymes involved in the metabolism of vitamin D, enabling them to locally convert 25(OH)D into its active metabolite 1,25(OH)2D. In this review, the effects of vitamin D on cells of the adaptive immune system are described. Experimental data in vitro show that vitamin D skews cells of the adaptive immune system toward a more tolerogenic status which might be exploited in the treatment of autoimmune diseases. However, it should be noticed that in vivo effects may differ from in vitro effects due to the cross-talk between different vitamin D sensitive cells, but data support the view that vitamin D is positively involved in maintaining or restoring immune homeostasis. Upcoming vitamin D supplementation trials will further elucidate the in vivo effects of vitamin D on the immune system and its potency to serve as an immune regulating agent in autoimmune diseases.