Search Results (850)

Introduction: Vitamin D deficiency, a reversible cause of osteoporosis, is increasingly prevalent, showing varying degrees of severity that are notably pronounced among the growing population of multimorbid elderly patients. Given that the aging pancreas undergoes senescent processes leading to impaired function—which negatively impacts enteral vitamin D absorption and, consequently, elderly bone metabolism—a specific diagnostic and treatment approach is crucial. Our study aimed to determine the prevalence of vitamin D deficiency and exocrine pancreatic insufficiency (EPI) in orthogeriatric patients. We also evaluated differences in vitamin D deficiency severity between patients with normal and impaired pancreatic function. Furthermore, a short-term monitoring of vitamin D level increases after 12 days of substitution therapy in both groups aimed to inform osteoanabolic therapy for specific high-fracture-risk patients, assessing the influence of pancreatic function on substitution efficacy. Methods: We conducted a retrospective, monocentric cohort study, evaluating data from all patients hospitalized with manifest osteoporosis in an orthogeriatric department during a six-month spring/summer period. Demographic data, relevant comorbidities, the type of fracture, the amount of faecal elastase 1 (CALEX^® Cap Bühlmann), and the serum levels of 25-hydroxyvitamin D (25(OH)D) were assessed. Results: We found a high prevalence (70.6%) of vitamin D deficiency (25(OH)D < 30 µg/L) among all orthogeriatric patients. Of these, 16% met the criteria for mild to severe EPI. The group with normal exocrine pancreatic function showed a higher average vitamin D value, and their increase in vitamin D levels following short-term substitution was up to 100% greater compared to the group with impaired pancreatic function. Notably, 69% of women and 20% of men met the therapeutic threshold for specific osteoanabolic osteoporosis therapy, even without a T-score. Conclusions: Our findings reveal a very high prevalence of vitamin D deficiency and a high prevalence of EPI in orthogeriatric patients. Those with impaired exocrine pancreatic function exhibit lower baseline vitamin D levels and a diminished capacity for vitamin D absorption during short-term monitoring. These results have significant clinical implications for osteoporotic therapy, given that a substantial proportion of patients, particularly women, meet the criteria for specific osteoanabolic treatment. Full article

Premature ovarian insufficiency (POI) is an important factor in female infertility and is often associated with oxidative stress. Alginate oligosaccharides (AOSs), derived from the degradation of alginate, have been demonstrated to have protective effects against various oxidative stress-related diseases. However, the impact of AOSs on POI has not been previously explored. The current study explored the effects of AOSs on ovarian dysfunction in a mouse model of POI induced by D-galactose (D-gal). Female C57BL/6 mice were randomly divided into five groups: the control (CON), POI model (D-gal), and low-, medium-, and high-dose AOS groups (AOS-L, 100 mg/kg/day; AOS-M, 150 mg/kg/day; AOS-H, 200 mg/kg/day). For 42 consecutive days, mice in the D-gal, AOS-L, AOS-M, and AOS-H groups received daily intraperitoneal injections of D-gal (200 mg/kg/day), whereas those in the CON group received equivalent volumes of sterile saline. Following D-gal injection, AOSs were administered via gavage at the specified doses; mice in the CON and D-gal groups received sterile saline instead. AOS treatment markedly improved estrous cycle irregularities, normalized serum hormone levels, reduced granulosa cell apoptosis, and increased follicle counts in POI mice. Moreover, AOSs significantly reduced ovarian oxidative stress and senescence in POI mice, as indicated by lower levels of malondialdehyde (MDA), higher activities of catalase (CAT) and superoxide dismutase (SOD), and decreased protein expression of 4-hydroxynonenal (4-HNE), nitrotyrosine (NTY), 8-hydroxydeoxyguanosine (8-OHdG), and p16 in ovarian tissue. Analysis of the gut microbiota through 16S rRNA gene sequencing and short-chain fatty acid (SCFA) analysis revealed significant differences in gut microbiota composition and SCFA levels (acetic acid and total SCFAs) between control and D-gal-induced POI mice. These differences were largely alleviated by AOS treatment. AOSs changed the gut microbiota by increasing the abundance of Ligilactobacillus and decreasing the abundance of Clostridiales, Clostridiaceae, Marinifilaceae, and Clostridium_T. Additionally, AOSs mitigated the decline in acetic acid and total SCFA levels observed in POI mice. Notably, the total SCFA level was significantly correlated with the abundance of Ligilactobacillus, Marinifilaceae, and Clostridium_T. In conclusion, AOS intervention effectively mitigates ovarian oxidative stress, restores gut microbiota homeostasis, and regulates the microbiota–SCFA axis, collectively improving D-gal-induced POI. Therefore, AOSs represent a promising therapeutic strategy for POI management. Full article

Cardiovascular disease (CVD) and dementia may share common pathogenic factors such as atherosclerosis and hyperlipoproteinemia. Dyslipidemia-induced oxidative stress contributes to dementia comorbidity in CVD. Abelmoschus esculentus (AE, okra) potentiates in alleviating hyperlipidemia and diabetes-related cognitive impairment. This study evaluated the effects of AE in hyperlipidemic ApoE^−/− mice treated with streptozotocin (50 mg/kg) and fed a high-fat diet (17% lard oil, 1.2% cholesterol). AE fractions F1 or F2 (0.65 mg/kg) were administered for 8 weeks. AE significantly reduced serum LDL-C, HDL-C, triglycerides, and glucose, improved cognitive and memory function, and protected hippocampal neurons. AE also lowered oxidative stress markers (8-hydroxy-2′-deoxyguanosine, 8-OHdG) and modulated neuronal nuclei (NeuN) and doublecortin (DCX) expression. In vitro, AE promoted neurite outgrowth and neuronal differentiation in retinoic acid (RA)-differentiated human SH-SY5Y cells under metabolic stress (glucose and palmitate), alongside the upregulation of heme oxygenase-1 (HO-1), Nuclear factor-erythroid 2-related factor 2 (Nrf2), and brain-derived neurotrophic factor (BDNF). These findings suggest AE may counter cognitive decline via oxidative stress regulation and the enhancement of neuronal differentiation. Full article

Background/Objective: In patients with acute lymphoblastic leukemia (ALL), it has been demonstrated that the treatment has a negative effect on bone health. The n-3 polyunsaturated fatty acids (LCPUFAs-ω3) may attenuate bone resorption. We evaluated the effects of LCPUFAs-ω3, vitamin D, and calcium supplementation on bone turnover markers and changes in vitamin D concentrations during 6 weeks of supplementation and during 6 weeks of post-intervention follow-up in pediatric patients with ALL. Methods: Thirty-six pediatric patients with ALL were randomly assigned to the ω-3VDCa group (100 mg/kg/d LCPUFAs-ω3 + 4000 IU vitamin D + 1000 mg calcium) or the VDCa group (4000 IU vitamin D + 1000 mg calcium) for 6 weeks. Blood samples were collected to determine 25(OH)D, PTH, ICTP, and TRAP-5b (biomarkers of bone resorption) and osteocalcin (OC, a biomarker of bone production) levels at baseline, 6 weeks, and 12 weeks after supplementation. The 25(OH)D analysis was performed using ultra-high-performance liquid chromatography coupled to a mass spectrometer, and PTH and bone turnover markers were measured by ELISA. Results: The 25(OH)D concentration increased in both groups (ω3VDCa group: 19.4 ng/mL vs. 44.0 ng/mL, p < 0.0001; VDCa group: 15.3 ng/mL vs. 42.8 ng/mL, p = 0.018) and remained significantly higher at 12 weeks. At 12 weeks, ICTP showed lower concentrations in the ω-3VDCa group than in the VDCa group (0.74 ng/mL vs. 1.05 ng/mL, p = 0.024). Conclusions: Combined omega-3 and 4000 IU vitamin D supplementation for 6 weeks had a positive effect on bone health, as indicated by serum ICTP, with no effect on serum 25(OH)D levels over vitamin D supplementation alone. Full article

The objective of this experiment was to investigate the effects of tartary buckwheat flavonoids (TBF) and 25-hydroxyvitamin D₃ (25-OHD) on fatty liver syndrome (FLS) in laying hens. A total of 450 35-wk-old Lohmann laying hens were selected and randomly divided into five groups, with six replicates per treatment and 15 laying hens in each replicate. The control group was fed a corn-soybean meal basal diet. The FLS group was fed a high- energy–low-protein (HELP) diet, and the other three experimental groups were fed HELP diets supplemented with 60 mg/kg TBF, 69 μg/kg 25-OHD, and 60 mg/kg TBF plus 69 μg/kg 25-OHD, respectively. The experiment lasted 8 weeks. The results demonstrated that feeding laying hens with a HELP diet led to a significant accumulation of fat in their livers, liver enlargement and yellowing, as well as a decline in liver antioxidant capacity and an aggravation of inflammation. TBF alone, 25-OHD alone, and their combination had no effect on the laying performance of laying hens fed with a HELP diet. However, 25-OHD significantly enhanced the albumin content, eggshell strength, and eggshell thickness of eggs (p < 0.05). Compared with the HELP group, TBF, 25-OHD, or their combination reduced serum LDL-C and TG (p < 0.05). The combined treatment further lowered serum NEFA and MDA, enhanced liver SOD activity (p < 0.05), and unlike TBF alone (which reduced hepatic TG) or 25-OHD alone (which decreased liver index), reduced both liver index and hepatic TG (p < 0.05). Liver gene expression analysis showed that combined TBF and 25-OHD significantly inhibited the expression of fat synthesis-related genes (ACC, FAS, GPAT1, ChREBP1, LXRα, SREBP-1C, SREBP-2, FABP) as well as inflammation-related genes (IL-6, TNF-α, NF-κB, TLR4) (p < 0.05). At the phylum level of the cecal microbiota, TBF increased the abundance of Bacteroidota (p < 0.05), and combined TBF and 25-OHD tended to increase the abundance of Firmicutes_D. At the genus level, TBF increased the abundance of Phocaeicola_A (p < 0.05). Furthermore, TBF, 25-OHD, or their combination reduced the abundance of Faecalibacterium (p < 0.05). These findings suggest that combined TBF and 25-OHD mitigates FLS in laying hens potentially through remodeling gut microbiota and maintaining lipid metabolic homeostasis. Full article

Although ART leads to viral suppression, people living with HIV (PLWH) still face an increased risk of comorbidities, such as cancer. The HIV-1 Tat protein may contribute to the promotion of chronic inflammation, oxidative stress, and genomic instability. While the presence of anti-Tat antibodies has been associated with slower disease progression, their potential role in modulating DNA damage remains unclear. Assess the effect of anti-Tat antibodies on cytotoxic and DNA damage in PLWH. A cross-sectional study was conducted in 178 PLWH. Serum anti-Tat IgG antibodies were measured using enzyme-linked immunosorbent assay (ELISA). Cytotoxicity and DNA damage were assessed via serum 8-hydroxy-2′-deoxyguanosine (8-OHdG) and nuclear anomalies (Micronucleus cytome assay) in 2000 buccal cells. Statistical significance was considered at p < 0.05. Anti-Tat antibodies were found in 24.2% of participants. Positive individuals had lower CD4+ T cell counts (p = 0.045) and higher levels of pyknosis (p = 0.0001). No differences in 8-OHdG were found, but 8-OHdG correlated positively with CD4+ counts (rho = 0.334, p = 0.006). Pyknosis negatively correlated with CD4+ counts (rho = −0.272, p = 0.027). Anti-Tat antibodies may not prevent DNA damage but could be related to cytotoxic effects in PLWH. Full article

Background and Objectives: Type 2 diabetes mellitus (T2DM) is associated with subclinical cardiovascular changes, such as increased arterial stiffness and myocardial dysfunction. Vitamin D deficiency has been recognized as a potential contributing factor to vascular disease; however, its impact on early cardiac changes associated with T2DM remains poorly understood. Our aim was to evaluate the association between serum levels of 25-hydroxyvitamin D3 [25(OH)D3], arterial stiffness, and left ventricular global longitudinal strain (LV GLS) in patients with T2DM who do not have a clinically evident cardiovascular disease. Material and methods: This cross-sectional study evaluated the carotid intima–media thickness (IMT), aortic pulse wave velocity (PWVao), LV GLS, and serum 25(OH)D3 levels in patients diagnosed with T2DM (n = 65) compared to healthy control subjects (n = 55). Independent predictors of arterial stiffness were identified by a multivariate logistic regression analysis. Results: Patients with T2DM showed a significant increase in IMT and PWVao, a reduction in LV GLS, and low levels of 25(OH)D3 compared to subjects in the control group (all p < 0.05). Both vitamin D deficiency and T2DM were found to be independently associated with an increased arterial stiffness, with odds ratios of 2.4 and 4.8, respectively. A significant inverse relationship was identified between 25(OH)D3 levels and markers of arterial stiffness, as well as LV GLS, suggesting a possible association between the vitamin D status and the early onset of cardiovascular dysfunction. Conclusions: Patients with T2DM show early signs of heart and blood vessel problems, even with an ejection fraction that remains within normal limits. There is a significant correlation between vitamin D deficiency and increased arterial stiffness, along with impaired LV GLS, indicating its possible involvement in cardiovascular complications associated with diabetes. These findings support the utility of integrating vascular, myocardial, and vitamin D assessments in early cardiovascular risk stratification for T2DM patients. Full article

Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) concentrations are decreased with metabolic syndrome (MetSy), and low serum 25(OH)D concentrations are associated with poor outcomes following anterior cruciate ligament (ACL) reconstruction (ACLR). It is unknown whether serum 25(OH)D concentrations are decreased in patients with MetSy following ACLR. The purpose of this study was to investigate whether serum 25(OH)D concentrations are decreased with MetSy following ACLR. Methods: This retrospective case–control study consisted of patients (≥18 years) who underwent ACLR. MetSy was defined as meeting any three of the five criteria (cases): (1) body mass index ≥ 30 kg/m², (2) triglycerides ≥ 150 mg/dL, (3) HDL < 40 mg/dL in men and <50 mg/dL in women, (4) systolic blood pressure ≥ 130 mmHg or diastolic blood pressure ≥ 85 mmHg, or (5) estimated (from hemoglobin A1c% [HbA1c]) fasting glucose ≥ 100 mg/dL. Participants without MetSy (meeting <3 criteria) served as controls. The first blood lipid, HbA1c, and 25(OH)D assessed ≥90 d after ACLR were included in this study. Results: The final analysis consisted of 219 patients (cases (with MetSy), n = 84; controls (without MetSy), n = 135). Serum 25(OH)D was significantly (p < 0.01) decreased (15.8%) in cases (mean [SD]; 25.1 [11.3] ng/mL) compared to controls (29.8 [14.8] ng/mL). An increasing number of MetSy components was associated with a decreased prevalence of vitamin D sufficiency (p < 0.01). Conclusions: We conclude that serum 25(OH)D concentrations are significantly lower with MetSy. These preliminary findings could provide justification for assessing serum 25(OH)D following ACLR in patients with MetSy and assist with risk stratification. Full article

Objectives: This study aimed to investigate both the linear and non-linear associations between serum 25-hydroxyvitamin D [25(OH)D] levels and serum uric acid concentrations in Korean adults, with a particular focus on the vitamin D-insufficient range (<30 ng/mL), and to explore the potential metabolic implications of this relationship. Methods: Using data from the Korea National Health and Nutrition Examination Survey (KNHANES), we analyzed 10,864 adults aged 19 years and older. Serum vitamin D levels were categorized into quartiles (Q1–Q4), and their relationships with uric acid concentrations were examined using Pearson correlation, analysis of variance (ANOVA), and restricted cubic spline regression. Multivariate models were adjusted for potential confounders including age, sex, body mass index (BMI), kidney function, chronic disease status, and macronutrient intake. Results: In unadjusted analysis, a statistically significant but weak negative correlation was observed between serum 25(OH)D and uric acid levels (Pearson’s r = −0.092, p < 0.001). However, in multivariate regression adjusting for confounders, a weak positive association emerged. Restricted cubic spline analysis revealed significant positive associations in the lower quartiles (Q1–Q3), with the strongest association in Q3 (β = 0.769, 95% CI: 0.34–1.19, p < 0.001). No significant association was observed in the highest quartile (Q4). Conclusions: Serum vitamin D and uric acid concentrations show a non-linear relationship, with a significant positive association within the vitamin D-insufficient range (<30 ng/mL). These findings provide new insights into the potential metabolic role of vitamin D and highlight the need for longitudinal and interventional studies to clarify causality and clinical significance. Full article

Background/Objectives: Adequate vitamin D levels are essential for various physiological functions, including cell growth, immune modulation, metabolic regulation, DNA repair, and overall health span. Despite its proven cost-effectiveness, widespread deficiency persists due to inadequate supplementation and limited sunlight exposure. Methods: This systematic review (SR) examines the relationship between vitamin D and the reduction of cancer risk and mortality, and the mechanisms involved in cancer prevention. This SR followed the PRISMA and PICOS guidelines and synthesized evidence from relevant studies. Results: Beyond genomic actions via calcitriol [1,25(OH)₂D]-receptor interactions, vitamin D exerts cancer-protective effects through mitigating inflammation, autocrine, paracrine, and membrane signaling. The findings reveal a strong inverse relationship between serum 25(OH)D levels and the incidence, metastasis, and mortality of several cancer types, including colon, gastric, rectal, breast, endometrial, bladder, esophageal, gallbladder, ovarian, pancreatic, renal, vulvar cancers, and both Hodgkin’s and non-Hodgkin’s lymphomas. While 25(OH)D levels of around 20 ng/mL suffice for musculoskeletal health, maintaining levels above 40 ng/mL (100 nmol/L: range, 40–80 ng/mL) significantly lowers cancer risks and mortality. Conclusions: While many observational studies support vitamin D’s protective role in incidents and deaths from cancer, some recent mega-RCTs have failed to demonstrate this. The latter is primarily due to critical study design flaws, like recruiting vitamin D sufficient subjects, inadequate dosing, short durations, and biased designs in nutrient supplementation studies. Consequently, conclusions from these cannot be relied upon. Well-designed, adequately powered clinical trials using appropriate methodologies, sufficient vitamin D₃ doses, and extended durations consistently demonstrate that proper supplementation significantly reduces cancer risk and markedly lowers cancer mortality. Full article

Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism caused by mutations in the ATP7B gene. While hepatic manifestations are frequent, psychiatric symptoms occur in up to 30% of patients and may precede neurological signs. This study was the first to assess the relationship between oxidative stress, selected genetic polymorphisms, and psychiatric symptoms in WD. A total of 464 patients under the care of the Institute of Psychiatry and Neurology in Warsaw were studied. Genotyping for GPX1 (rs1050450), SOD2 (rs4880), and CAT (rs1001179) was performed, along with biochemical analyses of copper metabolism, oxidative DNA, lipid and protein damage, and systemic antioxidant capacity. Among the most important observations are the following: the homozygous GPX1 rs1050450 TT and SOD2 rs4880 CC genotypes were associated with the lowest prevalence of psychiatric symptoms. The CAT rs1001179 TT genotype was linked to a delayed onset of psychiatric symptoms by 6.0–8.5 years. Patients with or without psychiatric symptoms did not differ significantly in saliva 8-OHdG, total antioxidant capacity, serum glutathione (GSH), catalase, and MnSOD; however, patients reporting psychiatric symptoms had significantly higher prostaglandin F2α 8-epimer (8-iso-PGF2α) concentrations and tended to have lower serum glutathione peroxidase (Gpx) concentrations compared to those without such symptoms. Our data firstly provide consistent evidence that oxidative stress balance associated with copper overload in the CNS may be associated with CNS damage and the development of psychiatric symptoms of WD. In particular, our findings of increased oxidative lipid damage together with decreased Gpx activity indirectly suggest that damage to neuronal membrane lipids, which may be potentially related to abnormalities in GSH metabolism, may have an etiological role in CNS damage and related symptoms. Full article

Vitamin D plays a crucial role in bone health and immune function, with serum 25(OH)D levels influenced by genetic, dietary, and metabolic factors. Background/Objectives: This study investigated the impact of VDR rs731236, CYP2R1 rs10741657, and GC rs2282679 polymorphisms, body mass index (BMI), and dietary vitamin D intake on vitamin D status. Methods: A total of 230 adults were classified into four BMI categories: normal weight (NW), overweight (OW), obesity class I (OB), and obesity class II/III (OP). Participants completed a Food Frequency Questionnaire (FFQ) and a 7-day Food Frequency Diary (FFD). Genotyping was performed using TaqMan assays, and serum 25(OH)D was quantified via spectrophotometry. Statistical analyses included ANOVA and multiple linear regression. Results: The VDR rs731236 CC genotype, CYP2R1 rs10741657 AG/GG, and GC rs2282679 AC/CC were associated with lower serum vitamin D levels. A higher BMI was significantly correlated with reduced serum 25(OH)D (p < 0.001), with BMI emerging as the strongest predictor of vitamin D status. FFQ-based dietary intake showed a modest positive correlation with 25(OH)D (r = 0.47, p < 0.001). Conclusions: BMI and genetic variants in VDR, CYP2R1, and GC significantly influence vitamin D metabolism. Personalized interventions addressing genetic predispositions and weight management may improve vitamin D status. Full article

Background and Objectives: Maternal vitamin D (25-hydroxyvitamin D, 25(OH)D) deficiency during pregnancy is associated with adverse outcomes for both mother and fetus. While vitamin D supplementation is commonly recommended, dietary and lifestyle factors influencing maternal 25(OH)D levels at term remain underexplored, particularly in Southern Europe. Aim: This study aimed to investigate prenatal determinants of maternal 25(OH)D levels at the time of delivery, focusing on dietary intake, supplement use, and seasonal variation. Materials and Methods: We conducted a cross-sectional study on 248 pregnant women admitted for delivery at the General Hospital of Piraeus “Tzaneio” between September 2019 and January 2022. A structured questionnaire was used to assess prenatal intake of vitamin D-rich foods (such as fatty fish, eggs, dairy, and fortified products), supplement use (dose, frequency), sun exposure habits, and lifestyle factors. Maternal serum 25(OH)D concentrations were measured from blood samples collected at the time of admission for delivery. Statistical analysis included descriptive statistics and multivariate linear regression to identify independent dietary and supplemental predictors of maternal vitamin D status. Results: A high prevalence of maternal vitamin D deficiency (VDD) was observed, particularly during the autumn and winter months. Women who reported regular intake of vitamin D supplements (400–800 IU daily) had significantly higher 25(OH)D levels compared to those who did not. Dietary intake of vitamin D-rich foods was positively associated with maternal 25(OH)D status, although the effect size was smaller compared to supplementation. Seasonal variation, BMI, and limited sun exposure were also independent predictors. Conclusions: Both vitamin D supplementation and increased dietary intake were positively associated with maternal 25(OH)D concentrations at delivery. These findings underscore the importance of prenatal nutritional assessment and targeted supplementation strategies to prevent maternal VDD in Mediterranean populations. Full article

Background/Objectives: Recent data on long-term consequences of prematurity on bone health are conflicting. The aim of this study was to assess the metabolic bone profile and bone mineral density (BMD) in prepubertal children born prematurely and to examine possible associations between bone health parameters and perinatal morbidity factors. Methods: This cross-sectional observational study included 144 children of mean (SD) age 10.9 (1.6) years: 49 children born very preterm (≤32 gestational weeks), 37 moderate-to-late preterm (32⁺¹ to 36⁺⁶ gestational weeks), and 58 born at term (controls). Serum levels of calcium/Ca, phosphorus/P, alkaline phosphatase/ALP, 25-hydroxyvitamin D/25(OH)D, bone formation markers (osteocalcin/OC, procollagen type I C-terminal propeptide/PICP, and insulin growth factor-1/IGF-1), and bone resorption markers (serum tartrate-resistant acid phosphatase 5b/bone TRAP5band urinary calcium-to-creatinine ratio) were measured. Total-body and lumbar-spine BMD and BMD Z-scores were calculated using dual-energy X-ray absorptiometry/DXA. Results: Children born very preterm showed significantly higher ALP, OC, PICP, and bone TRAP5b levels compared to controls, as well as compared to children born moderate-to-late preterm. Total-body and lumbar-spine BMD Z-scores were significantly lower in the very preterm-born group compared to controls. Gestational diabetes, preeclampsia, and bronchopulmonary dysplasia were associated with lower total-body BMD in the very preterm-born population. Conclusions: Preterm birth is associated with impaired metabolic bone profile and lower total-body and lumbar-spine BMD in childhood. Moderate-to-late preterm-born children exhibit altered metabolic bone parameters compared to very preterm-born children. Further research in children might allow better insight into the long-term impact of preterm birth on bone health. Full article

Objective: To investigate the association between serum 25-hydroxyvitamin D [25(OH)D] levels and clinical, hormonal, and auxological features in girls with idiopathic central precocious puberty (CPP). Methods: This retrospective study included 122 girls diagnosed with idiopathic CPP. Participants were stratified into three groups based on serum 25(OH)D concentrations: deficient (<20 ng/mL), insufficient (20–30 ng/mL), and sufficient (>30 ng/mL). Clinical and hormonal parameters were compared across groups. Spearman’s correlation and multiple linear regression analyses were used to explore the relationship between vitamin D levels and peak luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) stimulation. Results: No significant differences were observed among the vitamin D groups in terms of age at diagnosis, body mass index (BMI), or other auxological measures. However, serum 25(OH)D levels showed a weak but significant positive correlation with LH peak values (rho = 0.23, p = 0.037). In multivariable regression analysis, vitamin D levels remained an independent predictor of LH peak (β = 0.125, p = 0.036), whereas BMI standard deviations (SDS), growth velocity SDS, and age at diagnosis did not show significant associations. Conclusions: Higher serum vitamin D levels are independently associated with greater LH peak responses in girls with idiopathic CPP. These findings support a potential modulatory role of vitamin D in the neuroendocrine mechanisms underlying pubertal onset and warrant further prospective studies to clarify its clinical relevance. Full article