Optimisation of Vitamin D Status for Enhanced Immuno-protection Against Covid-19

Abstract Background Vitamin D deficiency (serum 25(OH)D\u3c50nmol/l) is common in Ireland, particularly amongst older adults, hospital inpatients and nursing home residents. Vitamin D deficiency is associated with increased risk of acute viral respiratory infection and community acquired pneumonia, with several molecular mechanisms proposed to explain this association. Vitamin D supplementation has also been shown to reduce the risk of respiratory infection. Vitamin D and Covid-19 Correction of vitamin D deficiency is thought to suppress CD26, a putative adhesion molecule for Covid-19 host cell invasion. Vitamin D may also attenuate interferon gamma (IFNγ) and interleukin-6 (IL-6) inflammatory responses, both potent predictors of poorer outcome in critically-ill ventilated patients including those with Covid-19. Vitamin D Requirements Irish adults require 25-30μg/d of vitamin D3, an intake not achievable by diet alone, to reliably maintain serum 25(OH)D levels \u3e50nmol/l. Supplementation with doses up to 100μg/d has been shown to be safe for adults, and many agencies and expert groups now advocate supplementation in older adults, albeit at lower levels than this. Conclusions and Recommendations Vitamin D deficiency is common and may contribute to increased risk of respiratory infection including Covid-19. We recommend that all older adults, hospital inpatients, nursing home residents and other vulnerable groups (e.g. those with diabetes mellitus or compromised immune function, those with darker skin, vegetarians and vegans, those who are overweight or obese, smokers and healthcare workers) be urgently supplemented with 20-50μg/d of vitamin D to enhance their resistance to Covid-19, and that this advice be quickly extended to the general adult population

The mechanism of phosphonium ylide alcoholysis and hydrolysis: concerted addition of the O-H bond across the P=C bond

The previous work on the hydrolysis and alcoholysis reactions of phosphonium ylides is summarized and reviewed in the context of their currently accepted mechanisms. Several experimental facts relating to ylide hydrolysis and to salt and ylide alcoholysis are shown to conflict with those mechanisms. In particular, we demonstrate that the pK(a) values of water and alcohols are too high in organic media to bring about protonation of ylide. Therefore, we propose concerted addition of the water or alcohol O-H bond across the ylide P=C bond. In support of this, we provide NMR spectroscopic evidence for equilibrium between ylide and aclohol that does not require the involvement of phosphonium hydroxide. We report the first P-alkoxyphosphorane to be characterised by NMR spectroscopy that does not undergo exchange on an NMR timescale. Two-dimensional NMR spectroscopic techniques have been applied to the characterisation to P-alkoxyphosphoranes for the first time

The modern interpretation of the Wittig reaction mechanism

The mechanism of the Wittig reaction has long been a contentious issue in organic chemistry. Even now, more than 50 years after its announcement, its presentation in many modern undergraduate textbooks is either overly simplified or entirely inaccurate. In this review, we gather together the huge body of evidence that has been amassed to show that the Li salt-free Wittig reactions of non-stabilised, semi-stabilised and stabilised ylides all occur under kinetic control by a common mechanism in which oxaphosphetane (OPA) is the first-formed and only intermediate. The numerous recent significant additions to the subject – including computational studies and experimental material pertinent to both steps of the reaction (OPA formation and its decomposition) are discussed in detail, and the currently accepted explanations for the source of the stereoselectivity in Wittig reactions are given. We also present the other mechanistic proposals that have been made during the history of the Wittig reaction, and show how they are unable to account for all of the experimental evidence that is now available. Details of certain experimental facts to do with Wittig reactions in the presence of Li cation are also included, although the precise mechanistic details of such reactions are yet to be established conclusively. We make the case that a clear distinction should henceforth be made between the unknown “Li-present” and the now well-established “Li salt-free” Wittig mechanisms

Pilot Evaluation of an Online Weight Management Programme

This intervention examined the efficacy of a six-week online weight loss programme. Students and staff of a third level institution (n=183) were recruited to the programme which provided individualised dietary advice for weight loss. Eighty-five participants (mean age 29.7 years, mean BMI 28.9kg/m2, 33% male) met the minimum inclusion criterion of logging on to the study website at least twice. All participants who completed the full six-week programme lost weight (n=31), with significant reductions in mean weight (2.8kg), BMI (0.9kg/m2) and waist circumference (4.1cm) observed between the start and end of the programme (all P5% of their bodyweight, with reductions in biscuit and alcohol consumption being most predictive of weight loss. These findings suggest that individualised online dietary advice is effective in achieving short-term weight loss, especially in males

First ever observation of the intermediate of phosphonium salt and ylide hydrolysis: P-hydroxytetraorganophosphorane

P-Hydroxytetraorganophosphorane, the long-postulated intermediate in phosphonium salt and ylide hydrolysis, has been observed and characterised by low temperature NMR, finally definitively establishing its involvement in these reactions. The results require modification of the previously accepted mechanism for ylide hydrolysis: P-hydroxy-tetraorganophosphorane is generated directly by 4-centre reaction of ylide with water

Investigations on the operation of stereochemical drift in the Wittig reaction by NMR and variable-temperature NMR spectroscopy of oxaphosphetane intermediates and their quench products

Within the currently accepted mechanism of the Li‐salt‐free Wittig reaction, the phenomenon of stereochemical drift remains the one remaining “loose end” in an otherwise internally consistent explanation of a large body of diverse observations. The term describes the nonstereospecific decomposition of the oxaphosphetane (OPA) intermediate in reactions of certain alkylides with certain aldehydes. In this paper, it is shown that the previous examples in which drift occurs are not merely isolated aberrations from the observed norm, but rather that there is a general phenomenon in reactions of ethylides with benzaldehydes. Variable‐temperature NMR (VTNMR) spectroscopy was used to establish that the amount and diastereomeric ratio of the OPA intermediates do not change below a certain temperature. At and above the temperature at which OPA decomposition to alkene and phosphine oxide begins to occur, the alkene shows a different diastereomeric ratio to the OPA, which indicates the occurrence of stereochemical drift. In one example, owing to an apparent remarkable coincidence of rates, the diastereomeric ratio of the OPA does not change above the decomposition temperature, even though stereochemical drift occurs in the formation of the alkene product. An alternative mechanism for drift involving its catalysis by aldehyde was not confirmed. Drift was also shown not to occur in similar Wittig reactions of structurally related longer‐chain alkylides by stereospecific decomposition of OPA intermediates generated from β‐hydroxyphosphonium salts (β‐HPSs). The extremely useful (and generally applicable) NMR techniques, 1H–31P HMBC and selective 1H{31P}, which we have utilised to establish kinetic diastereomeric ratios, are described in full for the first time. Details of the determination of the relative stereochemistry of two β‐HPSs (derived from acid quenching of OPAs) by X‐ray crystallography are also given

Pathways for nutrient loss to water with emphasis on phosphorus

Teagasc wishes to acknowledge the support of the Environmental Research Technological Development and Innovation (ERTDI) Programme under the Productive Sector Operational Programme which was financed by the Irish Government under the National Development Plan 2000-2006.End of project reportThe main objective of this project was to study phosphorus (P) loss from agricultural land under a range of conditions in Ireland, to quantify the main factors influencing losses and make recommendations on ways to reduce these losses. This report is a synthesis of the main conclusions and recommendations from the results of the studies. The final reports from the individual sub-projects in this project are available from the EPA (www.epa.ie).Environmental Protection Agenc

Understanding a Low Vitamin D State in the Context of COVID-19

While a low vitamin D state has been associated with an increased risk of infection by SARS-CoV-2 in addition to an increased severity of COVID-19 disease, a causal role is not yet established. Here, we review the evidence relating to i) vitamin D and its role in SARS-CoV-2 infection and COVID-19 disease ii) the vitamin D status in the Irish adult population iii) the use of supplemental vitamin D to treat a deficient status and iv) the application of the Bradford-Hill causation criteria. We conclude that reverse causality probably makes a minimal contribution to the presence of low vitamin D states in the setting of COVID-19. Applying the Bradford-Hill criteria, however, the collective literature supports a causal association between low vitamin D status, SARS-CoV-2 infection, and severe COVID-19 (respiratory failure, requirement for ventilation and mortality). A biologically plausible rationale exists for these findings, given vitamin D’s role in immune regulation. The thresholds which define low, deficient, and replete vitamin D states vary according to the disease studied, underscoring the complexities for determining the goals for supplementation. All are currently unknown in the setting of COVID-19. The design of vitamin D randomised controlled trials is notoriously problematic and these trials commonly fail for a number of behavioural and methodological reasons. In Ireland, as in most other countries, low vitamin D status is common in older adults, adults in institutions, and with obesity, dark skin, low UVB exposure, diabetes and low socio-economic status. Physiological vitamin D levels for optimal immune function are considerably higher than those that can be achieved from food and sunlight exposure alone in Ireland. A window exists in which a significant number of adults could benefit from vitamin D supplementation, not least because of recent data demonstrating an association between vitamin D status and COVID-19. During the COVID pandemic, we believe that supplementation with 20-25ug (800–1000 IU)/day or more may be required for adults with apparently normal immune systems to improve immunity against SARS-CoV-2. We expect that higher monitored doses of 37.5–50 ug (1,500–2,000)/day may be needed for vulnerable groups (e.g., those with obesity, darker skin, diabetes mellitus and older adults). Such doses are within the safe daily intakes cited by international advisory agencies

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification