Vitamin D receptor genotype influences risk of upper respiratory infection

Comparing vitamin D receptor gene polymorphisms in rs11568820, rs7970314, rs4334089 between COVID-19 patients with mild and severe symptoms: a case control study

The associations of vitamin D receptor (VDR)- single nucleotide polymorphisms (SNPs) with the symptoms of COVID-19 may vary between patients with different severities of COVID-19. Therefore, in the present study, we aim to compare VDR polymorphisms in severe and mild COVID-19 patients. In this study, a total number of 85 hospitalized patients and 91 mild/moderate patients with COVID-19 were recruited. SNPs in VDR genes were determined using ARMS and then confirmed by sanger sequencing. The mean (SD) age of participants in hospitalized and non-hospitalized group was 59.0 (12.4) and 47.8 (14.8) years, respectively. Almost 46% of participants in hospitalized and 48% of participant in non-hospitalized group were male. The frequency of TT genotype of SNP rs11568820 was significantly lower in hospitalized than non-hospitalized group (3.5% vs. 17.6%; P = 0.018). However, there was no significant differences between genotypes of SNPs rs7970314 and rs4334089 and also alleles frequencies in all SNPs of two groups. The genotype of rs11568820 SNP had an inverse association with hospitalization of patients with COVID-19 after adjustment for comorbidities [OR 0.18, 95% CI 0.04, 0.88; P = 0.034]. While, there was no relationship between genotypes of SNPs rs7970314 and rs4334089 and hospitalization. The TT genotype of rs11568820 plays protective role in sever COVID-19 and hospitalization. Further studies with a large sample size which consider various confounding factors are warranted to confirm our results.

Polymorphisms in LRP2 and CUBN genes and their association with serum vitamin D levels and sleep apnea

PURPOSE

Vitamin D deficiency has been associated with the occurrence of obstructive sleep apnea syndrome (OSAS). Megalin (LRP2) and cubilin (CUBN) are implicated in vitamin D metabolism, whereas LRP2 and CUBN polymorphisms have been previously associated with variable serum vitamin D levels. The present study aimed to evaluate the role of LRP2 rs2228171 c.8614C > T and CUBN rs1801222 c.758A > G polymorphisms in OSAS susceptibility, independently or in synergy with vitamin D levels.

METHODS

Vitamin D serum concentration of consecutive individuals was measured. PCR-RFLP was used for LRP2 rs2228171 and CUBN rs1801222 genotyping.

RESULTS

A total of 176 individuals was enrolled, including 144 patients with OSAS and 32 controls. Frequency of LRP2 rs2228171 c.8614 T and CUBN rs1801222 c.758G alleles was estimated at 22.4% and 79.8%, respectively. LRP2 and CUBN polymorphisms were not associated with OSAS occurrence (rs2228171Τ allele: 22.9% in OSAS group vs. 20.3% in controls, p = 0.651; rs1801222A allele 19.4% in OSAS group vs. 23.4% in controls, p = 0.471). Frequency of CUBN rs1801222A allele carriers was increased in patients with moderate or severe OSAS compared to mild OSAS (p = 0.028). Patients with OSAS homozygous for LRP2 CC and CUBN GG genotypes had lower vitamin D serum concentration compared to controls carrying the same genotype (18.0 vs 27.0 ng/mL, p = 0.006 and 19.0 vs 27.5 ng/mL, p = 0.007, respectively).

CONCLUSION

CUBN rs1801222 polymorphism may affect OSAS severity. Among other factors, low vitamin D concentration is associated with OSAS occurrence, irrespectively of LRP2 and CUBN polymorphisms.

Controlling Chronic Diseases and Acute Infections with Vitamin D Sufficiency

Apart from developmental disabilities, the prevalence of chronic diseases increases with age especially in those with co-morbidities: vitamin D deficiency plays a major role in it. Whether vitamin D deficiency initiates and/or aggravates chronic diseases or vice versa is unclear. It adversely affects all body systems but can be eliminated using proper doses of vitamin D supplementation and/or safe daily sun exposure. Maintaining the population serum 25(OH)D concentration above 40 ng/mL (i.e., sufficiency) ensures a sound immune system, minimizing symptomatic diseases and reducing infections and the prevalence of chronic diseases. This is the most cost-effective way to keep a population healthy and reduce healthcare costs. Vitamin D facilitates physiological functions, overcoming pathologies such as chronic inflammation and oxidative stress and maintaining broader immune functions. These are vital to overcoming chronic diseases and infections. Therefore, in addition to following essential public health and nutritional guidance, maintaining vitamin D sufficiency should be an integral part of better health, preventing acute and chronic diseases and minimize their complications. Those with severe vitamin D deficiency have the highest burdens of co-morbidities and are more vulnerable to developing complications and untimely deaths. Vitamin D adequacy improves innate and adaptive immune systems. It controls excessive inflammation and oxidative stress, generates antimicrobial peptides, and neutralizes antibodies via immune cells. Consequently, vitamin D sufficiency reduces infections and associated complications and deaths. Maintaining vitamin D sufficiency reduces chronic disease burden, illnesses, hospitalizations, and all-cause mortality. Vulnerable communities, such as ethnic minorities living in temperate countries, older people, those with co-morbidities, routine night workers, and institutionalized persons, have the highest prevalence of vitamin D deficiency-they would significantly benefit from vitamin D and targeted micronutrient supplementation. At least now, health departments, authorities, and health insurance companies should start assessing, prioritizing, and encouraging this economical, non-prescription, safe micronutrient to prevent and treat acute and chronic diseases. This approach will significantly reduce morbidity, mortality, and healthcare costs and ensure healthy aging.

Vitamin D and COVID-19: where are we now?

The pandemic caused by the SARS-CoV-2 virus has triggered great interest in the search for the pathophysiological mechanisms of COVID-19 and its associated hyperinflammatory state. The presence of prognostic factors such as diabetes, cardiovascular disease, hypertension, obesity, and age influence the expression of the disease's clinical severity. Other elements, such as 25-hydroxyvitamin D (25(OH)D3) concentrations, are currently being studied. Various studies, mostly observational, have sought to demonstrate whether there is truly a relationship between 25(OH)D3 levels and the acquisition and/or severity of the disease. The objective of this study was to carry out a review of the current data that associate vitamin D status with the acquisition, evolution, and/or severity of infection by the SARS-CoV-2 virus and to assess whether prevention through vitamin D supplementation can prevent infection and/or improve the evolution once acquired. Vitamin D system has an immunomodulatory function and plays a significant role in various bacterial and viral infections. The immune function of vitamin D is explained in part by the presence of its receptor (VDR) and its activating enzyme 25-hydroxyvitamin D-1alpha-hydroxylase (CYP27B1) in immune cells. The vitamin D, VDR, and Retinoid X Receptor complex allows the transcription of genes with antimicrobial activities, such as cathelicidins and defensins. COVID-19 characteristically presents a marked hyperimmune state, with the release of proinflammatory cytokines such as IL-6, TNF-α, and IL-1β. Thus, there are biological factors linking vitamin D to the cytokine storm, which can herald some of the most severe consequences of COVID-19, such as acute respiratory distress syndrome. Hypovitaminosis D is widespread worldwide, so the prevention of COVID-19 through vitamin D supplementation is being considered as a possible therapeutic strategy easy to implement. However, more-quality studies and well-designed randomized clinical trials are needed to address this relevant question.

Vitamin D in SARS-CoV-2 patients with non-invasive ventilation support

BACKGROUND

Vitamin D (VitD) deficiency has been reported to be associated with respiratory tract infection. In this work we evaluated the concentration of VitD in COVID-19 patients experiencing acute respiratory infections of different levels of severity excluding those who underwent invasive respiratory support.

METHODS

The levels of serum VitD and C-reactive protein (CRP) were analyzed in 118 consecutive hospitalized COVID-19 patients (74 male, 44 female), confirmed with rRT-PCR. Of these patients with ventilation support 52 (44.1%) received oxygen via nasal cannula, oxygen mask or an oxygen mask with a reservoir, 48 (40.7%) were on a continuous positive airway pressure device (CPAP) and 18 (15,3%) on non-invasive mechanical ventilation (NIMV).

RESULTS

The median values (range) of VitD and of CRP were 15.1 ng/mL (1.3-73.3) and 14.2 mg/L (5.0-151.2), respectively. A negative correlation from VitD levels and those of CRP (correlation coefficient: 0.259: P=0.005) was observed. VitD levels in O<inf>2</inf> support patients were significantly higher than in both CPAP and NIMV patients. No statistical differences were found for CRP levels (P=0.834) among the three type of oxygen support. Fewer patients with O<inf>2</inf> support had VitD <30 ng/mL and <20 ng/mL than CPAP and NIMV patients. There were no relationships between VitD and the three classes of IgM (P=0.419) and of IgG (P=0.862) SARS-CoV-2 antibodies values. The behavior was the same for CRP.

CONCLUSIONS

Our study shows that a significant proportion of COVID-19 patients have a VitD deficiency and that this condition is more frequent in CPAP and in NIMV patients.

Micronutrient perspective on COVID-19: Umbrella review and reanalysis of meta-analyses

INTRODUCTION

Micronutrients are clinically important in managing COVID-19, and numerous studies have been conducted, but inconsistent findings exist.

OBJECTIVE

To explore the association between micronutrients and COVID-19.

METHODS

PubMed, Web of Science, Embase, Cochrane Library and Scopus for study search on July 30, 2022 and October 15, 2022. Literature selection, data extraction and quality assessment were performed in a double-blinded, group discussion format. Meta-analysis with overlapping associations were reconsolidated using random effects models, and narrative evidence was performed in tabular presentations.

RESULTS

57 reviews and 57 latest original studies were included. 21 reviews and 53 original studies were of moderate to high quality. Vitamin D, vitamin B, zinc, selenium, and ferritin levels differed between patients and healthy people. Vitamin D and zinc deficiencies increased COVID-19 infection by 0.97-fold/0.39-fold and 1.53-fold. Vitamin D deficiency increased severity 0.86-fold, while low vitamin B and selenium levels reduced severity. Vitamin D and calcium deficiencies increased ICU admission by 1.09 and 4.09-fold. Vitamin D deficiency increased mechanical ventilation by 0.4-fold. Vitamin D, zinc, and calcium deficiencies increased COVID-19 mortality by 0.53-fold, 0.46-fold, and 5.99-fold, respectively.

CONCLUSION

The associations between vitamin D, zinc, and calcium deficiencies and adverse evolution of COVID-19 were positive, while the association between vitamin C and COVID-19 was insignificant.REGISTRATION: PROSPERO CRD42022353953.

Association between Single Nucleotide Polymorphisms Related to Vitamin D Metabolism and the Risk of Developing Asthma

Asthma is a chronic non-communicable disease that affects all age groups. The main challenge this condition poses is its heterogeneity. The role of vitamin D in asthma has aroused great interest, correlating low vitamin D levels and polymorphisms in the genes involved in its metabolic pathway with the risk of asthma. The aim of this study was to evaluate the influence of 13 single nucleotide polymorphisms (SNPs) related to the vitamin D metabolism on the susceptibility to asthma. An observational case-control study was performed, including 221 patients with asthma and 442 controls of Caucasian origin from southern Spain. The SNPs CYP24A1 (rs6068816, rs4809957), CYP27B1 (rs10877012, rs4646536, rs703842, rs3782130), GC (rs7041), CYP2R1 (rs10741657) and VDR (ApaI, BsmI, FokI, Cdx2, TaqI) were analyzed by real-time PCR, using TaqMan probes. The logistic regression model adjusted for body mass index revealed that in the genotype model, carriers of the Cdx2 rs11568820-AA genotype were associated with a higher risk of developing asthma (p = 0.005; OR = 2.73; 95% CI = 1.36-5.67; AA vs. GG). This association was maintained in the recessive model (p = 0.004). The haplotype analysis revealed an association between the ACTATGG haplotype and higher risk of asthma for the rs1544410, rs7975232, rs731236, rs4646536, rs703842, rs3782130 and rs10877012 genetic polymorphisms (p = 0.039). The other SNPs showed no effect on risk of developing asthma. The Cdx2 polymorphism was significantly associated with the susceptibility of asthma and could substantially act as a predictive biomarker of the disease.

Global Effect of COVID-19 Pandemic on Cancer Patients and its Treatment: A Systematic Review

Background

At a global level, the COVID-19 disease outbreak has had a major impact on health services and has induced disruption in routine care of health institutions, exposing cancer patients to severe risks. To provide uninterrupted tumor treatment throughout a pandemic lockdown is a major obstacle. Coronavirus disease (COVID-19) and its causative virus, SARS-CoV-2, stance considerable challenges for the management of oncology patients. COVID-19 presents particularly severe respiratory and systemic infection in aging and immunosuppressed individuals, including patients with cancer.

Objective

In the present review, we focused on emergent evidence from cancer sufferers that have been contaminated with COVID-19 and cancer patients who were at higher risk of severe COVID-19, and indicates that anticancer treatment may either rise COVID-19 susceptibility or have a duple therapeutic impact on cancer as well as COVID-19; moreover, how SARS-CoV-2 infection impacts cancer cells. Also, to assess the global effect of the COVID-19 disease outbreak on cancer and its treatment.

Methods

A literature survey was conducted using PubMed, Web of Science (WOS), Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and VIral Protein domain DataBase (VIP DB) between Dec 1, 2019 and Sep 23, 2021, for studies on anticancer treatments in patients with COVID-19. The characteristics of the patients, treatment types, mortality, and other additional outcomes were extracted and pooled for synthesis.

Results

This disease has a huge effect on sufferers who have cancer(s). Sufferers of COVID-19 have a greater percentage of tumor diagnoses than the rest of the population. Likewise, cancer and highest proportion is lung cancer sufferers are more susceptible to COVID-19 constriction than the rest of the population.

Conclusion

Sufferers who have both COVID-19 and tumor have a considerably elevated death risk than single COVID-19 positive patients overall. During the COVID-19 pandemic, there was a reduction in the screening of cancer and detection, and also deferral of routine therapies, which may contribute to an increase in cancer mortality there in future.

Differential distribution of vitamin D receptor (VDR) gene variants and its expression in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disorder that displays an important genetic background. Vitamin D₃ (VD₃ ) through its receptor (VDR) plays an important immunomodulatory role in autoimmune misbalance, being capable of modulating immune responses. Genetic alterations in VDR gene may contribute to an altered risk in SLE development and clinical manifestations. We investigated VDR SNPs (single nucleotide polymorphisms) frequencies in 128 SLE patients and 138 healthy controls (HC) and mRNA differential expression in 29 patients and 17 HC regarding SLE susceptibility as well as clinical features. We observed that rs11168268 G allele (OR = 1.55, p = .01) and G/G genotype (OR = 2.69, p = .008) were associated with increased SLE susceptibility. The rs2248098 G allele and A/G and G/G genotypes were associated to lower SLE susceptibility (OR = 0.66, p = .01; OR = 0.46, p = .01; OR = 0.44, p = .02, respectively). Regarding clinical features, we observed lower risk for: rs11168268 A/G genotype and nephritis (OR = 0.31, p = .01); rs4760648 T/T genotype and photosensitivity (OR = 0.24, p = .02); rs1540339 T/T genotype and antibody anti-dsDNA (OR = 0.19, p = .015); rs3890733 T/T genotype and serositis (OR = 0.10, p = .01). We identified a significant downregulation in VDR expression levels when compared patients and controls overall (p = 1.04e^-7 ), in Cdx-2 A/G and G/G (p = .008 and p = .014, respectively) and in patients with nephritis (p = .016) Our results suggested that VDR SNPs influence upon SLE susceptibility and in particular clinical features, acting on mRNA expression in SLE patients overall and the ones with nephritis.

Imbalance of the intestinal virome and altered viral-bacterial interactions caused by a conditional deletion of the vitamin D receptor

Vitamin D receptor (VDR) deficiency is associated with cancer, infection, and chronic inflammation. Prior research has demonstrated VDR regulation of bacteria; however, little is known regarding VDR and viruses. We hypothesize that VDR deficiency impacts on the intestinal virome and viral-bacterial interactions. We specifically deleted VDR from intestinal epithelial cells (VDR^ΔIEC), Paneth cells (VDR^ΔPC), and myeloid cells (VDR^ΔLyz) in mice. Feces were collected for shotgun metagenomic sequencing and metabolite profiling. To test the functional changes, we evaluated pattern recognition receptors (PRRs) and analyzed microbial metabolites. Vibrio phages, Lactobacillus phages, and Escherichia coli typing phages were significantly enriched in all three conditional VDR-knockout mice. In the VDR^ΔLyz mice, the levels of eight more virus species (2 enriched, 6 depleted) were significantly changed. Altered virus species were primarily observed in female VDR^ΔLyz (2 enriched, 3 depleted) versus male VDR^ΔLyz (1 enriched, 1 depleted). Altered alpha and beta diversity (family to species) were found in VDR^ΔLyz. In VDR^ΔIEC mice, bovine viral diarrhea virus 1 was significantly enriched. A significant correlation between viral and bacterial alterations was found in conditional VDR knockout mice. There was a positive correlation between Vibrio phage JSF5 and Cutibacterium acnes in VDR^ΔPC and VDR^ΔLyz mice. Also, there were more altered viral species in female conditional VDR knockout mice. Notably, there were significant changes in PRRs: upregulated TLR3, TLR7, and NOD2 in VDR^ΔLyz mice and increased CLEC4L expression in VDR^ΔIEC and VDR^ΔPC mice. Furthermore, we identified metabolites related to virus infection: decreased glucose in VDR^ΔIEC mice, increased ribulose/xylulose and xylose in VDR^ΔLyz mice, and increased long-chain fatty acids in VDR^ΔIEC and VDR^ΔLyz female mice. Tissue-specific deletion of VDR changes the virome and functionally changes viral receptors, which leads to dysbiosis, metabolic dysfunction, and infection risk. This study helps to elucidate VDR regulating the virome in a tissue-specific and sex-specific manner.

Evidences suggesting a possible role of Vitamin D in COVID 19: The missing link

The severe acute respiratory syndrome coronavirus 2 is spreading like wildfire with no specific recommended treatment in sight. While some risk factors such as the presence of comorbidities, old age, and ethnicity have been recognized, not a lot is known about who the virus will strike first or impact more. In this hopeless scenario, exploration of time-tested facts about viral infections, in general, seems to be a sound basis to prop further research upon. The fact that immunity and its various determinants (e.g., micronutrients, sleep, and hygiene) have a crucial role to play in the defense against invading organisms, may be a good starting point for commencing research into these as yet undisclosed territories. Herein, the excellent immunomodulatory, antiviral, and anti-inflammatory roles of Vitamin D necessitate thorough investigation, particularly in COVID-19 perspective. This article reviews mechanisms and evidence suggesting the role Vitamin D plays in people infected by the newly identified COVID-19 virus. For this review, we searched the databases of Medline, PubMed, and Embase. We studied several meta-analyses and randomized controlled trials evaluating the role of Vitamin D in influenza and other contagious viral infections. We also reviewed the circumstantial and anecdotal evidence connecting Vitamin D with COVID-19 emerging recently. Consequently, it seems logical to conclude that the immune-enhancing, antiviral, anti-inflammatory, and lung-protective role of Vitamin D can be potentially lifesaving. Hence, Vitamin D deserves exhaustive exploration through rigorously designed and controlled scientific trials. Using Vitamin D as prophylaxis and/or chemotherapeutic treatment of COVID-19 infection is an approach worth considering. In this regard, mass assessment and subsequent supplementation can be tried, especially considering the mechanistic evidence in respiratory infections, low potential for toxicity, and widespread prevalence of the deficiency of Vitamin D affecting many people worldwide.

The Immunomodulatory Function of Vitamin D, with Particular Reference to SARS-CoV-2

Vaccines are the only way to reduce the morbidity associated to SARS-CoV-2 infection. The appearance of new mutations urges us to increase the effectiveness of vaccines as a complementary alternative. In this context, the use of adjuvant strategies has improved the effectiveness of different vaccines against virus infections such as dengue, influenza, and common cold. Recent reports on patients infected by COVID-19 reveal that low levels of circulating vitamin D correlate with a severe respiratory insufficiency. The immunomodulatory activity of this micronutrient attenuates the synthesis of pro-inflammatory cytokines and at the same time, increases antibody production. Therefore, the present review proposes the use of vitamin D as adjuvant micronutrient to increase the efficacy of vaccines against SARS-CoV-2 infection.

Associations between Genetic Variants in the Vitamin D Metabolism Pathway and Severity of COVID-19 among UAE Residents

Vitamin D has many effects on cells in the immune system. Many studies have linked low vitamin D status with severity of COVID-19. Genetic variants involved in vitamin D metabolism have been implicated as potential risk factors for severe COVID-19 outcomes. This study investigated how genetic variations in humans affected the clinical presentation of COVID-19. In total, 646 patients with SARS-CoV-2 infection were divided into two groups: noncritical COVID-19 (n = 453; 70.12%) and a critical group (n = 193; 29.87%). Genotype data on the GC, NADSYN1, VDR, and CYP2R1 genes along with data on serum 25-hydroxyvitamin D levels were compiled in patients admitted to a major hospital in the United Arab Emirates between April 2020 and January 2021. We identified 12 single-nucleotide polymorphisms associated with the critical COVID-19 condition: rs59241277, rs113574864, rs182901986, rs60349934, and rs113876500; rs4944076, rs4944997, rs4944998, rs4944979, and rs10898210; and rs11574018 and rs11574024. We report significant associations between genetic determinants of vitamin D metabolism and COVID-19 severity in the UAE population. Further research needed to clarify the mechanism of action against viral infection in vitamin D deficiency. These variants could be used with vaccination to manage the spread of SARS-CoV-2 and could be particularly valuable in populations in which vitamin D deficiency is common.

Experimental Antiviral Therapeutic Studies for Human Rhinovirus Infections

Rhinovirus infection is common and usually causes mild, self-limiting upper respiratory tract symptoms. Rhinoviruses can cause exacerbation of chronic respiratory diseases, such as asthma or chronic obstructive pulmonary disease, leading to a significant burden of morbidity and mortality. There has been a great deal of progress in efforts to understand the immunological basis of rhinovirus infection. However, despite a number of in vitro and in vivo attempts, there have been no effective treatments developed. This review article summarises the up to date virological and immunological understanding of these infections. We discuss the challenges researchers face, and key solutions, in their work to investigate potential therapies including in vivo rhinovirus challenge studies. Finally, we explore past and present experimental therapeutic strategies employed in the treatment of rhinovirus infections and highlight promising areas of future work.

The Role of Nutrition in COVID-19 Susceptibility and Severity of Disease: A Systematic Review

BACKGROUND

Many nutrients have powerful immunomodulatory actions with the potential to alter susceptibility to coronavirus disease 2019 (COVID-19) infection, progression to symptoms, likelihood of severe disease, and survival.

OBJECTIVE

The aim was to review the latest evidence on how malnutrition across all its forms (under- and overnutrition and micronutrient status) may influence both susceptibility to, and progression of, COVID-19.

METHODS

We synthesized information on 13 nutrition-related components and their potential interactions with COVID-19: overweight, obesity, and diabetes; protein-energy malnutrition; anemia; vitamins A, C, D, and E; PUFAs; iron; selenium; zinc; antioxidants; and nutritional support. For each section we provide: 1) a landscape review of pertinent material; 2) a systematic search of the literature in PubMed and EMBASE databases, including a wide range of preprint servers; and 3) a screen of 6 clinical trial registries. All original research was considered, without restriction to study design, and included if it covered: 1) severe acute respiratory syndrome coronavirus (CoV) 2 (SARS-CoV-2), Middle East respiratory syndrome CoV (MERS-CoV), or SARS-CoV viruses and 2) disease susceptibility or 3) disease progression, and 4) the nutritional component of interest. Searches took place between 16 May and 11 August 2020.

RESULTS

Across the 13 searches, 2732 articles from PubMed and EMBASE, 4164 articles from the preprint servers, and 433 trials were returned. In the final narrative synthesis, we include 22 published articles, 38 preprint articles, and 79 trials.

CONCLUSIONS

Currently there is limited evidence that high-dose supplements of micronutrients will either prevent severe disease or speed up recovery. However, results of clinical trials are eagerly awaited. Given the known impacts of all forms of malnutrition on the immune system, public health strategies to reduce micronutrient deficiencies and undernutrition remain of critical importance. Furthermore, there is strong evidence that prevention of obesity and type 2 diabetes will reduce the risk of serious COVID-19 outcomes. This review is registered at PROSPERO as CRD42020186194.

Vitamin D supplementation and Covid‐19 outcomes: A systematic review, meta‐analysis and meta‐regression

Vitamin D has many protective properties and potential role against acute lung injury. Low serum vitamin D is associated with high risk of pneumonia and development of acute respiratory distress syndrome. This study sought to analyse the efficacy of vitamin D in improving the outcomes of coronavirus disease 2019 (Covid‐19) patients. Using specific keywords, we comprehensively searched the potential articles on PubMed, Europe PMC and ClinicalTrials.gov database until 8th May 2021. All published studies on Covid‐19 and vitamin D were retrieved. Statistical analysis was conducted using Review Manager 5.4 software. A total of 11 studies with 22,265 Covid‐19 patients were included in the meta‐analysis. Our data suggested that vitamin D supplementation was associated with reduction in intensive care unit admission rate (OR 0.27; 95% CI: 0.09–0.76, p = 0.010, I² = 70%, random‐effect modelling); reduction of the need for mechanical ventilation (OR 0.34; 95% CI: 0.16–0.72, p = 0.005, I² = 61%, random‐effect modelling) and reduction of mortality from Covid‐19 (OR 0.37; 95% CI: 0.21–0.66, p < 0.001, I² = 50%, random‐effect modelling). Further analysis showed that the associations were influenced by age (p = 0.020). Our study suggests that vitamin D supplementation may offer beneficial effects on Covid‐19 outcomes. However, more randomized clinical trials are required to confirm this conclusion.

Vitamin D and COVID-19: is there a role?

The COVID-19 pandemic requires a rapid understanding of the pathogenesis of the spectrum of the disease and factors associated with varied clinical presentations. Immune dysregulation with a cytokine storm (CS) progressing to ARDS with resemblance to sHLH is suggested as a main cause of tissue injury. Low levels of vitamin D were observed in COVID-19 cases with higher incidence of mortality in 20 European countries, increased risk of severity in COVID-19 contributing to ARDS or fulminant myocarditis and micro vascular thrombosis is proposed. Vitamin D may be protective against acute respiratory tract infections, as it regulates the inflammatory cytokine response of respiratory epithelial cells and macrophages, suppress CS and other manifestations seen in SARS-Cov-2. Hence, it is suggested as one of the therapies in SARS-CoV-2 infection. Major research gaps are identified globally in clinical management and this relationship. There is an imperative requisite to understand the interplay of markers in SARS-CoV-2, its risk factors and potential role of vitamin D to improve clinical outcome by pandemic of COVID-19. We therefore perform this review for understanding the pathophysiology of SARS-CoV-2 infections and the role of vitamin D in combating it.

Ultraviolet radiation, vitamin D, and COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has become pandemic on March 11^th, 2020. COVID-19 has a range of symptoms that includes fever, fatigue, dry cough, aches, and labored breathing to acute respiratory distress and possibly death. Health systems and hospitals have been completely rearranged since March 2020 in order to limit the high rate of virus spreading. Hence, a great debate on deferrable visits and treatments including phototherapy for skin diseases is developing. In particular, as regards phototherapy very few data are currently available regarding the chance to continue it, even if it may be a useful resource for treating numerous dermatological patients. However, phototherapy has an immunosuppressive action possibly facilitating virus infection. In the context of COVID-19 infection risk it is important to pointed out whether sunlight, phototherapy and in particular ultraviolet radiation (UV-R) constitute or not a risk for patients. In this review we aimed to focus on the relationship between UV-R, sunlight, phototherapy, and viral infections particularly focusing on COVID-19.

Up-Regulated Vitamin D Receptor by Pelargonium sidoides Extract EPs® 7630 Contributes to Rhinovirus Defense in Bronchial Epithelial Cells

EPs^®7630, extracted from Pelargonium sidoides, reduces the severity of viral upper respiratory tract infections. Vitamin D also improves anti-viral host defense through similar signaling pathways. This study assessed if EPs^®7630 modifies vitamin D receptor (VDR) expression and function by human bronchial epithelial cells. Bronchial epithelial cells were incubated with EPs^®7630 over 48 h before calcitriol stimulation and/or infection with Rhinovirus (RV)-16. Protein expression was determined by Western-blotting. Intracellular signaling of mitogen activated protein kinases (MAPK) was studied by chemical inhibitors. The anti-viral effect was assessed by immunofluorescence for RV-16 protein. EPs^®7630 upregulated VDR expression through Erk1/2 MAPK and thereby increased the cell's sensitivity to calcitriol. Compared ton untreated cells, the shift of the VDR into the nucleus at 5.3 times lower calcitriol concentration. EPs^®7630 increased Erk1/2 MAPK signaling, but reduced p38 phosphorylation, and had no effect on Jun N-terminal kinase (JNK). EPs^®7630 improved the anti-viral effect of vitamin D on RV-16 infection by 2.1 folds compared to vitamin D alone or to untreated cells. Furthermore, EPs^®7630 improved the differentiation of epithelial cells by upregulating E-cadherin expression through Erk1/2. In conclusion, EPs^®7630 increased host defense against Rhinovirus infection by upregulating the VDR and the differentiation of epithelial cells.

Non-classical effects of vitamin D: Non-bone effects of vitamin D

Our understanding of vitamin D has improved considerably in recent years. The role of vitamin D in preventing osteoporotic fractures is now well-established. However, an important controversy has emerged in the last decade concerning the effects of the active form of vitamin D (1,25-dihydroxy-vitamin D) on tissues other than bone (non-classical effects). The demonstration that the vitamin D receptor (VDR) is ubiquitously, expressed combined with increasing observational data supporting a relationship between the level of 25-hydroxy-vitamin D in the serum and chronic metabolic disorders, cardiovascular disease and neoplasms, have led to its redefinition as a steroid hormone and the proposal of its use in preventing and/or treating those diseases. This article is an update on the different non-bone or non-classical effects of "vitamin-hormone D", and its potential preventive or therapeutic role in certain diseases, however, this review is not exhaustive. The different modalities of substitution or supplementation proposed in France by the Groupe de Recherche et d'Information sur les Ostéoporoses (GRIO) are also summarised.

Association Between Vitamin D and Novel SARS-CoV-2 Respiratory Dysfunction - A Scoping Review of Current Evidence and Its Implication for COVID-19 Pandemic

OBJECTIVES

To assess the association between vitamin D deficiency and increased morbidity/mortality with COVID-19 respiratory dysfunction.

DESIGN

Scoping review.

DATA SOURCES

Ovid MEDLINE (1946 to 24 of April 2020) and PubMed (2020 to 17 of September 2020).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

A search using the search terms: [(cholecalciferol or ergocalciferol or vitamin D2 or vitamin D3 or vitamin D or 25OHD) and (SARS-CoV-2 or coronavirus or COVID or betacoronavirus or MERS-CoV or SARS-CoV or respiratory infection or acute respiratory distress syndrome or ARDS)]m.p. was conducted on the 24/04/2020 (Search A) and 17/09/2020 (Search B).

RESULTS

91 studies were identified as being concerned with Acute Respiratory Infection (ARI)/Acute Respiratory Distress Syndrome (ARDS) and vitamin D, and 25 publications specifically explored the role of vitamin D deficiency in the development and progression of SARS-CoV-2/COVID-19 related ARDS. Search "A" identified three main themes of indirect evidence supporting such an association. Consistent epidemiological evidence exists linking low vitamin D levels to increased risk and severity of respiratory tract infections. We also report on plausible biological processes supporting such an association; and present weaker evidence supporting the benefit of vitamin D supplementation in reducing the risk and severity of ARIs. Uncertainty remains about what constitutes an appropriate dosing regimen in relation to reducing risk/severity of ARI/ARDS. More recent evidence (Search B) provided new insights into some direct links between vitamin D and COVID-19; with a number of cohort and ecological studies supporting an association with PCR-positivity for SARS-CoV-2 and vitamin D deficiency. The exact efficacy of the vitamin D supplementation for prevention of, or as an adjunct treatment for COVID-19 remains to be determined; but a number of randomized control trials (RCTs) currently underway are actively investigating these potential benefits.

CONCLUSION

Our rapid review of literature supports the need for observational studies with COVID-19 infected populations to measure and assess vitamin D levels in relation to risk/severity and outcomes; alongside RCTs designed to evaluate the efficacy of supplementation both in preventive and therapeutic contexts. The overlap in the vitamin D associated biological pathways with the dysregulation reported to drive COVID-19 outcomes warrants further investigation.

Controversial Effects of Vitamin D and Related Genes on Viral Infections, Pathogenesis, and Treatment Outcomes

Vitamin D (VD) plays an essential role in mineral homeostasis and bone remodeling. A number of different VD-related genes (VDRG) are required for the metabolic activation of VD and the subsequent induction of its target genes. They include a set of genes that encode for VD-binding protein, metabolic enzymes, and the VD receptor. In addition to its well-characterized skeletal function, the immunoregulatory activities of VD and the related polymorphisms of VDRG have been reported and linked to its therapeutic and preventive actions for the control of several viral diseases. However, in regards to their roles in the progression of viral diseases, inconsistent and, in some cases, contradictory results also exist. To resolve this discrepancy, I conducted an extensive literature search by using relevant keywords on the PubMed website. Based on the volume of hit papers related to a certain viral infection, I summarized and compared the effects of VD and VDRG polymorphism on the infection, pathogenesis, and treatment outcomes of clinically important viral diseases. They include viral hepatitis, respiratory viral infections, acquired immunodeficiency syndrome (AIDS), and other viral diseases, which are caused by herpesviruses, dengue virus, rotavirus, and human papillomavirus. This review will provide the most current information on the nutritional and clinical utilization of VD and VDRG in the management of the key viral diseases. This information should be valuable not only to nutritionists but also to clinicians who wish to provide evidence-based recommendations on the use of VD to virally infected patients.

The Role of Vitamin D Deficiency in Children With Recurrent Wheezing-Clinical Significance

Recurrent wheezing (RW) in infancy is one of the most frequent reasons for parents to consult health care providers and creates a significant global burden. Clinical course of RW is difficult to predict, also which infants will progress to asthma, since no valid biomarkers have been established. Identification of those infants with RW who are at risk of further recurrences and/or severe acute respiratory tract infection (ARTI) could help pediatricians to improve their therapeutic decisions. Increasing research interest is focused on the extra-skeletal actions of vitamin D (VD) and the clinical impact of VD insufficiency/deficiency. As VD deficiency could be a risk factor for causing RW in children, measurement of their serum level of 25-hydroxycholecalciferol [25(OH)D] is recommended. In the case of deficiency, VD administration is recommended in age-appropriate doses for at least 6 weeks, until achievement of normal blood 25(OH)D level, followed by supplementation as long as exposure to sun is inadequate. Higher doses of VD given in an attempt to prevent asthma development appear to be of no additional benefit. In children with severe ARTI, VD level is recommended to be assess.

Association of polymorphisms in the vitamin D receptor gene with susceptibility to and severity of hand, foot, and mouth disease caused by coxsackievirus A16

Coxsackievirus A16 (CA16) remains the most common causative agent of hand, foot, and mouth disease (HFMD), and is related to high incidence and critical complications. Vitamin D receptor (VDR) activity might affect the outcome of CA16 infection. Our case-control research aims to evaluate the relationship between VDR polymorphisms in the gene encoding and susceptibility to and severity of HFMD due to CA16. Three single-nucleotide polymorphisms (SNPs) of VDR gene were selected according to functional prediction and linkage disequilibrium, and were examined utilizing the SNPscan method to identify possible associations with HFMD caused by CA16. A significant relationship was found in the HFMD cases of polymorphism rs11574129 (GA vs GG: odds ratio (OR) = 0.068, 95% confidence interval (CI) = 0.007-0.693, P = .023; GA + AA vs GG: OR = 0.322, 95%CI = 0.106-0.984, P = .047), and vitamin D levels in genotype AA were significantly higher than those in genotype GG (P < .05). These results suggest that VDR rs11574129 may influence genetic susceptibility to CA16-associated HFMD.

Vitamin D Deficiency is Associated with Increased Use of Antimicrobials among Preschool Girls in Ethiopia

Preschool children in Addis Ababa, Ethiopia, are highly exposed to influenza viruses. Factors related to infections, nutrition, and environmental conditions that might explain the burden of influenza among these children were investigated. Ninety-five preschool children, 48 girls and 47 boys, were followed clinically for 12 months. Illness and immune responses to influenza; three other respiratory viruses; five airway pathogenic bacteria; and levels of vitamins D, A, and B12 were assessed. Most of the children had antibodies to numerous respiratory viral and bacterial agents at study start, and many were infected during follow-up. Twenty-five girls and 25 boys fell ill during the study, and were treated with one or more courses of systemic antimicrobials. Ninety percent of both girls and boys had 25-hydroxyvitamin D [25(OH)D] levels below the recommended levels. While there was no overall difference in the levels of vitamins D, A, and B12 between girls and boys, treated girls had significantly lower 25(OH)D levels than non-treated girls and treated boys. There was a considerable number of short for age children, but only the short treated girls had significantly lower 25(OH)D levels than the non-treated children. Preschool girls with low 25(OH)D levels were more vulnerable to pathogenic microbes than boys.