Protective Effect of Vitamin D Supplementation on COVID-19-Related Intensive Care Hospitalization and Mortality: Definitive Evidence from Meta-Analysis and Trial Sequential Analysis

Impact of vitamin D on COVID-19 and other viral diseases

This editorial aims to elucidate the intricate relationship between vitamin D and viral pathogenesis. It explores the anticipated role of vitamin D as a modulator in the immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other viral pathogens. The editorial comments are based on the review article by Engin et al. The potential role of vitamin D in modulating immune responses has been highlighted by several studies, suggesting that it may influence both the risk and severity of infections. Vitamin D receptors are present in immunocompetent cells, which indicates that vitamin D can potentially modulate innate and adaptive immune responses. This context is relevant in the pathophysiology of coronavirus disease 2019 (COVID-19), where the immune response to the virus can significantly impact the disease progression and outcome. The immunomodulatory effects of vitamin D can protect against SARS-CoV-2 infection by enhancing innate and adaptive immune responses. It also maintains the integrity of the body's physical barriers and modulates inflammatory responses, thereby preventing entry and replication of the virus. Many studies have suggested that adequate vitamin D levels help alleviate morbidity and mortality associated with COVID-19. Furthermore, vitamin D supplementation has been linked with a lower risk of severe disease and mortality in COVID-19 patients, particularly in those with a deficiency during seasons with less sunlight exposure.

Beyond Antivirals: Alternative Therapies for Long COVID

Long COVID or Post-Acute Sequelae of SARS-CoV-2 infection (PASC) is a condition characterized by numerous lingering symptoms that persist for weeks to months following the viral illness. While treatment for PASC is still evolving, several therapeutic approaches beyond traditional antiviral therapies are being investigated, such as immune-modulating agents, anti-inflammatory drugs, and various supportive interventions focusing at alleviating symptoms and enhancing recovery. We aimed to summarize the breadth of available evidence, identify knowledge gaps, and highlight promising non-antiviral therapies for Long COVID/PASC. We followed the framework of a scoping methodology by mapping existing evidence from a range of studies, including randomized clinical trials, observational research, and case series. Treatments evaluated include metformin, low-dose naltrexone (LDN), dexamethasone, statins, omega-3 fatty acids, L-arginine, and emerging therapies like intravenous immunoglobulin (IVIg) and therapeutic apheresis. Early findings suggest that metformin has the strongest clinical evidence, particularly from large phase 3 trials, while LDN and dexamethasone show potential based on observational studies. However, many treatments lack robust, large-scale trials. This review emphasizes the need for further research to confirm the efficacy of these treatments and guide clinical practice for Long COVID management.

The Effect of Vitamin D Supplementation Post COVID-19 Infection and Related Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Vitamin D's role in COVID-19 management remains controversial. This meta-analysis aimed to evaluate the efficacy of vitamin D supplementation in patients with SARS-CoV-2 infection, focusing on mortality, intensive care unit (ICU) admissions, intubation rates, and hospital length of stay (LOS).

METHODS

A systematic review of PubMed/MEDLINE, Scopus, Cochrane, and Google Scholar databases was conducted. Randomized controlled trials (RCTs) and analytical studies investigating vitamin D supplementation in COVID-19 patients were included. The meta-analysis was performed using STATA MP 18.5, employing random-effect or fixed-effect models based on heterogeneity.

RESULTS

Twenty-nine studies (twenty-one RCTs, eight analytical) were analyzed. Vitamin D supplementation significantly reduced ICU admissions (OR = 0.55, 95% CI: 0.37 to 0.79) in RCTs and analytical studies (OR = 0.35, 95% CI: 0.18 to 0.66). Intubation rates were significantly reduced in RCTs (OR = 0.50, 95% CI: 0.27 to 0.92). Mortality reduction was significant in analytical studies (OR = 0.45, 95% CI: 0.24 to 0.86) but not in RCTs (OR = 0.80, 95% CI: 0.61 to 1.04). Subgroup analyses revealed more pronounced effects in older patients and severe COVID-19 cases. LOS showed a non-significant reduction (mean difference = -0.62 days, 95% CI: -1.41 to 0.18).

CONCLUSIONS

This meta-analysis suggests potential benefits of vitamin D supplementation in COVID-19 patients, particularly in reducing ICU admissions. However, the evidence varies across outcomes and patient subgroups. Discrepancies between RCTs and analytical studies highlight the need for further large-scale, well-designed trials accounting for baseline vitamin D status, standardized supplementation protocols, and patient characteristics to inform clinical guidelines for vitamin D use in COVID-19 management.

Bone Mineral Density, Bone Biomarkers, and Joints in Acute, Post, and Long COVID-19: A Systematic Review

SARS-CoV-2 is highly transmissible and affects the respiratory system. People with COVID-19 are at higher risk of physical and mental health conditions, which could impact bone health. The aim of this review was to explore the effects of COVID-19 on BMD, BTMs, and joints. An electronic search of the PubMed, Web of Science, Scopus, and Ovid Medline databases considered studies published between 1 January 2020 and 1 November 2023. The search was limited to English, original studies in adult humans. The title and abstract of the identified papers were screened, followed by a full-text review using inclusion and exclusion criteria. The data extracted included the study and participant characteristics, BTMs, BMD, and joint abnormalities. The Newcastle-Ottawa scale quality assessment tool was used to assess the risk of bias. Five studies involving 305 out of 495 infected individuals observed a reduced BMD after COVID-19, with the most significant reduction occurring a year later. Both bone resorption and bone formation markers decreased, while regulatory markers showed higher levels in infected patients. COVID-19 may harm bone health by increasing bone regulatory markers and reducing bone formation and absorption, leading to a lower BMD. Elderly, frail, and osteopenic or osteoporotic individuals are at higher risk and should be regularly monitored for bone loss if they have long COVID.

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.

Efficacy of vitamin D supplementation in the treatment of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials

Context

COVID-19 has substantial effects on respiratory health and overall well-being. Recent studies suggest vitamin D as a potential treatment, but the results are inconclusive.

Objective

The authors conducted a systematic review of randomized controlled trials (RCTs) to examine the link between vitamin D and patients with COVID-19.

Data sources

The authors searched electronic databases PubMed, Cochrane, CINAHL, EMBASE and Google Scholar from their inception till August 2023.

Study selection

Inclusion criteria used in our systematic review include: (1) patients who tested positive for COVID-19, (2) intervention was vitamin D supplementation, (3) the comparator was either a placebo, standard care of treatment, or, no treatment, (4) at least one of the clinical outcomes of interest were investigated, (5) study design being RCTs.

Data extraction

Two independent reviewers manually extracted information from selected articles, including study characteristics, patient characteristics, and the primary outcomes: all-cause mortality, ICU and hospital stay length and secondary outcomes: mechanical ventilation, supplemental oxygen, ICU admission, and adverse events. Risk ratios or mean differences and 95% CIs were calculated using a random-effects model.

Data synthesis

The authors' analysis included 14 RCTs with 2165 patients. Vitamin D significantly reduced ICU admissions and lowered the need for mechanical ventilation compared to placebo. However, it did not significantly affect hospital stay length, ICU stay length, mechanical ventilation duration, mortality, or the need for supplemental oxygen.

Conclusion

Vitamin D does not significantly improve certain clinical outcomes, such as hospital and ICU stay length, for patients with COVID-19. However, it still may be significantly beneficial in decreasing the burden on intensive care services.

COVID-19, Nutrients and Lifestyle Eating Behaviors: A Narrative Review

BACKGROUND

COVID-19 infection, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), quickly emerged as the most significant event of the new millennium. A balanced diet seems to ensure the proper functioning of the immune system and plays a fundamental role in the prevention of viral disease, inflammation, or thrombosis. The principal aim of this secondary study was to investigate the relationship between nutrients, lifestyle eating behaviors, and SARS-CoV-2 infection.

METHODS

A narrative review was conducted in the PubMed-Medline database, analyzing primary studies.

RESULTS

Our review identified 21 relevant studies: 13 focused on vitamins, 1 on omega-3 supplementation, 1 on probiotics, and 6 on lifestyle and dietary behaviors. Vitamin supplementation has shown promise in attenuating COVID-19 symptoms and reducing mortality risk. Specifically, vitamin D has demonstrated efficacy in enhancing immune responses among patients with the disease. While preliminary evidence suggests the potential benefits of omega-3 and probiotic supplementation in improving health outcomes for COVID-19 outpatients, further research is needed to solidify these findings.

CONCLUSIONS

The lifestyle changes imposed by lockdown measures have adversely affected psychological well-being and exacerbated health issues associated with reduced physical activity and poor dietary habits.

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.

Safety of High-Dose Vitamin C in Non-Intensive Care Hospitalized Patients with COVID-19: An Open-Label Clinical Study

Background: Vitamin C has been used as an antioxidant and has been proven effective in boosting immunity in different diseases, including coronavirus disease (COVID-19). An increasing awareness was directed to the role of intravenous vitamin C in COVID-19. Methods: In this study, we aimed to assess the safety of high-dose intravenous vitamin C added to the conventional regimens for patients with different stages of COVID-19. An open-label clinical trial was conducted on patients with COVID-19. One hundred four patients underwent high-dose intravenous administration of vitamin C (in addition to conventional therapy), precisely 10 g in 250 cc of saline solution in slow infusion (60 drops/min) for three consecutive days. At the same time, 42 patients took the standard-of-care therapy. Results: This study showed the safety of high-dose intravenous administration of vitamin C. No adverse reactions were found. When we evaluated the renal function indices and estimated the glomerular filtration rate (eGRF, calculated with the CKD-EPI Creatinine Equation) as the main side effect and contraindication related to chronic renal failure, no statistically significant differences between the two groups were found. High-dose vitamin C treatment was not associated with a statistically significant reduction in mortality and admission to the intensive care unit, even if the result was bound to the statistical significance. On the contrary, age was independently associated with admission to the intensive care unit and in-hospital mortality as well as noninvasive ventilation (N.I.V.) and continuous positive airway pressure (CPAP) (OR 2.17, 95% CI 1.41-3.35; OR 7.50, 95% CI 1.97-28.54; OR 8.84, 95% CI 2.62-29.88, respectively). When considering the length of hospital stay, treatment with high-dose vitamin C predicts shorter hospitalization (OR -4.95 CI -0.21--9.69). Conclusions: Our findings showed that an intravenous high dose of vitamin C is configured as a safe and promising therapy for patients with moderate to severe COVID-19.

Vitamin D Binding Protein: A Potential Factor in Geriatric COVID-19 Acute Lung Injury

Background

Previous research indicated that vitamin D binding protein (VDBP) is an independent multifunctional protein that plays a vital role in acute inflammatory and tissue damage. However, its role in acute lung injury (ALI) due to coronavirus disease 2019 (COVID-19) is unclear, and studies are lacking. This study intends to investigate the difference in serum VDBP levels in COVID-19 patients with ALI or without ALI and further explore the role of VDBP in the inflammatory response of ALI through cellular models.

Methods

The serum was collected from COVID-19 patients, and the concentration of serum VDBP was detected. Construct a VDBP gene-silencing plasmid and transfect it into human alveolar epithelial A549 cells. After 72 hours of lipopolysaccharide (LPS) intervention, The inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were detected, and cell counting kit-8 (CCK-8) assay was used to detect cell viability. Flow cytometry was used to detect cell apoptosis.

Results

The serum concentration of VDBP was significantly higher in COVID-19 with ALI (P < 0.05). Correlation analysis indicated serum VDBP positively correlated with leukocyte (r=0.329, P = 0.002), c-reaction protein (r = 0.470, P < 0.001), serum amyloid A (r = 0.900, P < 0.001), procalcitonin (r = 0.670, P < 0.001), and interleukin 6 (r = 0.452, P < 0.001). Simultaneously, the logistic regression analysis showed that increased serum VDBP was an independent risk factor for ALI in COVID-19 patients (OR 1.003 95% CI 1.001-1.006, P = 0.002). In human alveolar epithelial A549 cells, after LPS intervention, the inflammatory factor IL-1β and TNF-A significantly reduced in the VDBP gene silencing group compared to the negative control (NC) group (P < 0.05). The cell viability of the VDBP gene silencing group was significantly increased compared to the NC group, and the cell apoptosis rate was significantly reduced (P < 0.05).

Conclusion

In COVID-19 patients, acute lung injury may lead to increased serum concentration of VDBP. VDBP plays a vital role in promoting inflammatory response and apoptosis of bronchial epithelial cells.

Vitamin D regulates COVID-19 associated severity by suppressing the NLRP3 inflammasome pathway

BACKGROUND

The role of vitamin D3 (VitD3) in modulating innate and adaptive immunity has been reported in different disease contexts. Since the start of the coronavirus disease-2019 (COVID-19) pandemic, the role of VitD3 has been highlighted in many correlational and observational studies. However, the exact mechanisms of action are not well identified. One of the mechanisms via which VitD3 modulates innate immunity is by regulating the NLRP3-inflammasome pathway, being a main underlying cause of SARS-CoV-2-induced hyperinflammation.

AIMS AND MAIN METHODS

Blood specimens of severe COVID-19 patients with or without VitD3 treatment were collected during their stay in the intensive care unit and patients were followed up for 29 days. qPCR, western blot, and ELISA were done to investigate the mechanism of action of VitD3 on the NLRP3 inflammasome activation.

KEY FINDINGS

We here report the ability of VitD3 to downregulate the NLRP3-inflammsome pathway in severe COVID-19 patients. Lower inflammasome pathway activation was observed with significantly lower gene and protein expression of NLRP3, cleaved caspase-1, ASC and IL-1β among severe COVID-19 patients treated with VitD3. The reduction of the inflammasome pathway was associated with a reduction in disease severity markers and enhancement of type I IFN pathway.

SIGNIFICANCE

Our data reveals an important anti-inflammatory effect of VitD3 during SARS-CoV-2 infection. Further investigations are warranted to better characterize the ability of VitD3 to control disease pathogenesis and prevent progression to severe states. This will allow for a more efficient use of a low cost and accessible treatment like VitD3.

Vitamin D Levels and SARS-CoV-2 Infection among Medically Underserved Populations in the Minority and Rural Coronavirus Insights Study

BACKGROUND

Extant literature presents contradictory findings on the role of vitamin D on SARS-CoV-2 infection. Our study included an examination of the relationship between vitamin D levels and SARS-CoV-2 infection among the Minority and Rural Coronavirus Insights Study (MRCIS) cohort, a diverse population of medically underserved persons presenting at five Federally qualified health centers in the United States.

METHODS

We conducted a descriptive analysis to explore the relationship between vitamin D levels and SARS-CoV-2 infection among medically underserved participants. A combined molecular and serologic assessment was used to determine the prevalence of SARS-CoV-2 infection. Vitamin D was examined as both a categorical (vitamin D status: deficient, insufficient, optimal) and continuous (vitamin D level) variable. Chi-squared testing, polynomial regression models, and logistic regression models were used to assess the relationship between vitamin D and SARS-CoV-2 infection.

RESULTS

The overall SARS-CoV-2 infection rate among participants was 25.9%. Most participants were either vitamin D deficient (46.5%) or insufficient (29.7%), and 23.8% had an optimal level. Vitamin D status was significantly associated with key SARS-CoV-2 infection risk factors. As mean vitamin D levels increased, the proportion of participants with SARS-CoV-2 infection decreased. For every 10 ng/mL increase in vitamin D levels the odds of SARS-CoV-2 infection decreased by 12% when adjusting for race/ethnicity and age (main effect model). Participants who identified as Hispanic/Latino or Black non-Hispanic had approximately two times increased odds of SARS-CoV-2 infection when adjusting for age and vitamin D levels compared to white non-Hispanics. However, when additional factors were added to the main effect model, the relationship between vitamin D levels and SARS-CoV-2 infection did not remain significant.

CONCLUSION

Vitamin D levels were associated with an increased risk of SARS-CoV-2 infection. Hispanic/Latino and Black, non-Hispanic compared to White, non-Hispanic participants were at increased odds for infection, after adjusting for race/ethnicity and age.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

Mortality of hospitalized patients with COVID-19: Effects of treatment options (vitamin D, anticoagulation, isoprinosine, ivermectin) assessed by propensity score matching, retrospective analysis

INTRODUCTION

SARS-CoV-2 respiratory infection is associated with significant morbidity and mortality, especially in hospitalized high-risk patients. We aimed to evaluate the effects of treatment options (vitamin D, anticoagulation, isoprinosine, ivermectin) on hospital mortality in non-vaccinated patients during the 2021 spring wave in the Czech Republic.

METHODS

Initially, 991 patients hospitalized in the period January 1, 2021, to March 31, 2021, with PCR-confirmed SARS-CoV-2 acute respiratory infection in two university and five rural hospitals were included in the study. After exclusion of patients with an unknown outcome, a total of 790 patients entered the final analysis. The effects of different treatments were assessed in this cohort by means of propensity score matching.

RESULTS

Of the 790 patients, 282 patients died in the hospital; 37.7% were male and 33.3% were female. Age, sex, state of the disease, pneumonia, therapy, and several comorbidities were matched to simulate a case-control study. For anticoagulation treatment, 233 cases (full-dose) vs. 233 controls (prophylactic dose) were matched. The difference in mortality was significant in 16 of the 50 runs. For the treatment with isoprinosine, ivermectin, and vitamin D, none of the 50 runs led to a significant difference in hospital mortality.

CONCLUSION

Prophylactic-dose anticoagulation treatment in our study was found to be beneficial in comparison with the full dose. Supplementation with vitamin D did not show any meaningful benefit in terms of lowering the hospital mortality. Neither ivermectin nor, isoprinosine was found to significantly decrease hospital mortality.

Retrospective Analysis of Vitamin D Deficiency in an Adult Population of Arad County, Western Romania (2019-2022)

Vitamin D, a steroid hormone synthesized primarily in the skin upon exposure to ultraviolet light, is widely deficient across global populations. This study aimed to fill the data gap in Western Romania by measuring 25-hydroxy-vitamin D levels in a cohort of 7141 from Arad County. It was observed that women, younger adults (18-29 years), and older adults (70-79 years) had notably lower vitamin D levels compared to the average population. Additionally, there was a rise in vitamin D levels over the four-year span of 2018-2022, coinciding with the COVID-19 pandemic. Our research provides fresh data on those most susceptible to vitamin D deficiency and lays the groundwork for educational campaigns on vitamin D supplementation benefits.

Exploring demographical, clinical, and dietary determinants of vitamin D deficiency among adults in Douala, Cameroon during the COVID-19 era

Background and aim

Vitamin D deficiency (VDD) is a global public health problem in African populations. This study aimed at determining the prevalence, characteristics, and determinants of VDD in the era of SARS-CoV-2/COVID-19. This study was conducted from January to September 2022 in seven health facilities in Douala, Cameroon.

Methods

A structured, pre-tested questionnaire was administered to each participant to collect participants' information. Molecular detection of the SARS-CoV-2 genome was done. A serum level of 25-hydroxyvitamin D < 20 ng/mL was used to diagnose VDD.

Results

A total of 420 participants were included in the study. A Serum levels of 25(OH) vitamin D were reduced in SARS-CoV-2 (+) patients as compared to SARS-CoV-2 (-) patients (21.69 ± 5.64 ng/mL vs 42.09 ± 20.03 ng/mL, p < 0.0001). The overall prevalence of VDD was 10.2 %. SARS-CoV-2 (+) individuals had nearly two times more risk of being VDD compared to SARS-CoV-2 (-) individuals (aRR = 1.81, p < 0.0001). The risk of VDD was reduced by 46 % and 71 % in those consuming cocoa bean or powder regularly (aRR = 0.54, p = 0.03) and rarely (aRR = 0.29, p = 0.02) as compared to those never consuming it. Likewise, the risk of VDD was reduced by 59 % and 78 % in those consuming sardine fish regularly (aRR = 0.47, p = 0.002) and rarely (aRR = 0.22, p = 0.03). Overall, the association between VDD and SARS-CoV-2 infection was consistent, i.e., reduced risk of VDD in SARS-CoV-2 (-) individuals, after stratification for confounding variables.

Conclusion

This study outlined a high burden of VDD, a strong link between VDD and SARS-CoV-2, and suggests the possible utility of vitamin D supplementation for COVID-19 patients in Cameroon.

Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy

Nearly four years after its first appearance, and having gone from pandemic to endemic, the SARS-CoV-2 remains out of control globally. The purpose of this study was to evaluate the clinical efficacy of vitamin D (VD) in COVID-19 and long COVID-19, explain the discrepancy in clinical outcomes and highlight the potential impact of metformin on VD efficacy in recent articles. Articles from January 2022 to August 2023 were selected for this review. The objective of this study was achieved by reviewing, analyzing, and discussing articles demonstrating (1) the mechanism of action of VD (2) observational or randomized clinical trials (RCTs) that support or not the beneficial clinical effects of VD in COVID-19 or long COVID. (3) genetic and non-genetic reasons for the variation in the effects of VD. Articles were collected from electronic databases such as PubMed, Scopus, MEDLINE, Google Scholar, Egyptian Knowledge Bank, Science Direct, and Cochrane Database of Systematic Reviews. Twenty three studies conducted in vitro or in animal models indicated that VD may act in COVID-19 through protecting the respiratory system by antimicrobial peptide cathelicidins, reducing lung inflammation, regulating innate and adaptive immune functions and up regulation of autophagy gene activity. Our review identified 58 clinical studies that met the criteria. The number of publications supporting a beneficial clinical activity of VD in treating COVID-19 was 49 (86%), including 12 meta-analyses. Although the total patients included in all articles was 14,071,273, patients included in publications supporting a beneficial role of VD in COVID-19 were 14,029,411 (99.7%). Collectively, extensive observational studies indicated a decisive relationship between low VD levels and the severity of COVID-19 and mortality outcomes. Importantly, evidence from intervention studies has demonstrated the effectiveness of VD supplements in treating COVID-19. Furthermore, the results of 4 observational studies supported the beneficial role of VD in alleviating symptoms of long COVID-19 disease. However, eight RCTs and one meta-analysis of RCTs may contain low-grade evidence against a beneficial role of VD in COVID-19. Twenty-five articles have addressed the association between VDR and DBP genetic polymorphisms and treatment failure of VD in COVID-19. Impaired VDR signaling may underlie the variability of VD effects as non-genetic mechanisms. Interestingly, in recent studies, metformin has a beneficial therapeutic role in COVID-19 and long COVID-19, possibly by improving AMPK signaling of the VDR and enhancing the efficacy of the VD. In conclusion, evidence has been significantly strengthened over the past 18 months, with several meta-analyses and RCTs reporting conclusive beneficial effects of VD supplementation against COVID-19 and highlighting metformin to improve VDR sensitivity and efficacy in treating COVID-19 and long COVID-19.

Micronutrient Status of Critically Ill Patients with COVID-19 Pneumonia

Micronutrient deficiencies can develop in critically ill patients, arising from factors such as decreased intake, increased losses, drug interactions, and hypermetabolism. These deficiencies may compromise important immune functions, with potential implications for patient outcomes. Alternatively, micronutrient blood levels may become low due to inflammation-driven redistribution rather than consumption. This explorative pilot study investigates blood micronutrient concentrations during the first three weeks of ICU stay in critically ill COVID-19 patients and evaluates the impact of additional micronutrient administration. Moreover, associations between inflammation, disease severity, and micronutrient status were explored. We measured weekly concentrations of vitamins A, B6, D, and E; iron; zinc; copper; selenium; and CRP as a marker of inflammation state and the SOFA score indicating disease severity in 20 critically ill COVID-19 patients during three weeks of ICU stay. Half of the patients received additional (intravenous) micronutrient administration. Data were analyzed with linear mixed models and Pearson's correlation coefficient. High deficiency rates of vitamins A, B6, and D; zinc; and selenium (50-100%) were found at ICU admission, along with low iron status. After three weeks, vitamins B6 and D deficiencies persisted, and iron status remained low. Plasma levels of vitamins A and E, zinc, and selenium improved. No significant differences in micronutrient levels were found between patient groups. Negative correlations were identified between the CRP level and levels of vitamins A and E, iron, transferrin, zinc, and selenium. SOFA scores negatively correlated with vitamin D and selenium levels. Our findings reveal high micronutrient deficiency rates at ICU admission. Additional micronutrient administration did not enhance levels or expedite their increase. Spontaneous increases in vitamins A and E, zinc, and selenium levels were associated with inflammation resolution, suggesting that observed low levels may be attributed, at least in part, to redistribution rather than true deficiencies.

Shedding light on the next pandemic path, from outpatient to ICU, the effect of vitamin D deficiency in the SARS-CoV-2 pandemic

Background

Vitamin D insufficiency is named "the pandemic of our era" by some experts. World Health Organization warns against a "deadlier outbreak" than the COVID-19 pandemic. Critical evidence is hereby for future pandemic prevention, with special emphasis on Vitamin D.

Methods

A cross-sectional study was conducted with 172 unvaccinated adult participants, who presented to the emergency department. Blood measurements, radiological findings, and demographic features were evaluated in the four categories of "healthy adults, COVID-19 outpatients, hospitalized inpatients on the wards, and in the ICU."

Results

Results were statistically significant in association with age, gender, weight, Vitamin D, glucose, urea, creatinine, leucocyte, aspartate transaminase, hemoglobin, C-reactive protein, troponin, platelet/thrombocyte, ferritin, D-dimer, triglycerate, glycated haemoglobin, lactate dehydrogenase measurements, and chest computed tomography features (each p < 0.050).

Conclusion

This article presents evidence to support the importance of Vitamin D for global public health. Patients with adequate levels of Vitamin D, glucose, urea, creatinine, leucocyte, aspartate transaminase, hemoglobin, C-reactive protein, troponin, platelet/thrombocyte, ferritin, D-dimer, triglycerate, glycated haemoglobin, lactate dehydrogenase are less likely to be admitted to ICU versus being outpatients. Factors include gender, age, weight, comorbidities, and computed tomography findings. The ultimate goal is to globally minimize preventable burdens of disease and death.

Prevention of Parkinson's Disease: From Risk Factors to Early Interventions

Parkinson's disease (PD) is a debilitating neurological disorder characterized by progressively worsening motor dysfunction. Currently, available therapies merely alleviate symptoms, and there are no cures. Consequently, some researchers have now shifted their attention to identifying the modifiable risk factors of PD, with the intention of possibly implementing early interventions to prevent the development of PD. Four primary risk factors for PD are discussed including environmental factors (pesticides and heavy metals), lifestyle (physical activity and dietary intake), drug abuse, and individual comorbidities. Additionally, clinical biomarkers, neuroimaging, biochemical biomarkers, and genetic biomarkers could also help to detect prodromal PD. This review compiled available evidence that illustrates the relationship between modifiable risk factors, biomarkers, and PD. In summary, we raise the distinct possibility of preventing PD via early interventions of the modifiable risk factors and early diagnosis.

Methylprednisolone therapy induces differential metabolic trajectories in severe COVID-19 patients

IMPORTANCE

The SARS-CoV-2 virus infection in humans induces significant inflammatory and systemic reactions and complications of which corticosteroids like methylprednisolone have been recommended as treatment. Our understanding of the metabolic and metabolomic pathway dysregulations while using intravenous corticosteroids in COVID-19 is limited. This study will help enlighten the metabolic and metabolomic pathway dysregulations underlying high daily doses of intravenous methylprednisolone in COVID-19 patients compared to those receiving placebo. The information on key metabolites and pathways identified in this study together with the crosstalk with the inflammation and biochemistry components may be used, in the future, to leverage the use of methylprednisolone in any future pandemics from the coronavirus family.

Increased serum 1,25-dihydroxyvitamin D levels in gynecologic cancer patients with Post-Acute-Covid-Sequela (PASC)/Long COVID

Post-acute sequelae of COVID-19 (PASC), also known as Long-Covid (LC), may affect 10-30 % of COVID-infected patients, and is characterized by a variety of debilitating symptoms lasting over 3 months after the acute infection, including but not limited to dyspnea, fatigue, and musculoskeletal, cognitive, and/or mental health impairments. Vitamin D is an essential nutrient primarily recognized for its role in regulating calcium and bone health but also endowed with potent anti-inflammatory activity affecting a variety of immune cells. We retrospectively evaluated the plasmatic levels of both 1,25-dihydroxyvitamin-D (1,25 OH), and 25-hydroxyvitamin-D (25 OH), the active and storage forms of vitamin-D3, respectively, in the serum of gynecologic cancer patients affected by PASC/LC vs control cancer patients. We found elevated 1,25-dihydroxyvitamin-D levels in 5 out of 5 of the PASC/LC patients (mean ± SD = 97.2 ± 26.9 pg/mL) versus 0 out of 10 of randomly selected cancer control patients (44.9 ± 17.2 pg/mL, p = 0.0005). In contrast, no significant difference was noted in the levels of 25-dihydroxyvitamin-D in PASC/LC (mean ± SD = 48.2 ± 15.8 ng/mL) versus controls (43.0 ± 11.6 ng/mL, p = 0.48). Importantly, abnormal levels of vitamin D were found to persist for at least 2 years in patients with long covid symptoms. The active form (1,25OH) but not the storage form (25 OH) of vitamin-D is significantly elevated in PASC/LC cancer patients. Abnormally and persistently elevated 1,25OH levels, similarly to sarcoidosis patients, may represent the results of extrarenal conversion of vitamin D by activated macrophages, and a novel biomarker of persistent inflammation in gynecologic cancer patients with PASC/LC.

Association of Vitamin D with Severity and Outcome of COVID-19: Clinical and Experimental Evidence

INTRODUCTION

The role of vitamin in COVID-19 remains controversial. We investigated the association between endogenous vitamin D and the severity of COVID-19 as well as the mechanisms of action of vitamin D supplementation.

METHODS

25(OH)D3 in serum was associated with disease severity and outcome in 190 COVID-19 patients. In a COVID-19 animal model using intravenous injection of plasma from patients with COVID-19 acute respiratory distress syndrome into C57/BL6 mice, mice were treated with 0.25 μg human 1,25(OH)D3 or vehicle. Mice were sacrificed on day 4. Cytokines and myeloperoxidase (MPO) in tissues were measured. Changes in gene expression after vitamin D supplementation were measured.

RESULTS

Vitamin D deficiency and insufficiency were associated with increased severity and unfavorable outcome after 28 days. Vitamin D levels were negatively associated with biomarkers of COVID-19 severity. Vitamin D supplementation after challenge of mice with COVID-19 plasma led to reduced levels of TNFα, IL-6, IFNγ, and MPO in the lung, as well as down-regulation of pro-inflammatory pathways.

CONCLUSION

Normal levels of endogenous vitamin D are associated with reduced severity and risk of unfavorable outcome in COVID-19, possibly through attenuation of tissue-specific hyperinflammation.

The role of vitamin D in the prevention and treatment of SARS-CoV-2 infection: A meta-analysis of randomized controlled trials

BACKGROUND

Vitamin D (VitD) has been shown to be important for the immune response of the respiratory system, but the preventive and therapeutic effects of vitamin D supplementation on SARS-CoV-2 infection are controversial. This study aimed to determine the role of vitamin D supplementation in the prevention and treatment of SARS-CoV-2 infection through a meta-analysis of randomized controlled trials.

METHODS

The databases of PubMed, Cochrane Library, Embase, Web of Science and Google Scholar were searched systematically from inception to April 17,2023 to identify trials involving a randomized comparison of vitamin D supplementation versus non-vitamin D supplementation for SARS-CoV-2 infection prevention or treatment.

RESULTS

We retrieved 25 eligible trials, including 8128 participants. Four trials compared the preventive effects of vitamin D supplementation on SARS-CoV-2 infection, and the results (RR 0.31; 95%CI 0.07 to 1.32) were inconclusive. Regarding the treatment of SARS-CoV-2 infection with vitamin D supplementation, it was found that vitamin D supplementation could significantly reduce the rates of ICU admission (RR 0.63; 95%CI 0.44 to 0.89) and mechanical ventilation (RR 0.58; 95%CI 0.39 to 0.84), but had no statistically significant effect on mortality. However, in subgroup analyses based on the patients' specific conditions, vitamin D supplementation significantly reduced the mortality in patients with vitamin D deficiency (RR 0.76; 95%CI 0.58 to 0.98).

CONCLUSION

Vitamin D supplementation may have some beneficial impact on the severity of illness caused by SARS-CoV-2, particularly in VitD deficient patients, but further studies are still needed.

The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases.

The effect of 1-hydroxy-vitamin D treatment in hospitalized patients with COVID-19: A retrospective study

BACKGROUND & AIMS

The efficacy of vitamin D supplementation in coronavirus disease 2019 (COVID-19) remains unclear. This study aimed to evaluate the effect of 1-hydroxy-vitamin D on the prevention of severe disease and mortality in patients hospitalized for COVID-19.

METHODS

This retrospective study included 312 patients with COVID-19 who were admitted to our hospital between April 2021 and October 2021 (primarily the Delta variant) and between July 2022 and September 2022 (primarily Omicron variant). Serum 25-hydroxyvitamin D (25(OH)D) levels were measured at the time of admission and 1-hydroxy-vitamin D was prescribed by the treating physicians. The patients were divided into two groups: those administered 1-hydroxy-vitamin D (Vit D group) and those who were not (control group). The composite primary endpoint was the need for additional respiratory support, including high-flow oxygen therapy or invasive mechanical ventilation, and in-hospital mortality rate.

RESULTS

Of 312 patients, 122 (39%) received 1-hydroxy-vitamin D treatment. Although the median age was not significantly higher in the Vit D group than in the control group (66 vs. 58 years old, P = 0.06) and there was no significant difference in the proportion of vitamin D deficiency (defined as serum 25(OH)D level less than 20 ng/mL, 77% vs. 65%, P = 0.07), patients in the control group had a more severe baseline profile compared to the Vit D group according to the Japanese disease severity definition for COVID-19 (P = 0.01). The proportion of those requiring more respiratory support and in-hospital mortality was significantly lower in the Vit D group than in the control group (6% vs. 14%, P = 0.01 log-rank test). After propensity score matching, a statistically significant difference in the primary endpoint was observed (P = 0.03 log-rank test).

CONCLUSIONS

1-hydroxy-vitamin treatment may improve outcomes in hospitalized patients with COVID-19, reducing composite outcomes including the need for additional respiratory support and in-hospital mortality.

The Sunlight-Vitamin D Connection: Implications for Patient Outcomes in the Surgical Intensive Care Unit

This review delves into the intricate relationship between Vitamin D and patient outcomes in the Surgical Intensive Care Unit (SICU). Vitamin D, known for its multifaceted roles in immune modulation, inflammation regulation, and maintenance of calcium homeostasis, emerges as a pivotal factor in the care of critically ill patients. Our exploration reveals a high prevalence of Vitamin D deficiency in the SICU, primarily attributable to limited sunlight exposure, comorbidities, and medication use. Importantly, Vitamin D status impacts infection rates, mortality, and length of stay in the SICU, making it a clinically relevant consideration. Mechanistic insights into the immunomodulatory and anti-inflammatory effects of Vitamin D shed light on its potential benefits in critical care. However, challenges, including accurate assessment, individualised supplementation, and ethical considerations regarding sunlight exposure, are evident. The prospect of personalised Vitamin D supplementation strategies offers promise for optimising patient care. In conclusion, the Sunlight-Vitamin D Connection holds significant potential to improve outcomes in the SICU, emphasising the importance of further research and tailored approaches for the well-being of critically ill individuals.

Infections and Autoimmunity-The Immune System and Vitamin D: A Systematic Review

Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)2D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.

Vitamin D status and blood group among severe COVID-19 patients

Objective

Prognosis of COVID-19 infection has been indicated to be associated with vitamin D status and ABO blood group. However, owing to discrepancies and an increased number of cases globally, the findings remain unclear. This study aimed to evaluate the association between vitamin D and ABO blood group systems in patients with severe COVID-19.

Methods

In this cross-sectional study, COVID-19 patients referred to two hospitals in the capital of Iran, Tehran, admitted to the ICU ward due to the severity of COVID-19 were evaluated. Serum vitamin D and ABO levels were evaluated in these patients. The data obtained were statistically analyzed using SPSSv24.

Results

Of 305 patients, 33.1% patients had O+ blood type, 27.8% had A+ blood type and 22.4% had B+ blood type. Vitamin D deficiency was significantly associated with a mortality rate among these patients, P<0.05. The blood group of the patients was not correlated with mortality. Thirty-seven percent of the patients in the study died because of COVID-19.

Conclusion

In our study population, mortality due to COVID-19 was significantly associated with vitamin D deficiency but not the ABO blood group. We recommend further studies in this regard that include more variable and detailed biochemical analysis.

Systematic Mendelian randomization study of the effect of gut microbiome and plasma metabolome on severe COVID-19

Background

COVID-19 could develop severe respiratory symptoms in certain infected patients, especially in the patients with immune disorders. Gut microbiome and plasma metabolome act important immunological modulators in the human body and could contribute to the immune responses impacting the progression of COVID-19. However, the causal relationship between specific intestinal bacteria, metabolites and severe COVID-19 remains not clear.

Methods

Based on two-sample Mendelian randomization (MR) framework, the causal effects of 131 intestinal taxa and 452 plasma metabolites on severe COVID-19 were evaluated. Single nucleotide polymorphisms (SNPs) strongly associated with the abundance of intestinal taxa and the concentration of plasma metabolites had been utilized as the instrument variables to infer whether they were causal factors of severe COVID-19. In addition, mediation analysis was conducted to find the potential association between the taxon and metabolite, and further colocalization analysis had been performed to validate the causal relationships.

Results

MR analysis identified 13 taxa and 53 metabolites, which were significantly associated with severe COVID-19 as causal factors. Mediation analysis revealed 11 mediated relationships. Myo-inositol, 2-stearoylglycerophosphocholine, and alpha-glutamyltyrosine, potentially contributed to the association of Howardella and Ruminiclostridium 6 with severe COVID-19, respectively. Butyrivibrio and Ruminococcus gnavus could mediate the association of myo-inositol and N-acetylalanine, respectively. In addition, Ruminococcus torques abundance was colocalized with severe COVID-19 (PP.H4 = 0.77) and the colon expression of permeability related protein RASIP1 (PP.H4 = 0.95).

Conclusions

Our study highlights the potential causal relationships between gut microbiome, plasma metabolome and severe COVID-19, which potentially serve as clinical biomarkers for risk stratification and prognostication and benefit the mechanism mechanistic investigation of severe COVID-19.

Hospital Outcomes in Patients Hospitalized for COVID-19 Pneumonia: The Effect of SARS-CoV-2 Vaccination and Vitamin D Status

SARS-CoV-2 vaccination promises to improve outcomes for patients with COVID-19 pneumonia (most notably those with advanced age and at high risk for severe disease). Here, we examine serum 25-Hydroxyvitamin D (25(OH)D) status and outcomes in both old (>70 years) and young vaccinated (n = 80) and unvaccinated (n = 91) subjects, who were hospitalized due to COVID-19 pneumonia in a single center (Connolly Hospital Dublin). Outcomes included ICU admission and mortality. Serum 25(OH)D levels were categorized as D30 (<30 nmol/L), D40 (30-49.99 nmol/L) and D50 (≥50 nmol/L). In multivariate analyses, D30 was independently associated with ICU admission (OR: 6.87 (95% CI: 1.13-41.85) (p = 0.036)) and mortality (OR: 24.81 (95% CI: 1.57-392.1) (p = 0.023)) in unvaccinated patients, even after adjustment for major confounders including age, sex, obesity and pre-existing diabetes mellitus. While mortality was consistently higher in all categories of patients over 70 years of age, the highest observed mortality rate of 50%, seen in patients over 70 years with a low vitamin D state (D30), appeared to be almost completely corrected by either vaccination, or having a higher vitamin D state, i.e., mortality was 14% for vaccinated patients over 70 years with D30 and 16% for unvaccinated patients over 70 years with a 25(OH)D level greater than 30 nmol/L. We observe that high mortality from COVID-19 pneumonia occurs in older patients, especially those who are unvaccinated or have a low vitamin D state. Recent vaccination or having a high vitamin D status are both associated with reduced mortality, although these effects do not fully mitigate the mortality risk associated with advanced age.

Characteristics, comorbidities and laboratory measures associated with disease severity and poor prognosis in young and elderly patients with COVID-19 admitted to medical wards in Emilia-Romagna region, Italy: a multicentre retrospective study

Background and Objectives. A relatively small number of studies have investigated the characteristics, comorbidities and laboratory measures associated with prognosis in patients with COVID-19, admitted to Internal Medicine Units (IMU) in Italy. Therefore, we performed a retrospective multicentre study to identify baseline features, predisposing to severe disease and poor outcomes, in adult individuals with SARS-CoV-2 infection, hospitalized in 5 IMUs in the Emilia-Romagna region (Italy). Materials and Methods. We included 129 consecutive patients (male 75, median age 68 years) from 1st March 2020 to 31st October 2021. Patients’ baseline characteristics, comorbidities, laboratory measures, and outcomes were collected. Results. At admission, the factors significantly associated with a higher risk of in-hospital mortality included: age (median 68 vs. 83 years in survived vs. dead patients, P=0.000), diabetes [Odds Ratio (OR) 4.00, P=0.016], chronic obstructive pulmonary disease (OR 4.60, P=0.022), cancer (OR 5.81, P=0.021), acute- (OR 9.88, P=0.000) and chronic-renal failure (OR 6.76, P=0.004). During the study period, 16 individuals died (12.4%), all over 70 years old. In deceased vs. non-deceased patients were detected: i) more elevated white blood cells and neutrophils-counts and lower lymphocytes count; ii) higher levels of total/direct bilirubin, creatinine, C-reactive-protein, lactate-dehydrogenase, ferritin, but only a slight Interleukin-6 increase; iii) a trend of lower vitamin D values. Conclusions. We proposed a new I index, a modified form of the Age-Adjusted Charlson Comorbidity Index, by considering pO2/FiO2 ratio, to better characterize the severity of COVID-19. Furthermore, we critically discuss our results with the current assumption which considers COVID-19 as a pathological condition associated with cytokine storm.

Physiological Basis for Using Vitamin D to Improve Health

Vitamin D is essential for life-its sufficiency improves metabolism, hormonal release, immune functions, and maintaining health. Vitamin D deficiency increases the vulnerability and severity of type 2 diabetes, metabolic syndrome, cancer, obesity, and infections. The active enzyme that generates vitamin D [calcitriol: 1,25(OH)2D], CYP27B1 (1α-hydoxylase), and its receptors (VDRs) are distributed ubiquitously in cells. Once calcitriol binds with VDRs, the complexes are translocated to the nucleus and interact with responsive elements, up- or down-regulating the expression of over 1200 genes and modulating metabolic and physiological functions. Administration of vitamin D3 or correct metabolites at proper doses and frequency for longer periods would achieve the intended benefits. While various tissues have different thresholds for 25(OH)D concentrations, levels above 50 ng/mL are necessary to mitigate conditions such as infections/sepsis, cancer, and reduce premature deaths. Cholecalciferol (D3) (not its metabolites) should be used to correct vitamin D deficiency and raise serum 25(OH)D to the target concentration. In contrast, calcifediol [25(OH)D] raises serum 25(OH)D concentrations rapidly and is the agent of choice in emergencies such as infections, for those who are in ICUs, and for insufficient hepatic 25-hydroxylase (CYP2R1) activity. In contrast, calcitriol is necessary to maintain serum-ionized calcium concentration in persons with advanced renal failure and hypoparathyroidism. Calcitriol is, however, ineffective in most other conditions, including infections, and as vitamin D replacement therapy. Considering the high costs and higher incidence of adverse effects due to narrow therapeutic margins (ED50), 1α-vitamin D analogs, such as 1α-(OH)D and 1,25(OH)2D, should not be used for other conditions. Calcifediol analogs cost 20 times more than D3-thus, they are not indicated as a routine vitamin D supplement for hypovitaminosis D, osteoporosis, or renal failure. Healthcare workers should resist accepting inappropriate promotions, such as calcifediol for chronic renal failure and calcitriol for osteoporosis or infections-there is no physiological rationale for doing so. Maintaining the population's vitamin D sufficiency (above 40 ng/mL) with vitamin D3 supplements and/or daily sun exposure is the most cost-effective way to reduce chronic diseases and sepsis, overcome viral epidemics and pandemics, and reduce healthcare costs. Furthermore, vitamin D sufficiency improves overall health (hence reducing absenteeism), reduces the severity of chronic diseases such as metabolic and cardiovascular diseases and cancer, decreases all-cause mortality, and minimizes infection-related complications such as sepsis and COVID-19-related hospitalizations and deaths. Properly using vitamin D is the most cost-effective way to reduce chronic illnesses and healthcare costs: thus, it should be a part of routine clinical care.

The Role of Diet and Specific Nutrients during the COVID-19 Pandemic: What Have We Learned over the Last Three Years?

Nutrients and diets have an important impact on our immune system and infection risk and a huge number of papers have been published dealing with various aspects of nutrition in relation to SARS-CoV-2 infection risk or COVID-19 severity. This narrative review aims to give an update on this association and tries to summarize some of the most important findings after three years of pandemic. The analysis of major studies and systematic reviews leads to the conclusion that a healthy plant-based diet reduces the risks for SARS-CoV-2 infection and especially COVID-19 severity. Regarding micronutrients, vitamin D is to the fore, but also zinc, vitamin C and, to some extent, selenium may play a role in COVID-19. Furthermore, omega-3-fatty acids with their anti-inflammatory effects also deserve attention. Therefore, a major aim of societal nutritional efforts in future should be to foster a high quality plant-based diet, which not only exerts beneficial effects on the immune system but also reduces the risk for non-communicable diseases such as type 2 diabetes or obesity which are also primary risk factors for worse COVID-19 outcomes. Another aim should be to focus on a good supply of critical immune-effective nutrients, such as vitamin D and zinc.

25 Hydroxyvitamin D Serum Concentration and COVID-19 Severity and Outcome-A Retrospective Survey in a Romanian Hospital

Interest in the immunomodulatory function of vitamin D has grown since the COVID-19 pandemic started. Our study investigated the possible association between vitamin D deficiency and COVID-19 severity, intensive care needs, and mortality in patients hospitalized with COVID-19. A prospective cohort study was performed on 2342 COVID-19 hospitalized patients between April 2020 and May 2022 in a Romanian tertiary hospital for infectious diseases. A multivariate generalized linear model for binary data was fit with dependent variables: severe/critical form of COVID-19, intensive care need, and fatal outcome as a function of vitamin D deficiency, controlling for age, comorbidities, and vaccination status. More than half of the patients (50.9%) were classified with vitamin D deficiency based on a serum concentration of less than 20 ng/mL. There was a negative association between vitamin D and age. Vitamin D-deficient patients presented with more cardiovascular, neurological, and pulmonary diseases, as well as diabetes, and cancer. In multivariate logistic regression models, vitamin D-deficient patients had higher odds of severe/critical forms of COVID-19 [OR = 1.23 (95% CI 1.03-1.47), p = 0.023] and higher odds of death [OR = 1.49 (95% CI 1.06-2.08), p = 0.02]. Vitamin D deficiency was associated with disease severity and death outcome in hospitalized COVID-19 patients.

Evaluation of 25-hydroxyvitamin D (25(OH)D) levels before and during the COVID-19 pandemic: A cross-sectional study and trend analysis involving 86,772 samples

BACKGROUND

The aim of this paper was to evaluate the change in 25-hidroxyvitamin D (25(OH)D) levels before and during the COVID-19 pandemic.

METHODS

In this retrospective, cross-sectional and methodological study included 86,772 patients (18-75 years) samples who were admitted to the Izmir Dokuz Eylul University Hospital (latitude and longitude (Turkey): 27 E 09; 38 N 25, respectively) for various reasons and whose 25(OH)D levels were measured in the biochemistry unit between 2019-2020 and 2020-2021 (before and during the COVID-19 outbreak). A time series analysis of monthly averages for 25(OH)D was performed. For the purpose of seasonal study, the mean levels of 25(OH)D are grouped by years. Data were modeled in terms of 25(OH)D levels using the MATLAB Curve Fitting Toolbox.

RESULTS

There was no significant difference between the sexes according to 25(OH)D levels (p>0.05). 25(OH)D levels were significantly higher in the summer months and lower in the winter months (p<0.001). When comparing the spring months, 25(OH)D levels in 2020 (18 ± 10) were found to be significantly lower than in 2019 (22 ± 12) (p<0.001); on the contrary, when examined based on the summer, autumn, and winter months, it was determined that 25(OH)D levels increased in 2020 (summer: 25 ± 13, autumn: 25 ± 14, and winter: 19 ± 10) compared to 2019 (summer: 23 ± 11, autumn: 22 ± 10, and winter: 19 ± 11) (p<0.001). In the estimates curve obtained with an error margin of 11% in the time series analysis, it was estimated that the 25(OH)D averages after the pandemic would be similar to those before the pandemic.

CONCLUSIONS

Restrictions, partial or complete closures, and curfews can significantly affect individuals' 25(OH)D levels during the COVID-19 outbreak. There is a need for multicenter studies with larger populations covering different regions to strengthen and support our results.