Search Results (154)

Cancer-associated cachexia (CAC) is a complex metabolic syndrome characterised by progressive skeletal muscle loss, systemic inflammation, reduced treatment tolerance, and poor survival. Marked interindividual variability in CAC susceptibility suggests that host genetic factors may contribute to its development. Vitamin D plays an important role in muscle metabolism and inflammatory control through activation of the vitamin D receptor (VDR). VDR signalling influences myogenesis, mitochondrial function, insulin-like growth factor pathways, and pro-inflammatory cytokine expression, all of which are implicated in CAC pathogenesis. Hence, VDR variants, including the rs731236 (A>G) polymorphism, which modifies receptor activity, may affect CAC pathogenesis. Thus, this study investigated the association between the polymorphism and susceptibility to CAC as well as patient survival in a cohort of 140 adult cancer patients. Briefly, the rs731236 GG genotype was significantly associated with a lower prevalence of CAC across disease diagnostic approaches (chi-square tests, p < 0.05). Furthermore, GG genotype carriers demonstrated significantly improved survival compared with carriers of AA/AG genotypes (Log-rank and Tarone–Ware tests, p < 0.05). In summary, these findings suggest that the rs731236 polymorphism influences both susceptibility to CAC and survival outcomes in patients with cancer, further supporting a clinically relevant role for vitamin D signalling in supportive oncology care. Full article

The rs1544410 (BsmI) polymorphism of the vitamin D receptor (VDR) gene has been implicated in metabolic regulation, although its role in metabolic syndrome (MetS) and related phenotypes remains unclear. This study aimed to evaluate associations between rs1544410, MetS status, and anthropometric and biochemical parameters in institutionalized older adults. A total of 95 participants were included, of whom 40% met the criteria for MetS. Anthropometric and biochemical profiles were assessed, and rs1544410 genotyping was performed. Differences between MetS and non-MetS groups were analyzed, and two-way ANOVA was used to evaluate genotype, MetS status, and their interaction effects. Participants with MetS showed an adverse cardiometabolic profile, characterized by higher triglycerides (TGs), waist-to-hip ratio (WHR), and atherogenic index of plasma (AIP), as well as lower HDL-C levels compared with non-MetS individuals. No differences were observed for total cholesterol (TC), LDL-C, or non-esterified fatty acids (NEFAs) between groups. Genotype distributions did not differ between MetS and non-MetS participants. However, significant genotype × MetS interactions were observed for TG and NEFA, with a borderline interaction for WHR that was not confirmed in post hoc analyses. Carriers of the rs1544410 AA genotype within the MetS group exhibited higher TG and NEFA levels compared with other genotypes, whereas no genotype-dependent differences were observed in the non-MetS group. Importantly, AIP was higher in participants with MetS, with the highest values observed in AA genotype carriers. In conclusion, the rs1544410 polymorphism was not associated with MetS status but was linked to MetS-related differences in TG, NEFA, and AIP, suggesting selective effects on lipid metabolism. Full article

The active vitamin D metabolite, 1,25-dihydroxycholecalciferol [1,25(OH)₂D], exerts its biological effects through binding to the vitamin D receptor (VDR), a ligand-activated transcription factor regulating the expression of genes involved in calcium and phosphate homeostasis, immune modulation, and cell proliferation and differentiation. In addition to direct transcriptional regulation, 1,25(OH)₂D signaling also involves epigenetic mechanisms. A total of 90 studies were included in this narrative review, comprising experimental studies (n = 45), observational studies (n = 17), population-based studies (n = 8), interventional studies (n = 15), and mixed-design studies (n = 5). Experimental studies in cell cultures and animal models demonstrate that 1,25(OH)₂D may affect several major epigenetic regulatory pathways, including chromatin remodeling, DNA methylation, histone modifications, and the expression of non-coding RNAs, particularly microRNAs. Preclinical evidence suggests that the epigenetic actions of 1,25(OH)₂D are involved in metabolic regulation, immune responses, bone development, fibrotic processes, carcinogenesis, ageing, and fetal programming. However, evidence from observational studies and randomized controlled trials remains limited and inconclusive. Some studies have reported alterations in miRNA expression, methylation of selected loci, and epigenetic age markers. The clinical relevance of 1,25(OH)₂D–mediated epigenetic regulation has not yet been fully established. The interpretation of available findings is limited by substantial heterogeneity in study populations, exposure and intervention protocols, environmental factors, interindividual variability in response to vitamin D supplementation associated with genetic polymorphisms and methylation status, and the restricted range of analyzed cell types. This subject requires randomized controlled trials integrating molecular endpoints with clinically relevant outcomes. Full article

Objective: To investigate the association between genetic polymorphisms of the vitamin D receptor (VDR: rs1544410, rs2228570, rs731236), methylenetetrahydrofolate reductase (MTHFR: rs1801131), and DNA methyltransferase (DNMT1: rs2228611, DNMT3A: rs7590760, DNMT3B: rs6087990) genes and the coexistence of periodontitis and systemic lupus erythematosus (SLE). Methods: Systematically healthy individuals and patients with SLE of both sexes, aged over 20 years, were recruited and divided into four groups: healthy, periodontitis, SLE, and SLE with periodontitis. Seven polymorphisms in the VDR, MTHFR, DNMT1, DNMT3A, and DNMT3B genes were analyzed. Results: The frequency of the rs1801131 (MTHFR) AA genotype was higher in the healthy group than in the periodontitis group. The B allele of rs1544410 (VDR) was more frequent in patients with SLE, regardless of the presence of periodontitis. The t allele of rs731236 (VDR) was more frequent in patients with SLE without periodontitis. Conclusions: The polymorphisms studied do not show an exclusive association with the coexistence of periodontitis and SLE. However, the MTHFR rs1801131 polymorphism may be a protective factor against periodontitis, but not when it coexists with SLE. VDR rs1544410 is associated with SLE regardless of the presence of periodontitis, and rs731236 is associated with SLE, but not in coexistence with periodontitis. These data provide insights into the genetics of periodontitis and lupus; however, they are currently exploratory, as they were obtained from a single-center study in which it was not possible to adjust for demographic variables (age and sex) between groups due to the modest sample size. Full article

Background: Vitamin D receptor (VDR) polymorphisms have been widely investigated as genetic determinants of neurodegenerative diseases, yet findings remain inconsistent and population-dependent. Evidence from the Middle East, North Africa, and Türkiye (MENA&T) regions, which is characterized by widespread vitamin D deficiency and distinct genetic backgrounds, has not been comprehensively synthesized. Methods: We conducted a systematic review and meta-analysis evaluating associations between four common VDR polymorphisms (ApaI rs7975232, FokI rs2228570, TaqI rs731236, and BsmI rs1544410) and the risk of multiple sclerosis (MS), Parkinson’s disease (PD), and Alzheimer’s disease (AD) in MENA&T populations. Six databases were searched from inception to November 2025. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using fixed- and random-effects models across multiple genetic contrasts. Subgroup analyses by ethnicity were conducted for MS. Study quality was assessed using the Newcastle–Ottawa Scale (NOS), and the certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: Nineteen unique case–control studies (20 reports), including 4744 participants, were included. For MS, the ApaI polymorphism showed consistent associations with increased risk across genetic models (random-effects ORs = 1.4–1.9), with stronger effects in Arab and Iranian populations and no association in Turkish cohorts. FokI showed associations with MS under selected genetic models, particularly recessive and homozygous contrasts, although findings were not consistent across all analytical approaches. TaqI showed model-dependent associations with substantial heterogeneity, while BsmI showed no significant association. For AD, a meta-analysis of two studies showed no significant associations. For PD, ApaI showed associations with increased risk across several models without heterogeneity; however, these findings were based on a limited number of studies. Overall certainty of evidence ranged from very low to moderate. Conclusions: In MENA&T populations, VDR ApaI polymorphism shows consistent evidence of association with MS susceptibility, while FokI may be associated under specific genetic models; evidence for AD and PD remains limited and should be considered exploratory. These findings highlight population-specific genetic heterogeneity and underscore the need for further large-scale studies to confirm these associations. These population-specific genetic associations underscore the importance of incorporating VDR genotyping into precision medicine frameworks for neurodegenerative disease risk stratification in MENA&T populations, where vitamin D deficiency is highly prevalent. Full article

Recurrent pregnancy loss (RPL) is a multifactorial reproductive disorder with important genetic, endocrine, immune, and metabolic determinants. Growing evidence links vitamin D deficiency and vitamin D receptor (VDR) gene polymorphisms to pregnancy complications, including RPL. A narrative review was conducted via a literature search in major databases: PubMed, EMBASE, Scopus, and Web of Science from January 2010 to January 2026, which synthesized observational studies on maternal 25-hydroxyvitamin D [25(OH)D] status and/or VDR polymorphisms in RPL, with predefined eligibility criteria and qualitative risk-of-bias assessment. Most studies focused on FokI (rs2228570) and the 3′ regulatory block BsmI/ApaI/TaqI. FokI is the most extensively studied VDR variant in RPL and showed the most consistent directional association compared with other variants, particularly in Asian and Middle Eastern populations, though the effect varied by study design, ancestry, and covariate adjustment. Contrary to that, investigations of BsmI/ApaI/TaqI loci were not consistent due to ancestry-specific linkage disequilibrium (LD). Genotype and vitamin D interaction effects were scarcely studied, with stratified analyses indicating a more significant genotype effect under vitamin D deficiency. From clinical practice perspectives, VDR polymorphisms may explain why some patients with RPL have a poor response to standard vitamin D supplementation. Women with the FokI f allele polymorphism associated with lower VDR activity require higher vitamin D dosing or earlier immunomodulatory support to achieve adequate endometrial receptivity. VDR variation, particularly FokI, may contribute to RPL susceptibility within an endocrine–immune–metabolic framework. Clinical translation will require standardized RPL definitions, concurrent 25(OH)D assessment, robust control for confounders, and analytical models that account for gene–environment interactions. Full article

Survivors of childhood leukemia are at increased risk of long-term skeletal complications, including reduced bone mineral density (BMD). Vitamin D deficiency and genetic variations in the vitamin D receptor (VDR) gene are important factors influencing bone health, yet their combined effects remain insufficiently studied, particularly in North African populations. This case-control study included 130 survivors of childhood acute lymphoblastic leukemia (ALL) in remission (age range: 5–26 years) and 110 age- and sex-matched healthy controls recruited from Beni Messous Hospital. BMD was assessed at the lumbar spine and femoral neck using dual-energy X-ray absorptiometry and expressed as z-scores. Serum 25-hydroxyvitamin D levels were measured, and VDR polymorphisms (FokI, ApaI, and BsmI) were analyzed using PCR-RFLP. Hypovitaminosis D was observed in 43.85% of patients at diagnosis and 23.07% after remission. Survivors had significantly lower BMD compared with controls at both the lumbar spine (z-score: −4.26 ± 0.75 vs. 0 ± 1, p < 0.001) and femoral neck (−3.78 ± 0.45 vs. 0 ± 1, p < 0.001). Reduced BMD for age was identified in 30% of patients. Variant genotypes TT (FokI), AA (BsmI), and CC (ApaI) were more frequent in patients and were associated with lower BMD (p < 0.0001). These findings suggest that hypovitaminosis D and VDR polymorphisms may be associated with bone health in survivors of childhood leukemia. The coexistence of these factors may contribute to interindividual variability in BMD. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disease increasingly prevalent in adults. Vitamin D plays an important role in regulating immune responses, cellular differentiation, and inflammation. Several single-nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene have been suggested as biomarkers of AD susceptibility and severity. The aim of this study was to investigate six SNPs in the VDR gene (rs3847987, rs731236, rs7975232, rs1544410, rs2228570, and rs11168293) and their association with AD and blood biomarkers. Genotyping was performed in 91 adult patients with AD and 102 controls using real-time polymerase chain reaction. The genotype and allele distributions did not differ significantly between AD patients and controls. However, the G and T alleles of VDR rs731236 and rs1544410 were more frequently detected in individuals with serum 25-hydroxyvitamin D (25(OH)D) levels above 30 ng/mL. In contrast, the VDR rs7975232 C allele appears to be associated with lower odds of having a serum 25(OH)D level above 30 ng/mL. In genotype-stratified analysis, the T allele of VDR rs11168293 was more prevalent among individuals with eosinophil counts of 300 cells/μL. These findings suggest that VDR polymorphisms may contribute to variability in vitamin D status and inflammatory responses in adults with AD. Full article

Coronavirus disease-2019 COVID-19 exhibits marked inter-individual variability in susceptibility and clinical outcomes, suggesting a role for host genetic factors. Vitamin D exerts immunomodulatory effects through the vitamin D receptor (VDR), and genetic variation in the VDR gene may influence host responses to SARS-CoV-2 infection. This study aimed to investigate the association between VDR-gene polymorphisms—FokI (rs2228570), TaqI (rs731236), ApaI (rs7975232), and BsmI (rs1544410)—and COVID-19 susceptibility in the Kurdish population. The FokI polymorphism was significantly associated with COVID-19 susceptibility. Interestingly, the GG-genotype was more frequent among Patients than controls and was associated with increased odds of infection (OR = 9.00; 95% CI: 3.22–25.15; p < 0.0001), whereas the AG-genotype was associated with reduced susceptibility (OR = 0.33; 95% CI: 0.14–0.76; p = 0.001). Additionally, the G-allele was also more prevalent in Patients than controls (OR = 1.87; 95% CI: 1.21–2.89; p = 0.004). Similarly, the TaqI TT-genotype was more frequent among Patients and was associated with increased susceptibility (OR = 36.0; 95% CI: 11.2–115.8; p < 0.0001). In contrast, the ApaI AA-genotype was less frequent among Patients and was associated with reduced odds of COVID-19 susceptibility under a recessive model (OR = 0.15; 95% CI: 0.03–0.68; p = 0.003). Moreover, the BsmI polymorphism was monomorphic in both groups and therefore not informative. Genetic variation in the VDR gene, particularly at the FokI, TaqI, and ApaI loci, was associated with COVID-19 susceptibility in the case–control study, while BsmI showed no variations. These findings suggest that genetic variation in the VDR gene may contribute to inter-individual differences in susceptibility to SARS-CoV-2 infection in the Kurdish population. Larger studies incorporating functional validation and detailed clinical data are required to confirm these associations. Full article

Background/Objectives: Osteoporosis is a systemic skeletal disorder characterized by reduced bone mass and microarchitectural deterioration, resulting in an increased risk of fragility fractures, particularly vertebral fractures. Genetic factors are considered important in osteoporotic fracture susceptibility, and polymorphisms of the vitamin D receptor (VDR) gene have been widely studied because of their role in bone metabolism. To evaluate the distribution of VDR gene polymorphisms (FokI, BsmI, ApaI, and TaqI) in patients with osteoporotic vertebral fractures and to assess their association with fracture susceptibility. Methods: This case–control study included 86 individuals: 43 patients who underwent vertebroplasty for osteoporotic vertebral fractures and 43 osteoporotic individuals without vertebral fractures serving as controls. VDR gene polymorphisms ApaI, TaqI, BsmI and FokI were analyzed using real-time polymerase chain reaction. Genotype distributions were compared using Fisher’s exact test, and Hardy–Weinberg equilibrium was evaluated. Results: A significant difference between groups was observed only for the ApaI polymorphism (p = 0.002). The GG genotype was more frequent in patients, whereas the variant genotypes (GT and TT) were more prevalent in controls. The GG genotype was associated with an increased risk of vertebral fractures, while the presence of variant genotypes may be associated with reduced fracture susceptibility. No significant associations were found for TaqI, BsmI, or FokI polymorphisms. Conclusions: The ApaI polymorphism of the VDR gene may represent a protective genetic factor against osteoporotic vertebral fractures. In contrast, no associations were identified for the TaqI, BsmI, or FokI polymorphisms in this cohort. Larger studies in diverse populations are required to confirm these findings and to clarify the role of VDR gene variants in fracture susceptibility. Full article

Background: Vitamin D plays an important role in immune regulation, and vitamin D deficiency has been increasingly associated with susceptibility to infection and adverse outcomes in critically ill patients. Numerous systematic reviews and meta-analyses have examined the relationship between vitamin D status, vitamin D receptor (VDR) gene polymorphisms, and sepsis; however, the evidence remains fragmented. Objective: The aim of this work was to synthesize high-level evidence on the association between vitamin D deficiency, VDR gene polymorphisms, vitamin D supplementation, and sepsis-related outcomes through a PRISMA 2020-compliant umbrella review. Methods: An umbrella review of systematic reviews and meta-analyses published between 2014 and 2025 was conducted using PubMed, PubMed Central, and journal archives. Eligible studies included adult, pediatric, and neonatal populations and evaluated sepsis incidence, mortality, disease severity, secondary outcomes, and genetic associations. Data were synthesized qualitatively due to overlap of primary studies and heterogeneity. Conceptual forest plots and funnel plots were used to summarize evidence direction and potential publication bias. Results: Nineteen systematic reviews and meta-analyses encompassing over 300 primary studies were included. Vitamin D deficiency was consistently associated with an increased risk of sepsis, higher mortality, and greater disease severity across adult and pediatric populations. Stronger associations were observed in children and neonates, including higher PRISM III scores, increased need for mechanical ventilation, and longer hospital stays. VDR gene polymorphisms were modestly but consistently associated with increased sepsis susceptibility. In contrast, vitamin D supplementation did not demonstrate a consistent reduction in sepsis risk or mortality. Conclusions: Vitamin D deficiency is a robust marker of sepsis risk, severity, and poor prognosis, whereas current evidence does not support vitamin D supplementation as an effective treatment for established sepsis. Full article

Genetic polymorphisms contribute to inter-individual variability in cardiometabolic risk and quality-of-life outcomes, yet their clinical relevance often remains unclear due to population heterogeneity and reliance on single-variant analyses. Integrative approaches combining genetic and phenotypic data may improve the characterization of complex disease profiles, particularly in orthopedic populations burdened by cardiometabolic comorbidities. This study included 289 patients scheduled for orthopedic surgery. Polymorphisms in the vitamin D receptor (VDR; ApaI, FokI, BsmI), catechol-O-methyltransferase (COMT rs4680), and opioid receptor mu 1 (OPRM1 rs510769) genes were genotyped. Clinical, anthropometric, hematological, biochemical, and quality-of-life (SF-36) data were collected. Unsupervised k-means clustering was applied to standardized phenotypic variables to identify homogeneous patient subgroups. Inter-cluster differences were assessed using analysis of variance and chi-squared tests. Three distinct patient clusters were identified, characterized by specific combinations of cardiometabolic, inflammatory, and quality-of-life features. VDR polymorphisms were differentially distributed across clusters associated with differences in body mass index, hypertension prevalence, and inflammatory status. COMT and OPRM1 variants were primarily associated with variability in physical and mental quality-of-life dimensions. The cluster-based approach revealed multidimensional clinical heterogeneity not captured by conventional univariate analyses. Integrating genetic polymorphisms with clinical and quality-of-life data may support the identification and interpretation of distinct cardiometabolic profiles among orthopedic patients. Cluster-based stratification represents a valuable framework for capturing complex patient heterogeneity and supports future precision-oriented research in orthopedic and cardiometabolic populations. Full article

Background: Vitamin D receptor (VDR) gene polymorphisms are linked to muscle and bone physiology, yet their influence on individual differences in resistance training adaptations, especially between sexes, is not well understood. Methods: In total, 191 healthy Chinese Han adults (94 men, 97 women) completed a 12-week, twice-weekly resistance training program (squat and bench press). Key indicators of strength, power, body composition, and muscle morphology were assessed before and after the intervention. Participants were genotyped for VDR polymorphisms (rs731236/TaqI, rs7975232/ApaI, rs1544410/BsmI, rs2228570/FokI). Data were analyzed to compare responses across genotype groups. Results: Training induced significant improvements in multiple outcomes. Overall, the AG genotype of rs731236 and the CT genotype of rs1544410 were associated with greater gains in bone mineral content. Sex-specific analyses revealed distinct patterns: in women, the rs731236-AA genotype correlated with better strength and power gains, while the AG genotype linked to greater body composition improvements. In men, the rs1544410-CC genotype was associated with superior lower-limb muscle growth. The rs7975232 showed no significant overall effect, and rs2228570 deviated from Hardy–Weinberg equilibrium. Conclusions: VDR gene polymorphisms, particularly rs731236 and rs1544410, are associated with inter-individual variability in resistance training responses among Chinese Han adults, demonstrating clear sex and phenotype specificity. These findings offer preliminary support for genotype-informed personalized training. Full article

Background/aim: Vitamin D (VitD) has been implicated in neuroprotection, yet its role in Parkinson’s disease (PD) remains unclear. This systematic review and meta-analysis aimed to evaluate the association between VitD status, supplementation, and vitamin D receptor (VDR) gene polymorphisms with PD risk and outcomes. Methodology: Following PRISMA guidelines, we searched PubMed, Scopus, and Google Scholar through August 2025 for observational studies, clinical trials, and genetic association studies. Primary outcomes included serum VitD levels in PD versus healthy controls (HCs), prevalence of VitD insufficiency/deficiency, and effects of VitD supplementation on motor symptoms. Secondary outcomes assessed associations between VDR polymorphisms and PD susceptibility. Data were synthesized using random- and fixed-effects models, with heterogeneity and publication bias evaluated. PROSPERO (CRD420251133875). Results: Sixty-three studies (n ≈ 10,700 participants) met inclusion criteria. PD patients exhibited significantly lower VitD levels (SMD = −0.46; 95% CI: −0.51 to −0.41) and higher odds of insufficiency (OR = 1.52) and deficiency (OR = 2.20) compared to HC. Cohort data suggested sufficient VitD may reduce PD risk (HR = 0.83). Supplementation yielded modest, non-significant improvements in motor outcomes. Among 20 genetic studies, FokI (rs2228570) was most consistently associated with PD, while other VDR SNPs showed variable or null associations. Conclusions: VitD deficiency is common in PD and may influence disease risk and motor function. Current evidence indicates limited benefit of supplementation for motor outcomes, and genetic associations remain inconsistent. Full article

(1) Background: this study aimed to determine whether a serum parathyroid hormone (PTH) threshold of 40 pg/mL represents a clinically relevant risk factor for vitamin D (VitD) deficiency and reduced bone mineral density (BMD). It also investigated potential genetic interactions influencing PTH regulation and skeletal health in patients with periodontitis. (2) Methods: a cross-sectional analysis was conducted on 1038 periodontitis patients (35–75 years). Serum PTH, VitD, calcium (Ca), phosphate (P), and urinary parameters were assessed. Dual-energy X-ray absorptiometry (DXA) was used to evaluate BMD in 261 subjects. Vitamin D Receptor (VDR) and estrogen receptor alpha (ERα) polymorphisms were genotyped, and composite genetic risk scores were calculated. Statistical analyses included correlation tests, subgroup comparisons, and regression models. (3) Results: sixty-two percent of individuals had PTH > 40 pg/mL, which was associated with significantly lower 25(OH)D and Ca levels and reduced T-scores (p < 0.05). PTH levels negatively correlated with BMD (Pearson’s r = –0.159, p = 0.0105). Patients with higher ERα polymorphism scores showed increased PTH values (p < 0.05), while VDR variants demonstrated a positive but no significant trend. (4) Conclusions: a PTH threshold of 40 pg/mL identifies individuals at higher risk of VitD deficiency and skeletal fragility, even without overt hypercalcemia. Genetic factors, particularly ERα variants, may contribute to elevated PTH levels, suggesting value in integrating biochemical, densitometric, and genetic screening for early bone health risk stratification. Full article