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

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

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

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.

A Retrospective Chart Review Evaluating Changes in 25-Hydroxyvitamin D Levels among Patients Attending the University Healthcare Centre during the COVID-19 Pandemic

COVID-19-pandemic-related home confinement aids in limiting the spread of the virus but restricts exposure to sunlight, thereby possibly affecting 25(OH)D concentrations. This study aimed to investigate the effect of lockdown measures on 25(OH)D levels in outpatients visiting the healthcare centre over a period of two years. In this retrospective chart review, outpatients who visited a university healthcare centre for a health check-up over a period of two years were included. The patients' 25(OH)D serum levels and status were compared before, during, and after the lockdown periods. A total of 7234 patients were included in this study, with a mean age of 34.66 ± 16.78. The overall prevalence of 25(OH)D insufficiency, deficiency and sufficiency was 33.8%, 30.7% and 35.4%, respectively. The proportion of individuals with 25-(OH) D deficiency prior to lockdown was 29% and this proportion increased in the lockdown and post-lockdown periods to 31.1% and 32%, respectively. Although gender was less likely to have an impact on the 25 (OH) D level during the lockdown period (p = 0.630), we found an association between gender and 25 (OH) D status in the pre-lockdown and post-lockdown periods (p < 0.001 and p < 0.001, respectively). Another association between nationality and 25 (OH)D levels was found before, during and after the lockdown periods (p < 0.001). In addition, the youngest population, aged between 1 and 14, was strongly affected by the home confinement. Age had a positive and significant (p < 0.05) effect on 25 (OH) D status regardless of the different periods. Moreover, in the pre-lockdown period, male outpatients had 1.56 chance of having a sufficient level of 25 (OH)D. However, during the lockdown period, this chance decreased to 0.85 and then increased to 0.99 after the lockdown period. We found no statistically significant difference in the mean serum concentrations or in the prevalence of vitamin D insufficiency when we compared values from before, during and immediately after the COVID-19 lockdown period. However, there was a generally increased prevalence of vitamin D insufficiency in our study population. Another association between gender, nationality and age groups with 25(OH) D was found. Regular exposure to UVR is recommended for maintaining adequate vitamin D levels and to prevent vitamin D deficiency. Further research is needed to determine the best indications for vitamin D supplementation if confinement periods are extended and to consider the potential health consequences of prolonged confinement periods not only on vitamin D status but also on overall public health. The findings of this study may be considered by stakeholders for a targeted supplementation approach for risk groups.

Susceptibility to COVID-19 Nutrition Misinformation and Eating Behavior Change during Lockdowns: An International Web-Based Survey

To understand the susceptibility to nutrition-health misinformation related to preventing, treating, or mitigating the risk of COVID-19 during the initial lockdowns around the world, the present international web-based survey study (15 April-15 May 2020) gauged participants' (n = 3707) level of nutrition-health misinformation discernment by presenting them with 25 statements (including unfounded or unproven claims circulated at the time), alongside the influence of information sources of varying quality on the frequency of changes in their eating behavior and the extent of misinformation held, depending on the source used for such changes. Results revealed widespread misinformation about food, eating, and health practices related to COVID-19, with the 25 statements put to participants receiving up to 43% misinformed answers (e.g., 'It is safe to eat fruits and vegetables that have been washed with soap or diluted bleach'). Whereas higher quality information sources (nutrition scientists, nutrition professionals) had the biggest influence on eating behavior change, we found greater misinformation susceptibility when relying on poor quality sources for changing diet. Appropriate discernment of misinformation was weakest amongst participants who more frequently changed their eating behavior because of information from poor quality sources, suggesting disparities in the health risks/safety of the changes performed.

A Questionnaire Survey of Personal and Occupational Variables Associated With SARS-COV-2 Infection in Health Care Personnel of the Spanish Central Military Hospital

INTRODUCTION

Spain is the country with the highest number of health care workers affected by coronavirus disease 2019 (COVID-19) in the world. The aim of this study was to describe the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection in health care worker (HCW) at the Gómez Ulla Military Hospital (HCDGU).

MATERIALS AND METHODS

A case-control study was conducted during the first outbreak of COVID 19 at GUMH. The study was extended to the total number of HCW in the hospital who met the inclusion criteria. Health care worker of the HCDGU were civilian and military personnel that included nursing and medicine students of Spanish Military Academy, medicine specialty residents, and nursing residents of Medical Surgical Specialty in Operations (EMQO). A questionnaire of 33 items was prepared. The questionnaire was sent by e-mail to the entire population of study. With this questionnaire personnel were classified into sick (cases) or healthy.

RESULTS AND CONCLUSIONS

One hundred fifty professionals answered the questionnaire. Cases were defined as those who tested positive in the diagnostic tests (n = 28, 20.7%) and no cases were those who tested negative (n = 107, 79.3%). Therefore, the percentage of SARS-CoV-2 in the GUMH was 20.7%. Of the total number of cases, 64.3% were men (P < .05), with a mean age of 47.1 years (SD 13.3), a mean BMI of 25.3 (SD 3.8), and 48.2% being overweight. Of the total cases, 59.3% had "A" blood group type and 69.2% were Rh positive. 50% were physicians, 32.1% were nurses, and 17.9% were auxiliary nurses (P < .05). Cases and controls with vitamin D deficiency and who took supplements had a lower risk of suffering COVID-19, with significant differences. Fever, cough, and diarrhea were found in at least 50% of the samples with significant differences.

Recent advances in vitamin D implications in chronic respiratory diseases

Chronic airway inflammatory and infectious respiratory diseases are the most common medical respiratory conditions, associated with significant morbidity and mortality. Vitamin D (1,25(OH)₂D₃) deficiency has been shown to be highly prevalent in patients with chronic airway inflammatory and infectious diseases, correlated with increased disease severity. It has been established that vitamin D modulates ongoing abnormal immune responses in chronic respiratory diseases and is shown to restrict bacterial and viral colonization into the lungs. On the contrary, other studies revealed controversy findings regarding vitamin D efficacy in respiratory diseases. This review aims to update the current evidence regarding the role of vitamin D in airway inflammation and in various respiratory diseases. A comprehensive search of the last five years of literature was conducted using MEDLINE and non-MEDLINE PubMed databases, Ovid MEDLINE, SCOPUS-Elsevier, and data from in vitro and in vivo experiments, including clinical studies. This review highlights the importance of understanding the full range of implications that vitamin D may have on lung inflammation, infection, and disease severity in the context of chronic respiratory diseases.

Vitamin D and SARS-CoV2 infection, severity and mortality: A systematic review and meta-analysis

To assess the evidence on SARS-CoV2 infection and Covid-19 in relation to deficiency and supplementation of vitamin D, we conducted a systematic review up to April 2021. We summarised data from 38 eligible studies, which presented risk estimates for at least one endpoint, including two RCT and 27 cohort-studies: 205565 patients with information on 25OHD status and 2022 taking vitamin D supplementation with a total of 1197 admitted to the ICU or who needed invasive mechanical ventilation or intubation and hospital stay, and more than 910 Covid-19 deaths. Primary outcomes were severity and mortality and the main aim was to evaluate the association with vitamin D supplementation. Random effects models showed that supplementation was associated with a significant lower risk of both Covid-19 severe disease (SRR 0.38, 95% CI 0.20-0.72, 6 studies) and mortality (SRR 0.35, 95% CI 0.17-0.70, 8 studies). There were no statistically significant dose differences between studies: summary estimates with regular doses remain statistically significant, suggesting that higher doses are not necessary. For patients on vitamin D supplementation, a greater reduction in mortality risk emerged in older individuals and at higher latitudes. Regarding the quality of studies, assessed using the New Castle-Ottawa quality scale, the analysis revealed in most cases no statistically significant differences between low, medium or high quality studies. We found significant associations of vitamin D supplementation with Covid-19, encompassing risks of disease worsening and mortality, especially in seasons characterized by 25OHD deficiency and with not severe patients. Dedicated randomized clinical studies are encouraged to confirm these results.

Verifying the Theory of Climate Affecting Lethality of COVID-19 by an Analysis in Two Climatic Zones of Chile

Introduction:

The study of seasonal influences on the COVID-19 pandemic can take advantage of the unique position of Chile and its different climatic profiles in the north-south extension. The purpose is to verify the influence of seasonal climate changes on the COVID-19 in the temperate and sub-arctic areas of Chile.

Methods:

We monitored the evolution of CFR in temperate versus sub-boreal regions, reporting from the John Hopkins University COVID-19 Center on the CFR in each province in midwinter, spring, and early summer.

Results:

CFR worsened from mid-winter to mid-spring in the temperate zone of Chile, while in the sub-boreal area the CFR improves in the same period, (Kruskal Wallis Test, p=0.004). In the temperate zone after the increase in late winter-early spring, CRF tends to stabilize; on the contrary in the sub-boreal zone, there is a more marked tendency to worsen the CFR at the same time (Kruskal Wallis Test, p=0.010). The temperate zone of Chile shows a CFR increasing until spring-like temperate Europe, unlike Europe CFR does not decrease in summer, but the mean minimum temperature in temperate Chile is lower in summer than in temperate Europe. In Patagonian, CFR remains stable or drops from winter to spring but increases in early summer.

Conclusion:

The temperate and sub-boreal zones of Chile have a markedly different CFR variation profile during the COVID-19 pandemic.

Deficiency and Insufficiency of Vitamin D in Women of Childbearing Age: A Systematic Review and Meta-analysis

OBJECTIVE

 To estimate the prevalence of inadequate vitamin D level and its associated factors for women of childbearing age in Brazil.

METHODS

 A systematic review was conducted (last updated May 2020). Meta-analyses were performed using the inverse-variance for fixed models with summary proportion calculation by Freeman-Tukey double arcsine. Reporting and methodological quality were assessed using the Joanna Briggs Institute tool for prevalence studies.

RESULTS

 Our review identified 31 studies, comprising 4,006 participants. All the studies had at least one weakness, mainly due to the use of convenience sampling and small sample size. The overall prevalence of vitamin D deficiency, insufficiency, and both deficiency and insufficiency were 35% (confidence interval, 95%CI: 34-37%), 42% (95%CI: 41-44%), and 72% (95%CI: 71-74%), respectively.

CONCLUSION

 Although the magnitude of the prevalence of inadequate levels of vitamin D is uncertain, the evidence suggests that presence of vitamin D deficiency or insufficiency in women of reproductive age can cause moderate to severe problems.

Population vitamin D status might be related to COVID-19 mortality but not with infection rate in Africa: evidence from ecological analysis

Introduction

there is a large body of literature that has linked vitamin D status in the population with COVID-19 infection risk and disease severity. However, there is paucity of evidence in African context. Hence, this study aimed to conduct an ecological analysis to explore correlation between population level vitamin D status, COVID-19 infection, and mortality in Africa.

Methods

an ecological study was conducted using data from different open sources, published literatures and organizational databases. In the final analysis, we included 23 African countries which had data on prevalence of vitamin D deficiency, population level mean serum 25 (OH) D concentrations and COVID-19 data. We employed spearman correlation and linear regression. All tests were two-sided, and P- value <0.05 was considered statistically significant.

Results

based on our analysis, the prevalence of vitamin D deficiency is positively correlated (r=0.6265; p= 0.0094) while mean 25(OH) D concentration is negatively correlated (r=-0.4941; p= 0.0194) with COVID-19 mortality. In addition, the median age of the national population (r=0.7015; p= 0.0003), prevalence of current use of tobacco (r=0.6071; p= 0.0075) and prevalence of obesity among adult population (r=0.7143; p= 0.0003) were positively correlated with both COVID-19 infection and mortality in Africa. Nonetheless, vitamin D status was not positively correlated with observed case fatality rate and COVID-19 infection rate.

Conclusion

population vitamin D status might be related to COVID-19 mortality but not with infection rate in Africa. Due to the increasing weight of evidence that shows a link between COVID-19 and vitamin D, we strongly recommend well-designed controlled studies to explore causality and clinical trials to find out the effect of vitamin-D supplementation in the treatment and prevention of COVID-19 in African settings.

Nutritional risk of vitamin D, vitamin C, zinc, and selenium deficiency on risk and clinical outcomes of COVID-19: A narrative review

The pathogenicity of the current coronavirus disease (COVID-19) shows postulates that optimal status of essential nutrients is crucial in supporting both the early viraemic and later hyperinflammatory phases of COVID-19. Micronutrients such as vitamin C, D, zinc, and selenium play roles in antioxidant, anti-inflammatory, antithrombotic, antiviral, and immuno-modulatory functions and are useful in both innate and adaptive immunity. The purpose of this review is to provide a high-level summary of evidence on clinical outcomes associated with nutritional risk of these micronutrients observed in patients with COVID-19. A literature search was performed on PubMed and Google Scholar to obtain findings of cross-sectional and experimental studies in humans. The search resulted in a total of 1212 reports including all nutrients, but only 85 were included according to the eligibility criteria. Despite the diversity of studies and the lack of randomized clinical trials and prospective cohorts, there is evidence of the potential protective and therapeutic roles of vitamin C, D, zinc, and selenium in COVID-19. The findings summarized in this review will contribute to guide interventions in clinical practice or in future clinical studies.

Vitamin D Status and SARS-CoV-2 Infection in a Cohort of Kidney Transplanted Patients

BACKGROUND

Recently the protective role of 25-hydroxyvitamin D (25(OH)D) against viral infections has been hypothesized. We evaluated the association between vitamin D status and SARS-CoV-2 infection susceptibility and severity in a cohort of kidney transplanted patients (KTxp).

METHODS

A total of 61 KTxp with SARS-CoV-2 infection (COV+) were matched with 122 healthy KTxp controls (COV-). Main biochemical parameters at 1, 6, and 12 months before SARS-CoV-2 infection were recorded. Vitamin D status was considered as the mean of two 25(OH)D measures obtained 6 ± 2 months apart during the last year. The severity of SARS-CoV-2 infection was based on the need for hospitalization (HOSP+) and death (D+).

RESULTS

25(OH)D levels were lower in COV+ than in controls [19(12-26) vs. 23(17-31) ng/mL, p = 0.01]. No differences among the other biochemical parameters were found. The SARS-CoV-2 infection discriminative power of 25(OH)D was evaluated by ROC-curve (AUC 0.61, 95% CI 0.5-0.7, p = 0.01). 25(OH)D was not significantly different between HOSP+ and HOSP- [17(8-25) vs. 20(15-26) ng/mL, p = 0.19] and between D+ and D- [14(6-23) vs. 20(14-26) ng/mL, p = 0.22] and had no significant correlation with disease length.

CONCLUSIONS

During the year preceding the infection, 25(OH)D levels were lower in COV+ KTxp in comparison with controls matched for demographic features and comorbidities. No significant association between vitamin D status and SARS-CoV-2 infection related outcomes was found.

The Interaction of Vitamin D and Corticosteroids: A Mortality Analysis of 26,508 Veterans Who Tested Positive for SARS-CoV-2

This data-based cohort consisted of 26,508 (7%) United States veterans out of the 399,290 who tested positive for SARS-CoV-2 from 1 March to 10 September 2020. We aimed to assess the interaction of post-index vitamin D (Vit D) and corticosteroid (CRT) use on 30-day mortality among hospitalized and non-hospitalized patients with coronavirus disease 2019 (COVID-19). Combination Vit D and CRT drug use was assessed according to four multinomial pairs (-|+, -|-, +|+, +|-). Respective categorical effects were computed on a log-binomial scale as adjusted relative risk (aRR). Approximately 6% of veterans who tested positive for SARS-CoV-2 died within 30 days of their index date. Among hospitalized patients, a significantly decreased aRR was observed for the use of Vit D in the absence of CRTs relative to patients who received CRTs but not Vit D (aRR = 0.30; multiplicity corrected, p = 0.0004). Among patients receiving systemically administered CRTs (e.g., dexamethasone), the use of Vit D was associated with fewer deaths in hospitalized patients (aRR = 0.51) compared with non-hospitalized patients (aRR = 2.5) (P-for-Interaction = 0.0071). Evaluating the effect of modification of these compounds in the context of hospitalization may aid in the management of COVID-19 and provide a better understanding of the pathophysiological mechanisms underlying this and future infectious disease outbreaks.

Rays of immunity: Role of sunshine vitamin in management of COVID-19 infection and associated comorbidities

The catastrophic pandemic engendered due to the Novel coronavirus (COVID-19) outbreak which causes severe clinical afflictions on the respiratory system has severely high morbidity and mortality rates. The requirement of novel compounds is at utmost importance due to lack of targeted drug molecule to treat the afflictions and restrict the viral infection and for the usage of prophylactic treatment to avoid the spread of the infection is of utmost importance. Vitamin D is one such naturally available multifunctional molecule, which plays an eminent role in the immune system and instigation of numerous cellular pathways further promoting health benefits and enhancing the human quality of life. This article reviews the current standpoint scenario and future prevalence of vitamin D supplementation in the management of covid-19 patients. Novel findings of Vitamin D suggest that along with regulation of cell growth, neuroprotective and mood-stabilizing effects, it regulates the immune response also modulate cytokine Interleukin-6 (IL-6) by inducing progesterone-induced blocking factor (PIBF), given the IL-6 levels are considerably high in COVID-19 patients which increases the further complications. Vitamin D also have its effect on angiotensin converting enzyme (ACEII) inhibitor through which the COVID-19 virus makes cell entry. Numerous research data elucidate the play of Vitamin D, in complications of COVID-19 including the most common comorbid conditions, neurological manifestations and immunological aspects makes it an ideal molecule for adjuvant therapy. Including Vitamin D as add-on therapy in the management of COVID-19 might aid the arrest of infection and helps fight this arduous epidemic.

Killing Two Birds with One Stone by Administration of Soluble ACE2: A Promising Strategy to Treat Both Cardiovascular Diseases and SARS-CoV-2 Infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells mainly by the angiotensin converting enzyme 2 (ACE2) receptor, which can recognize the spike (S) protein by its extracellular domain. Previously, recombinant soluble ACE2 (sACE2) has been clinically used as a therapeutic treatment for cardiovascular diseases. Recent data demonstrated that sACE2 can also be exploited as a decoy to effectively inhibit the cell entry of SARS-CoV-2, through blocking SARS-CoV-2 binding to membrane-anchored ACE2. In this study, we summarized the current findings on the optimized sACE2-based strategies as a therapeutic agent, including Fc fusion to prolong the half-life of sACE2, deep mutagenesis to create high-affinity decoys for SARS-CoV-2, or designing the truncated functional fragments to enhance its safety, among others. Considering that COVID-19 patients are often accompanied by manifestations of cardiovascular complications, we think that administration of sACE2 in COVID-19 patients may be a promising therapeutic strategy to simultaneously treat both cardiovascular diseases and SARS-CoV-2 infection. This review would provide insights for the development of novel therapeutic agents against the COVID-19 pandemic.

Understanding the Co-Epidemic of Obesity and COVID-19: Current Evidence, Comparison with Previous Epidemics, Mechanisms, and Preventive and Therapeutic Perspectives

PURPOSE OF REVIEW

A growing body of evidence suggests that obesity and increased visceral adiposity are strongly and independently linked to adverse outcomes and death due to COVID-19. This review summarizes current epidemiologic data, highlights pathogenetic mechanisms on the association between excess body weight and COVID-19, compares data from previous pandemics, discusses why COVID-19 challenges the "obesity paradox," and presents implications in prevention and treatment as well as future perspectives.

RECENT FINDINGS

Data from meta-analyses based on recent observational studies have indicated that obesity increases the risks of infection from SARS-CoV-2, severe infection and hospitalization, admission to the ICU and need of invasive mechanical ventilation (IMV), and the risk of mortality, particularly in severe obesity. The risks of IMV and mortality associated with obesity are accentuated in younger individuals (age ≤ 50 years old). The meta-inflammation in obesity intersects with and exacerbates underlying pathogenetic mechanisms in COVID-19 through the following mechanisms and factors: (i) impaired innate and adaptive immune responses; (ii) chronic inflammation and oxidative stress; (iii) endothelial dysfunction, hypercoagulability, and aberrant activation of the complement; (iv) overactivation of the renin-angiotensin-aldosterone system; (v) overexpression of the angiotensin-converting enzyme 2 receptor in the adipose tissue; (vi) associated cardiometabolic comorbidities; (vii) vitamin D deficiency; (viii) gut dysbiosis; and (ix) mechanical and psychological issues. Mechanistic and large epidemiologic studies using big data sources with omics data exploring genetic determinants of risk and disease severity as well as large randomized controlled trials (RCTs) are necessary to shed light on the pathways connecting chronic subclinical inflammation/meta-inflammation with adverse COVID-19 outcomes and establish the ideal preventive and therapeutic approaches for patients with obesity.

Vitamin D and acute and severe illness - a mechanistic and pharmacokinetic perspective

The COVID-19 pandemic has generated high interest in factors modulating risk of infection, disease severity and recovery. Vitamin D has received interest since it is known to modulate immune function and vitamin D deficiency is associated with increased risk of respiratory infections and adverse health outcomes in severely ill patients. There are no population representative data on the direct relationship between vitamin D status and SARS-CoV-2 infection risk and severity of COVID-19. Data from intervention studies are limited to 4 studies. Here we summarise findings regarding vitamin D status and metabolism and their alterations during severe illness, relevant to COVID-19 patients. Further, we summarise vitamin D intervention studies with respiratory disease outcomes and in critically ill patients and provide an overview of relevant patient and population guidelines. Vitamin D deficiency is highly prevalent in hospitalised patients, particularly when critically ill including those with COVID-19. Acute and critical illness leads to pronounced changes in vitamin D metabolism and status, suggestive of increased requirements. This needs to be considered in the interpretation of potential links between vitamin D status and disease risk and severity and for patient management. There is some evidence that vitamin D supplementation decreases the risk of respiratory tract infections, while supplementation of ICU patients has shown little effect on disease severity or length of treatment. Considering the high prevalence of deficiency and low risks associated with supplementation, pro-actively applying current population and patient management guidelines to prevent, monitor and correct vitamin D deficiency is appropriate.

Vitamin D Status and Clinical Outcomes in Acute Respiratory Distress Syndrome: A Secondary Analysis From the Assessment of Low Tidal Volume and Elevated End-Expiratory Volume to Obviate Lung Injury (ALVEOLI) Trial

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a highly morbid condition that has limited therapeutic options. Optimal vitamin D status has been linked to immunological effects that may benefit critically ill patients. Therefore, we investigated whether admission 25-hydroxyvitamin D levels (25OHD) are associated with clinical outcomes in ARDS patients.

METHODS

We performed a secondary analysis of data from a randomized, controlled trial comparing oxygenation strategies in 549 patients with ARDS (NCT00000579). Baseline 25OHD was measured in stored plasma samples. We investigated the relationship between vitamin D status and ventilator-free days (VFD) as well as 90-day survival, using linear regression and Cox proportional hazard models, respectively. Analyses were adjusted for age, race, and Acute Physiology and Chronic Health Evaluation III score.

RESULTS

Baseline 25OHD was measured in 476 patients. 90% of these individuals had 25OHD <20 ng/ml and 40% had 25OHD <10 ng/ml. Patients with 25OHD <20 ng/ml were likely to be ventilated for 3 days longer than patients with levels ≥20 ng/ml (ß 3.41; 95%CI 0.42-6.39: P = 0.02). Patients with 25OHD <10 ng/ml were likely to be ventilated for 9 days longer (ß 9.27; 95%CI 7.24-11.02: P < 0.001) and to have a 34% higher risk of 90-day mortality (HR 1.34; 95% CI 1.06-1.71: P = 0.02) compared to patients with levels >10 ng/ml.

CONCLUSIONS

In patients with ARDS, vitamin D status is associated with duration of mechanical ventilation and 90-day mortality. Randomized, controlled trials are warranted to determine whether vitamin D supplementation improves clinical outcomes in ARDS patients.

Vitamin D Status in Adolescents during COVID-19 Pandemic: A Cross-Sectional Comparative Study

Vitamin D has been claimed to be effective in the response to infections, including the respiratory syndrome coronavirus 2 (SARS-CoV-2). It is supposed that lockdown measures and fear of SARS-CoV-2 infection might reduce vitamin D levels through the modification of lifestyle. However, very few data exist on the association between lockdown measures and vitamin D status in humans. For this cross-sectional comparative study, adolescents (n = 298) aged 18 to 19 years were enrolled during the compulsory military fitness-for-duty evaluation between July and December 2020 in Southern Switzerland. Beyond anthropometric measurements, participants filled in a structured questionnaire about their lifestyle and a blood specimen was sampled for the determination of total 25-hydroxy-vitamin D. The obtained data were compared with those of 437 adolescents enrolled at the military fitness-for-duty evaluation during the same period of the year in the context of the CENERI study (2014–2016). The anthropometric measures were similar between the two study groups. The levels of vitamin D were also comparable (77 (64–91) vs. 74 (60–92) nmol/L, p = 0.50; median and interquartile range). A total of 38 (13%) and 43 (9.8%) subjects presented insufficient (<50 nmol/L) levels of vitamin D (p = 0.42) during the current pandemic and in the CENERI study, respectively. These data do not support the hypothesis that during the SARS-CoV-2 pandemic, late adolescents are at higher risk of vitamin insufficiency.

New Roles for Vitamin D Superagonists: From COVID to Cancer

Vitamin D is a potent steroid hormone that induces widespread changes in gene expression and controls key biological pathways. Here we review pathophysiology of vitamin D with particular reference to COVID-19 and pancreatic cancer. Utility as a therapeutic agent is limited by hypercalcemic effects and attempts to circumvent this problem have used vitamin D superagonists, with increased efficacy and reduced calcemic effect. A further caveat is that vitamin D mediates multiple diverse effects. Some of these (anti-fibrosis) are likely beneficial in patients with COVID-19 and pancreatic cancer, whereas others (reduced immunity), may be beneficial through attenuation of the cytokine storm in patients with advanced COVID-19, but detrimental in pancreatic cancer. Vitamin D superagonists represent an untapped resource for development of effective therapeutic agents. However, to be successful this approach will require agonists with high cell-tissue specificity.

COVID-19: Role of Nutrition and Supplementation

At the end of 2019, a new coronavirus (COVID-19) appeared on the world scene, which mainly affects the respiratory system, causing pneumonia and multi-organ failure, and, although it starts with common symptoms such as shortness of breath and fever, in about 2-3% of cases it leads to death. Unfortunately, to date, no specific treatments have been found for the cure of this virus and, therefore, it is advisable to implement all possible strategies in order to prevent infection. In this context, it is important to better define the role of all behaviors, in particular nutrition, in order to establish whether these can both prevent infection and improve the outcome of the disease in patients with COVID-19. In the literature, it is widely shown that states of malnutrition, overweight, and obesity negatively affect the immune system, leading to viral infections, and several studies have shown that nutritional interventions can act as immunostimulators, helping to prevent viral infections. Even if several measures, such as the assumption of a specific diet regimen, the use of dietary supplements, and other similar interventions, are promising for the prevention, management, and recovery of COVID-19 patients, it is important to highlight that strong data from randomized clinical trials are needed to support any such assumption. Considering this particular scenario, we present a literature review addressing several important aspects related to diet and SARS-CoV-2 infection, in order to highlight the importance of diet and supplementation in prevention and management of, as well as recovery from COVID-19.

Folate Levels in Patients Hospitalized with Coronavirus Disease 2019

We aimed to investigate the prevalence of decreased folate levels in patients hospitalized with Coronavirus Disease 2019 (COVID-19) and evaluate their outcome and the prognostic signifi-cance associated with its different levels. In this retrospective cohort study, data were obtained from the electronic medical records at the Sheba Medical Center. Folic acid levels were available in 333 out of 1020 consecutive patients diagnosed with COVID-19 infection hospitalized from January 2020 to November 2020. Thirty-eight (11.4%) of the 333 patients comprising the present study population had low folate levels. No significant difference was found in the incidence of acute kidney injury, hypoxemia, invasive ventilation, length of hospital stay, and mortality be-tween patients with decreased and normal-range folate levels. When sub-dividing the study population according to quartiles of folate levels, similar findings were observed. In conclusion, decreased serum folate levels are common among hospitalized patients with COVID-19, but there was no association between serum folate levels and clinical outcomes. Due to the important role of folate in cell metabolism and the potential pathologic impact when deficient, a follow-up of folate levels or possible supplementation should be encouraged in hospitalized COVID-19 patients. Fur-ther studies are required to assess the prevalence and consequences of folate deficiency in COVID-19 patients.