Vitamin D deficiency (VDD) is highly prevalent after metabolic and bariatric surgery (MBS) and has been associated with depression in the general population. However, whether VDD is associated with incident depression specifically in the post-MBS population remains unknown. Using the TriNetX Global Collaborative Network, we conducted a retrospective cohort study of adults with a prior history of MBS who underwent serum 25-hydroxyvitamin D testing (2010-2024). Patients were classified into a VDD group (< 20 ng/mL) and a control group (≥ 30 ng/mL). Those with pre-existing depression were excluded, and a 6-month landmark period was applied. After 1:1 propensity score matching, the primary outcome was 3-year incident overall depression. Secondary outcomes included depressive episodes, recurrent depressive disorder, and a composite of suicidal behavior or intentional self-harm. Acute appendicitis served as a negative control outcome. After matching, 11,805 pairs were analyzed. VDD was associated with a higher risk of overall depression (4.64% vs. 2.53%; HR 1.87, 95%CI 1.62-2.15, P < 0.001), depressive episodes (HR 1.82, P < 0.001), and recurrent depressive disorder (HR 1.97, P < 0.001). No significant difference was observed in suicidal behavior (P = 0.986) or acute appendicitis (P = 0.879), whereas healthcare utilization was slightly lower in the VDD group (HR 0.92, P < 0.001). Sensitivity analysis restricted to 2016-2024 yielded consistent results (HR 1.87, P < 0.001). Subgroup analyses confirmed this association in subgroup analyses. VDD is associated with a significantly increased risk of incident depression after MBS, suggesting that vitamin D status may be a clinically relevant risk marker that warrants further prospective investigation.

Association of vitamin D status with the immune response in active pulmonary tuberculosis patients with chronic pulmonary aspergillosis.

Vitamin D deficiency (VDD) is highly prevalent worldwide; however, its association with pancreatic cancer risk remains inconclusive, and prior evidence has included a substantial proportion of case-control studies. This retrospective cohort study used the TriNetX Global Collaborative Network to identify adults (age ≥ 40 years) with at least two serum 25-hydroxyvitamin D measurements between 2010 and 2023. The VDD (<20 ng/ml) and control (≥30 ng/ml) cohorts were matched in a 1:1 ratio using propensity scores. A 2-year landmark period was applied. The primary outcome was incident pancreatic cancer within 10 years. Secondary outcomes included acute and chronic pancreatitis. After matching, 316 681 patients remained in each cohort. VDD was associated with a higher risk of pancreatic cancer (hazard ratio: 1.53, 95% confidence interval: 1.30-1.80, P < 0.001), acute pancreatitis (hazard ratio: 2.03, P < 0.001), and chronic pancreatitis (hazard ratio: 2.28, P < 0.001). The negative control outcome (appendicitis) showed no significant difference (hazard ratio: 1.04, P = 0.252), whereas healthcare visits used to assess detection bias were lower in the VDD group (hazard ratio: 0.88, P < 0.001). Results remained consistent across all sensitivity models. No significant interaction was observed according to sex or age. Severe VDD (<10 ng/ml) demonstrated a stronger association with pancreatic cancer (hazard ratio: 2.25, P < 0.001), supporting an exposure-gradient pattern. VDD was associated with higher subsequent risks of pancreatic cancer and pancreatitis, with stronger associations at lower vitamin D levels. These observational findings require prospective confirmation.

Vitamin D is essential for calcium absorption, bone mineralization, and immunological function; nonetheless, vitamin D deficiency (VDD) continues to be a significant health issue in children under five years. In Egypt, VDD is highly prevalent among preschool children, with maternal awareness and nursing practices playing significant roles in its occurrence. This study aimed to identify the relationship between maternal awareness and practices regarding vitamin D and their impact on health outcomes in children under five years. A cross-sectional, correlational, descriptive, and quantitative study was employed. Data collection occurred over eight months throughout three governorates in Egypt, involving 300 mothers and their children under five years of age. Children’s health status outcomes were assessed and linked with their mothers’ awareness and practice scores regarding vitamin D supplementation. It was found that two-thirds of mothers had satisfactory knowledge about vitamin D deficiency, but more than half showed unsatisfactory practice scores. A moderate positive correlation was found between maternal practices and children’s health outcomes as height (r = 0.301, p < 0.001), and weight (0.242, p < 0.001), as well as between mothers’ practices and knowledge scores (r = 0.323, p < 0.001). Additionally, maternal practices were significantly influenced by both age and educational level. Maternal practices emerged as a more convincing and coherent associated with child health outcomes than awareness alone. The findings underscore revealed that although over two-thirds of mothers had satisfactory knowledge about VDD, more than half showed unsatisfactory practices. Mothers of children without VDD, and those whose primary teeth erupted before one year demonstrated significantly higher practice scores. A moderate positive correlation was found between maternal practices and children’s health outcomes (weight, and height), as well as between mothers’ practices and awareness scores. Additionally, maternal practices were significantly influenced by both age and educational level.

Vitamin D deficiency and depression: A Neuroimmune review of complement-associated synaptic remodeling and VDBP-Megalin signaling.

Vdr-Pparα-Plin5-regulated lipid droplet dynamics mediates exercise protection against HFD-induced skeletal muscle ectopic lipid deposition and insulin resistance in mice.

Vitamin D (VD) is integral to lung maturation and immune regulation, yet its association with neonatal respiratory diseases remains debated. This study aimed to clarify the association between vitamin D (VD) status and neonatal respiratory diseases, to quantify the risk posed by VD deficiency (VDD), and to evaluate the therapeutic benefits of VD supplementation. A comprehensive search was conducted in PubMed, Web of Science, EMBASE, and other major databases for studies published up to October 1, 2025. Following the PRISMA guidelines, 2 reviewers independently screened the studies, extracted data, and assessed its quality. Observational studies and randomized controlled trials (RCTs) were included. Thirty-one studies (23 observational, 8 RCTs) involving over 3000 neonates were analyzed using a random-effects meta-analysis. Neonates with respiratory disease exhibited significantly lower 25(OH)D levels (standardized mean difference, SMD = -0.66; 95% CI: -0.90 to -0.41). Vitamin D deficiency was associated with an increased risk of respiratory distress syndrome (RDS) (adjusted odds ratio [aOR] = 2.57; 95% CI: 1.55-4.24); however, this association was attenuated after adjusting for publication bias. Vitamin D supplementation effectively restored VD status (SMD = 2.80, 95% CI: 1.70-3.89) and may reduce morbidity, particularly with higher doses (800-1000 IU/day) or maternal administration. Vitamin D deficiency represents a significant risk marker, but its role as an independent causal factor may be overestimated. Supplementation, particularly with higher doses or maternal administration, is a feasible adjunct strategy, but high-quality RCTs are imperative for establishing definitive intervention protocols. PROSPERO registration No. CRD420251152942.

Smoking has been reported to be associated with vitamin D (VD) status, but the evidence is limited. A cross-sectional study was conducted aiming to examine whether there is any effect of smoking on VD status in the adults based on the data sourced from the chronic diseases and nutrition surveillance in Henan. Multiple linear and multinomial logistic regression models based on the sampling design and weight were created to estimate the association between smoking and serum 25-hydroxyvitamin D concentration (S_25(OH)D_C) and VD status, respectively. It was found that in men, smokers had significantly lower S_25(OH)D_C and higher proportions of VD deficiency (VDD) and VD insufficiency (VDI) than non-smokers (S_25(OH)D_C: 18.2ng/ml vs 19.8ng/ml; proportion of VDD: 17.3% vs 14.3%; proportion of VDI: 44.7% vs 38.3%). Multivariate regression analyses demonstrated that in men smoking was independently associated with S_25(OH)D_C and VD status, reducing S_25(OH)D_C by 1.90ng/ml, and increasing the risk of VDD and VDI by 134% and 65%, respectively. Further analysis stratified by the levels of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) revealed that in men with low HDL-C and high LDL-C, smoking increased 8.24 and 4.08 times likely to having VDD and VDI, respectively. In conclusion, smoking reduced S_25(OH)D_C, and increased the risk of VDD and VDI in men, especially in men with low level of HDL-C and high level of LDL-C in Henan.

Globally, vitamin D deficiency (VDD) represents a significant public health concern. Population-level data on vitamin D status in Tunisia are lacking. This study aimed to estimate the national prevalence of VDD among Tunisian school-aged children and identify associated factors. A national cross-sectional survey in 2023 randomly sampled 2670 children aged 6-12years. Plasma 25-hydroxyvitamin D was measured. Dietary vitamin D (VD) intake and socio-demographics were assessed via questionnaires. Logistic regression identified factors associated to inadequate VD status. The prevalence of VDD (< 30nmol/L) was 15.8%. Adjusted analysis showed that older children (10-12years) had a 1.4-fold (P = 0.030) higher likelihood of VDD than younger children. Girls were twice as likely to be VD deficient as boys (adjusted relative prevalence ratio (aRPR) = 2.1; P = 0.001). Significant regional variations in VDD were observed (P < 0.0001). Low and moderate consumption of VD-rich foods was associated with significantly increased odds of severe deficiency (aRRR = 2.0, P = 0.026; aRRR = 1.6, P = 0.005, respectively) relative to high consumption. Finally, overweight status was associated with a 2.0-fold (P < 0.0001) increased odds of severe VDD compared to children with normal weight. VDD is prevalent and increases with age. Vitamin D supplementation strategies should be considered to optimize vitamin D status among children.

Vitamin D deficiency selectively exacerbates mitochondrial dysfunction in receptor-rich soleus muscle during disuse-induced atrophy.

Association between vitamin D status and bacterial vaginosis in non-pregnant women of reproductive age: a systematic review and meta-analysis.

Recent studies have demonstrated that vitamin D (VD) influences gut microbiota (GM) by regulating epithelial barrier function and immune responses, thereby affecting microbial composition and diversity. Additionally, host genetic factors, particularly single-nucleotide variants (SNVs) in genes related to VD metabolism, may influence GM composition. Postmenopausal women are a particularly relevant population to assess the impact of these SNVs, as this group experiences reduced hormonal variability and a higher burden of vitamin D deficiency (VDD), enabling clearer evaluation of the association between vitamin D-related genetic variants and gut microbiota composition. To explore the relationship between SNVs in genes involved in VD metabolism and their impact on GM. We genotyped nine variants: rs10741657 (CYP2R1), rs6013897 (CYP24A1), rs10877012 (CYP27B1), rs10783219 and rs4516035 (VDR), rs4588 and rs7041 (GC), rs4944957 and rs3794060 (NADSYN1). GM was characterized by sequencing the V4 hypervariable region of the 16S rRNA gene. We compared taxon abundance at the genus level across host genotypes using the dominant model. Quantile regression was used to analyze non-mean diversity responses, and PICRUSt2 identified functional pathways. We also calculated the genetic risk score (GRS) using rs4516035, rs3794060, and rs4944957, which were associated with lower alpha diversity. Alpha microbial diversity differed significantly for the VDR (rs4516035) and NADSYN1 (rs3794060, rs4944957) variants, both for risk alleles and genotypes. Differential abundance analysis identified taxonomic disparities, notably in the genera DTU014, Fusobacterium, Negativibacillus, Pseudomonas, Peptococcus, and [Clostridium]_innocuum_group. PICRUSt2-predicted functional pathways for the rs4516035- C allele revealed significant glutamine-glutamate, folate, galactose, and fatty acid metabolism. A GRS was associated with lower alpha diversity indices and differences in the insulin signaling pathway and oxidative phosphorylation. These findings highlight the role of SNVs in GM modulation and suggest potential implications for VD metabolism and host health.

Introduction: Medical students are particularly susceptible to nutritional deficiencies and mental health problems due to intensive study demands, stress, and lifestyle factors. Vitamin D3, vitamin B12, and folate deficiencies have been implicated in mental well-being, although evidence remains inconsistent. Objective: To assess the prevalence of vitamin D3, vitamin B12, and folate deficiencies among medical students at the University of Warmia and Mazury in Olsztyn, and to explore associations between serum concentrations of these vitamins, lifestyle factors, and self-reported well-being. Materials and Methods: The study included 97 medical students. Serum vitamin concentrations were measured using electrochemiluminescence immunoassay. Well-being was assessed with the WHO-5 Well-Being Index. Group comparisons were performed using non-parametric tests, and a Poisson regression model was applied as an exploratory analysis to examine associations between selected lifestyle factors and well-being. Results: Vitamin D3 deficiency was observed in 78% of students, folate deficiency in 20%, and vitamin B12 deficiency in 8%. In unadjusted analyses, differences in serum vitamin D3 and vitamin B12 concentrations were observed between students with lower and higher self-reported well-being, whereas folate concentrations did not differ. However, after correction for multiple testing using the Benjamini–Hochberg procedure, none of these associations remained statistically significant. Exploratory regression analysis suggested that physical activity and gender may be associated with well-being, while no association with vitamin D3 supplementation was observed. Conclusions: Vitamin D3, vitamin B12, and folate deficiencies were common among medical students. Exploratory analyses suggested differences in vitamin D3 and vitamin B12 concentrations across well-being groups; however, these findings did not remain significant after correction for multiple testing and should be interpreted with caution. Overall, the results indicate that lifestyle-related factors, particularly physical activity, may play a more prominent role in student well-being than serum vitamin concentrations alone. Further longitudinal studies are required to clarify these relationships.

Aerobic exercise attenuates cardiac fibrosis in mice via stimulating vitamin D receptor to suppress ferroptosis.

The impact of maternal vitamin D deficiency during pregnancy and lactation on autism-like behavior in offspring.

Preterm labor remains a major contributor to neonatal morbidity and mortality, particularly in regions where nutritional deficiencies are common. Objective: This study assessed the relationship between maternal vitamin D₃ deficiency and the occurrence of preterm labor. Methods: This cross-sectional analytical study was conducted at Central Park Teaching Hospital, Lahore, from December 2023 to December 2024, and included 316 pregnant women. Participants were categorized into a preterm labor group (n = 148) and a term delivery group (n = 168). Serum 25-OH-D₃ levels were measured using a chemiluminescent immunoassay and classified as deficient, insufficient, or sufficient. Results: Vitamin D₃ deficiency was highly prevalent (67.1%) and significantly more common in women with preterm labor (80.4%) than those with term deliveries (55.4%) (p < 0.001). Mean serum vitamin D₃ levels were markedly lower in the preterm group (15.8 ± 5.9 ng/mL) compared with the term group (22.4 ± 7.1 ng/mL) (p < 0.001). Logistic regression demonstrated that vitamin D₃ deficiency remained an independent predictor of preterm labor (adjusted OR = 2.51, 95% CI: 1.62-3.89). Additional significant factors included hemoglobin <10 g/dL (aOR = 1.68), sun exposure <30 minutes/day (aOR = 1.74), antenatal visits <4 (aOR = 1.82), and previous preterm birth (aOR = 1.91). Conclusions: Maternal vitamin D₃ deficiency is strongly associated with preterm labor and remains a significant independent predictor even after adjusting for clinical and demographic factors. Given its high prevalence and modifiable nature, routine screening and targeted vitamin D₃ supplementation may help reduce the burden of preterm birth.

BackgroundChemotherapy-induced peripheral neuropathy (CIPN) is a frequent adverse effect associated with platinum-based agents, vinca alkaloids, and taxanes, contributing to a significant increase in morbidity, reduced quality of life, and treatment of nonadherence. Evidence suggests that nutritional status, particularly vitamin D (VD) levels, could influence CIPN incidence and clinical manifestations.AimTo compile evidence on the association between VD status and CIPN incidence and severity in patients undergoing cytotoxic chemotherapy.MethodsA scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Searches were performed in MEDLINE, Embase, Web of Science, Scopus, and Cochrane for primary investigations published up to 25 September 2025.ResultsEleven observational studies were included. Based on the results from these studies, patients with breast or cervical cancer and VD deficiency receiving paclitaxel appear to exhibit higher incidence and risk of CIPN, highlighting VD levels as a predictor of CIPN development. Moreover, in patients with multiple myeloma on bortezomib, thalidomide and/or lenalidomide, and those receiving an oxaliplatin-based regimen for gastrointestinal tumors, lower VD levels seem to be associated with significantly higher incidence or prevalence of CIPN.ConclusionThese findings suggest a relation between low serum VD levels and an increased risk and severity of CIPN, hypothetically mediated by the neuroprotective, neuroregenerative, and anti-inflammatory properties of VD which could play a protective role in the development of CIPN. Future research should conduct stratified randomized controlled trials, standardize VD cutoffs and explore dose-response in high-risk groups, to elucidate its potential clinical implications.

To determine the efficacy and safety of daily supplementation of 800IU versus 400IU vitamin D3 in reducing the incidence of vitamin D insufficiency (VDI) (serum 25-OH-D < 20ng/mL) in exclusively breastfed term small-for-gestational-age (SGA) infants at 14weeks of age. An open-label randomized controlled trial including exclusively breastfed term SGA infants was conducted in a tertiary care hospital. Eligible infants were randomized within 24h of life to receive either 800IU or 400IU daily oral vitamin D3 supplementation until 14weeks of age. Primary outcome was proportion of infants with VDI at 14weeks, while secondary outcomes included vitamin D deficiency (VDD) (serum 25-OH-D < 12ng/mL), severe VDD (serum 25-OH-D < 5ng/mL), clinical rickets, and vitamin D toxicity (VDT) (serum 25-OH-D > 100ng/mL). Among 60 enrolled infants, the distribution of baseline variables was similar in both groups. The proportion of infants with VDI at 14weeks was significantly less in 800IU (30%) versus 400IU (63.3%) group (RR = 0.47, 95% CI 0.18, 0.73; P = 0.016). In the 800IU group, there was a trend towards reduction in the proportion of infants with VDD, and no infant with severe VDD. Clinical rickets was seen in 3 infants (1 in 800IU and 2 in 400IU), with all having VDD. None of the infants had VDT. Daily oral supplementation of 800IU vitamin D3 in exclusively breastfed term SGA infants significantly reduced the proportion of infants with vitamin D insufficiency without any toxicity. Trial registry CTRI/2023/08/071999.

Hashimoto’s thyroiditis (HT) is a common autoimmune thyroid disorder characterized by the gradual destruction of the thyroid gland. It is influenced by a complex interplay of genetic, environmental, and lifestyle factors. Among these, environmental triggers such as smoking, dietary patterns, psychosocial stress, and vitamin D3 deficiency are increasingly recognized for their potential to modulate thyroid autoimmunity. Iraq, with its unique environmental and dietary conditions, presents a valuable context to investigate these associations. Objective: to evaluate the relationship between key environmental factors – specifically smoking, dietary habits (iodine and gluten intake), psychosocial stress, and vitamin D3 levels – and the profiles of thyroid autoantibodies in Iraqi patients diagnosed with HT. This cross-sectional study enrolled 96 Iraqi patients (38 males, 58 females) diagnosed with HT from December 2023 to December 2024 in Baghdad. Data on lifestyle and dietary habits were collected through structured interviews. Laboratory assessments included measurements of thyroid hormones (T3, T4, TSH) and autoantibodies (anti-thyroglobulin [anti-TG], anti-thyroid peroxidase [anti-TPO], and TSH receptor antibody [TRAb]) using ECLIA and CMIA analyzers. Statistical analyses included chi-square tests and logistic regression models to identify associations. Female patients demonstrated a higher prevalence of anti-TPO positivity (75%) than males (55%). Smoking, more frequent among males, was significantly associated with lower TRAb levels. While all participants consumed iodine-rich diets, 85% also followed gluten-rich diets. Vitamin D3 deficiency was observed in over 40% of participants, though it was not significantly associated with autoantibody levels. Gluten intake showed a mild association with T4 levels. Psychosocial stress had no significant impact on thyroid biomarkers. Notably, anti-TPO levels showed a positive correlation with patient age. Environmental factors, particularly smoking and dietary habits, appear to influence thyroid autoimmunity in Iraqi HT patients. Public health interventions focusing on smoking cessation and dietary management may contribute to better disease control. Further prospective studies are needed to confirm these findings.

Vitamin D deficiency (VDD) has been implicated as a potential risk factor for thyroid cancer; however, existing evidence is derived primarily from case-control or cross-sectional studies. This study aimed to examine the association between pre-diagnostic VDD and the risk of incident thyroid cancer over a 10-year follow-up period. This retrospective propensity score-matched cohort study used the TriNetX Global Collaborative Network. Adults aged ≥ 18 y with serum 25-hydroxyvitamin D [25(OH)D] measurements between 2010 and 2023 were classified as having VDD (<20 ng/mL) or vitamin D sufficiency (≥30 ng/mL). One-to-one propensity score matching was performed on demographics, comorbidities, thyroid-related disorders, laboratory values, and vitamin D supplementation. The primary outcome was incident thyroid cancer ascertained ≥ 180 day after the index date (landmark approach) over 10 y of follow-up. Positive (osteoporotic fracture) and negative (appendicitis, goiter) control outcomes and thyroid procedure utilization were evaluated to assess detection bias. After matching, 571,669 pairs were analyzed over a median follow-up of 6.8 y. VDD was associated with an increased risk of incident thyroid cancer (HR: 1.41; 95% CI: 1.32, 1.50), and this risk was attenuated among patients with vitamin D insufficiency (25[OH]D 20-30 ng/mL; HR: 1.27; 95% CI: 1.20, 1.34), demonstrating a dose-dependent relationship. Thyroid biopsy and ultrasonography utilization were lower in the VDD cohort (HR: 0.95), arguing against detection bias. The positive control outcome (osteoporotic fracture; HR: 1.53) confirmed the validity of the exposure classification, whereas the negative control (appendicitis; HR: 1.02) showed no association. Findings were robust across all sensitivity and subgroup analyses. Pre-diagnostic VDD was associated with increased thyroid cancer risk in a dose-dependent manner. These findings support further investigation of vitamin D status as a potentially modifiable risk factor for thyroid cancer.