Rapid and Effective Vitamin D Supplementation May Present Better Clinical Outcomes in COVID-19 (SARS-CoV-2) Patients by Altering Serum INOS1, IL1B, IFNg, Cathelicidin-LL37, and ICAM1

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.

Unraveling the pathogenic interplay between SARS-CoV-2 and polycystic ovary syndrome using bioinformatics and experimental validation

The prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among polycystic ovary syndrome (PCOS) is significantly higher than in the general population. However, the mechanisms underlying this remain obscure. This study aimed to explore the mechanisms by identifying the genetic signature of SARS-CoV-2 infection in PCOS. In the present study, a total of 27 common differentially expressed genes (DEGs) were selected for subsequent analyses. Functional analyses showed that immunity and hormone-related pathways collectively participated in the development and progression of PCOS and SARS-CoV-2 infection. Under these, 7 significant hub genes were identified, including S100A9, MMP9, TLR2, THBD, ITGB2, ICAM1, and CD86 by using the algorithm in Cytoscape. Furthermore, hub gene expression was confirmed in the validation set, PCOS clinical samples, and mouse model. Immune microenvironment analysis with the CIBERSORTx database demonstrated that the hub genes were significantly correlated with T cells, dendritic cells, mast cells, B cells, NK cells, and eosinophils and positively correlated with immune scores. Among the hub genes, S100A9, MMP9, THBD, ITGB2, CD86, and ICAM1 demonstrated potential as possible diagnostic markers for COVID-19 and PCOS. In addition, we established the interaction networks of ovary-specific genes, transcription factors, miRNAs, drugs, and chemical compounds with hub genes with NetworkAnalyst. This work uncovered the common pathogenesis and genetic signature of PCOS and SARS-CoV-2 infection, which might provide a theoretical basis and innovative ideas for further mechanistic research and drug discovery of the comorbidity of the two diseases.

The role of cathelicidins in neutrophil biology

Despite their relatively short lifespan, neutrophils are tasked with counteracting pathogens through various functions, including phagocytosis, production of reactive oxygen species, neutrophil extracellular traps (NETs), and host defense peptides. Regarding the latter, small cationic cathelicidins present a conundrum in neutrophil function. Although primarily recognized as microbicides with an ability to provoke pores in microbial cell walls, the ability of cathelicidin to modulate key neutrophil functions is also of great importance, including the release of chemoattractants, cytokines, and reactive oxygen species, plus prolonging neutrophil lifespan. Cumulative evidence indicates a less recognized role of cathelicidin as an "immunomodulator"; however, this term is not always explicit, and its relevance in neutrophil responses during infection and inflammation is seldom discussed. This review compiles and discusses studies of how neutrophils use cathelicidin to respond to infections, while also acknowledging immunomodulatory aspects of cathelicidin through potential crosstalk between sources of the peptide.

The impact of supplementing vitamin D through different methods on the prognosis of COVID-19 patients: a systematic review and meta-analysis

Objective

To analyze the impact of different methods of Vitamin D administration on the prognosis of COVID-19 patients.

Methods

A comprehensive literature search was conducted across four databases: PubMed, Embase, Web of Science, and Cochrane, up to January 5, 2024. Eligible studies included randomized controlled trials and cohort studies that compared Vitamin D supplementation with control groups in COVID-19 patients. Outcomes of interest were mortality rate, ICU (Intensive Care Unit) admission rate, length of hospital stay, and endotracheal intubation rate. Subgroup analyses were performed based on the dosing regimen (single-dose vs. continuous-dose), total Vitamin D intake within 14 days (≥100,000 IU vs. <100,000 IU), and baseline serum Vitamin D levels (deficient group: 25OHD < 30 ng/mL vs. non-restricted group). A random-effects model was employed for meta-analysis to account for heterogeneity among studies.

Results

A total of 21 studies involving 4,553 participants were included. In terms of mortality, Vitamin D supplementation significantly reduced the mortality rate (RR = 0.72, 95% CI: 0.54-0.94, I 2 = 54%, p = 0.02), with continuous dosing being more effective (RR = 0.53, 95% CI: 0.34-0.83, I 2 = 55%, p = 0.006) compared to single-dose (RR = 0.88, 95% CI: 0.69-1.12, I 2 = 21%, p = 0.3), and lower total doses (<100,000 IU) showing greater benefit (RR = 0.30, 95% CI: 0.21-0.44, I 2 = 0%, p < 0.0001). Mortality was significantly reduced in the Vitamin D-deficient group (25OHD < 30 ng/mL) (RR = 0.73, 95% CI: 0.59-0.89, I 2 = 0%, p = 0.002) but not in the non-restricted group. Regarding ICU admission, supplementation reduced ICU admission rates (RR = 0.58, 95% CI: 0.38-0.88, I 2 = 74%, p = 0.01), with continuous dosing (RR = 0.44, 95% CI: 0.22-0.90, I 2 = 74%, p = 0.02) being more effective than single-dose (RR = 0.79, 95% CI: 0.61-1.03, I 2 = 22%, p = 0.08), and lower doses (<100,000 IU) providing more significant reduction (RR = 0.31, 95% CI: 0.21-0.47, I 2 = 0%, p = 0.001). ICU admission rates were significantly reduced in the Vitamin D-deficient group (RR = 0.63, 95% CI: 0.42-0.93, I 2 = 0%, p = 0.02) but not in the non-restricted group (RR = 0.59, 95% CI: 0.32-1.11, I 2 = 86%, p = 0.1). For length of hospital stay, no significant differences were observed between Vitamin D and control groups (MD = -1, 95% CI: -2.16 to 0.16, p = 0.13), and subgroup analyses by dosing regimen, total dose, and baseline Vitamin D levels also showed no significant differences. Similarly, for endotracheal intubation, there was no significant difference in intubation rates between groups (RR = 0.78, 95% CI: 0.56-1.08, p = 0.13), and subgroup analyses confirmed no significant effect of different dosing strategies or baseline Vitamin D status on intubation rates.

Conclusion

Vitamin D supplementation improves clinical outcomes in COVID-19 patients by reducing mortality and ICU admission rates, particularly when administered continuously with a total dose of less than 100,000 IU over 14 days, and among those with baseline Vitamin D deficiency (25OHD < 30 ng/mL). However, there were no significant effects on the length of hospital stay or endotracheal intubation rates, regardless of the dosing regimen or baseline Vitamin D levels. These findings emphasize the importance of considering both the total dose over 14 days and baseline Vitamin D status to optimize therapeutic benefits.

Therapeutic high-dose vitamin D for vitamin D-deficient severe COVID-19 disease: randomized, double-blind, placebo-controlled study (SHADE-S)

BACKGROUND

efficacy of therapeutic cholecalciferol supplementation for severe COVID-19 is sparingly studied.

OBJECTIVE

effect of single high-dose cholecalciferol supplementation on sequential organ failure assessment (SOFA) score in moderate-to-severe COVID-19.

METHODS

participants with moderate to severe COVID-19 with PaO2/FiO2 ratio < 200 were randomized to 0.6 million IU cholecalciferol oral (intervention) or placebo.

OUTCOMES

primary outcome was change in Day 7 SOFA score and pre-specified secondary outcomes were SOFA and 28-day all-cause mortality.

RESULTS

in all, 90 patients (45 each group) were included for intention-to-treat analysis. 25(OH)D3 levels were 12 (10-16) and 13 (12-18) ng/ml (P = 0.06) at baseline; and 60 (55-65) ng/ml and 4 (1-7) ng/ml by Day 7 in vitamin D and placebo groups, respectively. The SOFA score on Day 7 was better in the vitamin D group [3 (95% CI, 2-5) versus 5 (95% CI, 3-7), P = 0.01, intergroup difference - 2 (95% CI, -4 to -0.01); r = 0.4]. A lower all-cause 28-day mortality [24% compared to 44% (P = 0.046)] was observed with vitamin D.

CONCLUSIONS

single high-dose oral cholecalciferol supplementation on ICU admission can improve SOFA score at Day 7 and reduce in-hospital mortality in vitamin D-deficient COVID-19. ClinicalTrials.gov  id: NCT04952857 registered dated 7 July 2021. What is already known on this topic-vitamin D has immunomodulatory role. Observational and isolated intervention studies show some benefit in COVID-19. Targeted therapeutic vitamin D supplementation improve outcomes in severe COVID-19 is not studied in RCTs. What this study adds-high-dose vitamin D supplementation (0.6 Million IU) to increase 25(OH)D > 50 ng/ml is safe and reduces sequential organ failure assessment score, in-hospital mortality in moderate to severe COVID-19. How this study might affect research, practice or policy-vitamin D supplementation in vitamin D-deficient patients with severe COVID-19 is useful may be practiced.

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.

NBS superfood: a promising adjunctive therapy in critically ill ICU patients with omicron variant of COVID-19

This clinical trial aimed to assess the impact of Nutrition Bio-shield superfood (NBS) on clinical status among critically ill ICU patients suffering from acute respiratory distress syndrome (ARDS) due to the Omicron variant of COVID-19. A total of 400 patients with confirmed Omicron-related ARDS were randomly assigned to either the intervention group (n = 200) or the control group (n = 200). Patients in the intervention group received 1.5 g of NBS powder daily for 2 weeks in addition to standard antiviral treatment, while the control group received a placebo alongside standard antiviral therapy. Serum samples were collected from all patients in both groups, and various clinical and laboratory parameters, including ESR, CRP, D-Dimer, CPK, WBC count, lymphocyte count, and lymphocyte percentage, were measured using established methodologies. Following a 14-day intervention period, the intervention group exhibited a significant reduction in mean serum levels of CRP (15.39 vs. 48.49; P < 0.001), ESR (14.28 vs. 34.03; P < 0.001), D-Dimer (485.18 vs. 1009.13; P = 0.001), and CPK (68.93 vs. 131.48; P < 0.001) compared to the control group. Conversely, a significant increase was observed in the mean serum levels of lymphocytes (1537.06 vs. 1152.60; P < 0.001) in the intervention group after 14 days of treatment compared to the control group. The remarkable reduction in inflammatory markers and mortality rates observed with NBS supplementation alongside standard antiviral treatment underscores its crucial role in mitigating inflammation and achieving an important milestone in the fight against COVID-19.

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 supplementation reduced blood inflammatory cytokines expression and improved graft function in kidney transplant recipients

Background

Chronic allograft dysfunction(CAD) is the leading cause of graft loss in kidney transplant recipients (KTRs). Inflammatory process is believed to be one of the major contributors to CAD. The aim of this study is to explore the anti-inflammatory effect of vitamin D (VD) supplementation in KTRs and its role in the graft function improvement(protection).

Methods

A retrospective cohort of 39 KTRs with chronic antibody mediated rejection(CAMR)or stable renal function and a prospective cohort of 42 KTRs treated or untreated with VD were enrolled. Serum levels of vitamin D metabolism and serum inflammatory cytokines, renal graft function, and routine blood biomarkers were tested and dynamically tracked within 12 months post-transplant.

Results

Compared with the stable group, the CAMR group exhibited significantly elevated serum levels of inflammatory cytokines IL-1β, IFN-γ, IL-2, IL-10, IP-10, and HMGB1 (P <0.05). The supplementation of vitamin D effectively increased the serum concentration of vitamin D in kidney transplant recipients (KTRs) in the treated group. During the course of treatment, the treated group exhibited a gradual increase in eGFR levels, which were significantly higher than those observed in the untreated group at 12 months post-transplant (p<0.05). Notably, as eGFR improved, there was a significant decrease in levels of IL-1β, IFN-γ, IL-2, IL-10, IP-10 and HMGB1 in the treated group compared to the untreated group (P<0.05).

Conclusion

This study confirmed that immune-inflammation is a crucial factor in the development of CAD in KTRs.VD deficiency impairs its anti-inflammatory activity. By assisting in the regulation of excessive immune inflammation and restoration of immune homeostasis, effective VD supplementation contributes to protection and maintenance of graft function in KTRs.

Strategies for the Management of Spike Protein-Related Pathology

In the wake of the COVID-19 crisis, a need has arisen to prevent and treat two related conditions, COVID-19 vaccine injury and long COVID-19, both of which can trace at least part of their aetiology to the spike protein, which can cause harm through several mechanisms. One significant mechanism of harm is vascular, and it is mediated by the spike protein, a common element of the COVID-19 illness, and it is related to receiving a COVID-19 vaccine. Given the significant number of people experiencing these two related conditions, it is imperative to develop treatment protocols, as well as to consider the diversity of people experiencing long COVID-19 and vaccine injury. This review summarizes the known treatment options for long COVID-19 and vaccine injury, their mechanisms, and their evidentiary basis.

SARS-CoV-2 Infection-Blocking Immunity Post Natural Infection: The Role of Vitamin D

OBJECTIVE AND AIM

The extent of the protection against SARS-CoV-2 conferred by natural infection is unclear. Vitamin D may have a role in the interplay between SARS-CoV-2 infection and the evolving acquired immunity against it. We tested the correlation between baseline 25(OH) D content and both the reinfection rate and the anti-spike protein antibody titer following COVID-19 infection. Methods A retrospective observational survey that included a large convalescent COVID-19 population of subjects insured by the Leumit HMO was recorded between 1 February 2020 and 30 January 2022. Inclusion criteria required at least one available 25(OH)D level prior to enlistment. The association between 25(OH)D levels, the rate of breakthrough infection, and the anti-spike protein antibody titer was evaluated. Results A total of 10,132 COVID-19 convalescent subjects were included, of whom 322 (3.3%) sustained reinfection within a one-year follow-up. In the first 8 months after recovery, the reinfected patients were characterized by a higher incidence of low 25(OH)D levels (<30 ng/mL, 92% vs. 84.8%, p < 0.05), while during the following three months, the incidence of low 25(OH)D levels was non-significantly higher among PCR-negative convalescent subjects compared to those reinfected (86% vs. 81.7, p = 0.15). By multivariate analysis, age > 44 years (OR-0.39, 95% CI: 0.173-0.87, p = 0.02) and anti-spike protein antibody titer > 50 AU/mL (0.49, 95% CI: 0.25-0.96, p = 0.04) were inversely related to reinfection. No consistent correlation with vitamin D levels was observed among the 3351 available anti-spike protein antibody titers of convalescent subjects. However, the median anti-spike protein antibody titers tended to increase over time in the vitamin D-deficient group. Conclusion Higher pre-infection 25(OH)D level correlated with protective COVID-19 immunity during the first 8 months following COVID-19 infection, which could not be explained by anti-spike protein antibody titers. This effect dissipated beyond this period, demonstrating a biphasic 25(OH)D association that warrants future studies.

Vitamin D, a Secosteroid Hormone and Its Multifunctional Receptor, Vitamin D Receptor, in Alzheimer's Type Neurodegeneration

Vitamin D is a secosteroid hormone exerting neurosteroid-like properties. Its well-known nuclear hormone receptor, and recently proposed as a mitochondrial transcription factor, vitamin D receptor, acts for its primary functions. The second receptor is an endoplasmic reticulum protein, protein disulfide isomerase A3 (PDIA3), suggested to act as a rapid response. Vitamin D has effects on various systems, particularly through calcium metabolism. Among them, the nervous system has an important place in the context of our subject. Recent studies have shown that vitamin D and its receptors have numerous effects on the nervous system. Neurodegeneration is a long-term process. Throughout a human life span, so is vitamin D deficiency. Our previous studies and others have suggested that the out-come of long-term vitamin D deficiency (hypovitaminosis D or inefficient utilization of vitamin D), may lead neurons to be vulnerable to aging and neurodegeneration. We suggest that keeping vitamin D levels at adequate levels at all stages of life, considering new approaches such as agonists that can activate vitamin D receptors, and utilizing other derivatives produced in the synthesis process with UVB are crucial when considering vitamin D-based intervention studies. Given most aspects of vitamin D, this review outlines how vitamin D and its receptors work and are involved in neurodegeneration, emphasizing Alzheimer's disease.

The relationship between vitamin D deficiency and mortality in older adults before and during COVID-19 pandemic

BACKGROUND

Vitamin D is an essential fat-soluble vitamin thought to be associated with chronic diseases, mortality and COVID-19.

OBJECTIVE

To investigate the association between 25(OH) vitamin D levels and mortality of chronic diseases in subjects aged ≥65 years before and during COVID-19 pandemic.

METHODS

A single-center, retrospective study was performed using the hospital database of subjects aged 65 years and older who had undergone vitamin D measurement between 01.01.2019 and 31.12.2021. All patients with vitamin D measurement (N = 2155) were followed as a cohort from the date of serum vitamin D analysis through death date or 01.01.2022. Age, gender, chronic diseases, survival status, date of death of the deceased, laboratory values including complete blood count, liver/renal functions and 25(OH) vitamin D levels were all noted. Subjects were classified into three groups according to their 25(OH) vitamin D levels; severe deficient group (<10 ng/ml), moderate deficient group (10-19.9 ng/ml), and control group (≥20 ng/ml).

RESULTS

Data of 1949 subjects were included in this retrospective analysis and 206 of them (10.6%) had at least two vitamin D measurements. Until the time of data collection (01.01.2022), 94 of the cases had died within the last three years, and only five of them had repeated measurements. While the mean vitamin D level was lower, age and frequency of dyslipidemia, coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), arrhythmia, dementia and severe vitamin D deficiency (<10 ng/ml) were higher in subjectswho died (all p<0.05). According to the Cox proportional hazards model; age, presence of CAD, COPD, arrhythmia, dementia, anemia and severe vitamin D deficiency were independently related with mortality (all p<0.05). After adjusted by age, gender, and comorbidities, the probability of death was found to be 1.91 (95% CI=1.12-3.24) times higher in the severe vitamin D deficient group.

CONCLUSIONS

The results of this study have shown that - after having adjusted for potential factors - severe vitamin D deficiency (<10 ng/ml) seems to be an independent predictor for non-cancer mortality. Although vitamin D measurement/treatment is very easy and cheap where, on the contrary, severe vitamin D deficiency can be quite mortal.

Correlation between Baseline 25(OH) Vitamin D Levels and Both Humoral Immunity and Breakthrough Infection Post-COVID-19 Vaccination

Objective: Vaccines against COVID-19 induce specific antibodies whose titer is perceived as a reliable correlate of protection. Vitamin D confers complex regulatory effects on the innate and adaptive immunity. In this study, we explored a plausible impact of baseline vitamin D content on achieved immunity following COVID-19 vaccination. Methods: A retrospective observational study comprising 73,254 naïve subjects insured by the Leumit Health Service HMO, who were vaccinated between 1 February 2020 and 30 January 2022, with one available vitamin D level prior to vaccination, was performed. The association between 25(OH) vitamin D levels, SARS-CoV-2 antibody titer, and post-vaccination PCR results were evaluated. Results: Of the study population, 5026 (6.9%) tested positive for COVID-19. The proportion of low 25(OH)D levels (<30 ng/mL) was significantly higher in the PCR-positive group (81.5% vs. 79%, p < 0.001). Multivariate analysis showed a higher incidence of breakthrough infection among non-smokers [1.37 (95% CI 1.22−1.54, p < 0.001)] and lower incidences among subjects with sufficient 25(OH)D levels (>30 ng/mL) [0.87 (95% CI 0.79−0.95, p—0.004)], hyperlipidemia [0.84 (95% CI 0.76−0.93, p < 0.001], depression [OR-0.87 (95% CI: 0.79−0.96, p < 0.005], socio-economic status >10 [0.67 (95% CI 0.61−0.73, p < 0.001)], and age >44 years. SARS-CoV-2 antibody titers were available in 3659 vaccinated individuals. The prevalence of antibody titers (<50 AU) among PCR-positive subjects was 42% compared to 28% among PCR-negative subjects (p < 0.001). Baseline 25(OH)D levels showed an inverse relation to total antibody titers. However, no association was found with an antibody titer <50 AU/mL fraction. Conclusion Baseline 25(OH)D levels correlated with the vaccination-associated protective COVID-19 immunity. Antibody titers <50 AU/mL were significantly linked to breakthrough infection but did not correlate with 25(OH)D levels.

Vitamin D status during the COVID-19 pandemic: the experience of Russia and Belarus

During the COVID-19 pandemic, a high prevalence of vitamin D deficiency and insufficiency remains. Thus, the studies carried out on the territory of the Russian Federation (RF) and the Republic of Belarus over the last 3 years have shown the prevalence of vitamin D deficiency and insufficiency in the population, regardless of the gender of examined persons, the geographic location and the season of the year. Taking into account the known immunomodulatory functions of serum 25(OH)D, the aim of this review was to assess the data that were accumulated in the world, Russia and Belarus and were concerned with a possible contribution of vitamin D deficiency to COVID-19 infection, course and prognosis, as well as with the role of cholecalciferol therapy in prevention and treatment of the disease. Most of the studies demonstrate a negative association between the serum 25(OH)D level and COVID-19 severity and/or mortality. Previously, it has been shown that the serum 25(OH)D level less than 11.4 ng/ml is associated with an increased risk of COVID-19 mortality. At the same time, the results of the studies using cholecalciferol therapy for COVID-19 prevention and treatment are conflicting. Intervention  studies in the Russian Federation and the Republic of Belarus are scanty; however, the available data indicate a possible  benefit of therapy, which allows it to be considered as an addition to the main methods of treating COVID-19.

Vitamin D and COVID-19: Narrative Review after 3 Years of Pandemic

Active vitamin D [1,25(OH)₂D₃-calcitriol] is a secosteroid hormone whose receptor is expressed on all cells of the immune system. Vitamin D has a global anti-inflammatory effect and its role in the management of a SARS-CoV-2 infection has been investigated since the beginning of the COVID-19 pandemic. In this narrative review, the laboratory and clinical results of a vitamin D supplementation have been collected from both open-label and blinded randomized clinical trials. The results are generally in favor of the utility of maintaining the serum concentrations of calcifediol [25(OH)D₃] at around 40 ng/mL and of the absolute usefulness of its supplementation in subjects with deficient serum levels. However, two very recent large-scale studies (one open-label, one placebo-controlled) have called into question the contribution of vitamin D to clinical practice in the era of COVID-19 vaccinations. The precise role of a vitamin D supplementation in the anti-COVID-19 armamentarium requires further investigations in light of the breakthrough which has been achieved with mass vaccinations.

COVID-19 Prevention: Vitamin D Is Still a Valid Remedy

Seven meta-analyses and systematic reviews and three later clinical trials argued that low vitamin D status increased susceptibility to COVID-19 and the risk of greater disease severity and mortality [...].

Effect of vitamin D3 supplementation on cellular immunity and inflammatory markers in COVID-19 patients admitted to the ICU

Vitamin D as an immunomodulator has not been studied in patients with severe COVID-19. This study aimed to estimate the efficacy of vitamin D3 supplementation on cellular immunity and inflammatory markers in patients with COVID-19 admitted to the intensive care unit (ICU). A single-center, double-blind, randomized, placebo-controlled pilot trial was conducted (N = 110). Patients were randomly assigned to receive a weekly oral dose of 60,000 IU of vitamin D3 followed by daily maintenance doses of 5000 IU (n = 55) or placebo (n = 55). Primary outcomes were lymphocyte counts, natural killer (NK) and natural killer T (NKT) cell counts, neutrophil-to-lymphocyte ratio (NLR), and serum levels of inflammatory markers on 7th day of treatment. On day 7, patients in the vitamin D3 group displayed significantly higher NK and NKT cell counts and NLR than those in the placebo group did. The mortality rate (37% vs 50%, P = 0.16), need for mechanical ventilation (63% vs 69%, P = 0.58), incidence of nosocomial infection (60% vs 41%, P = 0.05) did not significantly differ between groups. Vitamin D3 supplementation, compared with placebo, significantly increased lymphocyte counts, but did not translate into reduced mortality in ICU.Trial Registration: ClinicalTrials.gov Identifier: NCT05092698.

A systems biology approach for investigating significantly expressed genes among COVID-19, hepatocellular carcinoma, and chronic hepatitis B

Background

Worldwide, COVID-19's death rate is about 2%, considering the incidence and mortality. However, the information on its complications in other organs, specifically the liver and its disorders, is limited in mild or severe cases. In this study, we aimed to computationally investigate the typical relationships between liver-related diseases [i.e., hepatocellular carcinoma (HCC), and chronic hepatitis B (CHB)] and COVID-19, considering the involved significant genes and their molecular mechanisms.

Methods

We investigated two GEO microarray datasets (GSE164805 and GSE58208) to identify differentially expressed genes (DEGs) among the generated four datasets for mild/severe COVID-19, HCC, and CHB. Then, the overlapping genes among them were identified for GO and KEGG enrichment analyses, protein-protein interaction network construction, hub genes determination, and their associations with immune cell infiltration.

Results

A total of 22 significant genes (i.e., ACTB, ATM, CDC42, DHX15, EPRS, GAPDH, HIF1A, HNRNPA1, HRAS, HSP90AB1, HSPA8, IL1B, JUN, POLR2B, PTPRC, RPS27A, SFRS1, SMARCA4, SRC, TNF, UBE2I, and VEGFA) were found to play essential roles among mild/severe COVID-19 associated with HCC and CHB. Moreover, the analysis of immune cell infiltration revealed that these genes are mostly positively correlated with tumor immune and inflammatory responses.

Conclusions

In summary, the current study demonstrated that 22 identified DEGs might play an essential role in understanding the associations between the mild/severe COVID-19 patients with HCC and CHB. So, the HCC and CHB patients involved in different types of COVID-19 can benefit from immune-based targets for therapeutic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43042-022-00360-3.

Role of Micronutrients and Gut Microbiota-Derived Metabolites in COVID-19 Recovery

A balanced and varied diet provides diverse beneficial effects on health, such as adequate micronutrient availability and a gut microbiome in homeostasis. Besides their participation in biochemical processes as cofactors and coenzymes, vitamins and minerals have an immunoregulatory function; meanwhile, gut microbiota and its metabolites coordinate directly and indirectly the cell response through the interaction with the host receptors. Malnourishment is a crucial risk factor for several pathologies, and its involvement during the Coronavirus Disease 2019 pandemic has been reported. This pandemic has caused a significant decline in the worldwide population, especially those with chronic diseases, reduced physical activity, and elder age. Diet and gut microbiota composition are probable causes for this susceptibility, and its supplementation can play a role in reestablishing microbial homeostasis and improving immunity response against Coronavirus Disease 2019 infection and recovery. This study reviews the role of micronutrients and microbiomes in the risk of infection, the severity of disease, and the Coronavirus Disease 2019 sequelae.

From Prescription Drugs to Natural Health Products: Medication Use in Canadian Infants

Limited data exist on pharmaceutical product use by infants, although available data suggests higher prevalence of use among children under 12 months of age. We conducted a descriptive study of 3050 infants recruited in the CHILD Cohort Study, a prospective, multicenter, longitudinal cohort following children from pregnancy through childhood. Parents were surveyed for use of prescription and over-the-counter drugs, and natural health products (NHPs, including homeopathic products and vitamins) at 3, 6, and 12 months after delivery. By one year of age, 96.0% of children had taken at least one pharmaceutical product. Among 307 reported products, 32 were given to at least 1% of cohort infants. Vitamin D, acetaminophen, ibuprofen, topical hydrocortisone, amoxicillin, and nystatin were the most common medications and natural health products (NHPs) received, with 8/32 of the most frequently used products being NHPs. Overall, 14.7% of pharmaceutical products administered to children were off-label and 35.8% were NHPs or products without a Drug Identification Number (DIN). The use of over-the-counter medications and NHPs is common and off-label use of drugs is frequent, even in the first year of life. This study highlights the importance of conducting studies on medication use in infants, and of infant medication use monitoring by healthcare providers.

The effect of Nutrition Bio-shield superfood (NBS) on disease severity and laboratory biomarkers in patients with COVID-19: A randomized clinical trial

BACKGROUND

Nutrition Bio-shield Superfood (NBS) is an organic and viable herbal supplement that could improve the function of the immune system. The present study aims to determine the effect of NBS on disease severity and laboratory biomarkers in patients with COVID-19.

METHODS

This current study was a randomized, comparative, parallel two-arm and single-blind clinical trial study performed in Tehran, Iran. In total, 70 patients with COVID-19 were included in the present study and assigned to two groups including 1) intervention group (n = 35) and 2) control group (n = 35). All patients included in the intervention group received 4.5 gr daily rate of NBS superfood, three times the daily rate of 1.5 gr for 14 days. In contrast, patients included in the control group received a placebo three times a day for 14 days. The measurement of laboratory parameters including CRP, ESR, D-Dimer, LDH, CPK, SGOT, SGPT, ALP, FBG, WBC count, PLT, and lymphocyte count was performed using standard kits and methods. Moreover, all serum samples were tested to determine the levels of IL-6 and TNF-ɑ using specific commercially available ELISA kits according to the instructions of the manufacturer.

RESULTS

A significant decrease in the mean serum level of several variables including CRP (p < 0.001), ESR (p < 0.001), D- Dimer (p = 0.001), LDH (p < 0.001), SGOT (p = 0.002), SGPT (p = 0.019), ALP (p < 0.001), WBC count (p < 0.001), body temperature (p = 0.013), IL-6 (p < 0.001), and TNF-α (p < 0.001) was seen 14 days after intervention from baseline in the intervention group than control group. In contrast, in the intervention group, the significant increase from baseline of lymphocyte percentage (p < 0.001) and oxygen saturation (p < 0.001) was seen 14 days after receiving NBS superfood than the control group.

CONCLUSION

Results showed that the use of NBS superfood had various beneficial effects on COVID-19 disease severity. These results suggest that NBS superfood can be used as an effective natural supplement in the treatment process of COVID-19 disease.

Bibliometric analysis of the global research status and trends of the association between Vitamin D and infections from 2001 to 2021

Objective

The objective of this study was the visualization of hot spots and evolving trends in research on the association between vitamin D and infections through the use of bibliometric analysis.

Methods

Based on 3046 relevant articles collected in the Web of Science Core Collection for the period of 2001–2021, the data were processed using CiteSpace software. GraphPad software was used for some of the graphics.

Results

A total of 3,046 literature were retrieved, with an average citation frequency of 27.89 times. The number of published papers in the direction of “Immunology” (453 articles, 14.9%) and “Infectious diseases” (312 articles, 10.2%) is much higher. The United States presents the highest publication count (890, 29.2%) and shows a strong leadership in this field. Country burst shows that since 2015, many developing countries and low-income countries have carried out enthusiastic research in this regard, including China, Pakistan, and Iran. As for institutions, the League of European Research Universities produces a larger proportion of articles (220, 7.2%). In terms of authors, Martineau AR and Camargo CA have the highest number of published articles, contributing 30 (0.99%) and 28 articles (0.92%), respectively. Major studies are supported by the United States Department of Health Human Services funding (394, 12.9%). According to the keyword co-occurrence diagram, the 10 most frequent keywords from 2001 to 2021 are “vitamin D”, “infection”, “d deficiency”, “risk”, “association”, “expression”, “disease”, “d supplementation”, “vitamin d deficiency”, and “children”. The top 10 cited articles in 2021 are all related to COVID-19, suggesting it is a hotspot in recent times.

Conclusion

Research on the association between vitamin D and infection has grown rapidly since 2012 and is generally developing well. While developed Western countries continue to be leading roles in this field, research trends in developing countries are also very promising. It is demonstrated that the relationship between vitamin D and respiratory infections, especially respiratory viruses and the more recently COVID-19, has received a lot of attention in the last two decades, suggesting that this is the hotspot and frontier of research issue.

Association of Vitamin D Prescribing and Clinical Outcomes in Adults Hospitalized with COVID-19

It is unclear whether vitamin D benefits inpatients with COVID-19. Objective: To examine the relationship between vitamin D and COVID-19 outcomes. Design: Cohort study. Setting: National COVID Cohort Collaborative (N3C) database. Patients: 158,835 patients with confirmed COVID-19 and a sub-cohort with severe disease (n = 81,381) hospitalized between 1 January 2020 and 31 July 2021. Methods: We identified vitamin D prescribing using codes for vitamin D and its derivatives. We created a sub-cohort defined as having severe disease as those who required mechanical ventilation or extracorporeal membrane oxygenation (ECMO), had hospitalization >5 days, or hospitalization ending in death or hospice. Using logistic regression, we adjusted for age, sex, race, BMI, Charlson Comorbidity Index, and urban/rural residence, time period, and study site. Outcomes of interest were death or transfer to hospice, longer length of stay, and mechanical ventilation/ECMO. Results: Patients treated with vitamin D were older, had more comorbidities, and higher BMI compared with patients who did not receive vitamin D. Vitamin D treatment was associated with an increased odds of death or referral for hospice (adjusted odds ratio (AOR) 1.10: 95% CI 1.05−1.14), hospital stay >5 days (AOR 1.78: 95% CI 1.74−1.83), and increased odds of mechanical ventilation/ECMO (AOR 1.49: 95% CI 1.44−1.55). In the sub-cohort of severe COVID-19, vitamin D decreased the odds of death or hospice (AOR 0.90, 95% CI 0.86−0.94), but increased the odds of hospital stay longer >5 days (AOR 2.03, 95% CI 1.87−2.21) and mechanical ventilation/ECMO (AOR 1.16, 95% CI 1.12−1.21). Limitations: Our findings could reflect more aggressive treatment due to higher severity. Conclusion: Vitamin D treatment was associated with greater odds of extended hospitalization, mechanical ventilation/ECMO, and death or hospice referral.

Beneficial Effect of Short-Term Supplementation of High Dose of Vitamin D3 in Hospitalized Patients With COVID-19: A Multicenter, Single-Blinded, Prospective Randomized Pilot Clinical Trial

There is now sufficient evidence to support that vitamin D deficiency may predispose to SARS-CoV-2 infection and increase COVID-19 severity and mortality. It has been suggested that vitamin D₃ supplementation may be used prophylactically as an affordable and safe strategy that could be added to the existing COVID-19 standard treatment. This multicenter, single-blinded, prospective randomized pilot clinical trial aimed to evaluate the safety, tolerability, and effectiveness of 10,000 IU/day in comparison with 2000 IU/day of cholecalciferol supplementation for 14 days to reduce the duration and severity of COVID-19 in 85 hospitalized individuals. The median age of the participants was 65 years (Interquartile range (IQR): 53–74), most of them (71%) were men and the mean baseline of 25-hydroxyvitamin D (25(OH)D) in serum was 15 ng/ml (standard deviation (SD):6). After 14 days of supplementation, serum 25(OH)D levels were significantly increased in the group who received 10,000IU/day (p < 0.0001) (n = 44) in comparison with the 2,000IU/day group (n = 41), especially in overweight and obese participants, and the higher dose was well tolerated. A fraction of the individuals in our cohort (10/85) developed acute respiratory distress syndrome (ARDS). The median length of hospital stay in these patients with ARDS was significantly different in the participants assigned to the 10,000IU/day group (n = 4; 7 days; IQR: 4–13) and the 2,000IU/day group (n = 6; 27 days; IQR: 12–45) (p = 0.04). Moreover, the inspired oxygen fraction was reduced 7.6-fold in the high dose group (p = 0.049). In terms of blood parameters, we did not identify overall significant improvements, although the platelet count showed a modest but significant difference in those patients who were supplemented with the higher dose (p = 0.0492). In conclusion, the administration of 10,000IU/day of vitamin D₃ for 14 days in association with the standard clinical care during hospitalization for COVID-19 was safe, tolerable, and beneficial, thereby helping to improve the prognosis during the recovery process.

Exploring the possible molecular targeting mechanism of Saussurea involucrata in the treatment of COVID-19 based on bioinformatics and network pharmacology

OBJECTIVE

Based on bioinformatics and network pharmacology, the treatment of Saussurea involucrata (SAIN) on novel coronavirus (COVID-19) was evaluated by the GEO clinical sample gene difference analysis, compound-target molecular docking, and molecular dynamics simulation. role in the discovery of new targets for the prevention or treatment of COVID-19, to better serve the discovery and clinical application of new drugs.

MATERIALS AND METHODS

Taking the Traditional Chinese Medicine System Pharmacology Database (TCMSP) as the starting point for the preliminary selection of compounds and targets, we used tools such as Cytoscape 3.8.0, TBtools 1.098, AutoDock vina, R 4.0.2, PyMol, and GROMACS to analyze the compounds of SAIN and targets were initially screened. To further screen the active ingredients and targets, we carried out genetic difference analysis (n = 72) through clinical samples of COVID-19 derived from GEO and carried out biological process (BP) analysis on these screened targets (P ≤ 0.05)., gene = 9), KEGG pathway analysis (FDR≤0.05, gene = 9), protein interaction network (PPI) analysis (gene = 9), and compounds-target-pathway network analysis (gene = 9), to obtain the target Point-regulated biological processes, disease pathways, and compounds-target-pathway relationships. Through the precise molecular docking between the compounds and the targets, we further screened SAIN's active ingredients (Affinity ≤ -7.2 kcal/mol) targets and visualized the data. After that, we performed molecular dynamics simulations and consulted a large number of related Validation of the results in the literature.

RESULTS

Through the screening, analysis, and verification of the data, it was finally confirmed that there are five main active ingredients in SAIN, which are Quercitrin, Rutin, Caffeic acid, Jaceosidin, and Beta-sitosterol, and mainly act on five targets. These targets mainly regulate Tuberculosis, TNF signaling pathway, Alzheimer's disease, Pertussis, Toll-like receptor signaling pathway, Influenza A, Non-alcoholic fatty liver disease (NAFLD), Neuroactive ligand-receptor interaction, Complement and coagulation cascades, Fructose and mannose metabolism, and Metabolic pathways, play a role in preventing or treating COVID-19. Molecular dynamics simulation results show that the four active ingredients of SAIN, Quercitrin, Rutin, Caffeic acid, and Jaceosidin, act on the four target proteins of COVID-19, AKR1B1, C5AR1, GSK3B, and IL1B to form complexes that can be very stable in the human environment. Tertiary structure exists.

CONCLUSION

Our study successfully explained the effective mechanism of SAIN in improving COVID-19, and at the same time predicted the potential targets of SAIN in the treatment of COVID-19, AKR1B1, IL1B, and GSK3B. It provides a new basis and provides great support for subsequent research on COVID-19.

Effect of Cholecalciferol Supplementation on the Clinical Features and Inflammatory Markers in Hospitalized COVID-19 Patients: A Randomized, Open-Label, Single-Center Study

Recent studies showed that a low 25-hydroxyvitamin D (25(OH)D) level was associated with a higher risk of morbidity and severe course of COVID-19. Our study aimed to evaluate the effects of cholecalciferol supplementation on the clinical features and inflammatory markers in patients with COVID-19. A serum 25(OH)D level was determined in 311 COVID-19 patients. Among them, 129 patients were then randomized into two groups with similar concomitant medication. Group I (n = 56) received a bolus of cholecalciferol at a dose of 50,000 IU on the first and the eighth days of hospitalization. Patients from Group II (n = 54) did not receive the supplementation. We found significant differences between groups with the preferential increase in serum 25(OH)D level and Δ 25(OH)D in Group I on the ninth day of hospitalization (p < 0.001). The serum 25(OH)D level on the ninth day was negatively associated with the number of bed days (r = −0.23, p = 0.006); we did not observe other clinical benefits in patients receiving an oral bolus of cholecalciferol. Moreover, in Group I, neutrophil and lymphocyte counts were significantly higher (p = 0.04; p = 0.02), while the C-reactive protein level was significantly lower on the ninth day of hospitalization (p = 0.02). Patients with supplementation of 100,000 IU of cholecalciferol, compared to those without supplementation, showed a decrease in the frequencies of CD38++CD27 transitional and CD27−CD38+ mature naive B cells (p = 0.006 and p = 0.02) and an increase in the level of CD27−CD38− DN B cells (p = 0.02). Thus, the rise in serum 25(OH)D level caused by vitamin D supplementation in vitamin D insufficient and deficient patients may positively affect immune status and hence the course of COVID-19.

Calcifediol for Use in Treatment of Respiratory Disease

Calcifediol is the prohormone of the vitamin D endocrine system (VDES). It requires hydroxylation to move to 1,25(OH)2D3 or calcitriol, the active form that exerts its functions by activating the vitamin D receptor (VDR) that is expressed in many organs, including the lungs. Due to its rapid oral absorption and because it does not require first hepatic hydroxylation, it is a good option to replace the prevalent deficiency of vitamin D (25 hydroxyvitamin D; 25OHD), to which patients with respiratory pathologies are no strangers. Correcting 25OHD deficiency can decrease the risk of upper respiratory infections and thus improve asthma and COPD control. The same happens with other respiratory pathologies and, in particular, COVID-19. Calcifediol may be a good option for raising 25OHD serum levels quickly because the profile of inflammatory cytokines exhibited by patients with inflammatory respiratory diseases, such as asthma, COPD or COVID-19, can increase the degradation of the active metabolites of the VDES. The aim of this narrative revision is to report the current evidence on the role of calcifediol in main respiratory diseases. In conclusion, good 25OHD status may have beneficial effects on the clinical course of respiratory diseases, including COVID-19. This hypothesis should be confirmed in large, randomized trials. Otherwise, a rapid correction of 25(OH)D deficiency can be useful for patients with respiratory disease.

IFNL4, ACE1, PKR, IFNG, MBL2 genetic polymorphisms and severe COVID-19: A protocol for systematic review and meta-analysis

BACKGROUND

Corona virus disease 2019 (COVID-19) is caused by SARS-CoV-2, the pathogenic process of SARS-Cov-2 is related to the angiotensin-2 converting enzyme (ACE-2) on host cells. The genetic polymorphisms among different populations may influence the progression of COVID-19. However, the effects of IFNL4, ACE1, PKR, IFNG, and MBL2 in severe COVID-19 have not been systematically assessed.

METHODS

We will include all relevant English and Chinese studies by searching the following electronic databases: PubMed, MEDLINE, Embase, Web of Science, Scopus, the Cochrane Library, and Google Scholar before March 31, 2022. Two researchers will independently screen and extract the literature. The methodological quality of the included studies will be evaluated by the Cochrane Handbook for Systematic Reviews of Interventions.

RESULT

This systematic review and meta-analysis will summarize the association of IFNL4, ACE1, PKR, IFNG, MBL2 genetic polymorphisms, and severe COVID-19. The results will be submitted to a peer-reviewed journal once completed.

CONCLUSION

The conclusion of our study will provide evidence for the early prevention of severe COVID-19.

PROSPERO REGISTRATION NUMBER

CRD42022301735.

Do Diet and Dietary Supplements Mitigate Clinical Outcomes in COVID-19?

The coronavirus disease 2019 (COVID-19) has caused a pandemic and upheaval that health authorities and citizens around the globe are still grappling with to this day. While public health measures, vaccine development, and new therapeutics have made great strides in understanding and managing the pandemic, there has been an increasing focus on the potential roles of diet and supplementation in disease prevention and adjuvant treatment. In the literature, the impact of nutrition on other respiratory illnesses, including the common cold, pneumonia, and influenza, has been widely demonstrated in both animal and human models. However, there is much less research on the impact related to COVID-19. The present study discusses the potential uses of diets, vitamins, and supplements, including the Mediterranean diet, glutathione, zinc, and traditional Chinese medicine, in the prevention of infection and severe illness. The evidence demonstrating the efficacy of diet supplementation on infection risk, disease duration, severity, and recovery is mixed and inconsistent. More clinical trials are necessary in order to clearly demonstrate the contribution of nutrition and to guide potential therapeutic protocols.

Vitamin D: A Role Also in Long COVID-19?

Coronavirus disease 2019 (COVID-19) has quickly become a global pandemic. Reports from different parts of the world indicate that a significant proportion of people who have recovered from COVID-19 are suffering from various health problems collectively referred to as “long COVID-19”. Common symptoms include fatigue, shortness of breath, cough, joint pain, chest pain, muscle aches, headaches, and so on. Vitamin D is an immunomodulatory hormone with proven efficacy against various upper respiratory tract infections. Vitamin D can inhibit hyperinflammatory reactions and accelerate the healing process in the affected areas, especially in lung tissue. Moreover, vitamin D deficiency has been associated with the severity and mortality of COVID-19 cases, with a high prevalence of hypovitaminosis D found in patients with COVID-19 and acute respiratory failure. Thus, there are promising reasons to promote research into the effects of vitamin D supplementation in COVID-19 patients. However, no studies to date have found that vitamin D affects post-COVID-19 symptoms or biomarkers. Based on this scenario, this review aims to provide an up-to-date overview of the potential role of vitamin D in long COVID-19 and of the current literature on this topic.

Low-Molecular-Weight Synthetic Antioxidants: Classification, Pharmacological Profile, Effectiveness and Trends

Mounting research has been performed and published on natural antioxidants, more so than on synthetic ones, as key molecules that control oxidative damage and its pathway to disease. Since the discovery of vitamins, various fully synthetic or natural-identical compounds have been developed as stable small molecules translated into constantly active and completely controlled products which are widely exploited in the food and pharmaceutical industries. There is currently a debate within the literature about their mechanism of action, bioavailability, safety and real benefit for human health. Using a semiquantitative method and eligible criteria of selection, this review aimed to provide a very useful classification of antioxidants and a comprehensive cross-disciplinary description of 32 approved synthetic/natural-identical antioxidants, in terms of regulatory, antioxidant mechanism of action, safety issues, pharmacological properties, effectiveness in human health, timeline and future trends. Enriched interpretation of the data was obtained from summary bibliometrics, useful to portray the “good antioxidant” within the period 1966–2021 and, hopefully, to encourage further research.

The Role of Vitamin D in Supporting Health in the COVID-19 Era

The genomic activity of vitamin D is associated with metabolic effects, and the hormone has a strong impact on several physiological functions and, therefore, on health. Among its renowned functions, vitamin D is an immunomodulator and a molecule with an anti-inflammatory effect, and, recently, it has been much studied in relation to its response against viral infections, especially against COVID-19. This review aims to take stock of the correlation studies between vitamin D deficiency and increased risks of severe COVID-19 disease and, similarly, between vitamin D deficiency and acute respiratory distress syndrome. Based on this evidence, supplementation with vitamin D has been tested in clinical trials, and the results are discussed. Finally, this study includes a biochemical analysis on the effects of vitamin D in the body's defense mechanisms against viral infection. In particular, the antioxidant and anti-inflammatory functions are considered in relation to energy metabolism, and the potential, beneficial effect of vitamin D in COVID-19 is described, with discussion of its influence on different biochemical pathways. The proposed, broader view of vitamin D activity could support a better-integrated approach in supplementation strategies against severe COVID-19, which could be valuable in a near future of living with an infection becoming endemic.

Dietary Recommendations for Post-COVID-19 Syndrome

At the beginning of the coronavirus disease (COVID-19) pandemic, global efforts focused on containing the spread of the virus and avoiding contagion. Currently, it is evident that health professionals should deal with the overall health status of COVID-19 survivors. Indeed, novel findings have identified post-COVID-19 syndrome, which is characterized by malnutrition, loss of fat-free mass, and low-grade inflammation. In addition, the recovery might be complicated by persistent functional impairment (i.e., fatigue and muscle weakness, dysphagia, appetite loss, and taste/smell alterations) as well as psychological distress. Therefore, the appropriate evaluation of nutritional status (assessment of dietary intake, anthropometrics, and body composition) is one of the pillars in the management of these patients. On the other hand, personalized dietary recommendations represent the best strategy to ensure recovery. Therefore, this review aimed to collect available evidence on the role of nutrients and their supplementation in post-COVID-19 syndrome to provide a practical guideline to nutritionists to tailor dietary interventions for patients recovering from COVID-19 infections.

A Narrative Review of the Evidence for Variations in Serum 25-Hydroxyvitamin D Concentration Thresholds for Optimal Health

Vitamin D3 has many important health benefits. Unfortunately, these benefits are not widely known among health care personnel and the general public. As a result, most of the world's population has serum 25-hydroxyvitamin D (25(OH)D) concentrations far below optimal values. This narrative review examines the evidence for the major causes of death including cardiovascular disease, hypertension, cancer, type 2 diabetes mellitus, and COVID-19 with regard to sub-optimal 25(OH)D concentrations. Evidence for the beneficial effects comes from a variety of approaches including ecological and observational studies, studies of mechanisms, and Mendelian randomization studies. Although randomized controlled trials (RCTs) are generally considered the strongest form of evidence for pharmaceutical drugs, the study designs and the conduct of RCTs performed for vitamin D have mostly been flawed for the following reasons: they have been based on vitamin D dose rather than on baseline and achieved 25(OH)D concentrations; they have involved participants with 25(OH)D concentrations above the population mean; they have given low vitamin D doses; and they have permitted other sources of vitamin D. Thus, the strongest evidence generally comes from the other types of studies. The general finding is that optimal 25(OH)D concentrations to support health and wellbeing are above 30 ng/mL (75 nmol/L) for cardiovascular disease and all-cause mortality rate, whereas the thresholds for several other outcomes appear to range up to 40 or 50 ng/mL. The most efficient way to achieve these concentrations is through vitamin D supplementation. Although additional studies are warranted, raising serum 25(OH)D concentrations to optimal concentrations will result in a significant reduction in preventable illness and death.

The Relationship Between Vitamin D Status and the Clinical Severity of COVID-19 Infection: A Retrospective Single-Center Analysis

Background and objective Some studies have suggested a potential protective role of vitamin D in coronavirus disease 2019 (COVID-19) patients, and this has led to a debate on the topic in the medical community. However, the reported data on the number of hospitalized patients who were vitamin D-deficient is not convincing. In light of this, the aim of the present study was to explore if vitamin D deficiency is correlated with severity and mortality rates of COVID-19 infection in hospitalized COVID-19 patients at a tertiary care hospital in Greece. Methods We conducted a single-center retrospective study involving 71 patients hospitalized with COVID-19 from August to October 2020. Serum 25-hydroxyvitamin D (25(OH)D) level was assessed in all patients within 48 hours of hospital admission. Serum 25(OH)D level ≤20 ng/ml was defined as a deficiency, while that >20 ng/ml as repletion. The primary outcomes of the infection were classified as partial/complete recovery and mortality during hospitalization. The secondary outcomes were blood markers of inflammation and thrombosis. Results Among the 71 COVID-19-positive patients [mean age: 63 years, range: 20-97; male (n=47; 66.2%): female (n=24; 33.8%)] who were enrolled in the study, 46 (64.8%) patients had 25(OH)D levels ≤20 ng/ml and 25 (35.2%) had a level >20 ng/ml. According to the patients' medical history, 55 patients (77.5%) had comorbidities. It appears that vitamin D deficiency (<20 ng/ml) significantly correlated with elevated biochemical markers such as procalcitonin and troponin (p<0.001). Moreover, male gender, advanced age (>60 years), and comorbidities were positively associated with more severe COVID-19 infection (elevated inflammation markers, radiographic findings on X-rays, and increased length of hospital stay). Conclusion These preliminary findings show that vitamin D status among the patients was not related to the severity of COVID-19 infection.

Vitamin D Intake May Reduce SARS-CoV-2 Infection Morbidity in Health Care Workers

In the last 2 years, observational studies have shown that a low 25-hydroxyvitamin D (25(OH)D) level affected the severity of infection with the novel coronavirus (COVID-19). This study aimed to analyze the potential effect of vitamin D supplementation in reducing SARS-CoV-2 infection morbidity and severity in health care workers. Of 128 health care workers, 91 (consisting of 38 medical doctors (42%), 38 nurses (42%), and 15 medical attendants (16%)) were randomized into two groups receiving vitamin D supplementation. Participants of group I (n = 45) received water-soluble cholecalciferol at a dose of 50,000 IU/week for 2 consecutive weeks, followed by 5000 IU/day for the rest of the study. Participants of group II (n = 46) received water-soluble cholecalciferol at a dose of 2000 IU/day. For both groups, treatment lasted 3 months. Baseline serum 25(OH)D level in health care workers varied from 3.0 to 65.1 ng/mL (median, 17.7 (interquartile range, 12.2; 24.7) ng/mL). Vitamin D deficiency, insufficiency, and normal vitamin D status were diagnosed in 60%, 30%, and 10%, respectively. Only 78 subjects completed the study. Vitamin D supplementation was associated with an increase in serum 25(OH)D level, but only intake of 5000 IU/day was accompanied by normalization of serum 25(OH)D level, which occurred in 53% of cases. Neither vitamin D intake nor vitamin D deficiency/insufficiency were associated with a decrease in SARS-CoV-2 morbidity (odds ratio = 2.27; 95% confidence interval, 0.72 to 7.12). However, subjects receiving high-dose vitamin D had only asymptomatic SARS-CoV-2 in 10 (26%) cases; at the same time, participants who received 2000 IU/day showed twice as many SARS-CoV-2 cases, with mild clinical features in half of them.

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

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

Vitamin D's Role in Reducing Risk of SARS-CoV-2 and COVID-19 Incidence, Severity, and Death

The article by D'Avolio and colleagues [...].

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.

Preventing the Adverse Effects of SARS-CoV-2 Infection and COVID-19 through Diet, Supplements, and Lifestyle

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen responsible for the coronavirus disease 2019 (COVID-19) and the ongoing worldwide pandemic, has cost the lives of almost 5 [...].