Search Results (424)

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is the etiologic agent that causes the coronavirus disease (COVID-19) identified in Wuhan, in 2019. Men are more prone to developing severe manifestations than women, suggesting a possible crucial role of sex hormones. 17,β-Estradiol (E2) and 1,25 α dihydroxyvitamin D₃ (calcitriol) act upon gene pathways as immunomodulators in several infectious respiratory diseases. In this study, we aimed to evaluate the influence of E2 and calcitriol on the VSV-based pseudovirus SARS-CoV-2 and SARS-CoV-2 infection in vitro. We infected Vero E6 cells with the recombinant VSV-based pseudovirus SARS-CoV-2 and the SARS-CoV-2 viruses according to the pre-treatment and pre–post-treatment models. The Angiotensin-Converting Enzyme 2 (ACE2) and Vitamin D Receptor (VDR) gene expression did not change under different treatments. The VSV-based pseudovirus SARS-CoV-2 infection showed a significant decrease in the focus-forming unit count in the presence of E2 and calcitriol (either alone or in combination) in the pre-treatment model, while in the pre–post-treatment model, the infection was inhibited only in the presence of E2. Th SARS-CoV-2 infection highlighted a decrease in viral titres in the presence of E2 and calcitriol only in the pre–post-treatment model. 17,β-Estradiol and calcitriol can exert an inhibitory effect on SARS-CoV-2 infections, demonstrating their protective role against viral infections. Full article

Sarcopenia is a progressive age-related musculoskeletal disorder characterized by loss of muscle mass, strength, and physical performance, contributing to functional decline and increased risk of disability. Emerging evidence suggests that vitamin D (Vit D) plays a pivotal role in skeletal muscle physiology beyond its classical functions in bone metabolism. This review aims to critically analyze the relationship between serum Vit D levels and sarcopenia in older adults, focusing on pathophysiological mechanisms, diagnostic criteria, clinical evidence, and preventive strategies. An integrative narrative review of observational studies, randomized controlled trials, and meta-analyses published in the last decade was conducted. The analysis incorporated international diagnostic criteria for sarcopenia (EWGSOP2, AWGS, FNIH, IWGS), current guidelines for Vit D sufficiency, and molecular mechanisms related to Vit D receptor (VDR) signaling in muscle tissue. Low serum 25-hydroxyvitamin D levels are consistently associated with decreased muscle strength, reduced physical performance, and increased prevalence of sarcopenia. Although interventional trials using Vit D supplementation report variable results, benefits are more evident in individuals with baseline deficiency and when combined with protein intake and resistance training. Mechanistically, Vit D influences muscle health via genomic and non-genomic pathways, regulating calcium homeostasis, mitochondrial function, oxidative stress, and inflammatory signaling. Vit D deficiency represents a modifiable risk factor for sarcopenia and functional impairment in older adults. While current evidence supports its role in muscular health, future high-quality trials are needed to establish optimal serum thresholds and dosing strategies for prevention and treatment. An individualized, multimodal approach involving supplementation, exercise, and nutritional optimization appears most promising. Full article

Recent breakthroughs in cancer immunotherapy have shown remarkable success, yet treatment efficacy varies significantly among individuals. Emerging evidence highlights the gut microbiota as a key modulator of immunotherapy response, while vitamin D (VD), an immunomodulatory hormone, has garnered increasing attention for its potential interactions with gut microbiota and immunotherapy outcomes. However, the precise mechanisms and clinical applications of VD in this context remain controversial. This study systematically analyzed peer-reviewed evidence from PubMed, Scopus, Web of Science, PsycINFO, and MEDLINE (January 2000–May 2025) to investigate the complex interplay among VD, gut microbiota, and cancer immunotherapy. This review demonstrates that VD exerts dual immunomodulatory effects by directly activating immune cells through vitamin D receptor (VDR) signaling while simultaneously reshaping gut microbial composition to enhance antitumor immunity. Clinical data reveal paradoxical outcomes: optimal VD levels correlate with improved immunotherapy responses and reduced toxicity in some studies yet are associated with immunosuppression and poorer survival in others. The bidirectional VD–microbiota interaction further complicates this relationship: VD supplementation enriches beneficial bacteria, which reciprocally regulate VD metabolism and amplify immune responses, whereas excessive VD intake may disrupt this balance, leading to dysbiosis and compromised therapeutic efficacy. These findings underscore the need to elucidate VD’s dose-dependent and microbiota-mediated mechanisms to optimize its clinical application in immunotherapy regimens. Future research should prioritize mechanistic studies of VD’s immunoregulatory pathways, personalized strategies accounting for host–microbiota variability, and large-scale clinical trials to validate VD’s role as an adjuvant in precision immunotherapy. Full article

Background: Vitamin D is increasingly recognized not only for its role in skeletal development but also for its immunomodulatory and gastrointestinal effects. Maternal and neonatal vitamin D deficiency (VDD) has been associated with alterations in gut microbiota, impaired intestinal barrier integrity, and increased susceptibility to inflammatory conditions in neonates. However, the exact mechanisms linking perinatal vitamin D status to neonatal gastrointestinal morbidity remain incompletely understood. Methods: This review synthesizes current evidence (2015–2024) from clinical studies, animal models, and mechanistic research on the impact of VDD during pregnancy and the neonatal period on gastrointestinal health. Databases such as PubMed, Scopus, and Web of Science were systematically searched using keywords, including “vitamin D”, “neonate”, “gut microbiome”, “intestinal barrier”, and “necrotizing enterocolitis”. Results: Emerging data suggest that VDD in utero and postnatally correlates with dysbiosis, increased intestinal permeability, and elevated inflammatory responses in neonates. Notably, low 25(OH)D levels in mothers and newborns have been linked with a higher incidence of necrotizing enterocolitis (NEC), delayed gut maturation, and altered mucosal immunity. Vitamin D appears to modulate the expression of tight junction proteins, regulate antimicrobial peptides, and maintain microbial diversity through the vitamin D receptor (VDR). Conclusions: Understanding the gastrointestinal implications of early-life VDD opens a potential window for preventive strategies in neonatal care. Timely maternal supplementation and targeted neonatal interventions may mitigate gut-related morbidities and improve early-life health outcomes. Further longitudinal and interventional studies are warranted to clarify causality and optimal intervention timing. Full article

Sepsis acts as the leading cause of mortality in intensive care units, characterized by life-threatening organ dysfunction due to a dysregulated host response to infection. Vitamin D (VD) pleiotropic functions were demonstrated in different biological processes, including inflammation and immunity. VD receptor (VDR) is a member of the nuclear receptor superfamily, involved in immunoregulation and resistance to infections. Previous studies have demonstrated that VD deficiency is a potential risk factor for sepsis development, which may be regulated by VDR-related physiological processes. In this review, we present a comprehensive overview of the roles of VD and VDR in sepsis, focusing on immune modulation, anti-inflammatory and anti-infective responses, oxidative stress regulation, gut microbiome enhancement, vascular endothelial cell modulation, and antiplatelet activity. We also discuss recent advances in clinical research on VD/VDR in sepsis, considering the clinical implications and potential interventions of VD analogs and VDR ligands in treatment. Despite its challenges, VD holds potential for personalized sepsis interventions. Additionally, VD/VDR may serve as a promising bidirectional immunomodulator, capable of addressing both hyperinflammatory and immunosuppressive phases of sepsis, yet require systematic investigations into its dynamic states and functions across different sepsis phases. Ongoing study and evidence-based guidelines are crucial to maximize its therapeutic benefits and improve clinical outcomes. Full article

Background: Vitamin D has anti-inflammatory and immunomodulatory properties that may influence the pathophysiology of endometriosis. This study investigated the association between vitamin D levels and endometriosis, and vitamin D receptor (VDR) expression in endometriotic tissue. Methods: A cross-sectional study was conducted involving 36 patients with endometriosis and 72 healthy control women, matched for age and BMI. Serum 25-hydroxyvitamin D levels were measured and categorized into four statuses (normal, insufficiency, deficiency, and severe deficiency). Endometriotic tissue samples were examined for VDR expression using immunohistochemistry and qualitatively quantified using histo-scores (H-scores). Endometriosis severity was assessed using the revised criteria of the American Society for Reproductive Medicine (rASRM). Results: No statistically significant difference in vitamin D levels between the groups (20.45 vs. 21.10 ng/dL, p = 0.190) was observed, even after adjusting for residence, body sunscreen use, pregnancy, and contraceptive use. VDR expression exhibited significantly higher H-scores in endometriotic epithelial cells than in stromal cells (209.51 vs. 73.32; p < 0.001). Additionally, the VDR H-score in both cell compartments showed no significant difference according to vitamin D status. No statistically significant association was found between vitamin D levels, VDR expression, or disease severity. The odds of severe endometriosis were 2.17 (95% CI: 0.14–33.80) for vitamin D insufficiency and 4.33 (95% CI: 0.24–115.67) for deficiency compared with normal vitamin D. Conclusions: There was no statistically significant association between vitamin D levels and endometriosis and VDR. Full article

Vitamin D deficiency is widespread. It increases the risk of several diseases. Therefore, researchers have long studied the factors that influence vitamin D levels in the body. These include its metabolism, catabolism, transport and binding of vitamin D to the receptor VDR. Currently, an increasing number of studies are focusing on genetic factors. Variations in vitamin D levels, including vitamin D deficiency, are under substantial genetic control. There is a reciprocity between the vitamin D system and epigenetic mechanisms. Vitamin D metabolism, on the one hand, is regulated by epigenetic mechanisms and, on the other hand, is involved in regulating epigenetic events. To appraise recent advances in nutrigenomics with its application in public health, several databases, including PubMed, Scopus and Web of Science, were investigated in detail. Nutri-epigenetics deals with the interplay between dietary components and the possible resulting changes in the epigenome. There is, therefore, great potential for the development of nutri-epigenetics. The purpose of the narrative review is to highlight the genetic aspects of vitamin D, its receptor VDR and vitamin D-related gene polymorphisms with a particular focus on vitamin D gene regulation. Particular attention is paid to the vitamin D response index. Full article

Background/Objectives: Endplate lesions of the lumbar spine are often asymptomatic and frequently observed incidentally by radiological assessment. Variants in the vitamin D receptor gene (VDR) and an increase in some biochemical markers related to the osteo-cartilaginous metabolism were found in patients with endplate lesions. The aim of this study was to identify biochemical and genetic markers putatively associated with the presence of endplate lesions of the lumbar spine. Methods: Quantification of circulating bone remodeling proteins was obtained from 10 patients with endplate lesions and compared with age- and sex-matched controls. Whole exome sequencing (WES) was performed on patient genomic DNA using the Novaseq 6000 platform (Illumina, San Diego, CA, USA), obtaining a median read depth of 117×–200×, with ≥98% of regions covering at least 20×. The sequencing product was aligned to the reference genome (GRCh38.p13-hg38) and analyzed with Geneyx software. Results: We observed modifications in the levels of circulating proteins involved in bone remodeling and angiogenesis. We identified variants of interest in aggrecan (ACAN), bone morphogenetic protein 4 (BMP4), cytochrome P450 family 3 subfamily A member 4 (CYP3A4), GLI family zinc finger 2 (GLI2), heparan sulfate proteoglycan 2 (HSPG2), and mesoderm posterior bHLH transcription factor 2 (MESP2). VDR polymorphism (rs2228570) was present in nine patients, with the homozygotic ones having more severe endplate lesions and higher levels of the analyzed circulating markers in comparison with heterozygotic patients. Conclusions: These data represent interesting evidence of genetic variants, particularly in VDR, and altered levels of circulating markers of bone remodeling associated with endplate lesions, which should be confirmed in a larger population. The hypothesis suggested by our results is that the endplate lesions could be the consequence of an altered ossification mechanism at the vertebral level. Full article

Bile acids (BAs), essential for lipid metabolism and fat-soluble vitamin absorption, also act as signaling molecules that regulate immune homeostasis. This review focuses on the roles of four key BA-activated receptors, farnesoid X receptor (FXR), G protein-coupled bile acid receptor 1 (GPBAR1), liver X receptors (LXRs), and vitamin D receptor (VDR), in modulating the functions of monocytes-macrophages, and dendritic cells (DCs). The biological synthesis, transport, and metabolism of BAs were discussed and highlighted the feedback mechanisms regulating the synthesis and enterohepatic circulation of BAs. Each receptor’s role in shaping immune responses is detailed, including their function in inflammation, apoptosis, phagocytosis, and pathogen clearance. FXR and GPBAR1 activation generally exhibits anti-inflammatory effects, while LXR and VDR modulate a more nuanced interplay between immune responses and lipid homeostasis. We also explored the cross-talk between BA-activated receptors and Toll-like receptors, providing a comprehensive understanding of the complex interplay between BA signaling and innate immunity. This review culminates by highlighting the therapeutic potential of targeting these receptors for the treatment of inflammatory and autoimmune diseases. Full article

Diabetic foot ulcers (DFUs) constitute a severe and debilitating complication of diabetes, imposing a substantial global health burden due to their intricate pathophysiology and impaired wound healing processes. Vitamin D deficiency is highly prevalent among diabetic populations, and accumulating evidence indicates its potential involvement in the pathogenesis and prognosis of DFUs. This review comprehensively explores the diverse roles of vitamin D in DFUs, encompassing its molecular mechanisms such as immunomodulation, promotion of angiogenesis, neuroprotection, and induction of antimicrobial peptides, as well as the metabolic characteristics associated with various vitamin D forms and compromised vitamin D receptor (VDR) signaling pathways. Although robust observational studies have established an association between vitamin D deficiency and adverse outcomes in DFUs, the clinical validation of supplementation efficacy through randomized controlled trials (RCTs) remains constrained by limitations such as small sample sizes, heterogeneity in study protocols, and insufficient long-term follow-up. This highlights the critical need for large-scale, high-quality studies to ascertain optimal treatment regimens and to cater to individualized patient requirements, particularly for individuals with obesity or those with renal impairments. Innovative strategies, such as the topical administration of vitamin D through intelligent delivery systems leveraging advanced biomaterials like nanofibers and hydrogels, exhibit substantial preclinical potential in enhancing stability, achieving targeted controlled release, and augmenting local biological effects, including the induction of antimicrobial peptides. Nevertheless, significant challenges persist in conclusively establishing clinical efficacy, comprehensively elucidating the underlying mechanisms, ensuring the safe translation of novel delivery systems, and developing personalized therapeutic strategies. The future success of these interventions hinges on meticulous research and interdisciplinary collaboration to seamlessly integrate validated vitamin D-based interventions into a comprehensive multidisciplinary management framework for DFUs, thereby holding promise for improving the clinical outcomes of this debilitating condition. Full article

Vitamin D is a key micronutrient in the function of the skeletomuscular system. Athletes are at increased risk of developing vitamin D deficiency during the execution of very demanding disciplines such as CrossFit^®. Single-nucleotide polymorphisms (SNPs) may influence circulating 25-hydroxy-vitamin D (25(OH)D) levels. An observational, longitudinal pilot study was conducted with 50 trained males according to specific inclusion criteria. Blood samples were obtained to determine 25(OH)D, vitamin D-binding protein (VDBP), vitamin D-receptor (VDR)circulating levels, and the presence of SNPs after DNA isolation and genotyping: rs10741657 to CYP2R1, rs2282679 to GC and rs2228570 to VDR genes. Significant differences (p < 0.05) in 25(OH)D concentration were determined between the biallelic combinations of rs228679 (GC) and rs228570 (VDR). The VDBP and VDR proteins did not show different levels in the case of the rs10741657 (CYP2R1) alleles. Statistically significant weak positive correlations (p < 0.05) were observed between 25(OH)D and AA-alleles of the CYP2R1 and VDR genes, and TT-alleles of the GC gene. Additionally, AA (rs10741657 and rs2228570) and TT (rs2282679) have a probability between 2 and 4 of having major effects on the concentration of 25(OH)D. Conversely, GG alleles present a probability of suboptimal values of 25(OH)D of 69%, 34%, and 24% for VDR, GC, and CYP2R1, respectively, showing a strong moderate positive correlation (r = 0.41) between the degrees of sports performance and 25(OH)D plasma levels. CYP2R1 (rs10741657), GC (rs2282679), and VDR (rs2228570) affect the concentration of serum 25(OH)D, as an indicator of vitamin D status and play a critical role in the sports performance of CrossFit^® practitioners. Full article

Multiple Sclerosis (MS) is a chronic disease with autoimmune and neurodegenerative features that affect the nervous system. Genetic predisposition and environmental factors, such as vitamin D deficiency and dysbiosis activating a pro-inflammatory response, have a role in the etiology of the disease. In this context, the interactions of vitamin D with the gut microbiota and immune system have attracted attention in recent years. Vitamin D (1,25-dihydroxycholecalciferol) modulates the immune response by binding to the Vitamin D receptor (VDR). This pathway supports the functions of regulatory T cells by suppressing the activity of T helper cells 1 and 17 (Th1 and Th17). In MS patients, dysbiosis is characterized by a decrease in microbial diversity, and an increase in pro-inflammatory species is observed when compared to healthy individuals. Vitamin D has protective effects on eubiosis via VDR in intestinal epithelial cells, also reducing intestinal permeability by regulating tight junction proteins. In this way, vitamin D may contribute to the prevention of systemic inflammation. Although the relationship between vitamin D and the immune system is well documented, studies that address the triad of vitamin D level, gut microbiota, and immune response in MS are still limited. Full article

Vitamin D, a hormone synthesized in the skin through ultraviolet B radiation (UVB), plays a crucial role not only in calcium and phosphate homeostasis but also in regulating skin homeostasis and modulating immune responses. In keratinocytes, vitamin D is converted to its active form, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D), which interacts with the vitamin D receptor (VDR) to regulate gene expression involved in proliferation, differentiation, and antimicrobial defense. Dysregulation of this pathway has been implicated in inflammatory skin diseases such as psoriasis, atopic dermatitis, acne vulgaris, and hidradenitis suppurativa. These conditions are associated with altered epidermal differentiation, immune imbalance, and microbial interactions, where vitamin D plays a modulatory role by suppressing proinflammatory cytokines, enhancing antimicrobial peptide synthesis, and restoring skin barrier integrity. Topical vitamin D analogues have shown therapeutic benefits in psoriasis, while emerging evidence supports the adjunctive role of vitamin D supplementation in acne, hidradenitis suppurativa, and atopic dermatitis. Despite promising associations between low serum vitamin D levels and disease severity, a causal relationship remains uncertain. This review integrates molecular mechanisms with clinical findings, emphasizing the role of vitamin D in cutaneous physiology and pathology, and highlights the need for further research into targeted supplementation strategies in dermatological disorders. Full article

Background and Objectives: Lumbar disc herniation (LDH) is influenced by genetic, mechanical, and behavioral factors, with genetic predisposition playing a key role. Vitamin D receptor (VDR) polymorphisms have been implicated in LDH susceptibility, warranting further investigation. This study aimed to assess the association between VDR polymorphisms (FokI, ApaI, and TaqI) and LDH risk through a systematic review, meta-analysis, and trial sequential analysis (TSA). Materials and Methods: A systematic literature search was conducted across PubMed, Web of Science, Scopus, Cochrane Library, and CNKI, up until 30 January 2025. A meta-analysis was performed using Review Manager 5.3, with odds ratios (ORs) and 95% confidence intervals (CIs), and heterogeneity assessed via the I² statistic. The publication bias and TSA were evaluated using CMA 3.0 and TSA software to ensure the reliability of the results. The FATHMM-XF method was applied to predict the functional effect of coding and non-coding polymorphisms. Results: From 79 records, 10 studies were entered into the meta-analysis. The meta-analysis results showed no significant association of FokI and ApaI polymorphisms with LDH, while TaqI exhibited a protective effect, particularly in Asian populations and larger studies. The subgroup analysis revealed significant ethnicity-specific associations for TaqI, with stronger effects observed in Asian compared to Caucasian individuals. The trial sequential analysis indicated that additional studies are required to confirm the findings for FokI, while the recessive model of TaqI polymorphism showed a near-sufficient sample size for reliable conclusions. Conclusions: The TaqI polymorphism, particularly the tt genotype, appears to have a protective effect against LDH, especially in Asian populations and larger studies. However, further large-scale, multi-ethnic research is needed to confirm these findings and explore underlying biological mechanisms. Full article

Psoriasis is a chronic inflammatory skin disease marked by abnormal keratinocyte proliferation and immune dysregulation. The vitamin D receptor (VDR) plays a crucial role in regulating skin cell growth and immune responses, but its expression in psoriatic skin and modulation by treatment remain unclear. This study aimed to analyze VDR mRNA expression in psoriatic skin tissue before and after etanercept therapy using RNAscope, an RNA in situ hybridization technique that, to the best of our knowledge, has not previously been applied in psoriasis research. Two bio-naïve adult patients with moderate to severe plaque psoriasis received etanercept (50 mg weekly) for 12 weeks. Skin biopsies from lesional and perilesional areas were collected at baseline and post-treatment. VDR expression was assessed in different epidermal layers and the dermis using a semi-quantitative scoring system. In one patient, a statistically significant decrease in VDR expression was observed in the perilesional dermis after treatment (p < 0.001), though this preliminary finding warrants careful interpretation given the very limited cohort size. Both patients exhibited a non-significant trend toward increased VDR expression in the lesional epidermis post-treatment. These preliminary findings suggest that etanercept may modulate VDR expression in psoriatic skin, but individual variability and the small sample size preclude definitive conclusions. The study primarily demonstrates the feasibility of using RNAscope for VDR analysis in patients with psoriasis, an approach that may be novel in this context, and underscores the need for larger investigations to confirm these preliminary findings and further clarify the role of VDR in disease pathogenesis and treatment response. Full article