Nutritional status of patients with COVID-19

Malnutrition in patients with COVID-19: assessment and consequences

PURPOSE OF REVIEW

COVID-19 disease often presents with malnutrition and nutrition impact symptoms, such as reduced appetite, nausea and loss of taste. This review summarizes the most up-to-date research on nutritional assessment in relation to mortality and morbidity risk in patients with COVID-19.

RECENT FINDINGS

Numerous studies have been published on malnutrition, muscle wasting, obesity, and nutrition impact symptoms associated with COVID-19, mostly observational and in hospitalized patients. These studies have shown a high prevalence of symptoms (loss of appetite, nausea, vomiting, diarrhea, dysphagia, fatigue, and loss of smell and taste), malnutrition, micronutrient deficiencies and obesity in patients with COVID-19, all of which were associated with increased mortality and morbidity risks.

SUMMARY

Early screening and assessment of malnutrition, muscle wasting, obesity, nutrition impact symptoms and micronutrient status in patients with COVID-19, followed by pro-active nutrition support is warranted, and expected to contribute to improved recovery. There is limited research on nutritional status or nutrition impact symptoms in patients living at home or in residential care. RCTs studying the effects of nutrition intervention on clinical outcomes are lacking. Future research should focus on these evidence gaps.

The role of vitamin D in the age of COVID-19: A systematic review and meta-analysis

BACKGROUND

Evidence recommends that vitamin D might be a crucial supportive agent for the immune system, mainly in cytokine response regulation against COVID-19. Hence, we carried out a systematic review and meta-analysis in order to maximise the use of everything that exists about the role of vitamin D in the COVID-19.

METHODS

A systematic search was performed in PubMed, Scopus, Embase and Web of Science up to December 18, 2020. Studies focused on the role of vitamin D in confirmed COVID-19 patients were entered into the systematic review.

RESULTS

Twenty-three studies containing 11 901 participants entered into the meta-analysis. The meta-analysis indicated that 41% of COVID-19 patients were suffering from vitamin D deficiency (95% CI, 29%-55%), and in 42% of patients, levels of vitamin D were insufficient (95% CI, 24%-63%). The serum 25-hydroxyvitamin D concentration was 20.3 ng/mL among all COVID-19 patients (95% CI, 12.1-19.8). The odds of getting infected with SARS-CoV-2 are 3.3 times higher among individuals with vitamin D deficiency (95% CI, 2.5-4.3). The chance of developing severe COVID-19 is about five times higher in patients with vitamin D deficiency (OR: 5.1, 95% CI, 2.6-10.3). There is no significant association between vitamin D status and higher mortality rates (OR: 1.6, 95% CI, 0.5-4.4).

CONCLUSION

This study found that most of the COVID-19 patients were suffering from vitamin D deficiency/insufficiency. Also, there is about three times higher chance of getting infected with SARS-CoV-2 among vitamin-D-deficient individuals and about five times higher probability of developing the severe disease in vitamin-D-deficient patients. Vitamin D deficiency showed no significant association with mortality rates in this population.

Corrigendum to: Influence of 25‑hydroxy-cholecalciferol levels on SARS-CoV-2 infection and COVID-19 severity: A systematic review and meta-analysis [EClinicalMedicine 37 (2021) 100,967]

[This corrects the article DOI: 10.1016/j.eclinm.2021.100967.].

The Role of an Anti-Inflammatory Diet in Conjunction to COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), otherwise known as COVID-19, has challenged healthcare systems at an international level. COVID-19 suppresses the immune system by causing a systemic inflammatory response, also known as cytokine release syndrome, leaving COVID-19 patients with high levels of proinflammatory cytokines and chemokines. Nutrition's function in the respiratory and immune systems has been investigated in much research, and its significance cannot be overstated, as the nutritional status of patients has been shown to be directly connected with the severity of the disease. Key dietary components such as vitamin C, D, omega-3 fatty acids, and zinc have shown potential in their anti-inflammatory effects, as well as the famous Mediterranean diet. This review aims to discuss the use of anti-inflammatory dietary approaches to prevent Sars-CoV-2 or lessen COVID-19 effects.

Is Ferroptosis a Key Component of the Process Leading to Multiorgan Damage in COVID-19?

Even though COVID-19 is mostly well-known for affecting respiratory pathology, it can also result in several extrapulmonary manifestations, leading to multiorgan damage. A recent reported case of SARS-CoV-2 myocarditis with cardiogenic shock showed a signature of myocardial and kidney ferroptosis, a novel, iron-dependent programmed cell death. The term ferroptosis was coined in the last decade to describe the form of cell death induced by the small molecule erastin. As a specific inducer of ferroptosis, erastin inhibits cystine-glutamate antiporter system Xc-, blocking transportation into the cytoplasm of cystine, a precursor of glutathione (GSH) in exchange with glutamate and the consequent malfunction of GPX4. Ferroptosis is also promoted by intracellular iron overload and by the iron-dependent accumulation of polyunsaturated fatty acids (PUFA)-derived lipid peroxides. Since depletion of GSH, inactivation of GPX4, altered iron metabolism, and upregulation of PUFA peroxidation by reactive oxygen species are peculiar signs of COVID-19, there is the possibility that SARS-CoV-2 may trigger ferroptosis in the cells of multiple organs, thus contributing to multiorgan damage. Here, we review the molecular mechanisms of ferroptosis and its possible relationship with SARS-CoV-2 infection and multiorgan damage. Finally, we analyze the potential interventions that may combat ferroptosis and, therefore, reduce multiorgan damage.

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis

This systematic review was conducted to summarize and clarify the evidence on the association between 25-hydroxyvitamin-D [25(OH)D] concentrations and coronavirus disease 2019 (COVID-19) risk and outcomes. PubMed, Scopus, and Web of Science databases and Google Scholar were searched up to 26 November 2020. All retrospective and prospective cohort, cross-sectional, case-control, and randomized controlled trial studies that investigated the relation between 25(OH)D and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19 severity were included. Thirty-nine studies were included in the current systematic review. In studies that were adjusted (OR: 1.77; 95% CI: 1.24, 2.53; I2: 44.2%) and nonadjusted for confounders (OR: 1.75; 95% CI: 1.44, 2.13; I2: 33.0%) there was a higher risk of SARS-CoV-2 infection in the vitamin D deficiency (VDD) group. Fifteen studies evaluated associations between VDD and composite severity. In the studies that were adjusted (OR: 2.57; 95% CI: 1.65, 4.01; I2 = 0.0%) and nonadjusted for confounders (OR: 10.61; 95% CI: 2.07, 54.23; I2 = 90.8%) there was a higher severity in the VDD group. Analysis of studies with crude OR (OR: 2.62; 95% CI: 1.13, 6.05; I2: 47.9%), and adjusted studies that used the Cox survival method (HR: 7.67; 95% CI: 3.92, 15.03; I2: 0.0%) indicated a significant association of VDD with mortality, while in adjusted studies that used logistic regression, no relation was observed (OR: 1.05; 95% CI: 0.63, 1.75; I2: 76.6%). The results of studies that examined relations between VDD and intensive care unit (ICU) admission, pulmonary complications, hospitalization, and inflammation were inconsistent. In conclusion, although studies were heterogeneous in methodological and statistical approach, most of them indicated a significant relation between 25(OH)D and SARS-CoV-2 infection, COVID-19 composite severity, and mortality. With regard to infection, caution should be taken in interpreting the results, due to inherent study limitations. For ICU admission, inflammation, hospitalization, and pulmonary involvement, the evidence is currently inconsistent and insufficient.

Patient Nutrition and Probiotic Therapy in COVID-19: What Do We Know in 2021?

BACKGROUND

The main nutritional consequences of COVID-19 include reduced food intake, hypercatabolism, and rapid muscle wasting. Some studies showed that malnutrition is a significant problem among patients hospitalized due to COVID-19 infection, and the outcome of patients with SARS-CoV-2 is strongly associated with their nutritional status. The purpose of this study was to collect useful information about the possible elements of nutritional and probiotic therapy in patients infected with the SARS-CoV-2 virus.

METHODS

A narrative review of the literature, including studies published up to 13 September 2021.

RESULTS

Probiotics may support patients by inhibiting the ACE2 receptor, i.e., the passage of the virus into the cell, and may also be effective in suppressing the immune response caused by the proinflammatory cytokine cascade. In patients' diet, it is crucial to ensure an adequate intake of micronutrients, such as omega-3 fatty acids (at 2-4 g/d), selenium (300-450 μg/d) and zinc (30-50 mg/d), and vitamins A (900-700 µg/d), E (135 mg/d), D (20,000-50,000 IU), C (1-2 g/d), B6, and B12. Moreover, the daily calorie intake should amount to ≥1500-2000 with 75-100 g of protein.

CONCLUSION

In conclusion, the treatment of gut dysbiosis involving an adequate intake of prebiotic dietary fiber and probiotics could turn out to be an immensely helpful instrument for immunomodulation, both in COVID-19 patients and prophylactically in individuals with no history of infection.

The Association between Vitamin D and Zinc Status and the Progression of Clinical Symptoms among Outpatients Infected with SARS-CoV-2 and Potentially Non-Infected Participants: A Cross-Sectional Study

Vitamin D and zinc are important components of nutritional immunity. This study compared the serum concentrations of 25-hydroxyvitamin D (25(OH)D) and zinc in COVID-19 outpatients with those of potentially non-infected participants. The association of clinical symptoms with vitamin D and zinc status was also examined. A checklist and laboratory examination were applied to collect data in a cross-sectional study conducted on 53 infected outpatients with COVID-19 and 53 potentially non-infected participants. Serum concentration of 25(OH)D were not significantly lower in patients with moderate illness (19 ± 12 ng/mL) than patients with asymptomatic or mild illness (29 ± 18 ng/mL), with a trend noted for a lower serum concentration of 25(OH)D in moderate than asymptomatic or mild illness patients (p = 0.054). Infected patients (101 ± 18 µg/dL) showed a lower serum concentration of zinc than potentially non-infected participants (114 ± 13 µg/dL) (p = 0.01). Patients with normal (odds ratio (OR), 0.19; p ≤ 0.001) and insufficient (OR, 0.3; p = 0.007) vitamin D status at the second to seventh days of disease had decreased OR of general symptoms compared to patients with vitamin D deficiency. This study revealed the importance of 25(OH)D measurement to predict the progression of general and pulmonary symptoms and showed that infected patients had significantly lower zinc concentrations than potentially non-infected participants.

The role of vitamin D deficiency on COVID-19: a systematic review and meta-analysis of observational studies

OBJECTIVES

Although vaccination has started, coronavirus disease 2019 (COVID-19) poses a continuing threat to public health. Therefore, in addition to vaccination, the use of supplements to support the immune system may be important. The purpose of this study was to synthesize evidence on the possible effect of low serum vitamin D levels (25[OH]D<20 ng/mL or 50 nmol/L) on COVID-19 infection and outcomes.

METHODS

We searched Google Scholar, PubMed, Scopus, Web of Science, and ScienceDirect without any language restrictions for articles published between January 1 and December 15, 2020. We performed 3 meta-analyses (called vitamin D and COVID-19 infection meta-analysis [D-CIMA], vitamin D and COVID-19 severity meta-analysis [D-CSMA], and vitamin D and COV ID-19 mortality meta-analysis [D-CMMA] for COVID-19 infection, severity, and mortality, respectively) to combine odds ratio values according to laboratory measurement units for vitamin D and the measured serum 25(OH)D level.

RESULTS

Twenty-one eligible studies were found to be relevant to the relationship between vitamin D and COVID-19 infection/outcomes (n=205,869). The D-CIMA meta-analysis showed that individuals with low serum vitamin D levels were 1.64 times (95% confidence interval [CI], 1.32 to 2.04; p<0.001) more likely to contract COVID-19. The D-CSMA meta-analysis showed that people with serum 25(OH)D levels below 20 ng/mL or 50 nmol/L were 2.42 times (95% CI, 1.13 to 5.18; p=0.022) more likely to have severe COVID-19. The D-CMMA meta-analysis showed that low vitamin D levels had no effect on COVID-19 mortality (OR, 1.64; 95% CI, 0.53 to 5.06, p=0.390).

CONCLUSIONS

According to our results, vitamin D deficiency may increase the risk of COVID-19 infection and the likelihood of severe disease. Therefore, we recommend vitamin D supplementation to prevent COVID-19 and its negative outcomes.

Recovery Focused Nutritional Therapy across the Continuum of Care: Learning from COVID-19

Targeted nutritional therapy should be started early in severe illness and sustained through to recovery if clinical and patient-centred outcomes are to be optimised. The coronavirus disease 2019 (COVID-19) pandemic has shone a light on this need. The literature on nutrition and COVID-19 mainly focuses on the importance of nutrition to preserve life and prevent clinical deterioration during the acute phase of illness. However, there is a lack of information guiding practice across the whole patient journey (e.g., hospital to home) with a focus on targeting recovery (e.g., long COVID). This review paper is of relevance to doctors and other healthcare professionals in acute care and primary care worldwide, since it addresses early, multi-modal individualised nutrition interventions across the continuum of care to improve COVID-19 patient outcomes. It is of relevance to nutrition experts and non-nutrition experts and can be used to promote inter-professional and inter-organisational knowledge transfer on the topic. The primary goal is to prevent complications and support recovery to enable COVID-19 patients to achieve the best possible nutritional, physical, functional and mental health status and to apply the learning to date from the COVID-19 pandemic to other patient groups experiencing acute severe illness.

Liver disorders in COVID-19, nutritional approaches and the use of phytochemicals

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has affected millions of people globally. It was declared a pandemic by the World Health Organization in March 2020. The hyperinflammatory response to the entry of SARS-CoV-2 into the host through angiotensin-converting enzyme 2 is the result of a "cytokine storm" and the high oxidative stress responsible for the associated symptomatology. Not only respiratory symptoms are reported, but gastrointestinal symptoms (diarrhea, vomiting, and nausea) and liver abnormalities (high levels of aspartate aminotransferase, alanine aminotransferase transaminases, and bilirubin) are observed in at least 30% of patients. Reduced food intake and a delay in medical services may lead to malnutrition, which increases mortality and poor outcomes. This review provides some strategies to identify malnutrition and establishes nutritional approaches for the management of COVID-19 and liver injury, taking energy and nutrient requirements and their impact on the immune response into account. The roles of certain phytochemicals in the prevention of the disease or as promising target drugs in the treatment of this disease are also considered.

The correlation between serum selenium, zinc, and COVID-19 severity: an observational study

BACKGROUND

Without an adequate immune response, SARS-CoV2 virus can simply spread throughout the body of the host. Two of the well-known immunonutrients are selenium (Se) and zinc (Zn). Se and Zn deficiency might lead to inflammation, oxidative stress, and viral entry into the cells by decreasing ACE-2 expression; three factors that are proposed to be involved in COVID-19 pathogenesis. Thus, in the current study we aimed at evaluating the correlation between serum Se and Zn status and COVID-19 severity.

METHODS

Eighty-four COVID-19 patients were enrolled in this observational study. Patients were diagnosed based on an infectious disease specialist diagnosis, using WHO interim guidance and the recommendations of the Iranian National Committee of Covid-19. The patients with acute respiratory tract infection symptoms were checked for compatibility of chest computed tomography (CT) scan results with that of Covid-19 and Real-time polymerase chain reaction (RT-PCR) for corona virus infection. The severity of Covid-19 was categorized into three groups (mild, moderate, and severe) using CDC criteria. Serum Zn and Se level of all subjects was measured. The severity of the disease was determined only once at the onset of disease.

RESULTS

According to the results of linear regression test, there was a significant association between Zn and Se level and COVID-19 severity (β = - 0.28, P-value = 0.01 for Se; β = - 0.26, P-value = 0.02). However the significance disappeared after adjusting for confounding factors. Spearman correlation analysis showed a significant negative association between serum Zn, Se and CRP level (r = - 0.35, P-value = 0.001 for Se; r = - 0.41, P-value < 0.001 for Zn).

CONCLUSION

Results suggest that increasing levels of Se and Zn were accompanied by a decrease in serum CRP level. However, the significant association between Se, Zn, and disease severity was lost after adjusting for confounding factors.

Nutritional and lifestyle changes required for minimizing the recovery period in home quarantined COVID-19 patients of Punjab, Pakistan

The COVID-19 pandemic has introduced a new battle in human history for a safe and fearless life. Therefore, this cross-sectional survey was conducted (Punjab, Pakistan) on healthy recovered, home quarantined COVID-19 patients to draw conclusive health support guidelines in the fight against this pandemic. COVID-19 recovered patients (n = 80) of age ≥14 years were randomly selected during the period November 2020 to February 2021. A nutrition and lifestyle changes questionnaire, containing ten sections and seventy questions, was completed through the telephone/WhatsApp. Data were transferred into an Excel spreadsheet and statistically analyzed by applying chi-square, correlation, and a t test of independent values using SPSS-16 software. The patients had an age range of 14 to 80 years, of which 52 (65%) were male and 28 (35%) were female, and 32 (40%) had a normal BMI. The patients had a peak COVID-19 recovery period of 2 weeks, and a mean recovery period of 2.8 ± 1.4 weeks. Certain variables, including gender (males), age (>40 years), sleep (≤5 hr), less/no physical activity, obesity, diabetes mellitus, and autoimmune diseases, were significantly associated with delayed recovery. Poor nutritional outcomes, including lower intakes of water, legumes, nuts, meat, and milk/yogurt; and higher consumption of fast/fried/junk/spicy foods and cold water/drinks, were also significantly associated with a longer recovery period. The results were similar for not taking daily doses of multivitamins, and vitamins C, D, E, and zinc. This study identified that staying physically active, maintaining sensible body weight, having a sleep of 7 hr, consuming more foods of plant origin especially plant-based proteins from nuts and legumes, taking supplemental doses of multivitamins, vitamin D, E, and zinc, along with drinking ≥2 L of water daily can provide a significant role in early and safe recovery from COVID-19.

Post COVID-19 Syndrome ("Long COVID") and Diabetes: Challenges in Diagnosis and Management

BACKGROUND AND AIMS

Post Covid-19 syndrome (PCS) is a major cause of morbidity. In this article we intend to review the association and consequences of PCS and diabetes.

METHODS

We reviewed all studies on "Long Covid", "Post COVID-19 Syndrome" and diabetes in PubMed and Google Scholar.

RESULTS

The symptoms of PCS can be due to organ dysfunction, effects of hospitalisation and drugs, or unrelated to these. Type 2 diabetes mellitus has a bidirectional relationship with COVID-19. Presence of diabetes also influences PCS via various pathophysiological mechanisms. COVID-19 can add to or exacerbate tachycardia, sarcopenia (and muscle fatigue), and microvascular dysfunction (and organ damage) in patients with diabetes.

CONCLUSION

PCS in patients with diabetes could be detrimental in multiple ways. Strict control of diabetes and other comorbidities, supervised rehabilitation and physical exercise, and optimal nutrition could help in reducing and managing PCS.

Evaluation of the relationship between serum levels of zinc, vitamin B12, vitamin D, and clinical outcomes in patients with COVID-19

Due to the known anti‐inflammatory and antiviral effects of zinc, 25(OH)D, and vitamin B12, in this study, we explored the association between serum levels of these micronutrients in coronavirus disease 2019 (COVID‐19) patients at the time of admission and the clinical outcomes. This study was carried out on 293 patients with COVID‐19, who were hospitalized at Imam Hassan hospital (Bojnourd, Iran). We collected demographic data, clinical characteristics, values of serum biochemical parameters in the first week of admission, and clinical outcomes from electronic medical records. We also measured serum levels of zinc, 25(OH)D, and vitamin B12 within 3 days of admission. Of the 293 hospitalized, the median age was 53 years, and 147 (50.17%) were female. Thirty‐seven patients (12.62%) were admitted to the intensive care unit (ICU), and forty‐two (14.32%) died. We found that the serum levels of zinc, vitamin B12, and 25(OH)D were lower in patients who died than those who were admitted to ICU or non‐ICU and survived; however, these differences were not statistically significant for vitamin B12 and 25(OH)D (p > 0.05). The serum concentrations of zinc, vitamin B12, and 25(OH)D at the time of admission did not affect the length of hospital stay in patients with COVID‐19. In general, it seems that serum levels of 25(OH)D, vitamin B12, and especially zinc at the time of admission can affect clinical outcomes in COVID‐19 patients.

Lower levels of zinc in death cases compared to surviving cases in Covid‐19.

Lower levels of B12 and D in death cases compared to surviving cases in Covid‐19.

No effect of levels of zinc, B12, and D on the length of hospital stay in COVID‐19.

Vitamin supplementation as a potential adjunctive therapeutic approach for COVID-19: biological and clinical plausibility

The recent pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19) has introduced itself into the human population in the 21st century after the coronavirus diseases SARS-CoV and Middle East respiratory syndrome (MERS-CoV). Major investigations are underway worldwide in the search for pharmaceutical interventions for COVID-19 and many agents are administered in off-label routes. Several cases are under study to check or restrict clinical manifestations of COVID-19. According to the fact that the efficacy of some micro-nutrients like vitamins is proven to treat or prevent infectious diseases because of their antimicrobial and immunomodulatory activity, the potential role of vitamins in the COVID-19 treatment or prevention must be considered.

A systematic review and meta-analysis of effect of vitamin D levels on the incidence of COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a disease primarily affecting the respiratory tract, however due to the nature of the pathogenesis it is able to affect the whole body. So far, no causative treatment has been found and the main strategy when dealing with COVID-19 relies on widespread vaccination programs and symptomatic treatment. Vitamin D due to its ability to modulate the immunological system has been proposed as a factor playing role in the organism response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Therefore, we decided to perform this meta-analysis which aimed to establish a connection between vitamin D status and COVID-19 infection.

METHODS

Study was designed as a systematic review and meta-analysis. PubMed, EMBASE, Web of Science, Cochrane Collaboration Databases and Scopus electronic databases were searched for relevant studies from database inception to May 10th, 2021. Mean differences (MDs) with their 95% confidence intervals (CI) were calculated.

RESULTS

Thirteen studies providing data for 14,485 participants met the inclusion criteria. Mean vitamin D levels in SARS-CoV-2 negative patients was 17.7 ± 6.9 ng/mL compared to SARS-CoV-2 positive patients 14.1 ± 8.2 ng/mL (MD = 3.93; 95% CI 2.84-5.02; I2 = 99%; p < 0.001).

CONCLUSIONS

Low serum vitamin D levels are statistically significantly associated with the risk of COVID-19 infection. Supplementation of vitamin D especially in the deficiency risk groups is indicated.

The Impact of Vitamin D Deficiency on the Severity of Symptoms and Mortality Rate among Adult Patients with Covid-19: A Systematic Review and Meta-Analysis

INTRODUCTION

We aimed to study the prevalence of vitamin D deficiency (VDD) in patients with COVID-19 infection and evaluate the impact of vitamin D levels on the severity of symptoms and the case fatality rate.

EVIDENCE ACQUISITION

A comprehensive literature search was performed up to December 20, 2020, using the following databases: MEDLINE, PubMed, EMBASE, SCOPUS, Web of Science, and preprint databases (BioRxiv and MedRxiv). Any individual observational study related to the prevalence and impact of vitamin D deficiency/insufficiency (VDD/VDI) on the severity of COVID-19 symptoms and mortality rates was included. No language restrictions were applied, and both published and non-published studies were included.

EVIDENCE SYNTHESIS

Two of the authors independently performed the literature search and assessed the eligibility of studies. The quality of studies included was assessed using the Newcastle-Ottawa Scale. Data were analyzed using the Review Manager Software (version 5) and Comprehensive Meta-analysis Software (version 3). A total of 43 studies were included with a sample size of 254,963 patients with COVID-19. Pooled analysis showed a higher prevalence of VDD and VDI in patients with COVID-19 (59.0% and 40.1%, respectively). Moreover, a significant association was noticed between vitamin D levels and severity of symptoms (odds ratio [OR] = 3.38, 95% confidence interval [CI]: 1.94-5.87, P < 0.0001), as well as the case fatality rate (OR = 2.30, 95% CI: 1.47-3.59, P < 0.00001).

CONCLUSIONS

VDD is highly prevalent in patients with COVID-19 infection. Lower vitamin D levels correlate with disease severity and poor prognosis although most of the data have been derived from moderate-quality observational studies.

Influence of 25-hydroxy-cholecalciferol levels on SARS-CoV-2 infection and COVID-19 severity: A systematic review and meta-analysis

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of coronavirus disease 19 (COVID-19), a respiratory infection that, starting from December 2019, has spread around the world in a few months, becoming a pandemic. The lack of initial knowledge on its management has led to a great effort in developing vaccines and in finding therapeutic weapons capable of improving the clinical outcome of the affected patients. In particular, the possible role of vitamin D status in the management of COVID-19 has been widely analysed, resulting in a great amount of data. This systematic review and meta-analysis aimed to assess whether hypovitaminosis D is a risk factor for developing SARS-CoV-2 infection and whether it affects the worsening of the clinical course of COVID-19.

METHODS

Data were extracted through extensive searches in the Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar, and Scopus databases from December 2019 to January 2021, using the keywords: "Vitamin D", "25 hydroxy Vitamin D", "25 hydroxycholecalciferol", "cholecalciferol", "COVID 19″, "SARS-CoV-2″. We included observational cohort, cross-sectional, and case-control studies that evaluated differences in serum levels of 25‑hydroxy-cholecalciferol [25(OH)D] in patients who were positive or negative for SARS-CoV-2, in patients with mild or severe forms of COVID-19, and in patients who died or were discharged from the hospital. Finally, studies that evaluated the risk of developing severe illness or death in patients with vitamin D deficiency (VDD), defined as levels of 25(OH)D <20 ng/ml, were also included. We calculated the mean difference (MD) and the 95% confidence intervals (CI) for quantitative variables such as 25(OH)D levels in patients with or without SARS-CoV-2 infection, in those with mild vs. severe COVID-19, or those who have died vs. those who have been discharged. Instead, we calculated odds ratios and 95% CI for qualitative ones, such as the number of patients with severe illness/death in the presence of VDD vs. those with normal serum 25(OH)D levels. A p-value lower than 0.05 was considered statistically significant. The study was registered on PROSPERO (CRD42021241473).

FINDINGS

Out of 662 records, 30 articles met inclusion criteria and, therefore, were included in the meta-analysis. We found that the serum levels of 25(OH)D were significantly lower in patients with SARS-CoV-2 infection than in negative ones [MD -3.99 (-5.34, -2.64); p <0.00001; I2= 95%]. Furthermore, its levels were significantly lower in patients with severe disease [MD -6.88 (-9.74, -4.03); p <0.00001; I2=98%] and in those who died of COVID-19 [MD -8.01 (-12.50, -3.51); p = 0.0005; I2=86%]. Finally, patients with VDD had an increased risk of developing severe disease [OR 4.58 (2.24, 9.35); p <0.0001; I2=84%] but not a fatal outcome [OR 4.92 (0.83, 29.31); p = 0.08; I2=94%].

INTERPRETATION

This meta-analysis revealed a large heterogeneity of the studies included due to the different enrolment criteria of patient samples (age, body mass index, ethnicity, comorbidities), the country where they live, all factors influencing serum 25(OH)D levels, and the different criteria used to define the severity of COVID-19. Furthermore, the observational nature of these studies does not allow to establish a cause-effect relationship, even taking into account that 25(OH)D represents a marker of acute inflammation. Treatment with vitamin D might be considered for the primary prevention of SARS-CoV-2 infection and the management of patients with COVID-19. However, further intervention studies are needed to prove this hypothesis.

COVID-19 and its effects on the digestive system

Coronavirus disease 2019 (COVID-19) is caused by infection of the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with typical respiratory symptoms. SARS-CoV-2 invades not only the respiratory system, but also other organs expressing the cell surface receptor angiotensin converting enzyme 2. In particular, the digestive system is a susceptible target of SARS-CoV-2. Gastrointestinal symptoms of COVID-19 include anorexia, nausea, vomiting, diarrhea, abdominal pain, and liver damage. Patients with digestive damage have a greater chance of progressing to severe or critical illness, a poorer prognosis, and a higher risk of death. This paper aims to summarize the digestive system symptoms of COVID-19 and discuss fecal-oral contagion of SARS-CoV-2. It also describes the characteristics of inflammatory bowel disease patients with SARS-CoV-2 infection and discusses precautions for preventing SARS-CoV-2 infection during gastrointestinal endoscopy procedures. Improved attention to digestive system abnormalities and gastrointestinal symptoms of COVID-19 patients may aid health care providers in the process of clinical diagnosis, treatment, and epidemic prevention and control.

Vitamin D Metabolites and Clinical Outcome in Hospitalized COVID-19 Patients

(1) Background: Vitamin D, a well-established regulator of calcium and phosphate metabolism, also has immune-modulatory functions. An uncontrolled immune response and cytokine storm are tightly linked to fatal courses of COVID-19. The present retrospective study aimed to inves-tigate vitamin D status markers and vitamin D degradation products in a mixed cohort of 148 hospitalized COVID-19 patients with various clinical courses of COVID-19. (2) Methods: The serum concentrations of 25(OH)D₃, 25(OH)D₂, 24,25(OH)₂D₃, and 25,26(OH)₂D₃ were determined by a validated liquid-chromatography tandem mass-spectrometry method in leftover serum samples from 148 COVID-19 patients that were admitted to the University Hospital of the Medical Uni-versity of Graz between April and November 2020. Anthropometric and clinical data, as well as outcomes were obtained from the laboratory and hospital information systems. (3) Results: From the 148 patients, 34 (23%) died within 30 days after admission. The frequency of fatal outcomes did not differ between males and females. Non-survivors were significantly older than survivors, had higher peak concentrations of IL-6 and CRP, and required mechanical ventilation more frequently. The serum concentrations of all vitamin D metabolites and the vitamin D metabolite ratio (VMR) did not differ significantly between survivors and non-survivors. Additionally, the need for res-piratory support was unrelated to the serum concentrations of 25(OH)D vitamin D and the two vitamin D catabolites, as well as the VMR. (4) Conclusion: The present results do not support a relevant role of vitamin D for the course and outcome of COVID-19.

Association of Vitamin D, Zinc and Selenium Related Genetic Variants With COVID-19 Disease Severity

Background: COVID-19 pandemic has proved to be an unrelenting health threat for more than a year now. The emerging amount of data indicates that vitamin D, zinc and selenium could be important for clinical presentation of COVID-19. Here, we investigated association of genetic variants related to the altered level and bioavailability of vitamin D, zinc and selenium with clinical severity of COVID-19. Methods: We analyzed variants in genes significant for the status of vitamin D (DHCR7/NADSYN1 rs12785878, GC rs2282679, CYP2R1 rs10741657, and VDR rs2228570), zinc (PPCDC rs2120019) and selenium (DMGDH rs17823744) in 120 Serbian adult and pediatric COVID-19 patients using allelic discrimination. Furthermore, we carried out comparative population genetic analysis among European and other worldwide populations to investigate variation in allelic frequencies of selected variants. Results: Study showed that DHCR7/NADSYN rs12785878 and CYP2R1 rs10741657 variants were associated with severe COVID-19 in adults (p = 0.03, p = 0.017, respectively); carriers of DHCR7/NADSYN TG+GG and CYP2R1 GG genotypes had 0.21 and 5.9 the odds for developing severe disease, OR 0.21 (0.05-0.9) and OR 5.9 (1.4-25.2), respectively. There were no associations between selected genetic variants and disease severity in pediatric patients. Comparative population genetic analysis revealed that Serbian population had the lowest frequency of CYP2R1 rs10741657 G allele compared to other non-Finish Europeans (0.58 compared to 0.69 and 0.66 in Spanish and Italian population, respectively), suggesting that other populations should also investigate the relationship of CYP2R1 variant and the COVID-19 disease course. Conclusion: The results of the study indicated that vitamin D related genetic variants were implicated in severe COVID-19 in adults. This could direct prevention strategies based on population specific nutrigenetic profiles.

Nutrition in the Actual COVID-19 Pandemic. A Narrative Review

The pandemic of Coronavirus Disease 2019 (COVID-19) has shocked world health authorities generating a global health crisis. The present study discusses the main finding in nutrition sciences associated with COVID-19 in the literature. We conducted a consensus critical review using primary sources, scientific articles, and secondary bibliographic indexes, databases, and web pages. The method was a narrative literature review of the available literature regarding nutrition interventions and nutrition-related factors during the COVID-19 pandemic. The main search engines used in the present research were PubMed, SciELO, and Google Scholar. We found how the COVID-19 lockdown promoted unhealthy dietary changes and increases in body weight of the population, showing obesity and low physical activity levels as increased risk factors of COVID-19 affection and physiopathology. In addition, hospitalized COVID-19 patients presented malnutrition and deficiencies in vitamin C, D, B12 selenium, iron, omega-3, and medium and long-chain fatty acids highlighting the potential health effect of vitamin C and D interventions. Further investigations are needed to show the complete role and implications of nutrition both in the prevention and in the treatment of patients with COVID-19.

The association between micronutrient and hemogram values and prognostic factors in COVID-19 patients: A single-center experience from Turkey

AIM

The contribution of micronutrients to the immune system has been known for a long time. This study aimed to investigate the association between the micronutrient levels and hemogram values and prognostic factors of the disease in COVID-19 patients in Ankara City Hospital.

MATERIALS AND METHODS

Our study is a descriptive observational study based on a retrospective review of patient files. COVID-19 patients over 18 years of age who were admitted to our hospital between 14 March and 1 June 2020, and with a complete micronutrient profile were included in the study. Age, gender, chronic diseases, micronutrient concentrations in the last 6 months, hemogram data on the day of hospitalization, total length of stay in hospital, and hospitalization to Intensive Care Unit (ICU)-intubation-death status of the patients were obtained from the patient files.

RESULTS

A total of 310 patients whose parameters were thoroughly examined were included in our study; 51.9% of them were men and the mean age of all patients was 57.02 ± 18.28 years, and the most common comorbid disease was hypertension. The percentage of patients who were followed in the ICU, were intubated, and died was 34.5%, 13.9%, and 9.4%, respectively. The mean length of hospital stay was 15.87 ± 12.79 days. Low folate, iron, vitamin D, and hemoglobin levels of the patients and high vitamin B12 concentration were more related to poor prognostic factors. The number of white blood cells was significantly higher in patients with a worse prognosis, and the number of lymphocytes was lower in patients with ICU admission but higher in intubated and dead patients.

CONCLUSION

Micronutrient and hemogram values, advanced age, being male, and having comorbid diseases were correlated with the poor prognosis of COVID-19 infection. Deficiency of Iron, Folate, and vitamin D should be well-considered in COVID-19. Excessive vitamin B12 and multivitamin supplementation should be avoided by choosing supplement wisely. In addition, attention should be paid to leukocytosis, lymphocyte counts, and anemia during COVID-19 patient follow-up. What's known Some micronutrients have an immunomodulatory and anti-inflammatory effect with antioxidant effects and thus play a protective role in respiratory tract infections as COVID-19. Vitamin D deficiency is found to be associated with poor prognostic factors in COVID-19. Lymphopenia is found to be associated with poor prognostic factors in COVID-19. What's new According to the results obtained from our study, low iron and folate levels should be controlled first in patients diagnosed with COVID-19, low vitamin D levels should also be well-considered, and supplementation should be provided in the case of deficiencies. On the other hand excessive use of vitamin B12 should be avoided. The fact that all micronutrients should be evaluated and managed by choosing wisely rather than a complete multivitamin supplement approach was demonstrated by the differences in the poor prognosis levels of vitamin B12 versus the other micronutrients. In addition, it was found in our study that leukocytosis, lymphocyte counts, and anemia should be taken into consideration together when evaluating hemogram parameters in the follow-up of COVID-19 patients.

Influence of nutritional status on clinical outcomes among hospitalized patients with COVID-19

BACKGROUND AND AIMS

Several factors that worsen the prognosis of the new coronavirus SARS-CoV-2 have been identified, such as obesity or diabetes. However, despite that nutrition may change in a lockdown situation, little is known about the influence of malnutrition among subjects hospitalized due to COVID-19. Our study aimed to assess whether the presence of malnutrition among patients admitted due to COVID-19 had any impact on clinical outcomes compared with patients with the same condition but well nourished.

METHODS

75 patients admitted to hospital due to COVID-19 were analyzed cross-sectionally. Subjective Global Assessment (SGA) was completed by phone interview. Clinical parameters included were extracted from the electronic medical record.

RESULTS

According to the SGA, 27 admitted due to a COVID-19 infection had malnutrition. Patients not well nourished were older than patients with a SGA grade A (65 ± 14.1 vs 49 ± 15.1 years; p < 0.0001). Length of hospital stay among poorly nourished patients was significantly higher (18.4 ± 15.6 vs 8.5 ± 7.7 days; p = 0.001). Mortality rates and admission to ICU were greater among subjects with any degree of malnutrition compared with well-nourished patients (7.4% vs 0%; p = 0.05 and 44.4% vs 6.3%; p < 0.0001). CRP (120.9 ± 106.2 vs 60.8 ± 62.9 mg/l; p = 0.03), D-dimer (1516.9 ± 1466.9 vs 461.1 ± 353.7 ng/mL; p < 0.0001) and ferritin (847.8 ± 741.1 vs 617.8 ± 598.7mcg/l; p = 0.03) were higher in the group with malnutrition. Haemoglobin (11.6 ± 2.1 vs 13.6 ± 1.5 g/dl; p < 0.0001) and albumin 3.2 ± 0.7 vs 4.1 ± 0.5 g/dl; p < 0.0001) were lower in patients with any degree of malnutrition.

CONCLUSIONS

The presence of a poor nutritional status is related to a longer stay in hospital, a greater admission in the ICU and a higher mortality.

The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis

BACKGROUND

Disease severity and mortality rates due to COVID-19 infection are greater in the elderly and chronically ill patients, populations at high risk for vitamin D deficiency. Vitamin D plays an important role in immune function and inflammation. This systematic review and meta-analysis assesses the impact of vitamin D status and supplementation on COVID-19 related mortality and health outcomes.

METHODS

We searched four databases until December 18th 2020, and trial registries until January 20th 2021. Two reviewers screened the studies, collected data, assessed the risk of bias, and graded the evidence for each outcome across studies, independently and in duplicate. Pre-specified outcomes of interest were mortality, ICU admission, invasive and non-invasive ventilation, hospitalization, time of hospital stay, disease severity and SARS-CoV-2 positivity. We only included data from peer-reviewed articles in our primary analyses.

RESULTS

We identified 31 peer-reviewed observational studies. In our primary analysis, there was a positive trend between serum 25(OH)D level <20 ng/ml and an increased risk of mortality, ICU admission, invasive ventilation, non-invasive ventilation or SARS-CoV-2 positivity. However, these associations were not statistically significant. Mean 25(OH)D levels was 5.9 ng/ml (95% CI [-9.5, -2.3]) significantly lower in COVID-19 positive, compared to negative patients. The certainty of the evidence was very low. We identified 32 clinical trial protocols, but only three have published results to-date. The trials administer vitamin D doses of 357 to 60,000 IU/day, from one week to 12 months. Eight megatrials investigate the efficacy of vitamin D in outpatient populations. A pilot trial revealed a significant decrease in ICU admission with calcifediol, compared to placebo (OR = 0.003), but the certainty of the evidence was unclear. Another small trial showed that supplementation with cholecalciferol, 60,000 IU/day, decreased fibrinogen levels, but did not have an effect on D-dimer, procalcitonin and CRP levels, compared to placebo. The third trial did not find any effect of vitamin D supplementation on COVID-19 related health outcomes.

CONCLUSION

While the available evidence to-date, from largely poor-quality observational studies, may be viewed as showing a trend for an association between low serum 25(OH)D levels and COVID-19 related health outcomes, this relationship was not found to be statistically significant. Calcifediol supplementation may have a protective effect on COVID-19 related ICU admissions. The current use of high doses of vitamin D in COVID-19 patients is not based on solid evidence. It awaits results from ongoing trials to determine the efficacy, desirable doses, and safety, of vitamin D supplementation to prevent and treat COVID-19 related health outcomes.

A Mechanistic Link Between Selenium and Coronavirus Disease 2019 (COVID-19)

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) is a rapidly emerging disease caused by a highly contagious virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and this disease has affected millions of people across the world and led to hundreds of thousands of deaths worldwide. Nutrition is a key factor related to this disease, and nutritional status may determine the risk and outcomes of SARS-CoV-2 infection. Selenium is one of the major trace elements required for redox functions and has significant roles in viral infections. The purpose of this review was to examine the current evidence on the role of selenium in COVID-19. We reviewed studies on selenium and COVID-19, and other relevant studies to understand how selenium status can modify the risk of SARS-CoV-2 infection, and how selenium status might affect a person post-infection.

RECENT FINDINGS

We found that oxidative stress is a characteristic feature of COVID-19 disease, which is linked with the immunopathological disorder observed in individuals with severe COVID-19. Selenium plays a key role in strengthening immunity, reducing oxidative stress, preventing viral infections and supporting critical illness. Moreover, selenium deficiency is related to oxidative stress and hyperinflammation seen in critical illness, and selenium deficiency is found to be associated with the severity of COVID-19 disease. Selenium supplementation at an appropriate dose may act as supportive therapy in COVID-19. Future studies in large cohorts of COVID-19 are warranted to verify the benefits of selenium supplementation for reducing risk and severity of COVID-19.

SARS-CoV-2 suppresses mRNA expression of selenoproteins associated with ferroptosis, endoplasmic reticulum stress and DNA synthesis

Higher selenium status has been shown to improve the clinical outcome of infections caused by a range of evolutionally diverse viruses, including SARS-CoV-2. However, the impact of SARS-CoV-2 on host-cell selenoproteins remains elusive. The present study investigated the influence of SARS-CoV-2 on expression of selenoprotein mRNAs in Vero cells. SARS-CoV-2 triggered an inflammatory response as evidenced by increased IL-6 expression. Of the 25 selenoproteins, SARS-CoV-2 significantly suppressed mRNA expression of ferroptosis-associated GPX4, DNA synthesis-related TXNRD3 and endoplasmic reticulum-resident SELENOF, SELENOK, SELENOM and SELENOS. Computational analysis has predicted an antisense interaction between SARS-CoV-2 and TXNRD3 mRNA, which is translated with high efficiency in the lung. Here, we confirmed the predicted SARS-CoV-2/TXNRD3 antisense interaction in vitro using DNA oligonucleotides, providing a plausible mechanism for the observed mRNA knockdown. Inhibition of TXNRD decreases DNA synthesis which is thereby likely to increase the ribonucleotide pool for RNA synthesis and, accordingly, RNA virus production. The present findings provide evidence for a direct inhibitory effect of SARS-CoV-2 replication on the expression of a specific set of selenoprotein mRNAs, which merits further investigation in the light of established evidence for correlations between dietary selenium status and the outcome of SARS-CoV-2 infection.

Evaluation of nutritional status in pediatric patients diagnosed with Covid-19 infection

Aim

The aim of this study was to evaluate the nutritional status, the nutritional effect on the risk of infection and the severity of the disease, and the contribution of nutrition to the course of the infection in pediatric patients diagnosed with coronavirus disease who required additional nutritional support after hospitalization.

Methods

The body weight, height, body mass index, upper arm circumference, and triceps skinfold thickness of 49 patients aged 1 month to 18 years and diagnosed with Covid-19 and then hospitalized at the Ankara City Hospital, Pediatric Health and Diseases Hospital, Pediatric Infection ward between 15 May and 15 June 2020 were measured. Total protein, albumin, prealbumin, selenium, zinc, ferritin, folate, and selenium, C, D, E, and B12 levels were studied from blood drawn simultaneously from the patients.

Results

A total of 49 patients aged 8–18 years were evaluated. The median age was 13 years (age range 8–18). The females made up 53% and the males 47% of the group. No patient needed intensive care admission. Only 3 patients received antibiotic treatment and the others were followed up without treatment. The weight was normal in 75% and the height was normal in 90%. Mid-arm circumference and triceps thickness were normal in 72% of the patients. Vitamin D deficiency was present in 82%, vitamin B12 deficiency in 18%, vitamin C deficiency in 17%, ferritin deficiency in 16%, folate deficiency in 15%, vitamin A deficiency in 13%, and vitamin E deficiency in 7%.

Conclusion

No patient required intensive care admission. Only 3 patients received antibiotic treatment and the others were followed up without treatment. Malnourishment was present in 3% of the patients while 9% were obese. Vitamin D deficiency was the most common vitamin deficiency while vitamin B12, vitamin C, Ferritin, vitamin A, vitamin E, and Folate deficiency were less common. Selenium and zinc levels were normal in all patients. There was no correlation between anthropometric values and susceptibility to childhood COVID-19 infection or the clinical course. It is possible that vitamin D deficiency increases susceptibility to the infection.

Micronutrients Deficiency, Supplementation and Novel Coronavirus Infections-A Systematic Review and Meta-Analysis

BACKGROUND

Micronutrients play roles in strengthening and maintaining immune function, but their supplementation and/or deficiency effects on respiratory tract infections are inconclusive. This review aims to systematically assess the associations between micronutrient supplementation or deficiency, with novel coronavirus incidence and disease severity.

METHODS

Systematic literature searches conducted in five electronic databases identified 751 unique studies, of which 33 studies (five supplementation studies, one supplementation and deficiency study, and 27 deficiency studies) were eventually included in this review. Proportions of incidence and severity outcomes in each group, and adjusted summary statistics with their relevant 95% confidence intervaIs (CI) were extracted. Data from 19 studies were pooled in meta-analysis using the generic inverse variance method.

FINDINGS

A total of 360,346 patients across 16 countries, with a mean age between 32 and 87.7 years, were involved across 33 studies. All studies were on COVID-19 infections. In individuals without micronutrient deficiency, there was a significant reduction on odds of COVID-19 incidence (pooled OR: 0.37, 95% CI: 0.18, 0.78), and ICU admissions or severe/critical disease onset when combined as a severity outcome (pooled OR: 0.26, 95% CI: 0.08, 0.89). Insignificant protective effects were observed on other outcome measures, namely mortality, ICU admission, progression to respiratory-related complications, severe/critical disease onset or requiring respiratory support and hospitalization rate.

CONCLUSION

The absence of micronutrient deficiency significantly reduced COVID-19 incidence and clinical deterioration in hospitalized patients. Usage of micronutrients as prophylaxis and complementary supplement in therapeutic management of COVID-19 patients may be a promising and cost-effective approach warranting in-depth investigation.

Dietary Supplements and Nutraceuticals under Investigation for COVID-19 Prevention and Treatment

Coronavirus disease 2019 (COVID-19) has caused global disruption and a significant loss of life. Existing treatments that can be repurposed as prophylactic and therapeutic agents may reduce the pandemic's devastation. Emerging evidence of potential applications in other therapeutic contexts has led to the investigation of dietary supplements and nutraceuticals for COVID-19. Such products include vitamin C, vitamin D, omega 3 polyunsaturated fatty acids, probiotics, and zinc, all of which are currently under clinical investigation. In this review, we critically appraise the evidence surrounding dietary supplements and nutraceuticals for the prophylaxis and treatment of COVID-19. Overall, further study is required before evidence-based recommendations can be formulated, but nutritional status plays a significant role in patient outcomes, and these products may help alleviate deficiencies. For example, evidence indicates that vitamin D deficiency may be associated with a greater incidence of infection and severity of COVID-19, suggesting that vitamin D supplementation may hold prophylactic or therapeutic value. A growing number of scientific organizations are now considering recommending vitamin D supplementation to those at high risk of COVID-19. Because research in vitamin D and other nutraceuticals and supplements is preliminary, here we evaluate the extent to which these nutraceutical and dietary supplements hold potential in the COVID-19 crisis.IMPORTANCE Sales of dietary supplements and nutraceuticals have increased during the pandemic due to their perceived "immune-boosting" effects. However, little is known about the efficacy of these dietary supplements and nutraceuticals against the novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) or the disease that it causes, CoV disease 2019 (COVID-19). This review provides a critical overview of the potential prophylactic and therapeutic value of various dietary supplements and nutraceuticals from the evidence available to date. These include vitamin C, vitamin D, and zinc, which are often perceived by the public as treating respiratory infections or supporting immune health. Consumers need to be aware of misinformation and false promises surrounding some supplements, which may be subject to limited regulation by authorities. However, considerably more research is required to determine whether dietary supplements and nutraceuticals exhibit prophylactic and therapeutic value against SARS-CoV-2 infection and COVID-19. This review provides perspective on which nutraceuticals and supplements are involved in biological processes that are relevant to recovery from or prevention of COVID-19.

Selenium (Se) plays a key role in the biological effects of some viruses: Implications for COVID-19

Host nutrition is an important factor affecting disease progression. Selenium (Se) is an essential trace element for the human body with anti-inflammatory, antioxidant, and immune effects, and Se deficiency increases RNA-virus replication and virulent mutations, which lead to more severe tissue damage and symptoms. Low Se status in the host may be an important cause of health complications induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this article, we describe the metabolic mechanisms by which Se is involved in anti-inflammatory, antioxidant, and immune effects, and review the role and clinical effects of Se in viral infection. We then discuss the potential relationship between Se and coronavirus disease 2019 (COVID-19). The association between soil Se level and the incidence of COVID-19 was observed in different cities of Hubei Province. The incidence of COVID-19 was more than 10 times lower in Se-enriched cities (Enshi, Shiyan, and Xiangyang) than in Se-deficient cities (Suizhou and Xiaogan). Although the relationship between soil Se levels and the incidence of COVID-19 in Hubei still needs further study, these findings provide baseline information demonstrating the effect of Se levels on SARS-CoV-2, which could contribute to the prevention and management of COVID-19.

Vitamin D and Its Potential Benefit for the COVID-19 Pandemic

Vitamin D is known not only for its importance for bone health but also for its biologic activities on many other organ systems. This is due to the presence of the vitamin D receptor in various types of cells and tissues, including the skin, skeletal muscle, adipose tissue, endocrine pancreas, immune cells, and blood vessels. Experimental studies have shown that vitamin D exerts several actions that are thought to be protective against coronavirus disease (COVID-19) infectivity and severity. These include the immunomodulatory effects on the innate and adaptive immune systems, the regulatory effects on the renin-angiotensin-aldosterone-system in the kidneys and the lungs, and the protective effects against endothelial dysfunction and thrombosis. Prior to the COVID-19 pandemic, studies have shown that vitamin D supplementation is beneficial in protecting against risk of acquiring acute respiratory viral infection and may improve outcomes in sepsis and critically ill patients. There are a growing number of data connecting COVID-19 infectivity and severity with vitamin D status, suggesting a potential benefit of vitamin D supplementation for primary prevention or as an adjunctive treatment of COVID-19. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake and having sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L) to minimize the risk of COVID-19 infection and its severity.

Relation between Vitamin D and COVID-19 in Aged People: A Systematic Review

BACKGROUND

Vitamin D has diverse and extensive effects on the immune system, including activating innate immunity and reducing the overactive adaptive immune response. A systematic review was performed to identify and synthesize the best available evidence on the association between vitamin D level and risk of COVID-19, adverse outcomes and possible benefits of supplementation in aged 60 years or over.

METHODS

A literature search was performed in PubMed© and Scopus© for all publications from inception published before 15 March 2021. Studies reporting data from aged patients on vitamin D use and COVID-19 were included. Basic science articles, editorials and correspondence were excluded. Publication year, study design and setting, characteristics of the study population were extracted. This study is registered with PROSPERO, under the number CRD42020223993.

RESULTS

In total, 707 studies were identified, of which 11 observational studies were included in the final review. Four studies compared vitamin D-supplemented COVID-19 patients to non-supplemented patients, and seven compared patients with vitamin D deficiency to patients without deficiency. In all four studies, patients with vitamin D supplementation had better rates of primary clinical outcomes (death, the severity of the disease, oxygen therapy requirement…). In studies comparing patients with vitamin D deficiency and patients without vitamin D deficiency, those without vitamin D deficiency had better primary clinical outcomes (death rate, the severity of the disease, oxygen therapy requirement, invasive mechanical ventilation need…).

CONCLUSION

This systematic review seems to support an association between vitamin D deficiency and the risk of COVID-19 in aged people. In addition, vitamin D deficiency appears to expose these subjects to a greater risk of adverse outcomes. Because of its simplicity of administration, and the rarity of side effects, including vitamin D in preventive strategies for certain viral diseases, it appears to be an attractive option.

Selenium to selenoproteins - role in COVID-19

The disruption of antioxidant defense has been demonstrated in severe acute respiratory syndrome due to SARS-CoV infection. Selenium plays a major role in decreasing the ROS produced in response to various viral infections. Selenoprotein enzymes are essential in combating oxidative stress caused due to excessive generation of ROS. Selenium also has a role in inhibiting the activation of NF-κB, thus alleviating inflammation. In viral infections, selenoproteins have also been found to inhibit type I interferon responses, modulate T cell proliferation and oxidative burst in macrophages, and inhibit viral transcriptional activators. Potential virally encoded selenoproteins have been identified by computational analysis in different viral genomes like HIV-1, Japanese encephalitis virus (JEV), and hepatitis C virus. This review discusses the role and the possible mechanisms of selenium, selenoproteins, and virally encoded selenoproteins in the pathogenicity of viral infections. Identification of potential selenoproteins in the COVID 19 genome by computational tools will give insights further into their role in the pathogenesis of viral infections.

Serum Zinc, Copper, and Other Biometals Are Associated with COVID-19 Severity Markers

The objective of the present study was to evaluate of serum metal levels in COVID-19 patients with different disease severity, and to investigate the independent association between serum metal profile and markers of lung damage. The cohort of COVID-19 patients consisted of groups of subjects with mild, moderate, and severe illness, 50 examinees each. Forty-four healthy subjects of the respective age were involved in the current study as the control group. Serum metal levels were evaluated using inductively-coupled plasma mass-spectrometry. Examination of COVID-19 patients demonstrated that heart rate, respiratory rate, body temperature, C-reactive protein levels, as well as lung damage increased significantly with COVID-19 severity, whereas SpO₂ decreased gradually. Increasing COVID-19 severity was also associated with a significant gradual decrease in serum Ca, Fe, Se, Zn levels as compared to controls, whereas serum Cu and especially Cu/Zn ratio were elevated. No significant group differences in serum Mg and Mn levels were observed. Serum Ca, Fe, Se, Zn correlated positively with SpO₂, being inversely associated with fever, lung damage, and C-reactive protein concentrations. Opposite correlations were observed for Cu and Cu/Zn ratio. In regression models, serum Se levels were inversely associated with lung damage independently of other markers of disease severity, anthropometric, biochemical, and hemostatic parameters. Cu/Zn ratio was also considered as a significant predictor of lower SpO₂ in adjusted regression models. Taken together, these findings demonstrated that metal metabolism significantly interferes with COVID-19 pathogenesis, although the causal relations as well as precise mechanisms are yet to be characterized.

The effects of some essential and toxic metals/metalloids in COVID-19: A review

Thousands of studies have been conducted in order to understand in depth the characteristics of the novel coronavirus SARS-CoV-2, its infectivity and ways of transmission, and very especially everything related to the clinical and severity of the COVID-19, as well as the potential treatments. In this sense, the role that essential and toxic metals/metalloids have in the development and course of this disease is being studied. Metals/metalloids such as arsenic, cadmium, lead, mercury or vanadium, are elements with known toxic effects in mammals, while trace elements such as cobalt, copper, iron, manganese, selenium and zinc are considered essential. Given the importance of metals/metalloids in nutrition and human health, the present review was aimed at assessing the relationship between various essential and toxic metals/metalloids and the health outcomes related with the COVID-19. We are in the position to conclude that particular attention must be paid to the load/levels of essential trace elements in COVID-19 patients, mainly zinc and selenium. On the other hand, the exposure to air pollutants in general, and toxic metal/metalloids in particular, should be avoided as much as possible to reduce the possibilities of viral infections, including SARS-CoV-2.

Low Serum 25-hydroxyvitamin D (Vitamin D) Level Is Associated With Susceptibility to COVID-19, Severity, and Mortality: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis aimed to assess whether low serum 25-hydroxyvitamin D (25-OHD) level is associated with susceptibility to COVID-19, severity, and mortality related to COVID-19. Methods: Systematic literature searches of PubMed, Scopus, and Embase database up until 9 December 2020. We include published observational prospective and retrospective studies with information on 25-OHD that reported main/secondary outcome. Low serum 25-OHD refers to participants with serum 25-OHD level below a cut-off point ranging from 20 to 30 ng/mL. Other cut-off values were excluded to reduce heterogeneity. The main outcome was mortality defined as non-survivor/death. The secondary outcome was susceptibility and severe COVID-19. Results: There were 14 studies comprising of 999,179 participants. Low serum 25-OHD was associated with higher rate of COVID-19 infection compared to the control group (OR = 2.71 [1.72, 4.29], p < 0.001; I 2: 92.6%). Higher rate of severe COVID-19 was observed in patients with low serum 25-OHD (OR = 1.90 [1.24, 2.93], p = 0.003; I 2: 55.3%), with a sensitivity of 83%, specificity of 39%, PLR of 1.4, NLR of 0.43, and DOR of 3. Low serum 25-OHD was associated with higher mortality (OR = 3.08 [1.35, 7.00], p = 0.011; I 2: 80.3%), with a sensitivity of 85%, specificity of 35%, PLR of 1.3, NLR of 0.44, and DOR of 3. Meta-regression analysis showed that the association between low serum 25-OHD and mortality was affected by male gender (OR = 1.22 [1.08, 1.39], p = 0.002), diabetes (OR = 0.88 [0.79, 0.98], p = 0.019). Conclusion: Low serum 25-OHD level was associated with COVID-19 infection, severe presentation, and mortality.

The Role of Nutrition in the COVID-19 Pandemic

SARS-CoV-2, the cause of the COVID-19 disease, is posing unprecedent challenges. In the literature, increasing evidence highlights how malnutrition negatively affects the immune system functionality, impairing protection from infections. The current review aims to summarize the complex relationship between SARS-CoV-2 infection and nutritional status and the effects of malnutrition in terms of disease severity, patients' recovery time, incidence of complications and mortality rate. Current studies evaluating the possibility of modulating nutrition and supplementation in combination with pharmacological treatments in the clinical setting to prevent, support, and overcome infection are also described. The discussion of the most recent pertinent literature aims to lay the foundations for making reasonable assumptions and evaluations for a nutritional "best practice" against COVID-19 pandemic and for the definition of sound cost-effective strategies to assist healthcare systems in managing patients and individuals in their recovery from COVID-19.

The Role of Oat Nutrients in the Immune System: A Narrative Review

Optimal nutrition is the foundation for the development and maintenance of a healthy immune system. An optimal supply of nutrients is required for biosynthesis of immune factors and immune cell proliferation. Nutrient deficiency/inadequacy and hidden hunger, which manifests as depleted nutrients reserves, increase the risk of infectious diseases and aggravate disease severity. Therefore, an adequate and balanced diet containing an abundant diversity of foods, nutrients, and non-nutrient chemicals is paramount for an optimal immune defense against infectious diseases, including cold/flu and non-communicable diseases. Some nutrients and foods play a larger role than others in the support of the immune system. Oats are a nutritious whole grain and contain several immunomodulating nutrients. In this narrative review, we discuss the contribution of oat nutrients, including dietary fiber (β-glucans), copper, iron, selenium, and zinc, polyphenolics (ferulic acid and avenanthramides), and proteins (glutamine) in optimizing the innate and adaptive immune system's response to infections directly by modulating the innate and adaptive immunity and indirectly by eliciting changes in the gut microbiota and related metabolites.

Approaches to Nutritional Screening in Patients with Coronavirus Disease 2019 (COVID-19)

Malnutrition is common among severe patients with coronavirus disease 2019 (COVID-19), mainly elderly adults and patients with comorbidities. It is also associated with atypical presentation of the disease. Despite the possible contribution of malnutrition to the acquisition and severity of COVID-19, it is not clear which nutritional screening measures may best diagnose malnutrition in these patients at early stages. This is of crucial importance given the urgency and rapid progression of the disease in vulnerable groups. Accordingly, this review examines the available literature for different nutritional screening approaches implemented among COVID-19 patients, with a special focus on elderly adults. After a literature search, we selected and scrutinized 14 studies assessing malnutrition among COVID-19 patients. The Nutrition Risk Screening 2002 (NRS-2002) has demonstrated superior sensitivity to other traditional screening measures. The controlling nutritional status (CONUT) score, which comprises serum albumin level, cholesterol level, and lymphocytes count, as well as a combined CONUT-lactate dehydrogenase-C-reactive protein score expressed a predictive capacity even superior to that of NRS-2002 (0.81% and 0.92% vs. 0.79%) in midlife and elder COVID-19 patients. Therefore, simple measures based on routinely conducted laboratory investigations such as the CONUT score may be timely, cheap, and valuable alternatives for identifying COVID-19 patients with high nutritional risk. Mini Nutritional Assessment (MNA) was the only measure used to detect residual malnutrition and high malnutrition risk in remitting patients-MNA scores correlated with hypoalbuminemia, hypercytokinemia, and weight loss. Older males with severe inflammation, gastrointestinal symptoms, and pre-existing comorbidities (diabetes, obesity, or hypertension) are more prone to malnutrition and subsequently poor COVID-19 prognosis both during the acute phase and during convalescence. Thus, they are in need of frequent nutritional monitoring and support while detecting and treating malnutrition in the general public might be necessary to increase resilience against COVID-19.

Trace Minerals, Vitamins and Nutraceuticals in Prevention and Treatment of COVID-19

Coronavirus disease 2019 (COVID-19) was first officially diagnosed in the city of Wuhan, China in January 2020. In reality, the disease was identified in December 2019 in the same city where patients began showing symptoms of pneumonia of unidentified origin. Very soon the disease became a global pandemic due to the suppression of information in the country of origin and inadequate testing for the COVID-19 virus. Currently, > 101 million people have been found positive for this virus and > 2.17 million people have died. There are no signs that COVID-19 is slowing down. This deadly virus affects multiple vital organs (lungs, heart, nervous system, blood, and immune system), yet its exact mechanism of pathophysiology remains obscure. Depending on the viral load, sick people often show symptoms of fever, cough, shortness of breath, coagulopathy, cardiac abnormalities, fatigue, and death. Great strides have been made in COVID-19 testing, thereby allowing timely therapeutic intervention. Currently, vaccines are on the market from Pfizer, Moderna and Astra Zeneca with limited supply. Phase III clinical trials are also underway from other manufacturers. In the current scenario, nutraceuticals and other phyto-mineral supplements appear to be promising alternative solutions for the prevention and treatment of COVID-19.

Folate Levels in Patients Hospitalized with Coronavirus Disease 2019

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

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis

BACKGROUND

Observational studies suggest that the risk and clinical prognosis of coronavirus disease 2019 (COVID-19) are related to low vitamin D status; however, the data are inconsistent.

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the association between low vitamin D status and COVID-19.

METHODS

A systematic search was conducted with PubMed, Embase, and the Cochrane Library from database inception to September 25, 2020. The standardized mean difference (SMD) or odds ratio (OR) and corresponding 95% confidence interval (CI) was applied to estimate pooled results. Random - or fixed-effect models based on heterogeneity were used for the meta-analysis. Funnel plots and Egger regression tests were used to assess publication bias.

RESULTS

A total of ten articles with 361,934 participants were selected for meta-analysis. Overall, the pooled OR in the fixed-effect model showed that vitamin D deficiency or insufficiency was associated with an increased risk of COVID-19 (OR = 1.43, 95% CI 1.00-2.05). In addition, COVID-19-positive individuals had lower vitamin D levels than COVID-19-negative individuals (SMD = -0.37, 95% CI = -0.52 to -0.21). Significant heterogeneity existed in both endpoints. Funnel plots and Egger regression tests revealed significant publication bias.

CONCLUSIONS

This systematic review and meta-analysis indicated that low vitamin D status might be associated with an increased risk of COVID-19 infection. Further studies are needed to evaluate the impact of vitamin D supplementation on the clinical severity and prognosis in patients with COVID-19.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no: CRD42020216740.

Notable Developments for Vitamin D Amid the COVID-19 Pandemic, but Caution Warranted Overall: A Narrative Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel contagion that has infected over 113 million people worldwide. It is responsible for the coronavirus disease (COVID-19), which has cost the lives of 2.5 million people. Ergo, the global scientific community has been scrambling to repurpose or develop therapeutics to treat COVID-19. Dietary supplements and nutraceuticals are among those under consideration due to the link between nutritional status and patient outcomes. Overall, poor vitamin D status seems to be associated with an increased risk of COVID-19. Severely ill COVID-19 patients appear to be deficient or have suboptimal levels of serum 25-hydroxyvitamin D, a measure of vitamin D status. Consequently, vitamin D is now the subject of several prophylactic and therapeutic clinical trials. In this review, the general status of nutraceuticals and dietary supplements amid the pandemic is appraised, with a particular focus on vitamin D. Consumers should be aware of misinformation and unsubstantiated promises for products marketed for COVID-19 protection. However, maintaining a healthy diet and lifestyle will likely maintain health including optimum immune function that may affect patient outcomes. Those who are deficient in key nutrients such as vitamin D should consider lifestyle changes and potentially supplementation in consultation with their physician and/or registered dieticians.

Vitamin D and Lung Outcomes in Elderly COVID-19 Patients

Background and aim: Vitamin D deficiency is frequently reported in patients with SARS-CoV-2 infection. The aim of this study was to correlate the 25OH-Vitamin D serum concentrations with clinical parameters of lung involvement, in elderly patients hospitalized for SARS-CoV-2 infection. Methods: Sixty-five consecutive COVID-19 patients (mean age 76 ± 13 years) and sixty-five sex- and age-matched control subjects (CNT) were analyzed. The following clinical parameters, including comorbidities, were collected at admission: type of pulmonary involvement, respiratory parameters (PaO2, SO2, PaCO2, PaO2/FiO2), laboratory parameters (including 25OH-vitamin D, D-dimer, C-reactive protein). Results: Significantly lower vitamin D serum levels were found in COVID-19 patients than in CNT (median 7.9 vs 16.3 ng/mL, p = 0.001). Interestingly, a statistically significant positive correlation was observed between vitamin D serum levels and PaO2 (p = 0.03), SO2 (p = 0.05), PaO2/FiO2 (p = 0.02), while a statistically significant negative correlation was found between vitamin D serum levels and D-dimer (p = 0.04), C-reactive protein (p = 0.04) and percentage of O2 in a venturi mask (p = 0.04). A negative correlation was also observed between vitamin D serum levels and severity of radiologic pulmonary involvement, evaluated by computed tomography: in particular, vitamin D was found significantly lower in COVID-19 patients with either multiple lung consolidations (p = 0.0001) or diffuse/severe interstitial lung involvement than in those with mild involvement (p = 0.05). Finally, significantly lower vitamin D serum levels were found in the elderly COVID-19 patients who died during hospitalization, compared to those who survived (median 3.0 vs 8.4 ng/mL, p = 0.046). Conclusions: This study confirms that 25OH-vitamin D serum deficiency is associated with more severe lung involvement, longer disease duration and risk of death, in elderly COVID-19 patients. The detection of low vitamin D levels also in younger COVID-19 patients with less comorbidities further suggests vitamin D deficiency as crucial risk factor at any age.

New Insights Into the Physiopathology of COVID-19: SARS-CoV-2-Associated Gastrointestinal Illness

Although SARS-CoV-2 is considered a lung-tropic virus that infects the respiratory tract through binding to the ACE2 cell-surface molecules present on alveolar lungs epithelial cells, gastrointestinal symptoms have been frequently reported in COVID-19 patients. What can be considered an apparent paradox is that these symptoms (e.g., diarrhea), sometimes precede the development of respiratory tract illness as if the breathing apparatus was not its first target during viral dissemination. Recently, evidence was reported that the gut is an active site of replication for SARS-CoV-2. This replication mainly occurs in mature enterocytes expressing the ACE2 viral receptor and TMPRSS4 protease. In this review we question how SARS-CoV-2 can cause intestinal disturbances, whether there are pneumocyte-tropic, enterocyte-tropic and/or dual tropic strains of SARS-CoV-2. We examine two major models: first, that of a virus directly causing damage locally (e.g., by inducing apoptosis of infected enterocytes); secondly, that of indirect effect of the virus (e.g., by inducing changes in the composition of the gut microbiota followed by the induction of an inflammatory process), and suggest that both situations probably occur simultaneously in COVID-19 patients. We eventually discuss the consequences of the virus replication in brush border of intestine on long-distance damages affecting other tissues/organs, particularly lungs.

COVID-19: A methyl-group assault?

The socio-economic implications of COVID-19 are devastating. Considerable morbidity is attributed to ‘long-COVID’ – an increasingly recognized complication of infection. Its diverse symptoms are reminiscent of vitamin B₁₂ deficiency, a condition in which methylation status is compromised.

We suggest why SARS-CoV-2 infection likely leads to increased methyl-group requirements and other disturbances of one-carbon metabolism. We propose these might explain the varied symptoms of long-COVID. Our suggested mechanism might also apply to similar conditions such as myalgic encephalomyelitis/chronic fatigue syndrome.

The hypothesis is evaluable by detailed determination of vitamin B₁₂ and folate status, including serum formate as well as homocysteine and methylmalonic acid, and correlation with viral and host RNA methylation and symptomatology. If confirmed, methyl-group support should prove beneficial in such individuals.

Fruits and Vegetables in the Management of Underlying Conditions for COVID-19 High-Risk Groups

SARS-CoV-2 or COVID-19 is a novel coronavirus, which is the cause of the current pandemic with 107,411,561 infections and 2,351,195 death worldwide so far. There are multiple symptoms that are linked with the infection of COVID-19 such as coughing, shortness of breath, congestion together with fatigue, fever, loss of taste or smell, headaches, diarrhea, vomiting, and loss of appetite. The lack of or early stage of development of a cure for COVID-19 illness, there is need for insuring the best possible position of health to be able to fight the virus naturally through a robust immune system to limit severe complication. In this article, we have discussed the role of fruits and vegetables consumption to boost the immune system and major emphasis has been given to high risk group. We have taken into consideration a number of underlying conditions such as people with cardiovascular diseases, obesity, diabetes, chronic obstructive pulmonary disease, chronic kidney disease, hemoglobin disorder such as sickle cell disease, weakened immune system due to organ transplant. Furthermore, factors to improve the immune system, risks associated with quarantine and lifestyle and food handling during COVID-19 has been discussed.