Immune Modulatory Effects of Vitamin D on Viral Infections

Klotho protein: A key modulator of aging and COVID-19 severity

The COVID-19 pandemic has drawn significant attention to factors affecting disease severity, especially in older adults. This study explores the relationship between Klotho, an anti-aging protein, and COVID-19 severity. Conducted at Tehran's Firouzgar Hospital, this case-control study involved 279 participants, assessing serum levels of Klotho, inflammatory markers (C-reactive protein (CRP), Interleukin 6 (IL-6)), and Vitamin D. The findings indicate significantly lower Klotho levels in COVID-19 patients, especially those in the ICU, which correlate with elevated inflammatory markers and reduced Vitamin D levels. This inverse relationship between Klotho levels and disease severity underscores the protein's potential modulatory role in the inflammatory response to COVID-19. The study not only highlights the importance of Klotho as a biomarker for aging and disease severity but also suggests its potential therapeutic value in managing COVID-19, offering a novel perspective on targeting aging-related pathways to mitigate the impact of the disease. These insights open new avenues for research and intervention strategies to leverage anti-aging mechanisms to combat COVID-19 and potentially other age-related diseases.

Higher vulnerability to poor circadian light hygiene in individuals with a history of COVID-19

Seven-day actigraphy was performed within 1 month in 122 community-dwelling adults (mean age 24.40 y, 31 (25.4%) men) in the same city of Tyumen, Russia. Groups with different COVID-19 status (present, COVID-19(+), n = 79 vs absent, COVID-19(-), n = 43) did not differ in mean age, gender distribution, or body mass index. Vaccination status was equally represented in the COVID groups. We found that COVID-19 status, a history of SARS-CoV-2 infection, was differentially associated with daylight susceptibility. Daylight exposure was estimated using parametric and non-parametric indices: 24-h Amplitude, MESOR or M10 of white and blue light exposure (BLE) and compared between the groups. Distinctively in COVID-19(+) individuals, a smaller normalized 24-h amplitude of BLE (NAbl) was associated with lower circadian robustness, assessed by a smaller relative non-parametric amplitude (RA), a lower circadian function index (CFI), later bedtime, later onset of least active 5 h (L5), shorter total sleep duration, later phase and smaller circadian amplitude of physical motor activity. Such associations were absent in the overall COVID-19(-) population or in the vaccinated COVID(-) group. Considering COVID-status and light hygiene, defined as NAbl ≥ 1 versus NAbl < 1, only those with COVID(+) and NAbl < 1 (poorer light hygiene) had a statistically significantly delayed phase of activity and sleep, reduced circadian amplitude of physical activity, and lower circadian robustness. Accounting for gender and BMI, participants diagnosed with COVID-19 at an earlier date were older and had poorer circadian light hygiene. Altogether, our data suggest that those with COVID-19 were more vulnerable to circadian disruption due to poor circadian light hygiene, manifested as phase delay, small amplitude, a less robust circadian pattern of activity, and as delayed sleep. Our data suggest that the need for optimal circadian light hygiene is greater in individuals with a history of SARS-CoV-2 infection.

Immunomodulatory Effects of Vitamin D and Zinc on Viral Infection

Several nutrients are crucial in enhancing the immune system and preserving the structural integrity of bodily tissue barriers. Vitamin D (VD) and zinc (Zn) have received considerable interest due to their immunomodulatory properties and ability to enhance the body's immune defenses. Due to their antiviral, anti-inflammatory, antioxidative, and immunomodulatory properties, the two nutritional powerhouses VD and Zn are crucial for innate and adaptive immunity. As observed with COVID-19, deficiencies in these micronutrients impair immune responses, increasing susceptibility to viral infections and severe disease. Ensuring an adequate intake of VD and Zn emerges as a promising strategy for fortifying the immune system. Ongoing clinical trials are actively investigating their potential therapeutic advantages. Beyond the immediate context of the pandemic, these micronutrients offer valuable tools for enhancing immunity and overall well-being, especially in the face of future viral threats. This analysis emphasizes the enduring significance of VD and Zn as both treatment and preventive measures against potential viral challenges beyond the current health crisis. The overview delves into the immunomodulatory potential of VD and Zn in combating viral infections, with particular attention to their effects on animals. It provides a comprehensive summary of current research findings regarding their individual and synergistic impacts on immune function, underlining their potential in treating and preventing viral infections. Overall, this overview underscores the need for further research to understand how VD and Zn can modulate the immune response in combatting viral diseases in animals.

Comparison of the role of vitamin D in normal organs and those affected by COVID-19

The outbreak of COVID-19 has opened up new avenues for exploring the importance of vitamin D in immunity, in addition to its role in calcium absorption. Recently, vitamin D supplementation has been found to enhance T regulatory lymphocytes, which are reduced in individuals with COVID-19. Increased risk of pneumonia and increases in inflammatory cytokines have been reported to be major threats associated with vitamin-D deficiency. Although vaccination reduces the threat of COVID-19 to a certain extent, herd immunity is the long-term solution to overcoming such diseases. Co-administration of vitamin D with certain inactivated vaccines has been reported to enhance the systemic immune response through stimulation of the production of antigen-specific mucosal immunity. COVID-19 was found to induce multiple organ damage, and vitamin D has a beneficial role in various organs, such as the intestines, pancreas, prostate, kidneys, liver, heart, brain, and immune cells. The consequences that occur after COVID-19 infection known as long COVID-19 are also a concern as they accumulate and target multiple organs, leading to immune dysregulation. The present review covers the overall role and impact of vitamin D and its deficiency for various organs in normal conditions and after COVID-19 infection, which is still a serious issue.

Lack of Association between Vitamin D Genetic Polymorphism and Virological Characteristics of Hepatitis B Infection

BACKGROUND

Exploring polymorphisms in vitamin D-related genes (VDR) within the Brazilian population provides a valuable model to contribute to the influence of the host genetic variants on chronic viral hepatitis B (CHB).

METHODS

126 CHB patients were enrolled in the current study and clinical, laboratory, and 25-hydroxyvitamin D [25(OD)D] level data were obtained. Four VDR (rs7975232, rs1544410, rs10735810, rs731236) and 2 vitamin D-binding protein/carrier globulin (GC) polymorphisms (rs4588 and rs7041) were determined using TaqMan assays and nucleotide sequencing. Association studies were conducted among viral infection parameters and the patient's genetic variants.

RESULTS

Most patients were male (52.38%) with a mean age of 44.28 (±14.24) years, self-identified as White (32.54%), and exhibited vitamin D insufficiency status (42.06%). The hepatitis B virus (HBV) genotype A was predominant (50%) and 62.7% of the patients had detectable HBV DNA levels ≤log10 3 IU/mL. A significant association was observed between HBV genotype A with ApaI and FokI single nucleotide polymorphisms. However, no statistical association between VDR polymorphisms and viral load, viral polymerase mutations, or vitamin D status was found. Vitamin D concentration did not correlate to HBV viral load.

CONCLUSIONS

Most HBV-infected individuals presented vitamin D insufficiency, and VDR polymorphism was not associated with virological characteristics except with HBV genotype A, demonstrating that some human genetic signatures are related to HBV genotype distribution.

Association of Vitamin D Status with Immune Markers in a Cohort of Healthy Adults

BACKGROUND

Immune function is affected by vitamin D status, but the optimal serum 25-hydroxy vitamin D [25(OH)D] concentration for immune function is not known.

OBJECTIVES

We hypothesized that 25(OH)D would be associated with markers of inflammation and immune activation.

METHODS

We identified associations between 25(OH)D and immune markers from 361 healthy adults using polynomial regression. Linear regression was used to define the slope (β) of significant linear associations, and piecewise regression identified inflection points (IPs) for curvilinear associations with P < 0.05. IPs with a slope difference (SD) P < 0.05 before and after were significant.

RESULTS

25(OH)D had linear, negative associations with interleukin (IL)-6 (β: -0.126; P = 0.009) and macrophage-derived chemokine (MDC) (β: -0.108; P = 0.04) and a linear, positive association with matrix metalloproteinase (MMP)-1 (β: 0.108; P = 0.04). Among the significant curvilinear associations, 2 showed negative associations below but positive associations above an IP with nearly significant SD P values, including percentage of effector-memory CD8 T cells (IP: 56.2 nmol/L; SD P = 0.067) and platelet concentration (IP: 38.9 nmol/L; SD P = 0.058). The opposite associations, positive below and negative above an IP, were seen for eotaxin (IP: 49.5 nmol/L; SD P = 0.049); interferon (IFN)-γ-induced protein-10 (IP-10) (IP: 71.8 nmol/L; SD P = 0.02); percentage of CD4 T cells expressing programmed cell death protein (PD)-1 (IP: 71.2 nmol/L; SD P = 0.01); percentage of Tregs expressing human leukocyte antigen, DR isotype (HLA-DR) (IP: 67.5 nmol/L; SD P < 0.0001); percentage of memory Tregs (IP: 68.8 nmol/L; SD P = 0.002); and percentage of memory Tregs expressing HLA-DR (IP: 68.8 nmol/L; SD P = 0.0008).

CONCLUSIONS

These findings are consistent with low vitamin D status allowing and higher vitamin D status dampening inflammation and immune activation. IP analysis identified possible thresholds for vitamin D effects on immune function. Two of 3 IPs at ∼50 nmol/L show higher inflammation below this concentration, suggesting 50 nmol/L as a minimum target for dampening inflammation. IPs at ∼70 nmol/L identify a threshold for CD4 T-cell activity, including Treg activation and IFN-γ-driven production of the T-cell chemokine IP-10, suggesting an optimal concentration for regulating adaptive immunity. This study was registered at clinicaltrials.gov as NCT02367287.

The Synergic Immunomodulatory Effect of Vitamin D and Chickpea Protein Hydrolysate in THP-1 Cells: An In Vitro Approach

Vitamin D (VD), a crucial micronutrient, regulates bone health and immune responses. Recent studies suggest that VD may confer protective effects against chronic inflammatory diseases. Additionally, plant-based peptides can show biological activities. Furthermore, the supplementation of protein hydrolysates with VD could potentially enhance the bioactivity of peptides, leading to synergistic effects. In this study, THP-1 cells were exposed to low concentrations of Lipopolysaccharide (LPS) to induce inflammation, followed by treatment with vitamin D at different concentrations (10, 25, or 50 nM) or a chickpea protein hydrolysate ("H30BIO") supplemented with VD. The cytotoxicity of VD was evaluated using viability assay to confirm its safety. The cytokine secretion of TNF-α, IL-1β, and IL6 was assessed in the cell supernatant, and the gene expression of TNF-α, IL-1β, IL6, IL8, CASP-1, COX2, NRF2, NF-ĸB, NLRP3, CCL2, CCR2, IP10, IL10, and RANTES was quantified by qRT-PCR. Treatment with VD alone significantly decreased the expression of the pro-inflammatory genes TNF-α and IL6, as well as their corresponding cytokine levels in the supernatants. While IL-1β gene expression remained unchanged, a reduction in its cytokine release was observed upon VD treatment. No dose-dependent effects were observed. Interestingly, the combination of VD with H30BIO led to an increase in TNF-α expression and secretion in contrast with the LPS control, coupled with a decrease in IL-1β levels. Additionally, genes such as IP10, NF-κB, CCL2, COX2, NRF2, and CASP-1 exhibited notable modulation, suggesting that the combination treatment primarily downregulates NF-κB-related gene activity. This study demonstrates a synergistic interaction between VD and H30BIO, suggesting that this combination may enhance pathways involving TNF-α, potentially aiding in the resolution and modulation of inflammation through adaptive processes. These findings open new avenues for research into the therapeutic applications of enriched protein hydrolysates with VD to manage low-grade inflammatory-related conditions.

The correlation between vitamin D and the occurrence of peripheral neuropathy induced by paclitaxel chemotherapy

Introduction

Paclitaxel, a widely used chemotherapeutic agent for various cancers, induces peripheral neuropathy (PIPN) in approximately 80% of patients, severely affecting their quality of life. The role of vitamin D in pain perception has gained attention, but its correlation with PIPN remains unclear.

Methods

This study included 129 cancer patients who received adjuvant paclitaxel chemotherapy from January to June 2023. Neuropathic pain was assessed using the Douleur Neuropathique 4 Questions (DN4) questionnaire, and serum levels of vitamin D and glutathione (GSH) were measured to explore the correlation between vitamin D levels and neuropathic pain induced by paclitaxel chemotherapy.

Results

The results showed a negative correlation between vitamin D deficiency and the occurrence of neuropathic pain (Spearman correlation coefficient of -0.324, P < 0.001). The receiver operating characteristic (ROC) curve analysis revealed that the area under the vitamin D curve for neuropathic pain was 0.681. Furthermore, after paclitaxel chemotherapy, there was a significant decrease in GSH levels in the serum of patients, with a more pronounced decline in the vitamin D-deficient group.

Discussion

The findings of this study indicate that higher levels of vitamin D are negatively associated with the occurrence of paclitaxel-induced neuropathic pain, suggesting that vitamin D might protect against oxidative stress. This discovery is significant for clinical treatment as it may help physicians better understand the mechanisms of pain during paclitaxel therapy and provide new strategies for the prevention and treatment of such pain. It also suggests that modulating vitamin D levels could reduce the neurotoxicity of paclitaxel, thereby improving patients' quality of life and treatment compliance.

Associations between traffic-related air pollution and allergic rhinitis outpatient visits in three cities of Gansu Province

Emerging evidence indicates an increasing prevalence of allergic rhinitis (AR), potentially linked to air quality. The aim of the present study was to assess the relationship between traffic-related air pollutants (TRAPs) and outpatient visits for AR. Daily outpatient data for AR, air pollutant concentrations, and meteorological data were collected from January 2018 to December 2020 in Dingxi, Longnan, and Tianshui. Utilizing a Quasi-Poisson distribution, a generalized additive model (GAM) was employed in conjunction with distributed lag non-linear models (DLNM) to explore the association and lag effects of TRAPs on AR outpatient visits across the three cities. Stratified analyses based on gender, age, and season were conducted. A total of 11 106 outpatient visits for AR were recorded in the three cities. For an increase of 10 μg m-3 in PM2.5, the effect estimates in Dingxi, Longnan, and Tianshui reached their maximum at lag04, lag06, and lag07, respectively, with relative risk (RR) values of 4.696 (95% CI: 1.890, 11.614), 2.842 (95% CI: 2.102, 4.922), and 1.102 (95% CI: 1.066, 1.140). For NO2, the highest associations were exhibited in Dingxi (RR = 1.262, 95% CI: 1.081, 1.473) at lag07, in Longnan (RR = 2.554, 95% CI: 2.100, 4.805) at lag06, and in Tianshui (RR = 1.158, 95% CI: 1.106, 1.213) at lag07. Meanwhile, the strongest effects observed for a 1 mg m-3 increase in CO were 2.786 (95% CI: 1.467, 5.291) for Dingxi at lag07, 1.502 (95% CI: 1.096, 2.059) for Longnan at lag05, and 1.385 (95% CI: 1.137, 1.686) for Tianshui at lag04. Adults aged 15-64 years appeared to be more susceptible to TRAPs, and the associations were stronger in the cold season. The results of the present study indicate that exposure to TRAPs was positively correlated with outpatient visits for AR.

Vitamin D supplementation and calcium: Many-faced gods or nobody in fighting against Corona Virus Disease 2019

In December 2019, Corona Virus Disease 2019 (COVID-19) was first identified and designated as a pandemic in March 2020 due to rapid spread of the virus globally. At the beginning of the pandemic, only a few treatment options, mainly focused on supportive care and repurposing medications, were available. Due to its effects on immune system, vitamin D was a topic of interest during the pandemic, and researchers investigated its potential impact on COVID-19 outcomes. However, the results of studies about the impact of vitamin D on the disease are inconclusive. In the present narrative review, different roles of vitamin D regarding the COVID-19 have been discussed to show that vitamin D supplementation should be recommended carefully.

Zika virus infection suppresses CYP24A1 and CAMP expression in human monocytes

Monocytes are the primary targets of Zika virus (ZIKV) and are associated with ZIKV pathogenesis. Currently, there is no effective treatment for ZIKV infection. It is known that 1,25-dihydroxy vitamin D3 (VitD3) has strong antiviral activity in dengue virus-infected macrophages, but it is unknown whether VitD3 inhibits ZIKV infection in monocytes. We investigated the relationship between ZIKV infection and the expression of genes of the VitD3 pathway, as well as the inflammatory response of infected monocytes in vitro. ZIKV replication was evaluated using a plaque assay, and VitD3 pathway gene expression was analyzed by RT-qPCR. Pro-inflammatory cytokines/chemokines were quantified using ELISA. We found that VitD3 did not suppress ZIKV replication. The results showed a significant decrease in the expression of vitamin D3 receptor (VDR), cytochrome P450 family 24 subfamily A member 1 (CYP24A1), and cathelicidin antimicrobial peptide (CAMP) genes upon ZIKV infection. Treatment with VitD3 was unable to down-modulate production of pro-inflammatory cytokines, except TNF-α, and chemokines. This suggests that ZIKV infection inhibits the expression of VitD3 pathway genes, thereby preventing VitD3-dependent inhibition of viral replication and the inflammatory response. This is the first study to examine the effects of VitD3 in the context of ZIKV infection, and it has important implications for the role of VitD3 in the control of viral replication and inflammatory responses during monocyte infection.

The Distinct Regulation of the Vitamin D and Aryl Hydrocarbon Receptors in COVID-19

(1) Background: SARS-CoV-2 affects several immune pathways, including the vitamin D (VDR) and the aryl hydrocarbon receptor pathways (AhR). The aim of the study was the evaluation of the VDR and AhR pathways in the blood of COVID-19 patients with regard to the severity of disease. (2) Methods: Observational, single-center, case-control design. A total of 240 samples were selected for exploration. Patients who tested negative for SARS-CoV-2 but suffered from other respiratory infections (ORIs) served as a control group. (3) Results: VDR-specific mRNA in the blood of patients with mild symptoms (131.2 ± 198.6) was significantly upregulated relative to the VDR expression of the ORI group (23.24 ± 42.60; p < 0.0001); however, VDR expression of critically ill patients showed an impaired upregulation (54.73 ± 68.34; p < 0.001). CYP27B1 expression was not significantly regulated during SARS-CoV-2 infection. There was a downregulation of VDR and CYP27B1 compared to survivors. There was no significant difference in 25(OH)-vitamin D3 levels between critically ill patients with regard to survival (24.3 ± 9.4 vs. 27.1 ± 11.3; p = 0.433). (4) Conclusion: The VDR and AhR pathways are distinctively regulated in patients suffering from COVID-19 depending on the severity of disease. A combination treatment of antiviral drugs and vitamin D substitution should be evaluated for potentially improved prognosis in COVID-19.

Relationship between human papillomavirus and serum vitamin D levels: a systematic review

BACKGROUND

Human papillomavirus (HPV) is one of the most prevalent sexually transmitted diseases worldwide. The present review was conducted to accumulate evidence on the relationship between cervicovaginal human papillomavirus infection and serum vitamin D status.

METHODS

Electronic databases including Web of Science, Embase, Scopus, and PubMed were searched by different combinations of keywords related to "human papillomavirus" and "vitamin D", obtained from Mesh and Emtree with AND, and OR operators without any time restriction until December 24, 2022. Selection of articles was based on the inclusion and exclusion criteria. Newcastle-Ottawa Scale was used for quality assessment. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was applied for reporting.

RESULTS

In total, 276 citations were retrieved. After removing duplicates, and non-related articles, the full texts of 7 articles were reviewed including 11168 participants. Three studies reported that there was a positive relationship between vitamin D deficiency and cervicovaginal human papillomavirus while three studies did not. One study showed a significant positive association between higher vitamin D stores and short-term high-risk human papillomavirus persistence.

CONCLUSIONS

The findings showed no firm evidence for any association between serum vitamin D level and cervicovaginal human papillomavirus infection, although the possible association could not be discarded. Further investigations are needed to reach sound evidence.

Vitamin D Influences the Activity of Mast Cells in Allergic Manifestations and Potentiates Their Effector Functions against Pathogens

Mast cells (MCs) are abundant at sites exposed to the external environment and pathogens. Local activation of these cells, either directly via pathogen recognition or indirectly via interaction with other activated immune cells and results in the release of pre-stored mediators in MC granules. The release of these pre-stored mediators helps to enhance pathogen clearance. While MCs are well known for their protective role against parasites, there is also significant evidence in the literature demonstrating their ability to respond to viral, bacterial, and fungal infections. Vitamin D is a fat-soluble vitamin and hormone that plays a vital role in regulating calcium and phosphorus metabolism to maintain skeletal homeostasis. Emerging evidence suggests that vitamin D also has immunomodulatory properties on both the innate and adaptive immune systems, making it a critical regulator of immune homeostasis. Vitamin D binds to its receptor, called the vitamin D receptor (VDR), which is present in almost all immune system cells. The literature suggests that a vitamin D deficiency can activate MCs, and vitamin D is necessary for MC stabilization. This manuscript explores the potential of vitamin D to regulate MC activity and combat pathogens, with a focus on its ability to fight viruses.

Survival implications vs. complications: unraveling the impact of vitamin D adjunctive use in critically ill patients with COVID-19-A multicenter cohort study

Background

Despite insufficient evidence, vitamin D has been used as adjunctive therapy in critically ill patients with COVID-19. This study evaluates the effectiveness and safety of vitamin D as an adjunctive therapy in critically ill COVID-19 patients.

Methods

A multicenter retrospective cohort study that included all adult COVID-19 patients admitted to the intensive care units (ICUs) between March 2020 and July 2021. Patients were categorized into two groups based on their vitamin D use throughout their ICU stay (control vs. vitamin D). The primary endpoint was in-hospital mortality. Secondary outcomes were the length of stay (LOS), mechanical ventilation (MV) duration, and ICU-acquired complications. Propensity score (PS) matching (1:1) was used based on the predefined criteria. Multivariable logistic, Cox proportional hazards, and negative binomial regression analyses were employed as appropriate.

Results

A total of 1,435 patients were included in the study. Vitamin D was initiated in 177 patients (12.3%), whereas 1,258 patients did not receive it. A total of 288 patients were matched (1:1) using PS. The in-hospital mortality showed no difference between patients who received vitamin D and the control group (HR 1.22, 95% CI 0.87-1.71; p = 0.26). However, MV duration and ICU LOS were longer in the vitamin D group (beta coefficient 0.24 (95% CI 0.00-0.47), p = 0.05 and beta coefficient 0.16 (95% CI -0.01 to 0.33), p = 0.07, respectively). As an exploratory outcome, patients who received vitamin D were more likely to develop major bleeding than those who did not [OR 3.48 (95% CI 1.10, 10.94), p = 0.03].

Conclusion

The use of vitamin D as adjunctive therapy in COVID-19 critically ill patients was not associated with survival benefits but was linked with longer MV duration, ICU LOS, and higher odds of major bleeding.

Vitamin D Deficiency Is Associated with Impaired Sensitivity to Thyroid Hormones in Euthyroid Adults

The relationship between vitamin D deficiency and sensitivity to thyroid hormones was unclear. We aimed to explore the association of 25-hydroxyvitamin D (25(OH)D) levels with thyroid hormone sensitivity in euthyroid adults. A total of 3143 subjects were included. The serum 25(OH)D, free thyroxine (FT3), free thyrotropin (FT4), thyroid-stimulating hormone (TSH), and other clinical variables were measured. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. Thyroid feedback quantile-based index (TFQI), parametric thyroid feedback quantile-based index (PTFQI), thyroid-stimulating hormone index (TSHI), thyrotrophic thyroxine resistance index (TT4RI), and FT3/FT4 were calculated to assess thyroid hormone sensitivity. Results showed that 58.8% of the participants had vitamin D deficiency. They had significantly higher levels of triglyceride, insulin, FT3, FT4, TSH, TFQI, PTFQI, TSHI, and TT4RI and lower levels of high-density lipoprotein cholesterol than those with sufficient vitamin D (all p < 0.05). Logistic regression analysis showed that the risk of impaired sensitivity to thyroid hormones evaluated by TFIQ, PTFQI, TSHI, and TT4RI increased by 68% (OR: 1.68; 95%CI: 1.45-1.95; and p < 0.001), 70% (OR: 1.70; 95%CI: 1.46-1.97; and p < 0.001), 66% (OR: 1.66; 95%CI: 1.43-1.92; and p < 0.001), and 50% (OR: 1.50; 95%CI: 1.30-1.74; and p < 0.001), respectively, in participants with vitamin D deficiency compared with those with sufficient vitamin D after adjusting for multiple confounders. In conclusion, in euthyroid populations, vitamin D deficiency was associated with impaired sensitivity to thyroid hormones.

Piscine Vitamin D Receptors Vdra/Vdrb in the Absence of Vitamin D Are Utilized by Grass Carp Reovirus for Promoting Viral Replication

The vitamin D receptor (VDR) plays a pivotal role in the biological actions of vitamin D (VitD). However, little is known about the functions of VDR in the production of viral inclusion bodies (VIBs). Using a representative strain of grass carp reovirus (GCRV) genotype I, GCRV-873, we show that GCRV-873 recruits grass carp Vdrs for promoting the production of VIBs in the absence of VitD. Inhibition of cholesterol synthesis by lovastatin impairs the production of VIBs and blocks the effects of grass carp Vdrs in promoting the production of VIBs in the absence of VitD. Furthermore, grass carp Vdrs are found to form the Vdra-Vdrb heterodimer, which is vital for 3-hydroxy-3-methylglutaryl-coenzyme A reductase (hmgcr)-dependent cholesterol synthesis and GCRV replication. Intriguingly in the presence of VitD, grass carp Vdra but not Vdrb forms the heterodimer with the retinoid X receptor beta b (Rxrbb), which induces the transcription of those genes involved in the RIG-I-like receptor (RLR) antiviral signaling pathway for inhibiting GCRV infection. Furthermore, the VitD-activated Vdra-Vdrb heterodimer attenuates the transcription of the RLR antiviral signaling pathway induced by VitD. In the presence of VitD, a balance between the Vdra-Rxrbb heterodimers as coactivators and Vdra-Vdrb heterodimers as corepressors in affecting the transcriptional regulation of the RLR antiviral signaling pathway may eventually determine the outcome of GCRV infection. Transfection with VitD can abolish the effect of grass carp Vdrs in promoting GCRV replication in a dose-dependent manner. Taken together, these findings demonstrate that GCRV utilizes host Vdrs to increase hmgcr-dependent cholesterol synthesis for promoting its replication, which can be prevented by VitD treatment. IMPORTANCE Grass carp reovirus (GCRV) is the causative agent of grass carp hemorrhagic disease, which seriously harms freshwater fish. Although many positive or negative regulators of GCRV infection have been identified in teleosts, little is known about the molecular mechanisms by which GCRV utilizes host factors to generate its infectious compartments beneficial for viral replication and infection. Here, we show that in the absence of VitD, the GCRV-873 strain utilizes host vitamin D receptors Vdra/Vdrb to increase hmgcr-dependent cholesterol synthesis for promoting the production of VIBs, which are important functional sites for aquareovirus replication and assembly. The negative regulation of Vdrs during viral infection can be prevented by VitD treatment. Thus, this present work broadens understanding of the pivotal roles of Vdrs in the interaction between the host and GCRV in the absence or presence of VitD, which might provide a rational basis for developing novel anti-GCRV strategies.

Diet, Inflammation, and Infectious Diseases

This Special Issue, "Diet, Inflammation, and Infectious Diseases", focuses on the potential of diet to modulate inflammation and infectious and chronic disease outcomes [...].

Seasonal associations between air pollutants and influenza in 10 cities of southern China

Few studies have explored the associations between air pollutants and influenza across seasons, especially at large scales. This study aimed to evaluate seasons' modifying effects on associations between air pollutants and influenza from 10 cities of southern China. Through scientific evidence, it provides mitigation and adaptation strategies with practical guidelines to local health authorities and environmental protection agencies. Daily influenza incidence, meteorological, and air pollutants data from 2016 to 2019 were collected. Quasi-Poisson regression with a distributed lag nonlinear model was used to evaluate city-specific air pollutants and influenza associations. Meta-analysis was used to pool site-specific estimates. Attributable fractions (AFs) of influenza incidence due to pollutants were calculated. Stratified analyses were conducted by season, sex, and age. Overall, the cumulative relative risk (CRR) of influenza incidence for a 10-unit increase in PM_2.5, PM₁₀, SO₂, NO₂, and CO was 1.45 (95% CI: 1.25, 1.68), 1.53 (95% CI: 1.29, 1.81), 1.87 (95% CI: 1.40, 2.48), 1.74 (95% CI: 1.49, 2.03), and 1.19 (95% CI: 1.04, 1.36), respectively. Children aged 0-17 were more sensitive to air pollutants in spring and winter. PM₁₀ had greater effect on influenza than PM_2.5 in autumn, winter, and overall, lesser in spring. The overall AF due to PM_2.5, PM₁₀, SO₂, NO_2, and CO was 4.46% (95% eCI: 2.43%, 6.43%), 5.03% (95% eCI: 2.33%, 7.56%), 5.36% (95% eCI: 3.12%, 7.58%), 24.88% (95% eCI: 18.02%, 31.67%), and 23.22% (95% eCI: 17.56%, 28.61%), respectively. AF due to O₃ was 10.00% (95% eCI: 4.76%, 14.95%) and 3.65% (95% eCI: 0.50%, 6.59%) in spring and summer, respectively. The seasonal variations in the associations between air pollutants and influenza in southern China would provide evidence to service providers for tailored intervention, especially for vulnerable populations.

Seasonal variation and disease distribution of cytophagocytic mononuclear cells in synovial fluid: A medical record study

Cytophagocytic mononuclear (CPM) cells, previously known as Reiter's cells, are macrophages containing apoptotic polymorphonuclear leucocytes. Although they can be found in synovial fluid (SF) from different arthropathies, their role remains unclear. This study was performed to determine the frequency and disease distribution of CPM cells in SF in a large cohort of patients with rheumatic diseases over a 12-year period. We also investigated the seasonal variation in their incidence. This record review study included the reports pertaining to SF analyses performed between January 2010 and December 2021. Data were retrieved from the charts of inpatients and outpatients at Rheumatology and Emergency Departments of Padova. The total number of SF samples containing CPM cells was 189: 69% was from patients with seronegative spondyloarthritis (SpA), thus indicating a strong association between CPM cells and SpA. SF samples containing CPM cells were predominantly inflammatory. Our analyses demonstrated a 6-month cyclical fluctuation in concentrations of CPM cells, with an increase in spring and autumn. The presence of CPM cells in SF might offer diagnostic insight into the definition of SpA. Further studies are warranted to ascertain the link between CPM cells and the apoptotic process, shedding light on the mechanisms leading to their formation.

Functionalized lipid-based drug delivery nanosystems for the treatment of human infectious diseases

Infectious diseases are still public health problems. Microorganisms such as fungi, bacteria, viruses, and parasites are the main causing agents related to these diseases. In this context, the search for new effective strategies in prevention and/or treatment is considered essential, since current drugs often have side effects or end up, causing microbial resistance, making it a serious health problem. As an alternative to these limitations, nanotechnology has been widely used. The use of lipid-based drug delivery nanosystems (DDNs) has some advantages, such as biocompatibility, low toxicity, controlled release, the ability to carry both hydrophilic and lipophilic drugs, in addition to be easel scalable. Besides, as an improvement, studies involving the conjugation of signalling molecules on the surfaces of these nanocarriers can allow the target of certain tissues or cells. Thus, this review summarizes the performance of functionalized lipid-based DDNs for the treatment of infectious diseases caused by viruses, including SARS-CoV-2, bacteria, fungi, and parasites.

VITAMIN D STATUS IN CHILDREN WITH PARALITIC SYNDROMS

OBJECTIVE

The aim: Determination of serum 25(OH)D in the children with paralytic syndromes and its distribution depending on age, sex, taking anticonvulsant drugs, nutritional status for a period of one year (autumn-spring) of one center.

PATIENTS AND METHODS

Materials and methods: There were recruited of 77 children with paralytic syndromes and 73 health children for the same period aged from 1 till 18 years. The study included a scrutiny of medical history and analysis of medical documents, assessment of motor dysfunction by GMFCS, and nutritional status.

RESULTS

Results: Among children with paralytic syndromes there were spastic tetraparesis 59.7%, malnutrition 92%, IV-V level of gross motor disfunction 80.5%, antiseizure medications 59.7% and cognitive impairment 77.9%. The variation of serum 25(OH)D is from 6.1 to 76.7 ng/mL with median 18.3 ng/mL in healthy children. The variation of serum 25(OH)D is from 2.2 to 83.0 ng/mL with median 14.8 ng/mL in children with paralytic syndromes (p=0.0103). Vitamin status among them is the following: insufficiency (21-29 ng/mL)-28.7% vs 16.8%; deficiency (<20 ng/mL)-56.1 vs 72.2% (p=0.0300). The 25.9% children with paralytic syndromes and those who have deficiency demonstrate severe deficiency (<10 ng/mL) compare 10.9% in healthy children (p=0.00189). There is a tendency to decrease of serum 25(OH)D in children with paralytic syndrome older 7 years.

CONCLUSION

Conclusions: We failed to record a significant difference in the 25(ОН)D between males and females, between different level of GMFCS, and anticonvulsants using. Deficiency of vitamin D in 2.25 times higher in children with paralytic syndromes and severe malnutrition. Additional researches with specific items are need in perspective.

Vitamin D attenuates biofilm-associated infections via immunomodulation and cathelicidin expression: a narrative review

INTRODUCTION

Infections are becoming more difficult to treat, at least partly on account of microbes that produce biofilms. Reports suggest that decreased levels of antimicrobial peptides like cathelicidin, elevated levels of inflammatory cytokines, and biofilm formation are all associated with vitamin D deficiency, making vitamin D - deficient individuals more susceptible to infection. Infections attributable to biofilm-producing microbes can be managed by adjuvant therapy with vitamin D because of its immunomodulatory role, particularly because of the ability of vitamin D-pathway to induce the antimicrobial peptides like cathelicidin and decrease proinflammatory cytokines.

AREAS COVERED

This narrative review covers biofilm formation, infections associated with biofilm due to vitamin D deficiency, putative role of vitamin D in host protection and the effect of vitamin D supplementation in biofilm-associated infections. A comprehensive literature search in PubMed and Google Scholar utilizing suitable keywords at multiple time points extracted relevant articles.

EXPERT OPINION

Although vitamin D deficiency has been associated with infections by biofilm producing microbes, comprehensive clinical trials in various ethnicities are required to understand the likely relationships between vitamin D receptor gene expression, cathelicidin levels, and infection outcome. Current evidence hypothesizes that maintaining normal vitamin D level can help prevent and treat these infections.

Association of Serum Vitamin D level and COVID-19 infection: A Case-control Study

BACKGROUND

Vitamin D is considered a potent modulator of the immune system, albeit its role in COVID-19 infection is a matter of debate. The present study aimed to estimate the association between serum vitamin D levels and COVID-19 among people in Qatar.

METHODS

This case-control study, approved by the Institutional Review Board of Primary Health Care Corporation (PHCC) Qatar, retrospectively evaluated the principal public healthcare sector population data repository retrieved from the cloud-based Electronic Health Record (EHR) software-Cerner, during April 2020-2021. The health records of all adult patients aged >18 years who had undergone the reverse transcription-polymerase chain reaction (RT-PCR) test and whose medical records had documented serum 25-hydroxyvitamin D [25 (OH)D] levels were analyzed.

RESULTS

A total of 924,173 EHRs were extracted, of which 62,451 EHR comprised of 16,446 (26.3%) COVID-19 patients and 46,005 (73.7%) negative-control group patients met the inclusion criteria. The odds ratio (OR) among different categories of vitamin D deficiency (VDD) revealed that people with mild/moderate VDD were 1.18 times (95% CI 1.126-1.258) and those with severe VDD were 1.90 times (95% CI 1.116-1.251) more likely to have COVID-19 infection when compared to the people with optimal serum vitamin D level. On applying multiple logistic regression, the odds of having COVID-19 infection were found to be 1.27 times (95% CI 1.184-1.371) higher among those with mild/moderate VDD and 1.32 times (95% CI 1.206-1.405) higher among those with severe VDD when compared to people with optimal vitamin D level (p < 0.001).

CONCLUSION

Our findings demonstrated a significant association between the suboptimal serum vitamin D level and COVID-19 infection. Further studies are required to determine the effects of VDD on the severity and outcomes of COVID-19 infections.

Vitamin D in Behcet's Disease, a Brief Review of the Literature

Behcet's disease is a chronic vasculitis of unknown etiopathogenesis. Serum vitamin D levels have been reported to be associated with a variety of inflammatory and autoimmune diseases one of which is Behcet's disease. The previous studies about vitamin D in Behcet's disease seem to be focused on 4 main categories; the studies evaluating serum vitamin D levels between patients with Behcet's disease and controls, the studies evaluating serum vitamin D in the susceptibility and pathogenesis of Behcet's disease, the studies evaluating serum vitamin D in clinical involvements and activity of Behcet's disease, and the studies evaluating the effect of serum vitamin D replacement in Behcet's disease. The aim of this manuscript was to evaluate the results of the studies on serum vitamin D in Behcet's disease and review the literature.

Association of serum 25-hydroxyvitamin D with metabolic disturbances in adolescents

OBJECTIVES

Data concerning the association of vitamin D with metabolic disturbances in adolescents are contradictory. The aim of this study was to identify metabolic abnormalities in adolescents with 25-hydroxyvitamin D (25[OH]D) deficiency and to determine informative indices for the early detection of these metabolic disturbances.

METHODS

A cross-sectional observational study including 90 adolescents aged 13-15 years was carried out during the winter. Anthropometric measures were collected. Fasting blood samples were assessed for the following parameters: serum 25(OH)D, lipids, and glucose.

RESULTS

The majority of the study adolescents had low 25(OH)D concentration. The prevalence of 25(OH)D deficiency (<12 ng/ml) and insufficiency (12-20 ng/ml) in adolescents was 34.4% and 55.6%, respectively. Among the metabolic disturbance, hypo-high-density lipoprotein cholesterolemia prevailed in the adolescents, while hypercholesterolemia, hypertriglyceridemia, and hyperglycemia were rare. 25(OH)D status showed an association with the metabolic score for insulin resistance (METS-IR, r = -0.40; p < .001), high-density lipoprotein cholesterol level (r = 0.31; p = .003), atherogenic index of plasma (r = -0.30; p = .004) and body mass index (r = -0.23, p = .032). There were no significant correlations between 25(OH)D level and other lipid or glucose levels. The degree of hypovitaminosis D affects METS-IR values.

CONCLUSIONS

25(OH)D deficiency in the studied adolescents had not yet manifested serious metabolic diseases. Of all the analyzed parameters, METS-IR was most strongly associated with 25(OH)D level and can be considered a useful marker of early metabolic disturbances in adolescents with 25(OH)D deficiency.

Vitamin D deficiency in dengue fever patients' coinfected with H. pylori in Pakistan. A case-control study

Introduction

Dengue fever is a vector-borne disease with an estimate of 390 million persons getting the infection each year with a significant public health impact. It has been reported DENV patients with vitamin D deficiency led to severe form of dengue infection; while H. pylori coinfection alters vitamin D receptors leading to vitamin D deficiency. We hypothesize that DENV patient's having low vitamin D along with H. pylori coinfection could have worsen dengue severity as well as vitamin D deficiency. In this case-control study, we compared (I) the vitamin D deficiency in dengue fever cases with or without H. pylori coinfection, and (II) negative dengue fever as a control with or without H. pylori coinfection. We have also assessed the correlation between vitamin D levels and its effect on warning signs of the dengue fever. Further, we have investigated whether coinfection with H. pylori has any effect on warning signs in the dengue fever patients and the vitamin D deficiency in all serotypes of the dengue virus infected patients.

Methods

In this case control study the association of the vitamin D levels with age, gender and H. pylori coinfection in dengue fever hospitalized patients was assessed using chi-square and multivariate logistic regression analysis.

Results

Four hundred dengue fever patients with H. pylori coinfection were compared with 400 dengue negative controls with H. pylori coinfection. The mean age was 29.96 ± 10.5 and 29.88 ± 10.7 years among cases and controls, respectively. Most dengue fever patients with H. pylori coinfection were deficient in vitamin D compared with negative dengue controls with H. pylori coinfection. In multivariate logistic regression, the dengue cases with H. pylori coinfection were.056 times (95% CI: 0.024, 0.128, P = 0.000) more likely to have vitamin D "deficiency', while compared with the cases who did not have H. pylori coinfection.

Conclusion

The present study proposes that vitamin D deficiency in dengue fever patients coinfected with H. pylori is much higher than the dengue fever negative controls coinfected with H. pylori. As hypothesized the DENV patient with H. pylori coinfection has vitamin D deficiency as well as increased dengue severity.

Transcriptomic analysis reveal the responses of dendritic cells to VDBP

BACKGROUND

Vitamin D binding protein (VDBP) is an essential plasma carrier protein, which plays possible roles in reproductive health, disease and so on. However, the effects of VDBP on immunity have not been fully studied and the pertinent literatures remain very limited.

OBJECTIVE

In this study, we introduced the exogenous VDBP into DC2.4 and established a stable DC2.4/VDBP cell line to explore the role of this gene in immunity.

METHODS

Dendritic cells (DCs), as the most effective antigen presenting cells (APC) found so far, are directly involved in regulating some innate immunity. In order to evaluate the biological role of VDBP in DCs, we stably overexpressed VDBP in DCs, and conducted Cell Counting Kit‑8 (CCK-8 kit) and flow cytometry to detect changes in cell function. CCK-8 kit was used to monitor the viability of DCs after gene overexpression, and flow cytometry was used to detect changes in cell cycle distribution and apoptosis. Subsequently, in order to reveal the mechanism of VDBP regulating DCs, we adopted RNA sequencing (RNA-seq).

RESULTS

CCK-8 results revealed VDBP successfully inhibited viability of DCs. Besides, we found that overexpression of this gene greatly promoted apoptosis and obviously altered the cell cycle distribution of DCs in G1 and G2 phases. Moreover, RNA-seq was carried out and 151 differently expression genes (DEGs) were obtained. In addition, gene differential expression analysis showed that most of them were uniformly enriched in immunity-related pathways.

CONCLUSION

These results indicated that VDBP greatly repressed proliferation, facilitated apoptosis and changed cell cycle in DCs via altering the expression levels of gene associated with their cellular immunity.

Serum vitamin D levels and COVID-19 during pregnancy: A systematic review and meta-analysis

Background

Serum vitamin D levels are reported to be associated with the risk of incidence and severity of COVID-19 in the general population. During pregnancy, immune system alterations in line with changes in vitamin D metabolism may affect the course of COVID-19. Thus, we aimed to systematically review the association between vitamin D, pregnancy, and COVID-19.

Methods

A systematic literature search was conducted in PubMed, Scopus, Web of Science, Embase, and Google Scholar until the end of May 2022. Mean differences (MD) with 95% CI were used as desired effect sizes to assess the association of serum vitamin D levels with the risk of incidence and severity of COVID-19 in pregnant women.

Results

Among 259 records, 7 and 6 studies were included in the systematic review and meta-analysis, respectively. All included studies had acceptable quality. Our results demonstrated an insignificant difference between infected women and non-infected controls (MD = -2.55 ng/ml, 95% CI: −6.85 – 1.74). But serum vitamin D levels in severe/moderate cases compared to mild ones (MD = −2.71 ng/ml, 95% CI: −4.18 to −1.24) are significantly lower.

Conclusion

Based on the current evidence, serum vitamin D level does not associate with the risk of SARS-CoV-2 infection among pregnant women, but we find a significant association with the severity of the disease. These findings may be helpful in similar conditions and future studies to better understand the complex immune alterations during pregnancy.

What Are the Effects of Vitamin A Oral Supplementation in the Prevention and Management of Viral Infections? A Systematic Review of Randomized Clinical Trials

Vitamin A (VA) deficiency is associated with increased host susceptibility to infections, but evidence on its role in the prevention and management of viral infections is still lacking. This review aimed at summarizing the effects of VA supplementation against viral infections to support clinicians in evaluating supplemental treatments. PubMed, Scopus, and Web of Science were searched. Randomized clinical trials comparing the direct effects of VA oral supplementation in any form vs. placebo or standard of care in the prevention and/or management of confirmed viral infections in people of any age were included. A narrative synthesis of the results was performed. The revised Cochrane Risk-Of-Bias tool was used to assess quality. Overall, 40 articles of heterogeneous quality were included. We found data on infections sustained by Retroviridae (n = 17), Caliciviradae (n = 2), Flaviviridae (n = 1), Papillomaviridae (n = 3), Pneumoviridae (n = 4), and Paramyxoviridae (n = 13). Studies were published between 1987 and 2017 and mostly conducted in Africa. The findings were heterogeneous across and within viral families regarding virological, immunological, and biological response, and no meaningful results were found in the prevention of viral infections. For a few diseases, VA-supplemented individuals had a better prognosis and improved outcomes, including clearance of HPV lesions or reduction in some measles-related complications. The effects of VA oral supplementation seem encouraging in relation to the management of a few viral infections. Difference in populations considered, variety in recruitment and treatment protocols might explain the heterogeneity of the results. Further investigations are needed to better identify the benefits of VA administration.

Molecular mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

Association of Serum 25(OH)D Deficiency with High Viral Load in HBV Infected Patients

Hepatitis B virus (HBV) is a significant public health concern, particularly in low-income countries. The host immune response plays an essential role in hepatitis B virus outcome, mainly orchestrated by cytokines and immune modulators molecules such as vitamin D. This study aimed to determine the levels of cytokines (IL-10), interferon-gamma (IFN-gamma), interferon-lambada (IFN-lambada), granzyme B, and vitamin D in Khartoum, Sudan, and to assess the association between them and variable HBV viral load as well as liver enzyme levels. A total of 174 participants were enrolled in the trial, with 100 HBV-infected patients (who were HIV and HCV negative) and 74 healthy volunteers. Patients’ HBV viral load, vitamin D levels, liver enzymes, and circulatory cytokines were measured. This study revealed a remarkable decrease in vitamin D levels in HBV infected patients with an elevation in levels of liver biomarkers. The level of IL-10 was significantly higher in patients than in apparently healthy controls (p-value <0.001). There was a positive correlation between IFN-ϒ, Granzyme B, and viral load. According to the findings of this study, there is a marked hypovitaminosis D among hepatitis B infected patients with a significant increase in IL-10, which may implicate the persistence of HBV infection. Moreover, HBV DNA levels were significantly associated with IFN- g and granzyme B levels.

An Update on the Effects of Vitamin D on the Immune System and Autoimmune Diseases

Vitamin D intervenes in calcium and phosphate metabolism and bone homeostasis. Experimental studies have shown that 1,25-dihydroxyvitamin D (calcitriol) generates immunologic activities on the innate and adaptive immune system and endothelial membrane stability. Low levels of serum 25-hydroxyvitamin D (25(OH)D) are associated with an increased risk of developing immune-related diseases such as psoriasis, type 1 diabetes, multiple sclerosis, and autoimmune diseases. Various clinical trials describe the efficacy of supplementation of vitamin D and its metabolites for treating these diseases that result in variable outcomes. Different disease outcomes are observed in treatment with vitamin D as high inter-individual difference is present with complex gene expression in human peripheral blood mononuclear cells. However, it is still not fully known what level of serum 25(OH)D is needed. The current recommendation is to increase vitamin D intake and have enough sunlight exposure to have serum 25(OH)D at a level of 30 ng/mL (75 nmol/L) and better at 40–60 ng/mL (100–150 nmol/L) to obtain the optimal health benefits of vitamin D.

Role of Vitamin D in Liver Disease and Complications of Advanced Chronic Liver Disease

Vitamin D is a crucial nutrient with many pleiotropic effects on health and various chronic diseases. The purpose of this review is to provide a detailed report on the pathophysiological mechanisms underlying vitamin D deficiency in patients with chronic liver disease, addressing the different liver etiologies and the condition of advanced chronic liver disease (cirrhosis) with related complications. To date, patients with liver disease, regardless of underlying etiology, have been shown to have reduced levels of vitamin D. There is also evidence of the predictive role of vitamin D values in complications and progression of advanced disease. However, specific indications of vitamin D supplementation are not conclusive concerning what is already recommended in the general population. Future studies should make an effort to unify and validate the role of vitamin D supplementation in chronic liver disease.

A Vitamin D-RelB/NF-κB Pathway Limits Chandipura Virus Multiplication by Rewiring the Homeostatic State of Autoregulatory Type 1 IFN-IRF7 Signaling

Besides its functions in the skeletomuscular system, vitamin D is known to alleviate viral-inflicted pathologies. However, the mechanism underlying protective vitamin D function remains unclear. We examined the role of vitamin D in controlling cellular infections by Chandipura virus, an RNA virus implicated in human epidemics. How immune signaling pathways, including those regulating NF-κB and IFN regulatory factors (IRFs), are activated in virus-infected cells has been well studied. Our investigation involving human- and mouse-derived cells revealed that vitamin D instructs the homeostatic state of these antiviral pathways, leading to cellular resilience to subsequent viral infections. In particular, vitamin D provoked autoregulatory type 1 IFN-IRF7 signaling even in the absence of virus infection by downmodulating the expression of the IFN-inhibitory NF-κB subunit RelB. Indeed, RelB deficiency rendered vitamin D treatment redundant, whereas IRF7 depletion abrogated antiviral vitamin D action. In sum, immune signaling homeostasis appears to connect micronutrients to antiviral immunity at the cellular level. The proposed link may have a bearing on shaping public health policy during an outbreak.

Immune System and Psychological State of Pregnant Women during COVID-19 Pandemic: Are Micronutrients Able to Support Pregnancy?

The immune system is highly dynamic and susceptible to many alterations throughout pregnancy. Since December 2019, a pandemic caused by coronavirus disease 19 (COVID-19) has swept the globe. To contain the spread of COVID-19, immediate measures such as quarantine and isolation were implemented. These containment measures have contributed to exacerbate situations of anxiety and stress, especially in pregnant women, who are already particularly anxious about their condition. Alterations in the psychological state of pregnant women are related to alterations in the immune system, which is more vulnerable under stress. COVID-19 could therefore find fertile soil in these individuals and risk more severe forms. Normally a controlled dietary regimen is followed during pregnancy, but the use of particular vitamins and micronutrients can help counteract depressive-anxiety states and stress, can improve the immune system, and provide an additional weapon in the defense against COVID-19 to bring the pregnancy to fruition. This review aims to gather data on the impact of COVID-19 on the immune system and psychological condition of pregnant women and to assess whether some micronutrients can improve their psychophysical symptoms.

Vitamin D Status and Parkinson's Disease

Parkinson’s disease (PD) is a complex and progressive neurodegenerative disease, characterized by resting tremor, rigidity, slowness of movement, and postural instability. Furthermore, PD is associated with a wide spectrum of non-motor symptoms that add to overall disability. In recent years, some investigations, from basic science to clinical applications, have focused on the role of vitamin D in PD, often with controversial findings. Vitamin D has widespread effects on several biological processes in the central nervous system, including neurotransmission in dopaminergic neural circuits. Various studies have recorded lower levels of vitamin D in PD patients than in healthy controls. Low vitamin D status has also been correlated with the risk for PD and motor severity, whereas less is known about the effects vitamin D has on cognitive function and other non-motor symptoms. This review aims to better characterize the correlation between vitamin D and PD, clarify the role of vitamin D in PD prevention and treatment, and discuss avenues for future research in this field.

Vitamin D: A Potential Mitigation Tool for the Endemic Stage of the COVID-19 Pandemic?

The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and associated development of clinical symptoms of COVID-19 have presented an enormous global impact on our health care systems, public health and economy. To date several observational epidemiological studies consistently found that vitamin D deficiency, measured as low levels of circulating 25-hydroxyvitamin D, is associated with cardiovascular diseases, diabetes, certain cancers, autoimmune diseases and many infectious diseases, including acute respiratory infections. Since vitamin D is not merely immunosuppressive but also acts as an immunomodulator in tolerance and homeostasis, many experts have considered a role of vitamin D in the prevalence and severity of immune mediated inflammatory diseases, such as SARS-CoV-2, adding to the evidence of the importance of vitamin D in the immune response against viral respiratory infections and reinforcing the need for targeted vitamin D supplementation, with a focus on high-risk populations and a high-dose supplementation treatment for COVID-19 hospitalized patients. The expected transition to endemicity of SARS-CoV-2 even further corroborates as a potential of vitamin D as an potential mitigation tool for the prevention of COVID-19. The aim of this paper is to analyse the current evidence regarding vitamin D and present a hypothesis of its potential role in the current COVID-19 pandemic and in the future as a potential preventive measurement in public health.

ASSOCIATION BETWEEN VITAMIN D STATUS AND PHYSICAL PERFORMANCE IN COVID-19 SURVIVORS: RESULTS FROM THE GEMELLI AGAINST COVID-19 POST-ACUTE CARE PROJECT

Aim

To determine the prevalence and associated factors of vitamin D deficiency in COVID-19 survivors and the relationship between vitamin D status and physical performance.

Methods

Vitamin D status was assessed in a sample of patients who had recovered from COVID-19 and were admitted to a post-acute outpatient service at the Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Rome, Italy). Participants were offered comprehensive medical assessment, including physical performance and muscle strength tests. Self-rated health was assessed. Vitamin D deficiency was defined as a serum concentration of 25-OH vitamin D < 20 ng/mL.

Results

Mean age of 681 participants was 53.4 ± 15.2 years and 49% were women. Vitamin D deficiency was detected in 35.6% of the whole study population, and in 40.2% of those 65 and older. Vitamin D deficiency was associated with diabetes, higher body mass index, and COVID-19 severity, and showed a seasonal pattern with a peak in autumn/winter. Participants with vitamin D deficiency performed poorer on the six-minute walking test, with the lowest performance observed in those 65 and older. No significant associations with any other parameters were found.

Conclusion

Our findings indicate that vitamin D deficiency is frequent in COVID-19 survivors, especially in older adults. Low vitamin D levels are associated with poor physical performance, in particular in old age.

Low Serum Vitamin D in COVID-19 Patients Is Not Related to Inflammatory Markers and Patients' Outcomes-A Single-Center Experience and a Brief Review of the Literature

The aim of the study was to evaluate the vitamin D status in hospitalized COVID-19 patients and the correlation with C reactive protein (CRP), ferritin, fibrinogen, and peripheral blood leukocytes, as well as inflammatory derived indices. A prospective study was performed on 203 COVID-19 hospitalized patients, classified by disease severity. Blood was collected after admission, and inflammatory biomarkers and vitamin D status were assessed using routine laboratory procedures. No significant correlation was found between vitamin D serum levels and disease severity stratified by different age groups. However, the highest vitamin D levels were found in patients with mild disease: median 29.39 (IQR 12.12-44.02) ng/mL, while for moderate and severe forms the serum levels were significantly lower: median 15.10 (IQR 9.56-24.11) ng/mL for moderate, and 18.86 (IQR 12.50-27.88) ng/mL for severe; p = 0.009. Patients with no comorbidities showed a significantly higher level of vitamin D median 24.72 (IQR 16.05-31.52) ng/mL compared to subjects with at least one comorbidity: median 16.02 (IQR 9.81-25.22) ng/mL, p = 0.004. We did not find an association between vitamin D levels and inflammatory biomarkers except for significantly lower vitamin D levels in moderate and severe COVID-19 compared to mild disease forms.

Priming stroma with a vitamin D analog to optimize viroimmunotherapy for pancreatic cancer

Pancreatic cancer resistance to immunotherapies is partly due to deficits in tumor-infiltrating immune cells and stromal density. Combination therapies that modify stroma and recruit immune cells are needed. Vitamin D analogs such as calcipotriol (Cal) decrease fibrosis in pancreas stroma, thus allowing increased chemotherapy delivery. OVs infect, replicate in, and kill cancer cells and recruit immune cells to immunodeficient microenvironments. We investigated whether stromal modification with Cal would enhance oncolytic viroimmunotherapy using recombinant orthopoxvirus, CF33. We assessed effect of Cal on CF33 replication using pancreas ductal adenocarcinoma (PDAC) cell lines and in vivo flank orthotopic models. Proliferation assays showed that Cal did not alter viral replication. Less replication was seen in cell lines whose division was slowed by Cal, but this appeared proportional to cell proliferation. Three-dimensional in vitro models demonstrated decreased myofibroblast integrity after Cal treatment. Cal increased vascular lumen size and immune cell infiltration in subcutaneous models of PDAC and increased viral delivery and replication. Cal plus serial OV dosing in the syngeneic Pan02 model caused more significant tumor abrogation than other treatments. Cal-treated tumors had less dense fibrosis, enhanced immune cell infiltration, and decreased T cell exhaustion. Calcipotriol is a possible adjunct for CF33-based oncolytic viroimmunotherapy against PDAC.

Exclusive Breastfeeding and Vitamin D Supplementation: A Positive Synergistic Effect on Prevention of Childhood Infections?

Human milk is the best food for infants. Breastfeeding has been associated with a reduced risk of viral and bacterial infections. Breast milk contains the perfect amount of nutrients needed to promote infant growth, except for vitamin D. Vitamin D is crucial for calcium metabolism and bone health, and it also has extra-skeletal actions, involving innate and adaptive immunity. As exclusive breastfeeding is a risk factor for vitamin D deficiency, infants should be supplemented with vitamin D at least during the first year. The promotion of breastfeeding and vitamin D supplementation represents an important objective of public health.

Vitamin D, respiratory infections, and chronic disease: Review of meta-analyses and randomized clinical trials

BACKGROUND

Observational studies have suggested associations of vitamin D deficiency (VDD) with respiratory tract infections, impaired bone health, and myriad chronic diseases.

OBJECTIVE

To assess potential causal relationships between vitamin D supplementation and a reduced risk of these conditions, a review of the evidence across available meta-analyses of randomized control trials (RCTs) and RCTs was performed.

METHOD

PubMed, Embase, Cochrane Library, and Web of Science were searched from their inception to March 2021. We included only RCTs and meta-analyses of RCTs focusing on the association between vitamin D and respiratory disease, bone health, cardiovascular disease (CVD), diabetes mellitus, and cancer.

RESULTS

A total of 107 RCTs and 62 meta-analysis of RCTs were included. Although most RCTs did not support benefits of vitamin D supplementation, suggestive evidence for benefit was found in populations at greater risk of VDD and for acute respiratory infections, fractures in institutionalized older adults, type 2 diabetes among patients with prediabetes, and cancer mortality. In contrast, no compelling evidence for benefit was found for other respiratory conditions, fractures in community-dwelling adults, falls, cancer incidence, or CVD.

CONCLUSIONS

Current evidence from RCTs and meta-analyses of RCTs is inconsistent regarding the effects of vitamin D supplementation on respiratory infections and chronic diseases. Individuals most likely to benefit are those with baseline VDD or with selected high-risk conditions. Public health initiatives are needed to eliminate VDD globally, and future research will be enhanced by a 'precision prevention' approach to identify those most likely to benefit from vitamin D supplementation.

The Immunologic Profile of Vitamin D and Its Role in Different Immune-Mediated Diseases: An Expert Opinion

Historically, vitamin D is recognized as an essential component for the maintenance of the musculoskeletal system. The immunomodulatory role of vitamin D in health and disease has gained much interest in recent years due to the many pathologies that share underlying immunological features where vitamin D has been shown to exert a potential role. Evidence from pre-clinical studies show that vitamin D elicits biological effects on both the innate and adaptive immune systems. Furthermore, in vivo studies have shown that administration of vitamin D can lead to changes in or the development of a range of immune-related diseases. This encourages the hypothesis that data derived from clinical and epidemiological studies connect vitamin D with the incidence and severity of many immune-mediated disorders such as rheumatoid arthritis, diabetes, and infectious diseases. Since some other immune-mediated diseases share similar features to that of viral infection such as COVID-19, in this review, we examined these other areas and the role of vitamin D in these diseases.

Vitamin D, the immune system, and its relationship with diseases

Background

Vitamin D is classified as an immunomodulatory hormone that is synthesized because of skin exposure to sunlight. It is known to come into play during the regulation of hormone secretion, immune functions, cell proliferation, and differentiation. Its deficiency can cause many diseases and their associated pleiotropic effects. In addition, in relation to its eminent function as regards adaptive immune response and innate immune response, vitamin D level is associated with immune tolerance.

Methods

Literature search prior to May 2021 was conducted through selected websites, including the MEDLINE, Embase, Web of Science, Cochrane Central, www.ClinicalTrials.gov, PubMed, Science Direct, Google Scholar, and EFSA.

Results

Vitamin D is found effective for the regulation of hormone secretion, immune functions, and cell proliferation along with differentiation. Its role as an immune modulator is based on the presence of receptors on many immune cells and the synthesis of its active metabolite from these cells. Vitamin D, an immune system modulator, inhibits cell proliferation and stimulates cell differentiation. A fair number of immune system diseases, encompassing autoimmune disorders alongside infectious diseases, can occur because of low serum vitamin D levels. Supplementation of vitamin D has positive effects in lessening the severity nature of disease activity; there exists no consensus on the dose to be used.

Conclusion

It is figured out that a higher number of randomized controlled trials are essential to evaluate efficacy pertaining to clinical cases, treatment duration, type, and dose of supplementation and pathophysiology of diseases, immune system functioning, and the effect of vitamin D to be administered.

An exploratory review of Potential Adjunct Therapies for the Treatment of Coronavirus Infections

Objective

The purpose of this exploratory review c, including vitamin D, zinc, vitamin A, elderberry (S nigra), garlic (A sativum), licorice (G glabra), stinging nettle (U dioica), N-acetylcysteine, quercetin and selenium as potential adjunct therapies for the treatment of coronavirus infections.

Methods

A search of PubMed was performed for articles published from 2005 to 2021. Key words searched were zinc, vitamin A, vitamin D, Sambucus nigra, Allium sativum, Glycyrrhiza glabra, Urtica dioica, N-Acetylcysteine, quercetin, selenium and coronavirus.

Results

There were 47 articles selected for this review. Findings included that vitamin D, zinc, vitamin A, S nigra, A sativum, G glabra, U dioica, N-acetylcysteine, quercetin and selenium have been shown to produce anti-inflammatory, immunostimulatory or antiviral effects that may enhance the actions of standard therapeutics for the treatment of CoV infections. We found only research articles related to the effects of vitamin D, zinc, G glabra, quercetin and selenium against COVID-19.

Conclusion

We identified non-pharmaceutical supplements (Vitamin D, zinc, vitamin A, S nigra, A sativum, G glabra and U dioica) which may have potential to provide support for those with coronavirus infections. However, rigorous clinical studies need to be performed before any clinical recommendations can be made at this time.