Vitamin D, infections and immunity

Association between serum 25-hydroxyvitamin D concentrations and urinary vitamin D metabolite concentrations measured by the NLucVDR assay

It is well known that vitamin D is essential for human health; however, many people suffer from vitamin D deficiency or insufficiency worldwide, including in Japan. Serum 25-hydroxyvitamin D (25(OH)D) concentrations are typically measured to evaluate vitamin D status. In a previous study, we demonstrated that the concentrations of vitamin D metabolites in urine, measured using the NLucVDR assay system composed of a split-type nanoluciferase and the ligand-binding domain (LBD) of the human vitamin D receptor, correlated with serum 25(OH)D concentrations measured using liquid chromatography-mass spectrometry (LC-MS) or electrochemiluminescence immunoassays (ECLIAs). However, the number of participants was limited to 23. In the present study, we investigated the relationship between urinary vitamin D metabolite concentrations measured using the NLucVDR assay and serum 25(OH)D concentrations measured using ECLIA in 292 healthy individuals aged 20-69 years. We observed a significant positive correlation between 25(OH)D concentrations and urinary vitamin D metabolite concentrations (r = 0.400, p < 0.001). Furthermore, in a multiple regression model with serum 25(OH)D concentrations as the dependent variable and urinary vitamin D metabolite concentrations, sex, age, body mass index (BMI), and vitamin D intake as independent variables, urinary vitamin D metabolite concentrations showed a significant positive association with serum 25(OH)D concentrations regardless of sex, age, BMI, and vitamin D intake. Additionally, receiver operating characteristic (ROC) curve analysis was performed to evaluate whether this multiple regression model could predict vitamin D deficiency. The area under the curve (AUC) was 0.743 and 0.708 for women and men with vitamin D deficiency (serum 25(OH)D < 20 ng/mL), respectively. Our results suggest that urinary vitamin D metabolite concentrations, measured by the NLucVDR assay, may be useful for the noninvasive predictive tool of vitamin D deficiency.

Serum 25-hydroxyvitamin D levels and peripheral blood eosinophil percentages as predictive indicators for eosinophilic chronic sinusitis with nasal polyps

PURPOSE

Chronic rhinosinusitis (CRS) has a high incidence rate and different endotypes. Serum 25-hydroxyvitamin D (25(OH)D) deficiency is common in patients with eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP and nECRSwNP, respectively). This study explored the relationship between serum 25(OH)D levels and CRS risk and determined the value of combining serum 25(OH)D with peripheral blood markers in distinguishing between ECRSwNP and nECRSwNP.

METHODS

This study enrolled 275 CRS patients and 298 healthy controls. The relationship between serum 25(OH)D levels and CRS risk was determined using logistic regression after propensity score matching (PSM). The efficiency of various peripheral blood markers in distinguishing between ECRSwNP and nECRSwNP was assessed using a decision-tree model.

RESULTS

The final analysis included 189 CRS patients and 189 controls after 1:1 PSM. Serum 25(OH)D levels were significantly lower in CRS patients than in controls. Patients with mild CRS showed higher serum 25(OH)D levels than those with moderate or severe CRS, and ECRSwNP patients had lower serum 25(OH)D levels than nECRSwNP patients (all Ps < 0.05). Eosinophil percentages and IgE levels were independent risk factors for ECRSwNP, whereas serum 25(OH)D was an independent protective factor. 25(OH)D deficiency increased the ECRSwNP risk (OR = 3.074, P = 0.04). An eosinophil percentage ≥ 5% and a 25(OH)D level < 61.8 nmol/L could be used to predict ECRSwNP, with training and test set accuracies of 89.7% and 85.7%, respectively.

CONCLUSION

Our findings suggest that serum 25(OH)D deficiency is an independent risk factor for CRS, especially ECRSwNP. Combining serum 25(OH)D levels with peripheral eosinophil percentages could be a promising biomarker for ECRSwNP.

Daily Vitamin D3 Versus Stoss Vitamin D3 for Correction of 25OHD Deficiency in Children with Inflammatory Bowel Disease, a Randomised Controlled Trial

INTRODUCTION

Vitamin D deficiency is common in Paediatric Inflammatory Bowel Disease (PIBD) and has been implicated in disease pathogenesis and disease exacerbation. Current guidelines recommend oral vitamin D supplementation when 25OHD levels are below 50 nmol/L. Supplementation comes in two forms: either a daily supplement of a low dose of vitamin D3 (2000 IU) for several months or a single high dose of oral vitamin D3-termed 'stoss' therapy, with no consensus regarding optimum treatment.

METHODS

A randomised controlled trial was conducted in children with a prior diagnosis of PIBD with 25OHD deficiency (< 50 nmol/L), comparing 2000 IU oral D3 daily to a stoss protocol (oral D3 dosage 400,000 IU for 3-12 years of age or 800,000 IU for > 12 years). Children were followed for 12 months, with biochemistry (25OHD, calcium, magnesium, phosphate, parathyroid hormone, haemoglobin, haematocrit, platelets, albumin), stool markers (calprotectin, S100A12), anthropometrics (weight, height, body mass index) as well as clinical disease indices (Paediatric Crohn's Disease Activity Index, Paediatric Ulcerative Colitis Activity Index) and medication use collected at 3, 6, 9 and 12 months.

RESULTS

74 children aged 5-18 years completed the study. Both 2000 IU daily and stoss protocol significantly increased 25OHD from baseline values at 3, 6, 9 and 12 months. One patient randomised to stoss protocol had a 25OHD level of 263 nmol/L with normal serum calcium. There was no difference in biochemical, stool or clinical markers between groups at any time point, nor was there any correlation between 25OHD level and calprotectin or 25OHD level and clinical disease activity scores.

CONCLUSION

Stoss protocol was non-inferior to 2000 IU daily vitamin D3 in raising 25OHD levels at 12 months. There was also no difference between 25OHD levels at 3, 6 and 9 months between groups.

Knowledge and Predictors of Vitamin D Awareness Among Greek Women: A Cross-Sectional Study

BACKGROUND

Vitamin D plays a crucial role in bone health, calcium absorption, and immune function, yet significant misconceptions and knowledge gaps persist. This study aimed to assess knowledge regarding vitamin D among Greek women and identify factors associated with vitamin D knowledge.

METHODS

A cross-sectional study was conducted among 761 Greek women (mean age: 41.2 ± 7.7 years) using an online self-administered questionnaire designed in Google Forms. Participants were recruited via social media platforms to ensure a geographically diverse sample.

RESULTS

Overall, 57.4% of participants demonstrated knowledge of vitamin D's functions, primarily linking it to bone health (34.4%) and immune function (26.8%). The multiple regression model identified significant predictors of knowledge of vitamin D's functions, including age (OR = 1.041, 95% CI: 1.019-1.062, p < 0.001), weight (OR = 0.964, 95% CI: 0.938-0.992, p = 0.010), and frequent vitamin D testing (>2 times: OR = 2.280, 95% CI: 1.392-3.736, p = 0.001; once-twice: OR = 1.776, 95% CI: 1.111-2.829, p = 0.016). Furthermore, age (OR = 1.054, 95% CI: 1.027-1.081, p < 0.001), weight (OR = 0.987, 95% CI: 0.975-0.999, p = 0.028), higher city population (>50,000 citizens: OR = 1.598, 95% CI: 1.021-2.502, p = 0.040), frequent vitamin D testing (>2 times: OR = 2.616, 95% CI: 1.529-4.447, p < 0.003; one-two times: OR = 1.773, 95% CI: 1.052-2.989, p = 0.032), and children's supplementation (OR = 1.414, 95% CI: 1.007-1.987, p = 0.046) were significant predictors of knowledge regarding diseases preventable by vitamin D.

CONCLUSIONS

Greek women demonstrated moderate awareness of vitamin D's functions, but significant knowledge gaps persist, particularly regarding its role in calcium absorption and dietary sources. Age, frequent vitamin D testing, and urban residence were significant predictors of knowledge. Targeted public health campaigns are essential to address misconceptions and improve vitamin D awareness and practices.

Vitamin D Deficiency Meets Hill's Criteria for Causation in SARS-CoV-2 Susceptibility, Complications, and Mortality: A Systematic Review

Clinical trials consistently demonstrate an inverse correlation between serum 25-hydroxyvitamin D [25(OH)D; calcifediol] levels and the risk of symptomatic SARS-CoV-2 disease, complications, and mortality. This systematic review (SR), guided by Bradford Hill's causality criteria, analyzed 294 peer-reviewed manuscripts published between December 2019 and November 2024, focusing on plausibility, consistency, and biological gradient. Evidence confirms that cholecalciferol (D3) and calcifediol significantly reduce symptomatic disease, complications, hospitalizations, and mortality, with optimal effects above 50 ng/mL. While vitamin D requires 3-4 days to act, calcifediol shows effects within 24 h. Among 329 trials, only 11 (3%) showed no benefit due to flawed designs. At USD 2/patient, D3 supplementation is far cheaper than hospitalization costs and more effective than standard interventions. This SR establishes a strong inverse relationship between 25(OH)D levels and SARS-CoV-2 vulnerability, meeting Hill's criteria. Vitamin D3 and calcifediol reduce infections, complications, hospitalizations, and deaths by ~50%, outperforming all patented, FDA-approved COVID-19 therapies. With over 300 trials confirming these findings, waiting for further studies is unnecessary before incorporating them into clinical protocols. Health agencies and scientific societies must recognize the significance of these results and incorporate D3 and calcifediol for prophylaxis and early treatment protocols of SARS-CoV-2 and similar viral infections. Promoting safe sun exposure and adequate vitamin D3 supplementation within communities to maintain 25(OH)D levels above 40 ng/mL (therapeutic range: 40-80 ng/mL) strengthens immune systems, reduces hospitalizations and deaths, and significantly lowers healthcare costs. When serum 25(OH)D levels exceed 70 ng/mL, taking vitamin K2 (100 µg/day or 800 µg/week) alongside vitamin D helps direct any excess calcium to bones. The recommended vitamin D dosage (approximately 70 IU/kg of body weight for a non-obese adult) to maintain 25(OH)D levels between 50-100 ng/mL is safe and cost-effective for disease prevention, ensuring optimal health outcomes.

Vitamin D can mitigate sepsis-associated neurodegeneration by inhibiting exogenous histone-induced pyroptosis and ferroptosis: Implications for brain protection and cognitive preservation

BACKGROUND

Sepsis-induced neurodegeneration and cognitive dysfunction remain critical challenges worldwide. Vitamin D was reported to reduce neuronal injury and neurotoxicity and its deficiency was associated with neurocognitive disorders. This study investigates the mechanisms by which vitamin D exerts neuroprotective potential against damage-associated molecular patterns (DAMPs), specifically extracellular histones, in sepsis-related brain dysfunction.

METHODS

The cultured mouse hippocampal neuronal HT22 cells were exposed to 20 µg/ml exogenous histone for 24 h to induce pyroptosis and ferroptosis in the presence or absence of the active form of vitamin D, calcitriol (1 nM). A cecal ligation and puncture mouse sepsis model was used to evaluate histone release and pyroptosis/ferroptosis biomarkers in the brain together with neurobehavioral performance with or without calcitriol treatment (1 µg/kg, i.p. injection) at 24 h or 1 week after sepsis onset.

RESULTS

In vitro, histone exposure triggered both pyroptosis and ferroptosis in neuronal cells, which was significantly suppressed by calcitriol treatment with the reduced expression of caspase-1 by 38 %, GSDMD by 30 %, ACSL4 by 33 %, and the increased expression of GPX4 by 35 % (n = 6, P < 0.05). Similarly, in vivo, calcitriol treatment inhibited both neuronal pyroptosis and ferroptosis by reducing expression of pyroptosis marker, GSDMD/NeuN (11.6 ± 1.2 % vs. 19.4 ± 1.1 %) and increasing expression of ferroptosis marker, GPX4/NeuN (21.4 ± 1.7 % vs. 13.5 ± 1.1 %), in the brain of septic mice (n = 6, P < 0.01). In addition, calcitriol increased survival rate (72 % vs. 41 %) and ameliorated cognitive dysfunction of septic mice (n = 8-13, P < 0.05).

CONCLUSIONS

This study demonstrates that vitamin D exerts a neuroprotective effect against sepsis by attenuating histone-induced pyroptosis and ferroptosis. These findings highlight the potential therapeutic role of vitamin D supplementation in mitigating brain dysfunction associated with sepsis which needs for further investigation.

Vitamin D3/VDR alleviates double-stranded RNA virus -induced biliary epithelial cell damage by inhibiting autophagy

BACKGROUND

The increased apoptosis of bile duct epithelial cells (BECs) due to some damage factors is considered the initiating factor in the occurrence and progression of biliary atresia (BA). Vitamin D receptor (VDR) is thought to play a crucial role in maintaining the intrinsic immune balance and integrity of bile duct epithelial cells (BECs). To investigate the role of VDRs in the pathogenesis and progression of BA using in vitro and in vivo models.

MATERIALS AND METHODS

The VDR expression levels in intrahepatic bile duct epithelial cells (IBDECs) in pediatric patients with BA were examined using immunohistochemical analysis. The correlation of the VDR levels with the incidence of refractory cholangitis after Kasai portoenterostomy (KPE) and the autologous liver survival time was analyzed. The levels of genes and proteins involved in related pathways were examined using quantitative real-time polymerase chain reaction and western blotting, respectively. The secretory levels of inflammatory factors were analyzed using enzyme-linked immunosorbent assay. A BA mouse model was established through the intraperitoneal sequential injection of rhesus rotavirus (RRV). The role of VDR in the pathogenesis and progression of BA was examined using in vitro and in vivo models. Retrospective analysis of patients with BA to examine the therapeutic efficacy of VDR activators on BA.

RESULTS

15 pediatric BA patients exhibiting VDR downregulation in IBDECs showed a higher incidence of refractory cholangitis after Kasai portoenterostomy (p = 0.037) and a lower native liver survival time compare to 23 BA patients without VDR downregulation (p = 0.032). 1,25-VD3 inhibited the degree of autophagy induction in HIBECs by poly(I: C) (p < 0.05), mitigated poly(I: C)-induced BEC damage and apoptosis by inhibiting autophagy (p < 0.05). 1,25-VD3 significantly suppressed the poly(I: C)-induced downregulation of SRC (p < 0.05) and ERK1/2 phosphorylation (p < 0.05). 1,25-VD3 exert a protective effect against RRV-induced BEC damage by inhibiting autophagy in BA mouse model. The incidence of cholangitis and the native liver survival time after surgery in the calcitriol-treated group was significantly lower than that in the control group. (p = 0.033, p = 0.035, respectively).

CONCLUSIONS

VDR activator mitigated dsRNA-induced BEC damage and apoptosis by inhibiting autophagy in vitro and in vivo. The 1,25-VD3/VDR/Src axis alleviated poly(I: C)-induced HIBEC damage and apoptosis through the PLA2/PKC/ERK pathway.

In vitro evaluation of the immunomodulatory and antibacterial activities of calcitriol (1,25-dihydroxy-vitamin D3) as a potential application for aerobic vaginitis treatment - preliminary study results

BACKGROUND

Aerobic vaginitis (AV) is a state of abnormal vaginal microbiota, which is associated with increased numbers of aerobic, enteric bacteria and inflammation of the vaginal epithelium. Anti-microbial treatment combined with anti-inflammatory therapy could be useful in the treatment of this condition. It is known that calcitriol, the active form of vitamin D, plays an important role in modulating the immune response in several inflammatory diseases. The aim of this preliminary study was to evaluate in vitro the influence of calcitriol on the immune response of human vaginal epithelial cells to bacterial infection. Moreover, we assessed the anti-bacterial properties of calcitriol, as well as its synergistic activity with antibiotics that are used for the treatment of AV.

RESULTS

Human vaginal A431 epithelial cells were treated with calcitriol (100 nM) and then stimulated with thermally inactivated strains of AV-associated bacteria (Escherichia coli, Enterococcus faecalis, Streptococcus agalactiae), or first stimulated with heat-treated bacteria and then incubated with calcitriol (30 nM). After 24 h, 48 h, and 72 h post-infection, culture supernatants were collected, and levels of pro-inflammatory cytokines IL-6 and IL-1β were analyzed using enzyme-linked immunosorbent assays (ELISA). As it turned out, calcitriol treatment pre- or post-bacterial stimulation of vaginal epithelial cells significantly decreased the levels of IL-6 and IL-1β compared to cells stimulated only with bacteria. Downregulation of pro-inflammatory cytokines was more frequently significant when cells were pre-treated with calcitriol. Additionally, this study evaluated the anti-bacterial properties and synergistic activity of calcitriol with antibiotics by determining the Minimal Inhibitory Concentration (MIC) using colorimetric, Resazurin-based microdilution method detecting the active metabolism of bacteria. As a result, calcitriol by itself did not exhibit clinically relevant anti-bacterial activity; however, when combined with antibiotics, calcitriol significantly reduced the MIC values.

CONCLUSIONS

The results of this preliminary study confirm that calcitriol treatment influences cytokine-mediated immune response during infection and indicate that it can be effective in enhancing antibiotic activity. Such properties could be very useful in the treatment of inflammatory diseases. However, conclusions regarding the potential use of calcitriol in the treatment of AV require further confirmation in in vivo studies as well as in well-designed clinical trials.

Flunarizine as a Candidate for Drug Repurposing Against Human Pathogenic Mammarenaviruses

Lassa fever (LF), a viral hemorrhagic fever disease with a case fatality rate that can be over 20% among hospitalized LF patients, is endemic to many West African countries. Currently, no vaccines or therapies are specifically licensed to prevent or treat LF, hence the significance of developing therapeutics against the mammarenavirus Lassa virus (LASV), the causative agent of LF. We used in silico docking approaches to investigate the binding affinities of 2015 existing drugs to LASV proteins known to play critical roles in the formation and activity of the virus ribonucleoprotein complex (vRNP) responsible for directing replication and transcription of the viral genome. Validation of docking protocols were achieved with reference inhibitors of the respective targets. Our in silico docking screen identified five drugs (dexamethasone, tadalafil, mefloquine, ergocalciferol, and flunarizine) with strong predicted binding affinity to LASV proteins involved in the formation of the vRNP. We used cell-based functional assays to evaluate the antiviral activity of the five selected drugs. We found that flunarizine, a calcium-entry blocker, inhibited the vRNP activity of LASV and LCMV and virus surface glycoprotein fusion activity required for mammarenavirus cell entry. Consistently with these findings, flunarizine significantly reduced peak titers of LCMV in a multi-step growth kinetics assay in human A549 cells. Flunarizine is being used in several countries worldwide to treat vertigo and migraine, supporting the interest in exploring its repurposing as a candidate drug to treat LASV infections.

Association between serum vitamin D and severe headache or migraine: A population-based analysis

BACKGROUND

Vitamin D is thought to play a role in the development of migraine, but the nature of the relationship is still not fully understood. Although some studies have shown an association between vitamin D deficiency and migraine, other studies have had inconsistent or inconclusive results. Therefore, further research is needed to better understand the relationship between vitamin D and migraine headaches.

METHODS

We selected 9142 participants from the 2001-2004 National Health and Nutrition Examination Survey (NHANES). In our study, the term "serum vitamin D" refers to the concentration of 25OHD2 + 25OHD3 (nmol/L) in the blood. Migraine was assessed based on self-reports in the miscellaneous pain section of the NHANES questionnaire. Associations between vitamin D and the risk of migraine were examined using multiple logistic regression, smoothed curve fitting, and stratified analyses.

RESULTS

In our study, 20.53% of the participants suffered from migraine. The prevalence of migraine was higher in those with lower serum vitamin D levels. Participants in the highest quartile of serum vitamin D levels were found to have a 16% lower prevalence than those in the lowest quartile in the fully adjusted model (OR = 0.84, 95% CI 0.71-0.99). This result was supported by stratified analysis and smoothed curve fitting.

CONCLUSION

Our study showed a significant negative correlation between serum vitamin D levels and the prevalence of migraine in American adults.

Impact of Vitamin D Levels on Clinical Outcomes in SARS-CoV-2 Infections

BACKGROUND AND AIM

Since its emergence in 2019, SARS-CoV-2 has caused the global COVID-19 pandemic, presenting significant challenges for healthcare systems worldwide. Extensive research has focused on diagnostics, treatments, and vaccine development to combat the virus. Given the need for effective strategies to reduce infection rates, disease progression, and severity, this study aimed to investigate the potential role of vitamin D (25OHD) in mitigating the severity of COVID-19.

METHODS

A cross-sectional study was conducted to evaluate the relationship between serum vitamin D levels and the severity of COVID-19 symptoms. Vitamin D levels were measured using the Roche Diagnostics Vitamin D assay in 100 SARS-CoV-2-infected patients confirmed by real-time polymerase chain reaction (PCR). Patients were categorized as symptomatic or asymptomatic, and the correlation between vitamin D levels and symptom severity was analyzed.

RESULTS

The findings demonstrated that a significant proportion of symptomatic patients had vitamin D levels below 20 ng/mL. In contrast, approximately 25% of asymptomatic patients had vitamin D levels exceeding 30 ng/mL. Statistical analysis confirmed a significant association between low vitamin D levels and increased symptom severity (p=0.007).

CONCLUSION

This study suggests that vitamin D deficiency may contribute to the severity of COVID-19 symptoms. Vitamin D supplementation could potentially reduce the risk of severe disease. However, to confirm these findings and support these recommendations, further research, including randomized controlled trials and large-scale population studies, is necessary.

The Impact and Efficacy of Vitamin D Fortification

Vitamin D deficiency is a global health issue linked to various chronic diseases and overall mortality. It primarily arises from insufficient sunlight exposure, compounded by dietary limitations. Vitamin D fortification of commonly consumed foods has emerged as a viable public health intervention to address this deficiency. This review evaluates the impact of vitamin D food fortification on serum levels, intake, and health outcomes and explores the stability, bio-accessibility, bioavailability, and cost-effectiveness of such interventions. A comprehensive literature search was conducted in PubMed and Google Scholar, focusing on studies from 2015 to 2024. The criteria included primary research on healthy adults that addressed the effects of vitamin D fortification on health, intake, and serum levels, as well as the fortification's stability, bio-accessibility, bioavailability, and cost-effectiveness. Studies were extracted and analyzed according to PRISMA guidelines. The review included 31 studies from diverse geographic locations, revealing that fortifying dairy products, cereals, fats, oils, and other food items effectively increased serum 25-hydroxyvitamin D levels. The fortification methods varied, with vitamin D3 showing superior efficacy over vitamin D2. Encapsulation techniques improved stability and bioavailability. Fortifying staple foods like milk and eggs proved cost-effective compared with pharmaceutical interventions. Vitamin D food fortification significantly enhances serum levels and intake, with dairy and cereals being the most frequently fortified. Standardized fortification guidelines are essential to ensure safety and efficacy. Ongoing evaluation and region-specific policies are crucial for effectively optimizing fortification strategies and addressing vitamin D deficiency.

Association between 25(OH) vitamin D and schizophrenia: shared genetic correlation, pleiotropy, and causality

Background

This study delves into the complex interplay between genetics, 25-hydroxyvitamin D (25OHD), and schizophrenia (SCZ). It leverages extensive sample data derived from Genome-Wide Association Studies (GWAS) to uncover genetic correlations.

Methods

Employing Linkage Disequilibrium Score Regression (LDSC) and S-LDSC, this study investigates genetic connections between 25OHD and SCZ. It examines Single Nucleotide Polymorphism (SNP) heritability in specific tissues and incorporates diverse immune cell datasets for genetic enrichment analysis. Local genetic correlations were analyzed using HESS software, and pleiotropy analysis identified shared genetic loci in brain tissues. Hyprcoloc analysis was used to explore shared genetic factors between 25OHD, immune cells, and SCZ, complemented by a bidirectional Mendelian Randomization (MR) to probe potential causal links.

Results

We identified a significant negative genetic correlation between 25OHD levels and SCZ. PLACO analysis revealed 35 pleiotropic loci with strong enrichment in brain regions, particularly the cerebellum, frontal cortex, and hippocampus. Eight loci (1p34.2, 2p23.3, 3p21.1, 5q31.2, 12q23.2, 14q32.33, 16p13.3, and 16q24.3) exhibited strong colocalization, highlighting potential drug targets. Gene and tissue enrichment analyses emphasized neurological and immune-related mechanisms, including hyaluronan metabolism. Bidirectional MR analysis supported a causal effect of SCZ on 25OHD levels.

Conclusion

Our study identifies NEK4 as a potential therapeutic target and highlights the involvement of hyaluronan metabolism in the genetic association between 25OHD and SCZ. These findings provide valuable insights into shared genetic pathways, immune-related connections, and causal interactions in the context of SCZ.

Association of dietary inflammatory index and systemic inflammatory markers with mortality risk in depressed adults: a mediation analysis of NHANES data

Background

Previous research has linked systemic inflammatory markers and the Dietary Inflammatory Index (DII) with depression. However, the relationship between DII and these markers, and their impact on mortality risk among depressed adults, remains underexplored. This study aims to explore the association between DII and systemic inflammatory markers and their mediating effect on mortality risk in adults with depression.

Methods

This study analyzed data from 4,981 adults with depression in the National Health and Nutrition Examination Survey (NHANES). This study quantified dietary inflammatory potential with the DII and systemic inflammation with the Systemic Immune-Inflammation Index (SII) and Systemic Inflammation Response Index (SIRI). Cox proportional hazards regression and inverse probability weighting evaluated the impact of DII, SII, and SIRI on mortality risk in depressed adults, as well as their mediating effects. Multiple linear regression analyzed the associations between DII and SII/SIRI. Restricted cubic spline analysis explored the non-linear relationship between DII and mortality risk.

Results

In adjusted regression models, DII, SII, and SIRI were significantly associated with all-cause mortality risk in depressed adults, with hazard ratios (HRs) (95% CIs) from 1.333 to 1.497 (1.051-1.233, 1.689-1.832). DII was linearly related to SII, with βs (95% CIs) from 0.001 to 0.121 (0.001-0.017, 0.001-0.224). SII significantly mediated the DII-mortality risk link, especially in males (8.07%). The DII-mortality relationship was linear (P non-linear = 0.174), with a beneficial threshold at 1.62.

Conclusion

DII and SII are associated with increased all-cause mortality risk in depressed adults. The DII-related mortality risk in depression can be partially mediated by SII, with a more pronounced effect in males.

Vitamin D: A key player in COVID-19 immunity and lessons from the pandemic to combat immune-evasive variants

As of the 7th of July 2024, 775,754,322 confirmed cases of COVID-19, including 7,053,902 deaths worldwide, had been reported to the WHO (World Health Organization). Nevertheless, untill the 15th of July 2024, a total of 13,578,710,228 vaccine doses had been administered, with almost no country spared from COVID-19 attacks. The pathophysiology of this virus is complicated, and several symptoms require a deep understanding of the actual mechanisms. It is unclear why some patients develop severe symptoms while others do not, although literature suggests a role for vitamin D. Vitamin D plays a crucial role in the infection or in ameliorating the severity of symptoms. The mechanism of action of vitamin D and vitamin D deficiency (VDD) is well understood. VDD is associated with increased hospitalization of severely ill patients and increased levels of COVID-19-caused mortality. Recent studies suggest that vitamin D levels and genetic variations in the vitamin D receptor (VDR) gene significantly impact the severity and outcomes of COVID-19, especially in the infections caused by Delta and Omicron variants. Furthermore, VDD causes immune system dysregulation upon infection with SARS-CoV-2, indicating that vitamin D sufficiency is crucial in fighting against COVID-19 infection. The therapeutic effect of vitamin D raises interest in its potential role as a prophylactic and treatment adjunct. We evaluate the immunomodulatory effects of vitamin D and its ability to enhance the efficacy of new antiviral drugs like molnupiravir and paxlovid against SARS-CoV-2. This review discusses the role of vitamin D sufficiency and VDD in COVID-19 initiation and progression, emphasizing the molecular mechanisms by which vitamin D exerts its actions as a proactive step for the next pandemic. However, there is still no clear evidence of vitamin D's impact on prevention and treatment, leading to contradictory findings. Therefore, large-scale randomized trials are required to reach a definitive conclusion. A bibliometric analysis of publications related to vitamin D, immunity, and COVID-19 revealed a significant increase in research activity in this area, particularly in 2020-2024, underscoring the growing recognition of vitamin D's potential role in the context of the pandemic.

Clinical Study of Vitamin D Levels in Hospitalized Children with Acute Respiratory Infections

The aim of our research was to evaluate and analyze serum 25(OH) vitamin D and parathyroid hormone (PTH) levels to investigate whether vitamin D deficiency serves as a risk factor for an increased incidence of acute respiratory infections (ARI) in children. Serum PTH levels were used as an indicator of vitamin D sufficiency, as normal PTH levels require an optimal concentration of 25(OH) vitamin D. The study included 129 children, divided into five subgroups: children with acute bronchopneumonia (n = 42), acute laryngotracheitis (n = 7), acute bronchiolitis (n = 32), acute bronchitis (n = 18), and a control group (n = 30). No statistically significant differences in 25(OH)D levels were observed between the overall population of children with ARI and the control group (p = 0.073). However, significant differences in 25(OH)D levels were identified between the control group and children with bronchopneumonia, acute bronchitis, and laryngotracheitis (p < 0.01, p < 0.05). Regarding PTH levels, statistical significance was found between the control group and the acute bronchiolitis group, due to the high percentage of children with hypervitaminosis in this subgroup. These results highlight the crucial role of vitamin D in the onset and progression of acute respiratory tract infections in children, emphasizing its impact on their overall respiratory health.

25-Hydroxyvitamin D status does not affect energy metabolism among young, healthy, non-obese adults: a metabolic chamber study

Purpose

here is a general consensus that an inverse relationship exists between vitamin D status and body mass index (BMI) in overweight and obese individuals, leading to the hypothesis that vitamin D deficiency may contribute to the development of unfavorable metabolic phenotypes. However, evidence from non-obese adults remains limited. This study measured energy metabolism in non-obese adults using a metabolic chamber and explored its association with vitamin D status.

Methods

Sixty-nine healthy adults (mean age = 22.8 years, mean BMI = 20.7 kg/m2) participated in this cross-sectional study. Participants were categorized into vitamin D-deficient, insufficient, and sufficient groups based on the Chinese classification for total 25(OH)D levels (WS/T 677-2020). They performed typical daily activities in a metabolic chamber, where their baseline lipid profile, 24-hour energy expenditure, and substrate oxidation were measured.

Results

A two-way ANOVA (seasonality × 25(OH)D) revealed no statistically significant differences in total energy expenditure, resting energy expenditure, sleeping energy expenditure, walking energy expenditure, carbohydrate oxidation rate, or fat oxidation rate among the three groups (p > 0.05). These results remained consistent even after adjusting for fat-free mass. Although statistically significant correlations were found between 25(OH)D status and certain lipid profile markers (i.e., total cholesterol, high-density lipoprotein, and free fatty acid) (p < 0.05), these correlations were weak, with Pearson's correlation coefficients below 0.3.

Conclusions

Total 25(OH)D status does not affect energy metabolism in young, healthy, non-obese adults. Along with existing evidence, this suggests that low 25(OH)D status is more likely a consequence of unfavorable metabolic phenotypes rather than a contributing factor.

Clinical trial registration

https://www.chictr.org.cn, identifier ChiCTR-IIR-17010604.

High Doses of Vitamin D and Specific Metabolic Parameters in Type 2 Diabetes Patients: Systematic Review

Background/Objectives: Type II diabetes mellitus (T2DM) is recognized as a condition of mild chronic inflammation, marked by increased levels of acute-phase proteins and various inflammatory indicators. These inflammatory substances, along with inflammation of adipose tissue and the secretion of adipocytokines, can contribute to insulin resistance and β cell dysfunction. By influencing both innate and adaptive immunity, vitamin D can inhibit the production of inflammatory cytokines and help mitigate the low-grade chronic inflammation associated with T2DM. Several strategies have been proposed to increase vitamin D levels effectively and safely, but the recent and strong ones have common tactics. Short-term high doses increase the level acutely, and long-term lower doses maintain sufficient levels. Methods: The aim of our work was to determine and verify the effectiveness of high doses of vitamin D to safely increase its level in patients with type 2 diabetes mellitus, as well as the effect of these doses on selected metabolic parameters. Data from 20 studies (vitamin D group n = 612, and control group n = 592) regarding the influence of vitamin D supplementation with doses above 4000 IU on serum 25(OH)D, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), blood pressure, serum calcium, and parathormone were pooled. Results: Vitamin D supplementation significantly improved serum 25(OH)D levels, with an average increase after intervention versus baseline at 177.09%. Our studies suggest that vitamin D supplementation may benefit various parameters in T2DM patients, including glycemic control, blood pressure, and PTH levels. Conclusions: Vitamin D supplementation may have beneficial effects on various parameters in type 2 diabetes patients, including glycemic control, blood pressure, and parathormone levels. However, the results are only sometimes consistent across all studies. Further examination is needed.

The effect of vitamin D supplementation on antibiotic use: a meta-analysis based on randomized controlled trials

Objective

This meta-analysis explores the impact of vitamin D supplementation on antibiotic utilization.

Methods

We systematically searched for relevant randomized controlled trials (RCTs) in PubMed, Web of Science, EMBASE, and Science Direct from inception to April 2024. These trials compared antibiotic use rates between groups receiving vitamin D supplements and placebo.

Results

We included seven RCTs involving 35,160 participants. There was no significant difference in antibiotic use between the two groups in the general population (Odds Ratio [OR] = 0.98, p = 0.232), including elderly participants (OR = 0.98, p = 0.295). However, antibiotic use was lower in the intervention group compared to the placebo group among participants under 70 years of age (OR = 0.95, p = 0.015), those with relative vitamin D deficiency [25(OH)D < 75 nmol/L, OR = 0.95, p = 0.024; 25(OH)D < 50 nmol/L, OR = 0.96, p = 0.026], and those with respiratory tract infections (RTIs) (OR = 0.51, 95% CI: 0.24-1.08, p = 0.080), although these differences were not statistically significant for RTIs.

Conclusion

Vitamin D supplementation does not affect antibiotic use in the general population. However, it does reduce antibiotic utilization in individuals with RTIs, relative vitamin D deficiency, or aged below 70 years.

Systematic review registration

This meta-analysis adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and is registered with the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42024543246.

Association between anemia and vitamin D deficiency in German seniors : A retrospective data analysis

BACKGROUND

Anemia and deficiency of vitamin D (VDD) are frequently seen in seniors and an association is suspected. Approximately one third of the German population is affected by VDD, with a rising prevalence among seniors.

AIM

To analyze the association between anemia and VDD among German seniors aged ≥ 60 years.

METHODS

Retrospective cross-sectional data analysis (n = 4008) in a nationwide working laboratory medical center (January-December 2019). Study parameters included amongst others: hemoglobin (Hb), calcifediol (25D) and calcitriol (1.25D), glomerular filtration rate (GFR) to assess the kidney disease outcomes quality initiative (KDOQI) state. The inclusion criteria were age ≥ 60 years, normal C‑reactive protein (CRP) and leucocyte levels.

RESULTS

The 25D was estimated in 4008 patients and 1.25D only in 411 patients. Mean age 75 years (± 8.61 years; 60-99 years) with 30.6% males; mean GFR 62 ml/min/1.73 m3 (± 22.74); 20% of patients were anemic, 35% were deficient for 25D (< 50 nmol/l), with men > women (p = 0.014). Linear regression analysis revealed a significant effect of 25D values < 30 nmol/l on hemoglobin in males of KDOQI I-III and females of KDOQI I-IV (R2 = 0.052; p = 0.005; and R2 = 0.124; p < 0.001, respectively). For 1.25D a weak but significant effect on hemoglobin independent of KDOQI was only seen in women (R2 = 0.200; p = 0.005).

CONCLUSION

In this cohort deficiency of 25D and 1.25D was significantly associated with hemoglobin independent of renal function only in women but not in men.

Post-Transplant Vitamin D Deficiency in Lung Transplant Recipients: Impact on Outcomes and Prognosis

Despite the recognized clinical significance of vitamin D deficiency in other solid organ transplant recipients, its specific relevance in lung transplantation remains to be fully understood. In this study, we performed a retrospective observational study on the impact of vitamin D deficiency on clinical outcomes and prognosis in 125 lung transplant recipients (LTRs) from October 2014 to March 2020 at a university hospital in Seoul, South Korea. Among 125 LTRs, 51 patients (40.8%) were vitamin D deficient. LTRs in the vitamin D-deficient group exhibited a higher incidence of post-transplant pneumonia and overall mortality than those with normal vitamin D levels during the follow-up period. This trend persisted when subjects were stratified into vitamin D tertiles. Furthermore, post-transplant vitamin D levels and C-reactive protein (CRP) significantly impacted pneumonia incidence and survival outcomes. Prognosis also varied based on cumulative vitamin D supplementation after transplantation, with patients receiving higher cumulative supplementation demonstrating improved prognosis. Our findings underscore the importance of assessing and maintaining optimal vitamin D levels post-transplantation, suggesting a potential avenue for improving outcomes in lung transplant recipients, especially in mitigating infection risk and enhancing long-term survival. Further research into optimal vitamin D levels and supplementation strategies in this population is warranted.

Unveiling the Interplay-Vitamin D and ACE-2 Molecular Interactions in Mitigating Complications and Deaths from SARS-CoV-2

The interaction of the SARS-CoV-2 spike protein with membrane-bound angiotensin-converting enzyme-2 (ACE-2) receptors in epithelial cells facilitates viral entry into human cells. Despite this, ACE-2 exerts significant protective effects against coronaviruses by neutralizing viruses in circulation and mitigating inflammation. While SARS-CoV-2 reduces ACE-2 expression, vitamin D increases it, counteracting the virus's harmful effects. Vitamin D's beneficial actions are mediated through complex molecular mechanisms involving innate and adaptive immune systems. Meanwhile, vitamin D status [25(OH)D concentration] is inversely correlated with severity, complications, and mortality rates from COVID-19. This study explores mechanisms through which vitamin D inhibits SARS-CoV-2 replication, including the suppression of transcription enzymes, reduced inflammation and oxidative stress, and increased expression of neutralizing antibodies and antimicrobial peptides. Both hypovitaminosis D and SARS-CoV-2 elevate renin levels, the rate-limiting step in the renin-angiotensin-aldosterone system (RAS); it increases ACE-1 but reduces ACE-2 expression. This imbalance leads to elevated levels of the pro-inflammatory, pro-coagulatory, and vasoconstricting peptide angiotensin-II (Ang-II), leading to widespread inflammation. It also causes increased membrane permeability, allowing fluid and viruses to infiltrate soft tissues, lungs, and the vascular system. In contrast, sufficient vitamin D levels suppress renin expression, reducing RAS activity, lowering ACE-1, and increasing ACE-2 levels. ACE-2 cleaves Ang-II to generate Ang(1-7), a vasodilatory, anti-inflammatory, and anti-thrombotic peptide that mitigates oxidative stress and counteracts the harmful effects of SARS-CoV-2. Excess ACE-2 molecules spill into the bloodstream as soluble receptors, neutralizing and facilitating the destruction of the virus. These combined mechanisms reduce viral replication, load, and spread. Hence, vitamin D facilitates rapid recovery and minimizes transmission to others. Overall, vitamin D enhances the immune response and counteracts the pathological effects of SARS-CoV-2. Additionally, data suggests that widely used anti-hypertensive agents-angiotensin receptor blockers and ACE inhibitors-may lessen the adverse impacts of SARS-CoV-2, although they are less potent than vitamin D.

Epidemiological and genetic aspects of pulmonary tuberculosis in Kazakhstan

OBJECTIVE

Tuberculosis is a major health problem in many countries, including Kazakhstan. Host genetics can affect TB risk, and epidemiological and social factors may contribute to disease progression. Due to the high incidence of pulmonary tuberculosis in the country, our research aimed to study the epidemiological and genetic aspects of pulmonary tuberculosis in Kazakhstan.

MATERIAL AND METHODS

1026 participants of Central Asian origin were recruited in the study: 342 individuals diagnosed with active PTB, 342 household contacts, and 342 controls without a family history of TB. Genetic polymorphisms of selected genes were determined by real-time polymerase chain reaction. The association between the risk of pulmonary TB and polymorphisms was evaluated using logistic regression and assessed with the ORs and their corresponding 95 % CIs, and the significance level was determined as p < 0.05.

RESULTS

Epidemiological data revealed that underweight BMI (χ² = 89.97, p < 0.001), employment (χ² = 39.28, p < 0.001), and diabetes (χ² = 12.38, p < 0.001) showed a significant association with PTB. A/T polymorphism of the IFG gene showed a lower risk, and A/A polymorphism showed an increased risk of susceptibility to TB. A/A polymorphism of the IFG gene was associated with an almost 3-fold increased risk of PTB, and A/T polymorphism of the IFG gene was associated with a decreased risk of PTB (OR = 0.67, 95 % CI = 0.49-0.92, p = 0.01). The analysis revealed a decreased risk of PTB for A/A polymorphism of the VDR ApaI (OR = 0.67, 95 % CI = 0.46-0.97, p < 0.05). A/A polymorphism of the TLR8 gene was associated with a 1.5-fold increased risk of PTB (OR = 1.53, 95 % CI = 1.00-2.33, p < 0.05).

CONCLUSION

Results showed that gender, employment, underweight BMI and diabetes are associated with PTB incidence in our study cohort. The A/A genotype of the IFG (rs2430561) and an A/A genotype of the TLR8 (rs3764880) genes were associated with an increased risk of PTB. A/T polymorphism of the IFG (rs2430561) and A/A polymorphism of the VDR ApaI were associated with a decreased risk of PTB.

Associations between serum 25-hydroxyvitamin D and prognosis of chronic kidney disease: a prospective cohort study

BACKGROUND AND OBJECTIVES

25-hydroxyvitamin D [25(OH)D] deficiency is prevalent in patients with chronic kidney disease (CKD), the associations between serum 25(OH)D levels and mortality in patients with CKD remain unclear, and this study aimed to explore these associations further.

METHODS

4989 participants with CKD were enrolled in the study, and the Cox regression model was used to assess the effects of serum 25(OH)D concentrations on mortality risk. A restricted cubic spline model was used to explore the dose-response relationships, and threshold effect analysis was performed based on inflection points identified by a two-piecewise linear regression model. In addition, subgroup and sensitivity analyses were employed.

RESULTS

1255 participants died during a mean follow-up period of 70 months. Compared with the 25(OH)D-deficient group, the fully adjusted hazard ratios and 95% confidence intervals for the 25(OH)D-adequate group were 0.631 (0.545, 0.730) for all-cause mortality, 0.569 (0.435, 0.743) for cardiovascular mortality, 0.637 (0.461, 0.878) for hypertension mortality, and cancer mortality was 0.596 (0.426, 0.834). The inflection points of serum 25(OH)D concentration affecting all-cause and cardiovascular mortality were 89 nmol/L, and 107 nmol/L, respectively. Subgroup analyses and interaction tests suggested that the effects varied across populations. The results of sensitivity analyses indicated a reliable correlation.

CONCLUSION

We found an association between serum 25(OH)D concentrations and the prognosis of patients with CKD as a reliable predictor of early intervention and intensive care.

Antiviral activity of vitamin D derivatives against severe fever with thrombocytopenia syndrome virus in vitro and in vivo

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne virus that causes the severe fever thrombocytopenia syndrome, which manifests as fever and haemorrhage, accompanied by severe neurological complications. To date, no specific antiviral drugs have been approved for this indication. Herein, we investigated whether vitamin D derivatives inhibit SFTSV both in vitro and in vivo. An in vitro study demonstrated that vitamin D derivatives significantly suppressed viral RNA replication, plaque formation, and protein expression in a dose-dependent manner. Subsequently, in vivo studies revealed that doxercalciferol and alfacalcidol were associated with increased survival and reduced viral RNA load in the blood. Time-of-addition assay suggested that vitamin D derivatives primarily acted during the post-entry phase of SFTSV infection. However, cytopathic effect protective activity was not observed in RIG-I immunodeficient cell line Huh7.5, and the administration of vitamin D derivatives did not improve the survival rates or reduce the blood viral loads in adult A129 mice. Further transcriptome exploration into the antiviral mechanism revealed that alfacalcidol stimulates host innate immunity to exert antiviral effects. To expand the application of vitamin D derivatives, in vitro and in vivo drug combination assays were performed, which highlighted the synergistic effects of vitamin D derivatives and T-705 on SFTSV. The combination of alfacalcidol and T-705 significantly enhanced the therapeutic effects in mice. This study highlights the potential of vitamin D derivatives against SFTSV and suggests that they may have synergistic effects with other compounds used in the treatment of SFTSV infection.

Vitamin D in Primary Sjogren's Syndrome (pSS) and the Identification of Novel Single-Nucleotide Polymorphisms Involved in the Development of pSS-Associated Diseases

Sjögren's syndrome (SS) is a chronic autoimmune disorder characterised by lymphocytic infiltration of the exocrine glands, which leads to dryness of the eyes and mouth; systemic manifestations such as arthritis, vasculitis, and interstitial lung disease; and increased risks of lymphoma and cardiovascular diseases. SS predominantly affects women, with a strong genetic component linked to sex chromosomes. Genome-wide association studies (GWASs) have identified numerous single-nucleotide polymorphisms (SNPs) associated with primary SS (pSS), revealing insights into its pathogenesis. The adaptive and innate immune systems are crucial to SS's development, with viral infections implicated as environmental triggers that exacerbate autoimmune responses in genetically susceptible individuals. Moreover, recent research has highlighted the role of vitamin D in modulating immune responses in pSS patients, suggesting its potential therapeutic implications. In this review, we focus on the recently identified SNPs in genes like OAS1, NUDT15, LINC00243, TNXB, and THBS1, which have been associated with increased risks of developing more severe symptoms and other diseases such as fatigue, lymphoma, neuromyelitis optica spectrum disorder (NMOSD), dry eye syndrome (DES), and adverse drug reactions. Future studies should focus on larger, multi-ethnic cohorts with standardised protocols to validate findings and identify new associations. Integrating genetic testing into clinical practise holds promise for improving SS management and treatment strategies, enabling personalised interventions based on comprehensive genetic profiles. By focusing on specific SNPs, vitamin D, and their implications, future research can lead to more effective and personalised approaches for managing pSS and its complications.

Randomized trial of influence of vitamin D on the prevention and improvement of symptomatic COVID-19

We aimed to investigate the preventive effect of vitamin D2 on COVID-19 and the improvement of symptoms after COVID-19 infection. The study recruited 228 health care workers who tested negative PCR or antigen for COVID-19. Subjects were randomly allocated to vitamin D2 or non-intervention at a ratio 1:1. Subjects recorded PCR or antigen tests and the symptoms of COVID-19 twice a week during the follow-up visit. The concentration of serum 25-hydroxyvitamin D (25(OH)D), C-reaction protein (CRP), complement component C1q and inflammatory cytokines were measured. The rates of COVID-19 infection were 50.5% in the vitamin D2 group and 52.4% in the non-intervention group (P = 0.785). There was no difference in the COVID-19 symptoms between the two groups. The mean 25(OH)D level significantly increased from 14.1 to 31.1 ng/mL after administration (P < 0.001). The difference between the two groups was not significant for the concentrations of CRP, C1q and inflammatory cytokines on the thirtieth day of the trial. According to the second level of vitamin D, there was a 14.3% difference in positive infection rates between the vitamin D adequate (> 30 ng/mL) and deficient groups (< 20 ng/mL). Adequate vitamin D had a tendency to prevent COVID-19.Trial registration: ClinicalTrials.gov NCT05673980, dated: 12/2022.

Vitamin D and systemic lupus erythematosus: Causality and association with disease activity and therapeutics

The major role of bioactive vitamin 1,25-dihydroxyvitamin D3 (1,25(OH)2D or calcitriol) is to maintain the levels of calcium and phosphorus to achieve bone and mineral homeostasis. Dietary intake and adequate natural light exposure are the main contributors to normal vitamin D status. In addition to regulating metabolism, vitamin D exerts various immunomodulatory effects that regulate innate and adaptive immunity through immune effector cells such as monocytes, macrophages, T and B lymphocytes, and natural killer cells and nonimmune cells that express vitamin D receptors. Systemic lupus erythematosus (SLE) is an autoimmune disease with an unknown etiology, and the association between vitamin D and SLE remains incompletely understood. Given that the current treatment for SLE relies heavily on corticosteroids and that SLE patients tend to have low vitamin D status, vitamin D supplementation may help to reduce the dosage of corticosteroids and/or attenuate disease severity. In this review, we address the associations between vitamin D and several clinical aspects of SLE. In addition, the underlying immunomodulatory mechanisms accounting for the potential vitamin D-mediated therapeutic effects are discussed. Finally, several confounding factors in data interpretation and the execution of clinical trials and perspectives targeting vitamin D supplementation in patients with SLE are also addressed.

Pulmonary Blastomycosis in Two Immunocompetent Patients: The Role of Obesity and Vitamin D Deficiency

This case report depicts two patients with morbid obesity who presented to the ED with signs and symptoms of community-acquired pneumonia and were treated accordingly. Despite empiric antibiotic therapy, their symptoms did not subside, prompting further evaluation, which revealed pulmonary blastomycosis. Both patients were also found to have severe vitamin D deficiency. Treatment with amphotericin B followed by itraconazole, along with aggressive vitamin D supplementation, led to clinical improvement and resolution of lung lesions in both cases. Although blastomycosis is not rare in immunocompetent individuals, its severe forms are usually associated with underlying immunosuppression or significantly high inoculum. Blastomycosis presents a diagnostic challenge due to its nonspecific symptoms and radiographic findings. This case series underscores the importance of considering blastomycosis in the differential diagnosis of persistent pneumonia in obese individuals, particularly in endemic areas. It also suggests that vitamin D deficiency may play a role in disease susceptibility and severity. This report contributes to existing medical literature by emphasizing the potential link between obesity, vitamin D deficiency, and the risk of blastomycosis, highlighting the need for further research into this association.

Correlation between serum vitamin D level and acute invasive enteritis in children

BACKGROUND

Diarrhea is a leading cause of death in young children worldwide. Vitamin D deficiency impairs the body's ability to clear pathogens, reduces tight junction protein expression in intestinal epithelial cells, and enhances Th1-mediated intestinal inflammation. This study aimed to investigate the effects of serum vitamin D levels on acute invasive enteritis in children.

METHODS

This prospective cohort study included 82 children aged 1-3 years with clinically diagnosed acute invasive enteritis at Sichuan Maternal and Child Health Hospital from February 2021 to February 2022, alongside a control group of 80 healthy children. Fecal specimens were collected for routine tests and occult blood analysis, while blood samples were taken for routine tests, C-reactive protein, and 25-OHD levels. Comparative analyses were performed between groups, and multifactorial logistic regression was used to identify factors influencing invasive enteritis.

RESULTS

The study group showed significantly lower serum 25-OHD levels (27.95 ± 9.91 ng/mL) compared to controls (32.76 ± 10.23 ng/mL, p < .01). Among the study group, 19.5% (16/82) had levels <20 ng/mL, versus 12.5% (10/80) in controls. Regular vitamin D supplementation was lower in the study group (58.5% vs. 77.5%, p < .05). Outdoor activity duration was also reduced (2.57 ± 0.98 h vs. 3.04 ± 0.88 h, p < .01). Multivariate analysis identified that exclusive breastfeeding, greater outdoor activity time and regular vitamin D supplementation were all associated with reduced risk of invasive enteritis (p < .05).

CONCLUSION

The findings indicate an association between low serum 25-OHD levels and acute invasive enteritis in children aged 1-3 years, suggesting that consistent vitamin D supplementation and sufficient outdoor activity may protect against this condition.

Bringing Vitamin D and the Vitamin D Receptor into the Limelight

Classically, vitamin D is known to regulate skeletal and mineral ion homeostasis [...].

Crisaborole combined with vitamin D demonstrates superior therapeutic efficacy over either monotherapy in mice with allergic contact dermatitis

This study evaluated the therapeutic efficacy and underlying mechanisms of crisaborole combined with vitamin D in the treatment of allergic contact dermatitis. While crisaborole, a phosphodiesterase 4 inhibitor, and vitamin D analogs are commonly used in the treatment of atopic dermatitis, their combined therapeutic potential in allergic contact dermatitis (ACD) remains unexplored. Given their anti-inflammatory properties, we hypothesized that the combination of crisaborole and vitamin D could offer superior efficacy in mitigating the symptoms and underlying mechanisms of allergic contact dermatitis. In vitro, HaCaT cells stimulated with tumor necrosis factor-α and interferon-γ were treated with a combination of crisaborole and vitamin D, followed by cytokine expression analysis. In vivo, male C57BL/6 mice were divided into five groups and treated accordingly: blank control, dinitrochlorobenzene-induced model, crisaborole alone, vitamin D alone, and a combination of crisaborole and vitamin D. On day 14, dorsal skin and ear thickness were measured, followed by comprehensive pathological evaluations. In vivo and in vitro experiments showed that the expression levels of inflammatory factors were significantly lower in the DNCB + VD + Cri group than in the DNCB group. Histological analyses revealed that, compared with the DNCB group, the combined treatment group significantly reduced epidermal hyperkeratosis, improved epidermal transdermal water loss, decreased dermatitis scores, and diminished mast cell infiltration. Moreover, it lowered the expression levels of IL-6, IL-4, TNF-α, iNOS, IL-17, CC chemokine ligand 2 (CCL2), and CC chemokine receptor 2 (CCR2). CCL2 recognizes CCR2 and stimulates inflammatory cells, enhancing the inflammatory response. Increased CCL2 expression correlates with heightened inflammation and dendritic cell infiltration in ACD, while downregulation of CCL2 attenuates inflammation. Thus, the combined use of crisaborole and vitamin D demonstrates superior therapeutic efficacy over monotherapy in a mouse model of ACD. The combination of vitamin D and crisaborole significantly reduces inflammation and epidermal hyperkeratosis in a mouse model of allergic contact dermatitis, demonstrating superior therapeutic efficacy compared to either treatment alone. This suggests that the combined therapy could be a promising approach for the prevention and treatment of allergic contact dermatitis.

Monocyte-to-HDL cholesterol ratio and uric acid-to-HDL cholesterol ratio as predictors of vitamin D deficiency in healthy young adults: a cross-sectional study

Objective

This study aimed to assess vitamin D deficiency in a cohort of healthy young adults using the novel inflammatory parameters neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), monocyte-to-high-density lipoprotein (HDL) cholesterol ratio (MHR), and uric acid-to-HDL cholesterol ratio (UHR).

Subjects and methods

The study included 1,190 participants, with demographic and laboratory data retrieved retrospectively from our institution's database. The inclusion criteria were ages 22-35 years; absence of acute, subacute, or chronic diseases; no regular medication use; and laboratory values within specified reference ranges. The exclusion criteria were pregnancy, diagnosis of malignancy, and laboratory measurements indicating infection. Participants were categorized into four groups based on vitamin D levels for comparative analysis of study parameters. Correlation analyses were conducted between these parameters and 25-hydroxyvitamin D levels, followed by receiver-operating characteristic analyses to determine the parameters' sensitivity and specificity in detecting vitamin D deficiency. Additionally, regression analyses were performed to identify potential risk factors for vitamin D deficiency.

Results

Subjects in Groups A1 and A2 exhibited higher MHR and UHR than those in Groups A3 and A4 (p < 0.001). Both MHR and UHR correlated negatively with vitamin D levels (r = -0.377 and r = -0.363, respectively; p < 0.001). The area under the curve for MHR was 0.766 (95% confidence interval [CI] 0.739-0.794), with a 79% sensitivity and 61% specificity for identification of vitamin D deficiency. Increased MHR and UHR were independent risk factors for vitamin D deficiency (β = 0.219, odds ratio 1.244 95% CI 1.178-1.315, and β = 2.202, odds ratio 1.224, 95% CI 1.150-1.303).

Conclusions

Both MHR and UHR can be useful in predicting vitamin D deficiency in healthy young adults and may serve as valuable screening tools.

Effects of the COVID-19 pandemic on serum vitamin D concentration in Korean children

PURPOSE

Social distancing policies and school closures in South Korea induced by coronavirus disease 2019 have raised concerns about a lower chance of exposure to sunlight in children and adolescents. This study investigates changes in the vitamin D status of children and adolescents following the pandemic.

METHODS

This retrospective study includes healthy children aged 3-18 years who visited Hanyang University Hospitals in Seoul or Guri during pre-coronavirus disease 2019 (COVID-19) and post-COVID-19 pandemic periods. August 2017 to July 2019 is defined as the pre-COVID-19 pandemic period, while the period from July 2020 to July 2021 is defined as post-COVID-19 or "during the pandemic." Propensity scores were used to match the prepandemic and pandemic groups 1:1 based on age, sex, season of blood collection, and body mass index z-score to compare vitamin D status among subjects.

RESULTS

Among 786 eligible children, 506 were matched using propensity scores. There were no significant differences in mean serum 25-hydroxyvitamin D (25(OH) D) levels (20.1±6.5 ng/mL vs. 19.9±6.3 ng/mL, P>0.05) or vitamin D deficiency rates (53.0% vs. 54.9%, P>0.05) between the prepandemic and pandemic groups. Seasonal analysis revealed lower mean serum 25(OH)D levels during the pandemic in winter/spring seasons in comparison to these levels in subjects in prepandemic winter/spring seasons (19.1±3.8 ng/mL vs. 17.2±3.7 ng/mL, P=0.006).

CONCLUSION

During the COVID-19 pandemic, Korean children and adolescents showed similar serum 25(OH)D levels and vitamin D status to the prepandemic period, with a significant decrease in these measures observed in winter/spring seasons only. Prolonged confinement, such as in pandemic circumstances, underscores the need for vigilant monitoring of vitamin D status and supplementation, particularly in high-risk seasons.

New evidence that vitamin D prevents headache: a bidirectional two-sample Mendelian randomization analysis

Background

Previous observational clinical studies and meta-analyses have yielded inconsistent results regarding the relationship between vitamin D and headache, and the causal relationship remains unclear. The aim of this study was to investigate the causal relationship between vitamin D and headache by bidirectional two-sample Mendelian randomisation (MR) analysis.

Methods

The relationship between high levels of vitamin D and headache was investigated by two-sample MR analysis using publicly available genome-wide association study (GWAS) data. The primary method was inverse variance weighting (IVW), and secondary methods were weighted median and MR-Egger methods. No heterogeneity or horizontal multidirectionality was found in the MR results. The robustness and validity of the findings were assessed using the leave-behind method.

Results

A significant causal relationship was found between high vitamin D levels and headache using the IVW method (OR = 0.848; p = 0.007; 95% CI = 0.752-0.956). However, in a reverse analysis, no evidence of a causal relationship between headache and high levels of vitamin D was found using the IVW method (OR = 1.001; p = 0.906; 95% CI = 0.994-1.006). Our MR analyses showed no significant horizontal multidimensionality or heterogeneity (p > 0.05). Sensitivity analyses confirmed that MR estimates were not affected by single nucleotide polymorphisms (SNPs). Confirmation that our results are robust and valid has been obtained by the leave-one-out method.

Conclusion

Our study suggests that high levels of vitamin D prevent the risk of headache. However, there is no evidence of a causal relationship between headache and high levels of vitamin D. Vitamin D may reduce the risk of headache.

Chronic Atrophic Autoimmune Gastritis: The Evolving Role of Vitamin D

Vitamin D possesses a crucial role in preserving bone health, modulating the immune system responses, and supporting various physiological functions throughout the body. Chronic atrophic autoimmune gastritis (CAAG) constitutes an autoimmune condition marked by inflammation and damage to the stomach cells, often resulting in a decreased ability to absorb certain nutrients, including vitamin B12 and iron. Although, vitamin D is not directly affected by this condition, the sufficiency of this micronutrient seems to have important implications for overall health and management of the disease. The aim of the current review was to assess the incidence and related features of vitamin D deficiency in patients with CAAG and to elucidate the complex regulatory role of this nutrient, in an effort to improve patient outcomes. Vitamin D greatly contributes to the regulation of the immune system. In patients with CAAG, the immune system attacks the stomach lining; thus, the maintenance of a healthy and balanced immune response is important. In autoimmune conditions such as CAAG, where inflammation plays a decisive role in disease progression, vitamin D could potentially exert a role in managing and controlling the associated symptoms. Adequate vitamin D levels may help in regulating the immune response and reducing inflammation. In addition, patients with CAAG are at risk of nutrient deficiencies, including vitamin B12 and iron, which can lead to anemia and bone health issues. As vitamin D is critical for calcium absorption and bone health, assurance of sufficient levels of this micronutrient can be beneficial in preventing or mitigating bone-related complications. In conclusion, regular monitoring of vitamin D levels, among other nutrients, and appropriate supplementation, when necessary, can help improve overall health and well-being in these patients.

Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline

BACKGROUND

Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain.

OBJECTIVE

To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing.

METHODS

A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D.

RESULTS

The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity.

CONCLUSION

The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.

Association Among Vitamin D Supplementation, Serum 25(OH)D Concentrations, and Mortality Risk: A Prospective Cohort Study Using NHANES 2007-2018 Data

BACKGROUND

To determine the associations among self-reported vitamin D (VD) supplementation, measured serum 25-hydroxyvitamin D (25[OH]D) concentrations, and all-cause and cause-specific mortality risks.

METHODS

Self-reported VD supplementation, serum 25(OH)D concentration, and all-cause and cause-specific mortality data from the National Health and Nutrition Examination Survey 2007-2018 were examined for 10,793 adults ≥20 years from the United States. VD dosage was categorized as <800 or ≥800 IU/d. The mortality status and causes of mortality up to 2019 were determined using the National Death Index. The relationships among VD, 25(OH)D levels, and mortality were analyzed using Cox regression before and after propensity score matching (PSM).

RESULTS

Over a median of 6.6 years, 915 deaths were recorded, 230 because of cardiovascular disease (CVD), 240 because of cancer, and 445 because of other specific causes. Mortality risk did not differ between VD <800 IU/d and ≥800 IU/d before or after PSM. However, serum 25(OH)D concentrations were statistically different before and after PSM. The upper 2 quartiles of 25(OH)D levels were associated with lower all-cause mortality, and the fourth quartile was associated with reduced other-specific mortality before and after PSM. No correlation was found between the 25(OH)D concentration and CVD- or cancer-specific mortality after PSM. The inverse 25(OH)D-mortality relationship was consistent across subgroups.

CONCLUSIONS

Based on this large cohort study, higher 25(OH)D levels are robustly associated with reduced all-cause and other specific mortality but not CVD- or cancer-specific mortality. These findings support the benefits of maintaining adequate VD status for longevity. Further research is required to elucidate these mechanisms and define the optimal VD concentration to reduce mortality. These results underscore the importance of public health strategies for preventing VD deficiency.

Vitamin D and Atherosclerosis: Unraveling the Impact on Macrophage Function

Vitamin D plays a crucial role in preventing atherosclerosis and in the regulation of macrophage function. This review aims to provide a comprehensive summary of the clinical evidence regarding the impact of vitamin D on atherosclerotic cardiovascular disease, atherosclerotic cerebrovascular disease, peripheral arterial disease, and associated risk factors. Additionally, it explores the mechanistic studies investigating the influence of vitamin D on macrophage function in atherosclerosis. Numerous findings indicate that vitamin D inhibits monocyte or macrophage recruitment, macrophage cholesterol uptake, and esterification. Moreover, it induces autophagy of lipid droplets in macrophages, promotes cholesterol efflux from macrophages, and regulates macrophage polarization. This review particularly focuses on analyzing the molecular mechanisms and signaling pathways through which vitamin D modulates macrophage function in atherosclerosis. It claims that vitamin D has a direct inhibitory effect on the formation, adhesion, and migration of lipid-loaded monocytes, thus exerting anti-atherosclerotic effects. Therefore, this review emphasizes the crucial role of vitamin D in regulating macrophage function and preventing the development of atherosclerosis.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system’s surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system's surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.

1,25 dihydroxyvitamin D3-mediated effects on bovine innate immunity and on biofilm-forming Staphylococcus spp. isolated from cattle with mastitis

Mastitis is one the most widespread and serious diseases in dairy cattle. Recurrent and chronic infections are often attributable to certain pathogenicity mechanisms in mastitis-causing pathogens such as Staphylococcus spp. These include growing in biofilm and invading cells, both of which make it possible to resist or evade antimicrobial therapies and the host's immune system. This study tested the effects of active vitamin D3 (i.e., calcitriol or 1,25-dihydroxyvitamin D3) on the internalization and phagocytosis of biofilm-forming Staphylococcus spp. isolated from animals with mastitis. Two established bovine cell lines were used: MAC-T (mammary epithelial cells) and BoMac (macrophages). Calcitriol (0-200 nM) did not affect the viability of MAC-T cells nor that of BoMac cells after 24 and 72 h. Concentrations of 0-100 mM for 24 h upregulated the expression of 24-hydroxylase in MAC-T cells, but did not alter that of VDR. Pre-treatment of the cells with calcitriol for 24 h decreased the internalization of S. aureus V329 into MAC-T cells (0-100 nM), and stimulated the phagocytosis of the same strain and of S. xylosus 4913 (0-10 nM). Calcitriol and two conditioned media, obtained by treating the cells with 25-200 nM of the metabolite for 24 h, were also assessed in terms of their antimicrobial and antibiofilm activity. Neither calcitriol by itself nor the conditioned media affected staphylococcal growth or biofilm formation (0-200 nM for 12 and 24 h, respectively). In contrast, the conditioned media (0-100 nM for 24 h) decreased the biomass of preformed non-aureus staphylococcal biofilms and killed the bacteria within them, without affecting metabolic activity. These effects may be mediated by reactive oxygen species and proteins with antimicrobial and/or antibiofilm activity. In short, calcitriol could make pathogens more accessible to antimicrobial therapies and enhance bacterial clearance by professional phagocytes. Moreover, it may modulate the host's endogenous defenses in the bovine udder and help combat preformed non-aureus staphylococcal biofilms (S. chromogenes 40, S. xylosus 4913, and/or S. haemolyticus 6). The findings confirm calcitriol's potential as an adjuvant to prevent and/or treat intramammary infections caused by Staphylococcus spp., which would in turn contribute to reducing antibiotic use on dairy farms.

Dietary intakes of vitamin D promote growth performance and disease resistance in juvenile grass carp (Ctenopharyngodon idella)

Vitamin D3 (VD3) is an essential nutrient for fish and participates in a variety of physiological activities. Notably, both insufficient and excessive supplementation of VD3 severely impede fish growth, and the requirements of VD3 for fish vary considerably in different species and growth periods. The present study aimed to evaluate the appropriate requirements of VD3 for juvenile grass carp (Ctenopharyngodon idella) according to growth performance and disease prevention capacity. In this study, diets containing six supplemental levels of VD3 (0, 300, 600, 1200, 2400, and 4800 IU/kg diet) were formulated to investigate the effect(s) of VD3 on the growth performance, antioxidant enzyme activities, and antimicrobial ability in juvenile grass carp. Compared with the VD3 deficiency group (0 IU/kg), the supplementation of 300-2400 IU/kg VD3 significantly enhanced growth performance and increased antioxidant enzyme activities in the fish liver. Moreover, dietary supplementation of VD3 significantly improved the intestinal health by manipulating the composition of intestinal microbiota in juvenile grass carp. In agreement with this notion, the mortality of juvenile grass carp fed with dietary VD3 was much lower than that in VD3 deficient group upon infection with Aeromonas hydrophila. Meanwhile, dietary supplementation of 300-2400 IU/kg VD3 reduced bacterial load in the spleen and head kidney of the infected fish, and 1200 IU/kg VD3 supplementation could decrease enteritis morbidity and increase lysozyme activities in the intestine. These findings strengthened the essential role of dietary VD3 in managing fish growth and antimicrobial capacity. Additionally, based on weight gain ratio and lysozyme activities, the appropriate VD3 requirements for juvenile grass carp were estimated to be 1994.80 and 2321.80 IU/kg diet, respectively.

Emerging Parameters Justifying a Revised Quality Concept for Cow Milk

Milk has become a staple food product globally. Traditionally, milk quality assessment has been primarily focused on hygiene and composition to ensure its safety for consumption and processing. However, in recent years, the concept of milk quality has expanded to encompass a broader range of factors. Consumers now also consider animal welfare, environmental impact, and the presence of additional beneficial components in milk when assessing its quality. This shifting consumer demand has led to increased attention on the overall production and sourcing practices of milk. Reflecting on this trend, this review critically explores such novel quality parameters, offering insights into how such practices meet the modern consumer's holistic expectations. The multifaceted aspects of milk quality are examined, revealing the intertwined relationship between milk safety, compositional integrity, and the additional health benefits provided by milk's bioactive properties. By embracing sustainable farming practices, dairy farmers and processors are encouraged not only to fulfill but to anticipate consumer standards for premium milk quality. This comprehensive approach to milk quality underscores the necessity of adapting dairy production to address the evolving nutritional landscape and consumption patterns.

Protective Effects of Dietary Vitamin D3, Turmeric Powder, and Their Combination against Gasoline Intoxication in Rats

The inhalation of gasoline vapors (GV) is associated with developing various pathologies. Particularly, oil refinery and gas station workers are at a greater risk of developing lung cancer, kidney cancer, bladder cancer, and hematological disorders, including acute myeloid leukemia. Therefore, preventing the harmful effects of GV and alleviating their consequences appear to be important and timely issues. In this study, we investigated the potential of vitamin D3, turmeric powder, and their combination to ameliorate the toxicity of gasoline fumes in rats. Separate groups of animals fed with a standard rodent diet, with or without the supplementation of vitamin D3 (750 IU/kg body weight) and/or turmeric powder (0.5%, w/w, in food), were untreated or treated with GV (11.5 ± 1.3 cm3/h/m3/day) for 30, 60, or 90 days. Changes in the body weight were monitored weekly. Histological, biochemical, and hematological parameters were determined at the end of each treatment period. While the exposure of rats to GV resulted in a time-dependent reduction in body weight, supplementation with vitamin D3, but not with turmeric root powder or their combination, partially prevented weight loss. Macroscopical and histological analyses showed pronounced time-dependent changes in the organs and tissues of GV-treated rats. These included alveolar wall collapse in the lungs, the destruction of the lobular structure and hepatocytolysis in the liver, the shrinkage and fragmentation of glomeruli in the kidneys, and the disorganization of the lymphoid follicles in the spleen. However, co-treatment with the nutritional supplements tested, especially vitamin D3, noticeably alleviated the above conditions. This was accompanied by a significant improvement in the blood chemistry and hematological parameters. Collectively, our results demonstrate that the harmful effects of environmental exposure to GV can be reduced upon supplementation of vitamin D3. The fact that the protective activity of vitamin D3 alone was higher than that of turmeric root powder or the combined treatment suggests that combinations of these supplements may not always be more beneficial than each agent applied separately.

Evaluating the Impact of Vitamin D3 on NF-κB and JAK/STAT Signaling Pathways in Drosophila melanogaster

This study delved into the consequences of prolonged administration of vitamin D3 on innate immune systems, particularly NF-κB and JAK/STAT, in Drosophila melanogaster. The outcomes indicated that vitamin D3 treatment exhibited a notable capacity to improve the survival of adult flies with compromised immune functions, a condition induced by the loss of PGRP-LB, particularly when the flies were exposed to heat-killed Escherichia coli. The PGRP-LBΔ mutant line that was treated with heat-killed E. coli experienced reduced survival. Treatment of heat-killed E. coli-treated PGRP-LBΔ with vitamin D3 resulted in improved survival, and this phenotypic feature might be due to the downregulation of gene expression in the NF-κB and JAK/STAT pathways. However, a higher concentration of vitamin D3 was associated with decreased survival, potentially linked to intricate immunological responses. The research also underscored the influence of vitamin D3 on the expression of antioxidant genes, sod1 and sod2, indicating an augmented resistance to oxidative stress. Further, this study revealed the effect of vitamin D3 on the reproductive status of the autoinflammatory model, showing an increase in pupae and adult flies with a treatment of 10 mM vitamin D3, suggesting the potential benefits of vitamin D3 on the reproductive profile. Overall, this study provides preliminary insights into the complex interactions between vitamin D3, immune pathways, oxidative responses in the cell, and reproduction in Drosophila.

Pulmonary tuberculosis epidemiology and genetics in Kazakhstan

Background

Tuberculosis (TB) is a major public health emergency in many countries, including Kazakhstan. Despite the decline in the incidence rate and having one of the highest treatment effectiveness in the world, the incidence rate of TB remains high in Kazakhstan. Social and environmental factors along with host genetics contribute to pulmonary tuberculosis (PTB) incidence. Due to the high incidence rate of TB in Kazakhstan, our research aimed to study the epidemiology and genetics of PTB in Kazakhstan.

Materials and methods

1,555 participants were recruited to the case-control study. The epidemiology data was taken during an interview. Polymorphisms of selected genes were determined by real-time PCR using pre-designed TaqMan probes.

Results

Epidemiological risk factors like diabetes (χ2 = 57.71, p < 0.001), unemployment (χ2 = 81.1, p < 0.001), and underweight-ranged BMI (<18.49, χ2 = 206.39, p < 0.001) were significantly associated with PTB. VDR FokI (rs2228570) and VDR BsmI (rs1544410) polymorphisms were associated with an increased risk of PTB. A/A genotype of the TLR8 gene (rs3764880) showed a significant association with an increased risk of PTB in Asians and Asian males. The G allele of the rs2278589 polymorphism of the MARCO gene increases PTB susceptibility in Asians and Asian females. VDR BsmI (rs1544410) polymorphism was significantly associated with PTB in Asian females. A significant association between VDR ApaI polymorphism and PTB susceptibility in the Caucasian population of Kazakhstan was found.

Conclusion

This is the first study that evaluated the epidemiology and genetics of PTB in Kazakhstan on a relatively large cohort. Social and environmental risk factors play a crucial role in TB incidence in Kazakhstan. Underweight BMI (<18.49 kg/m2), diabetes, and unemployment showed a statistically significant association with PTB in our study group. FokI (rs2228570) and BsmI (rs1544410) polymorphisms of the VDR gene can be used as possible biomarkers of PTB in Asian males. rs2278589 polymorphism of the MARCO gene may act as a potential biomarker of PTB in Kazakhs. BsmI polymorphism of the VDR gene and rs2278589 polymorphism of the MARCO gene can be used as possible biomarkers of PTB risk in Asian females as well as VDR ApaI polymorphism in Caucasians.

Vitamin D effects on Chlamydia trachomatis infection: a case-control and experimental study

Introduction

Vitamin D deficiency is the most common nutritional deficiency worldwide. Chronic vitamin D deficiency causes immune system dysfunction, which increases susceptibility to pathogens such as bacteria, especially intracellular parasites, and viruses. Chlamydia trachomatis (C. t) is an obligate intracellular parasitic bacterium that causes a variety of sequelae. We speculated that vitamin D might be associated with C. t infection. This study aimed to address this gap in knowledge by investigating the relationship between vitamin D and C. t infection using both in vitro and in vivo models.

Methods and results

The addition of calcitriol to McCoy cell culture in vitro delayed and reduced the quantity and volume of inclusions compared to the control group. Macrophages of peritoneally lavaged mice co-cultured with McCoy decreased the infection rate and delayed the appearance of inclusions. In mice models of vitamin D deficiency, mice in the VD-group exhibited more severe genital tract inflammation and a longer duration of infection after inoculation with C. t in the genital tract. Supplementing these mice with vitamin D3 during treatment enhanced the therapeutic effect of antibiotics. We also conducted a case-control study involving 174 C. t-positive patients (95 males and 79 females) and 380 healthy volunteers (211 males and 169 females) aged 20-49 from January 2016 to March 15, 2017. Serum 25-(OH)D concentration was measured by assessing morning fasting blood samples of healthy volunteers and C. t-positive patients 1 day before antibiotic treatment and the next day after one course of treatment. The patients were followed up for 1 month and evaluated for recovery. The results showed that vitamin D deficiency was a risk factor for C. t infection and treatment failure.

Conclusion

In summary, findings from experimental and clinical studies indicate a close association between vitamin D levels and C. t infection and treatment outcomes. Given the affordability and safety of vitamin D, both healthy individuals and patients should focus on vitamin D intake. Vitamin D supplementation could enhance treatment success and should be used as an adjunctive therapy alongside antibiotic therapy for C. t infections, pending confirmation in larger, prospective, randomized controlled trials.