Possible association of vitamin D status with lung involvement and outcome in patients with COVID-19: a retrospective study

Dietary patterns and micronutrients in respiratory infections including COVID-19: a narrative review

BACKGROUND

COVID-19 is a pandemic caused by nCoV-2019, a new beta-coronavirus from Wuhan, China, that mainly affects the respiratory system and can be modulated by nutrition.

METHODS

This review aims to summarize the current literature on the association between dietary intake and serum levels of micronutrients, malnutrition, and dietary patterns and respiratory infections, including flu, pneumonia, and acute respiratory syndrome, with a focus on COVID-19. We searched for relevant articles in various databases and selected those that met our inclusion criteria.

RESULTS

Some studies suggest that dietary patterns, malnutrition, and certain nutrients such as vitamins D, E, A, iron, zinc, selenium, magnesium, omega-3 fatty acids, and fiber may have a significant role in preventing respiratory diseases, alleviating symptoms, and lowering mortality rates. However, the evidence is not consistent and conclusive, and more research is needed to clarify the mechanisms and the optimal doses of these dietary components. The impact of omega-3 and fiber on respiratory diseases has been mainly studied in children and adults, respectively, and few studies have examined the effect of dietary components on COVID-19 prevention, with a greater focus on vitamin D.

CONCLUSION

This review highlights the potential of nutrition as a modifiable factor in the prevention and management of respiratory infections and suggests some directions for future research. However, it also acknowledges the limitations of the existing literature, such as the heterogeneity of the study designs, populations, interventions, and outcomes, and the difficulty of isolating the effects of single nutrients from the complex interactions of the whole diet.

Risk Factors Associated with Severity and Death from COVID-19 in Iran: A Systematic Review and Meta-Analysis Study

Objectives: This study aims to investigate the risk factors associated with severity and death from COVID-19 through a systematic review and meta-analysis of the published documents in Iran. Methods: A systematic search was performed based on all articles indexed in Scopus, Embase, Web of Science (WOS), PubMed, and Google Scholar in English and Scientific Information Database (SID) and Iranian Research Institute for Information Science and Technology (IRA)NDOC indexes in Persian. To assess quality, we used the Newcastle Ottawa Scale. Publication bias was assessed using Egger's tests. Forest plots were used for a graphical description of the results. We used HRs, and ORs reported for the association between risk factors and COVID-19 severity and death. Results: Sixty-nine studies were included in the meta-analysis, of which 62 and 13 had assessed risk factors for death and severity, respectively. The results showed a significant association between death from COVID-19 and age, male gender, diabetes, hypertension, cardiovascular disease (CVD), cerebrovascular disease, chronic kidney disease (CKD), Headache, and Dyspnea. We observed a significant association between increased white blood cell (WBC), decreased Lymphocyte, increased blood urea nitrogen (BUN), increased creatinine, vitamin D deficiency, and death from COVID-19. There was only a significant relationship between CVD and disease severity. Conclusion: It is recommended that the predictive risk factors of COVID-19 severity and death mentioned in this study to be used for therapeutic and health interventions, to update clinical guidelines and determine patients' prognoses.

Is the vitamin D status of patients with COVID-19 associated with reduced mortality? A systematic review and meta-analysis

To conduct a systematic review and meta-analysis of studies assessing the association between serum vitamin D status and mortality in patients with COVID- 19. We searched PubMed and Embase for studies addressing the association of serum vitamin D levels and COVID-19 mortality published until April 24, 2022. Risk ratios (RRs) and 95% confidence interval (CIs) were pooled using fixed or random effects models. The risk of bias was assessed using the Newcastle-Ottawa Scale. The meta-analysis included 21 studies that measured serum vitamin D levels close to the date of admission, of which 2 were case-control and 19 were cohort studies. Vitamin D deficiency was associated with COVID-19 mortality in the overall analysis but not when the analysis was adjusted to vitamin D cutoff levels < 10 or < 12 ng/mL (RR 1.60, 95% CI 0.93-2.27, I2 60.2%). Similarly, analyses including only studies that adjusted measures of effect for confounders showed no association between vitamin D status and death. However, when the analysis included studies without adjustments for confounding factors, the RR was 1.51 (95% CI 1.28-1.74, I2 0.0%), suggesting that confounders may have led to many observational studies incorrectly estimating the association between vitamin D status and mortality in patients with COVID-19. Deficient vitamin D levels were not associated with increased mortality rate in patients with COVID-19 when the analysis included studies with adjustments for confounders. Randomized clinical trials are needed to assess this association.

Protective role of vitamin D status against COVID-19: a mini-review

An outbreak of pneumonia caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is called COVID-19 and has led to a pandemic worldwide. It is reasonable to investigate and control factors affecting disease severity and mortality. The relation between vitamin D and viral pneumonia has been previously reported. Vitamin D deficiency is common and may increase hospital admission and mortality rate in patients with COVID-19. This mini-review examines the pathways that show the association between vitamin D and COVID-19. On the other hand, it deals with the available evidence related to the relationship between vitamin D deficiency and the effect of vitamin D supplementation on the prevalence, severity, and mortality of COVID-19. Also, we described the pathophysiology of the organs' involvement in COVID-19 and the effect of vitamin D on these outcomes. Vitamin D strengthens the innate and adaptive immune system, modulates immune responses, prevents lung and cardiovascular system damage, and reduces thrombotic events. Vitamin D exerts these effects in several pathways. Vitamin D prevents virus entry and replication by maintaining the integrity of the body's physical barrier. Vitamin D reduces the damage to vital organs and thrombotic events by increasing the level of Angiotensin-converting enzyme 2 (ACE2), nitric oxide, and antioxidants or by reducing inflammatory cytokines and free radicals. Sufficient vitamin D may be reduced morbidity and mortality due to COVID-19. However, this issue should be investigated and confirmed by further research in the future.

Predictors of pulmonary involvement in children with COVID-19: How strongly associated is viral load?

The purpose of this study was to identify risk factors for pulmonary involvement by examining the demographic, clinical, and laboratory characteristics of children with COVID-19. We performed a retrospective single-center study of COVID-19 in children treated at a tertiary care hospital in Turkey from December 2020 to June 2021. During the course of the study, 126 patients were evaluated, of whom 70/126 were male. The patients' ages ranged from 1 to 216 (mean, 4.73 ± 81.11) months. Fever (65.9%), cough (52.4%), and shortness of breath (18.3%) were the most common symptoms of COVID-19. Ten patients required noninvasive mechanical ventilation. Sixty-nine patients (54.8%) had pneumonia. Longer duration of fever, hospitalization, and the presence of cough were significantly associated with pulmonary involvement. Children with pneumonia had significantly higher levels of C-reactive protein (CRP), procalcitonin, erythrocyte sedimentation rate (ESR), and viral load, and significantly lower counts of lymphocytes and thrombocytes. The cutoff viral load, CRP, and procalcitonin values for predicting pulmonary involvement were 26.5 cycle threshold (Ct; 95% confidence interval [CI], 0.54-0.74; sensitivity, 0.65; specificity, 0.56; area under curve [AUC]: 0.647, p = 0.005), 7.85 mg/L (95% CI, 0.56-0.75; sensitivity, 0.66; specificity, 0.64; AUC = 0.656; p = 0.003) and 0.105 ng/ml (95% CI, 0.52-0.72; sensitivity, 0.55; specificity, 0.58; AUC = 0.626; p = 0.02), respectively. High CRP, procalcitonin levels, ESR, and viral load, and low lymphocyte and thrombocyte counts can predict pulmonary involvement in children with COVID-19, so better management may be provided for good prognosis.

Vitamin D in Health and Disease

Vitamin D (VD) is a fat-soluble hormone that plays a fundamental role not only in calcium homeostasis and bone metabolism, but also has anti-inflammatory and antioxidant properties, acting on both innate and adaptive immunity [...].

Association of Serum Vitamin D level and COVID-19 infection: A Case-control Study

BACKGROUND

Vitamin D is considered a potent modulator of the immune system, albeit its role in COVID-19 infection is a matter of debate. The present study aimed to estimate the association between serum vitamin D levels and COVID-19 among people in Qatar.

METHODS

This case-control study, approved by the Institutional Review Board of Primary Health Care Corporation (PHCC) Qatar, retrospectively evaluated the principal public healthcare sector population data repository retrieved from the cloud-based Electronic Health Record (EHR) software-Cerner, during April 2020-2021. The health records of all adult patients aged >18 years who had undergone the reverse transcription-polymerase chain reaction (RT-PCR) test and whose medical records had documented serum 25-hydroxyvitamin D [25 (OH)D] levels were analyzed.

RESULTS

A total of 924,173 EHRs were extracted, of which 62,451 EHR comprised of 16,446 (26.3%) COVID-19 patients and 46,005 (73.7%) negative-control group patients met the inclusion criteria. The odds ratio (OR) among different categories of vitamin D deficiency (VDD) revealed that people with mild/moderate VDD were 1.18 times (95% CI 1.126-1.258) and those with severe VDD were 1.90 times (95% CI 1.116-1.251) more likely to have COVID-19 infection when compared to the people with optimal serum vitamin D level. On applying multiple logistic regression, the odds of having COVID-19 infection were found to be 1.27 times (95% CI 1.184-1.371) higher among those with mild/moderate VDD and 1.32 times (95% CI 1.206-1.405) higher among those with severe VDD when compared to people with optimal vitamin D level (p < 0.001).

CONCLUSION

Our findings demonstrated a significant association between the suboptimal serum vitamin D level and COVID-19 infection. Further studies are required to determine the effects of VDD on the severity and outcomes of COVID-19 infections.

A Review: Highlighting the Links between Epigenetics, COVID-19 Infection, and Vitamin D

The highly transmittable and infectious COVID-19 remains a major threat worldwide, with the elderly and comorbid individuals being the most vulnerable. While vaccines are currently available, therapeutic drugs will help ease the viral outbreak and prevent serious health outcomes. Epigenetic modifications regulate gene expression through changes in chromatin structure and have been linked to viral pathophysiology. Since epigenetic modifications contribute to the life cycle of the virus and host immune responses to infection, epigenetic drugs are promising treatment targets to ameliorate COVID-19. Deficiency of the multifunctional secosteroid hormone vitamin D is a global health threat. Vitamin D and its receptor function to regulate genes involved in immunity, apoptosis, proliferation, differentiation, and inflammation. Amassed evidence also indicates the biological relations of vitamin D with reduced disease risk, while its receptor can be modulated by epigenetic mechanisms. The immunomodulatory effects of vitamin D suggest a role for vitamin D as a COVID-19 therapeutic agent. Therefore, this review highlights the epigenetic effects on COVID-19 and vitamin D while also proposing a role for vitamin D in COVID-19 infections.

Vitamin D Level in Laboratory Confirmed COVID-19 and Disease Progression

OBJECTIVE

There is no conclusive evidence to suggest vitamin D level can prevent or treat infection with the new coronavirus disease 2019. This study aimed to investigate the effects of serum level of vitamin D in patients with coronavirus disease 2019 on death, severity, and hospitalization duration.

MATERIALS AND METHODS

Baseline characteristic of patients was extracted from the Isfahan coronavirus disease 2019 registry database (I-CORE). Blood samples were taken from all patients to measure the level of vitamin D (25-hydroxyvitamin D) and categorized. The effect of 25(OH) D on death, severity, and hospitalization duration was analyzed by logistic regression.

RESULTS

Among our study patients, 5.5% had a severe deficiency of vitamin D, 23.7% deficiency, and 24.8% insufficiency. Of the 107 patients who died, 7.5% were severely deficient in vitamin D. We found that vitamin D deficiency had no significant effect on death, disease severity, and hospitalization (P > .05). However, having at least one comorbidity increased the odds of death five times after adjusting age > 60 years and gender (P < .0001). The results showed that among all comorbidities, diabetes has the greatest impact on the outcomes as it raised the odds of death, disease severity, and length of hospital stay by 2.23,1.72, and 1.48, respectively, after controlling the age > 60 and gender (P = .0002, P=.08, P=.012).

CONCLUSIONS

The mortality, disease severity, and hospitalization of coronavirus disease 2019 patients seem to be not affected by the low levels of 25(OH)D. However, the synergy between vitamin D levels and comorbidities, age, and gender could affect the outcome of coronavirus disease 2019 patients.

Clinical and Laboratory Findings by Serum Vitamin D Levels in Children with COVID-19

OBJECTIVE

The studies on children with COVID-19 are very limited. The aim of this study is to reveal the effect of serum 25-hydroxy vitamin D level on clinical and laboratory parameters.

MATERIALS AND METHODS

The study included 74 children (35 boys and 39 girls) diagnosed with COVID-19. The retrospective data were obtained from the file records of the patients. Seventy-four patients were divided into 3 groups (group 1, deficient; group 2, insufficient; and group 3, sufficient) according to their serum 25-hydroxy vitamin D levels.

RESULTS

The mean age of all patients was 113.25 ± 64.55 months. The mean leucocyte count was substantially higher in group 3 compared to groups 1 and 2 (P = .05 and P = .002, respectively). The mean lymphocyte and platelet count in group 3 was remarkably higher than both groups 1 and 2 (P = .001 and P = .002; and P = .04 and P = .01, respectively). The mean serum parathyroid hormone concentration in group 1 was markedly higher than both groups 2 and 3 (P=.003 and P = .002, respectively) while the mean serum 25-hydroxy vitamin D level in group 1 was remarkably lower than both groups 2 and 3 (P=.001 and P=.001, respectively). Serum 25-hydroxy vitamin D concentrations were positively correlated with leucocyte, lymphocyte, and platelet counts (r=0.221, P=.05; r=0.396, P=.001; and r=0.249, P=.03, respectively) while there was a negative correlation with parathyroid hormone concentrations (r=-0,436, P=.001).

CONCLUSION

This study suggests that COVID-19 has a benign course in children and that serum 25-hydroxy vitamin D concentration may have a role in the lymphocyte count.

Antioxidants and clinical outcomes of patients with coronavirus disease 2019: A systematic review of observational and interventional studies

Coronavirus disease 2019 (COVID-19) is a newly emerging viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Oxidative stress appears to be a prominent contributor to the pathogenicity of SARS-CoV-2. Therefore, we carried out a systematic review of human observational and interventional studies to investigate the role of some antioxidants such as vitamins A, E, D, and C, selenium, zinc, and α-lipoic acid in the main clinical outcomes of subjects with COVID-19. Google Scholar, Cochrane Library, Web of Science, Scopus, and Medline were searched using Medical Subject Headings (MeSH) and non-MeSH terms without restrictions. Finally, 36 studies for vitamins C and D, selenium, and zinc were included in this systematic review; however, no eligible studies were found for vitamins A and E as well as α-lipoic acid. The results showed the promising role of vitamin C in inflammation, Horowitz index, and mortality; vitamin D in disease manifestations and severity, inflammatory markers, lung involvement, ventilation requirement, hospitalization, intensive care unit (ICU) admission, and mortality; selenium in cure rate and mortality; and zinc in ventilation requirement, hospitalization, ICU admission, biomarkers of inflammation and bacterial infection, and disease complications. In conclusion, it seems that antioxidants, especially vitamins C and D, selenium, and zinc, can improve multiple COVID-19 clinical outcomes. Nevertheless, more studies are necessary to affirm these results.

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

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

The Association Between Vitamin D Serum Level and COVID-19 Patients’ Outcomes in a Tertiary Center in Saudi Arabia: A Retrospective Cohort Study

Vitamin D deficiency has been associated with the risk for immune-mediated inflammatory reactions in various respiratory infections. Our study investigated the association between vitamin D deficiency and coronavirus disease 2019 (COVID-19) patients’ outcomes. We included 545 patients who were admitted to a tertiary center in Jeddah, Saudi Arabia from March 2020 to July 2021 with a vitamin D serum test result at the time of infection or prior to disease onset. The data were extracted retrospectively using a data collection sheet. Our primary outcomes were intensive care unit (ICU) admission and in-hospital mortality. The cut-off values for vitamin D were <25, 25-49, and 50-250 for deficient, suboptimal, and optimal levels respectively. Our result revealed that there is no association between vitamin D serum levels deficiency and ICU admission (OR=1.08, p=0.75) or in-hospital mortality (OR=1.74, p=0.97). ICU admission and in-hospital mortality percentages in patients with vitamin D deficiency were 14.1% and 6.4%, respectively. In comparison, percentages for patients with optimal levels were 16.67% and 6.15% for ICU admission and in-hospital mortality, respectively. Smoking was not associated with ICU admission (p=0.05) or in-hospital mortality (p=0.38). Our study does not support a relationship between vitamin D deficiency and COVID-19 patients’ outcomes. Future studies should be directed toward conducting randomized clinical trials to determine whether vitamin D has an effective role in reducing COVID-19 severity.

Analyzing the relationship between the vitamin D deficiency and COVID-19 mortality rate and modeling the time-delay interactions between body's immune healthy cells, infected cells, and virus particles with the effect of vitamin D levels

This paper presents some recent views on the aspects of vitamin D levels in relation to the COVID-19 infections and analyzes the relationship between the prevalence rates of vitamin D deficiency and COVID-19 death rates per million of various countries in Europe and Asia using the data from the PubMed database. The paper also discusses a new mathematical model of time-delay interactions between the body's immune healthy cells, infected cells, and virus particles with the effect of vitamin D levels. The model can be used to monitor the timely progression of healthy immune cells with the effects of the levels of vitamin D and probiotics supplement. It also can help to predict when the infected cells and virus particles free state can ever be reached as time progresses. The consideration of the time delay in the modeling due to effects of the infected cells or virus particles and the growth of healthy cells is also an important factor that can significantly change the outcomes of the body's immune cells as well as the infections.

Vitamin D: A Potential Mitigation Tool for the Endemic Stage of the COVID-19 Pandemic?

The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and associated development of clinical symptoms of COVID-19 have presented an enormous global impact on our health care systems, public health and economy. To date several observational epidemiological studies consistently found that vitamin D deficiency, measured as low levels of circulating 25-hydroxyvitamin D, is associated with cardiovascular diseases, diabetes, certain cancers, autoimmune diseases and many infectious diseases, including acute respiratory infections. Since vitamin D is not merely immunosuppressive but also acts as an immunomodulator in tolerance and homeostasis, many experts have considered a role of vitamin D in the prevalence and severity of immune mediated inflammatory diseases, such as SARS-CoV-2, adding to the evidence of the importance of vitamin D in the immune response against viral respiratory infections and reinforcing the need for targeted vitamin D supplementation, with a focus on high-risk populations and a high-dose supplementation treatment for COVID-19 hospitalized patients. The expected transition to endemicity of SARS-CoV-2 even further corroborates as a potential of vitamin D as an potential mitigation tool for the prevention of COVID-19. The aim of this paper is to analyse the current evidence regarding vitamin D and present a hypothesis of its potential role in the current COVID-19 pandemic and in the future as a potential preventive measurement in public health.

Serum 25-hydroxyvitamin D Concentration Significantly Decreases in Patients with COVID-19 Pneumonia during the First 48 Hours after Hospital Admission

It is unclear how ongoing inflammation in Coronavirus Disease 2019 (COVID-19) affects 25-hydroxyvitamin D (25[OH]D) concentration. The objective of our study was to examine serum 25(OH)D levels during COVID-19 pneumonia. Patients were admitted between 1 November and 31 December 2021. Blood samples were taken on admission (day 0) and every 24 h for the subsequent four days (day 1−4). On admission, 59% of patients were 25(OH)D sufficient (>30 ng/mL), and 41% had 25(OH)D inadequacy (<30 ng/mL). A significant fall in mean 25(OH)D concentration from admission to day 2 (first 48 h) was observed (30.7 ng/mL vs. 26.4 ng/mL; p < 0.0001). No subsequent significant change in 25(OH)D concentration was observed between day 2 and 3 (26.4 ng/mL vs. 25.9 ng/mL; p = 0.230) and day 3 and day 4 (25.8 ng/mL vs. 25.9 ng/mL; p = 0.703). The absolute 25(OH)D change between hospital admission and day 4 was 16% (4.8 ng/mL; p < 0.0001). On day 4, the number of patients with 25(OH)D inadequacy increased by 18% (p = 0.018). Therefore, serum 25(OH)D concentration after hospital admission in acutely ill COVID-19 patients should be interpreted with caution. Whether low 25(OH)D in COVID-19 reflects tissue level vitamin D deficiency or represents only a laboratory phenomenon remains to be elucidated in further prospective trials of vitamin D supplementation.

The effect of prescribing vitamin D analogues and serum vitamin D status on both contracting COVID-19 and clinical outcomes in kidney dialysis patients'

Aims

Vitamin D plays a role in innate immune system activation, and deficiency increases susceptibility to respiratory infections and disease severity including COVID‐19. We determined whether vitamin D levels and medications were associated with contracting COVID‐19, and disease severity defined by hospitalisation and dialysis patient mortality.

Methods

We reviewed serum vitamin D levels, and prescription of cholecalciferol and alfacalcidol along with corresponding medical records of adult dialysis patients from a United Kingdom tertiary centre between March 2020 and May 2021. COVID‐19 infection was determined by polymerase chain reaction (PCR) results.

Results

362 (35%) of 1035 dialysis patients tested PCR positive for COVID‐19. COVID‐19 positive patients had lower native median vitamin D (65 (39–95) versus 74 (40.5–101) nmol/L (p = .009) despite greater prescription of cholecalciferol (median 20 000 (20000‐20 000) versus 20 000 (0–20 000) IU/week), p < .001, but lower prescription of alfacalcidol 0 (0–3.0) versus 2.0 (0.–5.0) ug/week, p < .001. On multivariate logistic regression COVID‐19 infection was associated with haemodialysis versus peritoneal dialysis (p < .001), cholecalciferol dose (p < .001) and negatively with alfacalcidol (p < .001). However, serum vitamin D levels and alfacalcidol dosages were not significantly different for those requiring hospitalisation compared to those managed at home, although those who died were prescribed lower alfacalcidol dosages.

Conclusion

Dialysis patients who contracted COVID‐19 had lower levels of native vitamin D prior to COVID‐19 and were prescribed lower dosages of alfacalcidol. However, there was no association between vitamin D status and disease severity. This retrospective observational analysis supports a potential role for vitamin D and susceptibility to COVID‐19 infection in dialysis patients.

Vitamin D plays a key role in activating the innate immune system and deficiency increases susceptibility to respiratory infections. We report on the effect of vitamin D levels and medications in more than 1000 dialysis patients during the first two pandemic waves of COVID‐19.

Comparison of the cardiovascular system, clinical condition, and laboratory results in COVID-19 patients with and without vitamin D insufficiency

BACKGROUND

Serum vitamin D levels may have a protective role against severe coronavirus disease 2019 (COVID-19). Studies have shown that deficiency in vitamin D may be a significant risk factor for poor outcomes. This study aims to compare the outcome and clinical condition of patients diagnosed with COVID-19 infection considering serum vitamin D levels.

METHODS

In this cross-sectional study, 202 COVID-19 patients without known cardiovascular disease (reduced ejection fraction, uncontrolled arrhythmia, pericardial effusion, cardiac block, valvular disease, or hypertension) were included. Patients were divided into three groups of insufficient (< 30 ng/mL), normal (30 to 50 ng/mL), and high (> 50 ng/mL) serum vitamin D levels. Clinical outcome was defined as severe if invasive respiratory intervention and ICU admission was required.

RESULTS

The patients were divided into three groups based on their vitamin D level: 127 cases in the insufficient vitamin D group, 53 cases in the normal vitamin D group, and 22 cases in the high vitamin D group. The mean age of the population study was 56 years. Thirty-four patients had severe clinical outcomes. The distribution of this group was as follows: 21 patients in the insufficient vitamin D group (16.5%), eight patients in the normal vitamin D group (15.1%), and five patients in the high vitamin D group (22.7%); P = 0.74. No significant differences were found between the groups in terms of mortality rate (P = 0.46). Moreover, the mean of leukocytes (mean ± SD = 6873.5 ± 4236.2), ESR (mean ± SD = 38.42 ± 26.7), and CPK-MB (mean ± SD = 63 ± 140.7) were higher in the insufficient vitamin D group, but it was not statistically significant (P > 0.05).

CONCLUSION

The finding of the present study showed that vitamin D could not make a significant difference in cardiovascular systems, laboratory results, and severity of the disease in COVID-19 patients.

Remote management of osteoporosis in the first wave of the COVID-19 pandemic

We conducted a survey during the first pandemic wave of coronavirus disease 2019 (COVID-19) on a large group of osteoporotic patients to evaluate the general conditions of osteoporotic patients and the impact of the pandemic on the management of osteoporosis, finding high compliance to treatments and low COVID-19 lethality.

INTRODUCTION

During the first pandemic wave of coronavirus disease 2019 (COVID-19), 209,254 cases were diagnosed in Italy; fatalities were 26,892 and were overwhelmingly older patients. The high prevalence of osteoporosis in this age group suggests a potential relationship between SARS-CoV-2 infection and bone metabolism.

METHODS

In a telephone survey conducted from April to May 2020, patients from the Osteoporosis Center, Clinic of Endocrinology and Metabolic Diseases of Umberto I Hospital (Ancona, Italy), were interviewed to evaluate the general clinical conditions of osteoporotic patients, compliance with osteoporosis medications, COVID-19 prevalence, hospitalization rate, COVID-19 mortality, and lethality.

RESULTS

Among the 892 patients interviewed, 77.9% were taking osteoporosis treatment and 94.6% vitamin D supplementation as prescribed at the last visit. COVID-19-like symptoms were reported by 5.1%, whereas confirmed cases were 1.2%. A total number of 33 patients had been in hospital and the hospitalization rate of those who had not discontinued vitamin D supplementation was less than 4%. There were eight deaths, two with a concomitant COVID-19 diagnosis. The prevalence of severe osteoporosis was 50% in total COVID-19 patients and 87.5% in deceased COVID-19 patients. The overall COVID-19 mortality was 0.2%; lethality was 20%, lower than the national rate of the same age group.

CONCLUSIONS

This large group of osteoporotic patients showed high compliance and lower COVID-19 lethality compared to patients of the same age. Novel approaches such as telemedicine can provide critical support for the remote follow-up of patients with chronic diseases also in the setting of routine care.

Cell-Free DNA: Potential Application in COVID-19 Diagnostics and Management

WHO has declared COVID-19 as a worldwide, public health emergency. The elderly, pregnant women, and people with associated co-morbidities, including pulmonary disease, heart failure, diabetes, and cancer are the most predisposed population groups to infection. Cell-free DNA is a very commonly applied marker, which is elevated in various pathological conditions. However, it has a much higher sensitivity than standard biochemical markers. cfDNA appears to be an effective marker of COVID-19 complications, and also serves as a marker of certain underlying health conditions and risk factors of severe illness during COVID-19 infection. We aimed to present the possible mechanisms and sources of cfDNA released during moderate and severe infections. Moreover, we attempt to verify how efficiently cfDNA increase could be applied in COVID-19 risk assessment and how it corresponds with epidemiological data.

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

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

The Association between TNF-α, IL-6, and Vitamin D Levels and COVID-19 Severity and Mortality: A Systematic Review and Meta-Analysis

BACKGROUND

An increasing number of scientific journals have proposed a connection between tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and the severity of COVID-19. Vitamin D has been discussed as a potential therapy for COVID-19 due to its immunomodulatory effects. This meta-analysis aims to determine the relationship, if any, between TNF-α, IL-6, vitamin D, and COVID-19 severity and mortality.

METHODS

The design of the study is a systematic review and meta-analysis. A literature search is performed using PubMed, Cochrane, ProQuest, and Google Scholar.

RESULTS

TNF-α insignificantly increases the risk of COVID-19 severity (adjusted odds ratio (aOR) = 1.0304; 95% CI 0.8178-1.2983; p = 0.80) but significantly increases the risk of COVID-19 mortality (crude hazard ratio (HR) = 1.0640; 95% CI 1.0259-1.1036; p = 0.0009). IL-6 significantly increases the risk of COVID-19 severity (aOR = 1.0284; 95% CI 1.0130-1.0441; p = 0.0003) and mortality (aOR = 1.0076; 95% CI 1.0004-1.0148; p = 0.04; adjusted hazard ratio (aHR) = 1.0036; 95% CI 1.0010-1.0061; p = 0.006). There is a statistically insignificant difference of the mean vitamin D levels between patients with severe COVID-19 and non-severe COVID-19 (mean difference (MD) = -5.0232; 95% CI 11.6832-1.6368; p = 0.14). A vitamin D deficiency insignificantly increases the risk of mortality of COVID-19 patients (aOR = 1.3827; 95% CI 0.7103-2.6916; p = 0.34).

CONCLUSION

IL-6 is an independent prognostic factor towards COVID-19 severity and mortality.

Vitamin D supplementation and COVID-19 risk: a population-based, cohort study

PURPOSE

To analyze the associations between cholecalciferol or calcifediol supplementation, serum 25-hydroxyvitamin D (25OHD) levels and COVID-19 outcomes in a large population.

METHODS

All individuals ≥ 18 years old living in Barcelona-Central Catalonia (n = 4.6 million) supplemented with cholecalciferol or calcifediol from April 2019 to February 2020 were compared with propensity score-matched untreated controls. Outcome variables were SARS-CoV2 infection, severe COVID-19 and COVID-19 mortality occuring during the first wave of the pandemic. Demographical data, comorbidities, serum 25OHD levels and concomitant pharmacological treatments were collected as covariates. Associations between cholecalciferol or calcifediol use and outcome variables were analyzed using multivariate Cox proportional regression.

RESULTS

Cholecalciferol supplementation (n = 108,343) was associated with slight protection from SARS-CoV2 infection (n = 4352 [4.0%] vs 9142/216,686 [4.2%] in controls; HR 0.95 [CI 95% 0.91-0.98], p = 0.004). Patients on cholecalciferol treatment achieving 25OHD levels ≥ 30 ng/ml had lower risk of SARS-CoV2 infection, lower risk of severe COVID-19 and lower COVID-19 mortality than unsupplemented 25OHD-deficient patients (56/9474 [0.6%] vs 96/7616 [1.3%]; HR 0.66 [CI 95% 0.46-0.93], p = 0.018). Calcifediol use (n = 134,703) was not associated with reduced risk of SARS-CoV2 infection or mortality in the whole cohort. However, patients on calcifediol treatment achieving serum 25OHD levels ≥ 30 ng/ml also had lower risk of SARS-CoV2 infection, lower risk of severe COVID-19, and lower COVID-19 mortality compared to 25OHD-deficient patients not receiving vitamin D supplements (88/16276 [0.5%] vs 96/7616 [1.3%]; HR 0.56 [CI 95% 0.42-0.76], p < 0.001).

CONCLUSIONS

In this large, population-based study, we observed that patients supplemented with cholecalciferol or calcifediol achieving serum 25OHD levels ≥ 30 ng/ml were associated with better COVID-19 outcomes.

A review of natural foods consumed during the COVID-19 pandemic life

Coronavirus 2019 (COVID-19) is an infectious disease that has brought life to a standstill around the world. Until a vaccine was found to combat COVID-19, the world conducted research and made recommendations for nutritional natural foods. Considering the risks incurred by contracting the disease, even though the production of various vaccines and vaccination of healthy people has started in some countries, individuals need useful foods to be ready for the COVID-19 pandemic. Recently, nutrient contents such as antioxidant compounds, vitamins, minerals, and probiotics that contribute to the immune system have been investigated. This paper attempts to determine the role of these dietary supplements in reducing the risk of COVID-19 and/or changing the course of the disease in COVID-19 patients and their effects on mortality. Supplements used and recommended for the COVID-19 pandemic life were investigated. In conclusion, more research is needed to determine the effectiveness of nutrients, vitamins, minerals, probiotics, prebiotics, and antioxidants used during the COVID-19 pandemic to inhibit the effect of SARS-CoV-2. In order to overcome the new global crisis, nutritional cures and treatments should be upgraded. However, additional research on the subject is needed.

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

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

Vitamin D Status and SARS-CoV-2 Infection and COVID-19 Clinical Outcomes

Background: Several studies suggest an association between serum 25-hydroxyvitamin D (25OHD) and the outcomes of Severe Acute Respiratory Syndrome Corona-Virus-2 (SARS-CoV-2) infection, in particular Coronavirus Disease-2019 (COVID-19) related severity and mortality. The aim of the present meta-analysis was to investigate whether vitamin D status is associated with the COVID-19 severity, defined as ARDS requiring admission to intensive care unit (ICU) or mortality (primary endpoints) and with the susceptibility to SARS-CoV-2 and COVID-19-related hospitalization (secondary endpoints). Methods: A search in PubMed, ScienceDirect, Web of Science, Google Scholar, Scopus, and preprints repositories was performed until March 31th 2021 to identify all original observational studies reporting association measures, or enough data to calculate them, between Vitamin D status (insufficiency <75, deficiency <50, or severe deficiency <25 nmol/L) and risk of SARS-CoV-2 infection, COVID-19 hospitalization, ICU admission, or death during COVID-19 hospitalization. Findings: Fifty-four studies (49 as fully-printed and 5 as pre-print publications) were included for a total of 1,403,715 individuals. The association between vitamin D status and SARS-CoV2 infection, COVID-19 related hospitalization, COVID-19 related ICU admission, and COVID-19 related mortality was reported in 17, 9, 27, and 35 studies, respectively. Severe deficiency, deficiency and insufficiency of vitamin D were all associated with ICU admission (odds ratio [OR], 95% confidence intervals [95%CIs]: 2.63, 1.45-4.77; 2.16, 1.43-3.26; 2.83, 1.74-4.61, respectively), mortality (OR, 95%CIs: 2.60, 1.93-3.49; 1.84, 1.26-2.69; 4.15, 1.76-9.77, respectively), SARS-CoV-2 infection (OR, 95%CIs: 1.68, 1.32-2.13; 1.83, 1.43-2.33; 1.49, 1.16-1.91, respectively) and COVID-19 hospitalization (OR, 95%CIs 2.51, 1.63-3.85; 2.38, 1.56-3.63; 1.82, 1.43-2.33). Considering specific subgroups (i.e., Caucasian patients, high quality studies, and studies reporting adjusted association estimates) the results of primary endpoints did not change. Interpretations: Patients with low vitamin D levels present an increased risk of ARDS requiring admission to intensive care unit (ICU) or mortality due to SARS-CoV-2 infection and a higher susceptibility to SARS-CoV-2 infection and related hospitalization.

Association between vitamin D status and risk of covid-19 in-hospital mortality: A systematic review and meta-analysis of observational studies

Some earlier studies reported higher risk of COVID-19 mortality in patients with vitamin D deficiency, while some others failed to find such as association. Due to inconsistences between earlier meta-analyses and needs for an updated study, we conducted current systematic review and meta-analysis on the association between vitamin D status and risk of COVID-19 in-hospital mortality among observational studies. We searched PubMed, Scopus and Web of Science up to 27 July 2021. We conduct our systematic review and meta-analysis in according to PRISM statement. Two authors independently screened studies and extracted data from the relevant ones. All types of observational studies about the association between vitamin D status and in hospital COVID-19 mortality were included. Data was pooled using a random-effect model. P-values ˂ 0.05 was assumed as statistically significant. We identified 13 observational studies. Pooling 9 studies which categorized vitamin D level, a significant positive relationship was found between vitamin D deficiency and risk of COVID-19 in-hospital mortality (Odds Ratio (OR): 2.11; 95% Confidence Interval (CI): 1.03, 4.32). All subgroup analyses also showed significant relationship between vitamin D deficiency and risk of COVID-19 in-hospital mortality. In the other analysis, pooling data from 5 studies in which vitamin D level was entered as a continues variable, we found an inverse significant association between each unit increment in serum vitamin D concentrations and risk of COVID-19 in-hospital mortality (OR: 0.94; 95% CI: 0.89, 0.99). We found a significant direct association between vitamin D deficiency and elevated risk of COVID-19 in-hospital mortality. Moreover, each unit increment in serum vitamin D levels was associated to significant reduction in risk of COVID-19 mortality. Further prospective studies are needed to confirm our findings.

Current Overview on Therapeutic Potential of Vitamin D in Inflammatory Lung Diseases

Inflammatory lung disorders (ILDs) are one of the world's major reasons for fatalities and sickness, impacting millions of individuals of all ages and constituting a severe and pervasive health hazard. Asthma, lung cancer, bronchiectasis, pulmonary fibrosis acute respiratory distress syndrome, and COPD all include inflammation as a significant component. Microbe invasions, as well as the damage and even death of host cells, can cause and sustain inflammation. To counteract the negative consequences of irritants, the airways are equipped with cellular and host defense immunological systems that block the cellular entrance of these irritants or eliminate them from airway regions by triggering the immune system. Failure to activate the host defense system will trigger chronic inflammatory cataracts, leading to permanent lung damage. This damage makes the lungs more susceptible to various respiratory diseases. There are certain restrictions of the available therapy for lung illnesses. Vitamins are nutritional molecules that are required for optimal health but are not produced by the human body. Cholecalciferol (Vitamin D) is classified as a vitamin, although it is a hormone. Vitamin D is thought to perform a function in bone and calcium homeostasis. Recent research has found that vitamin D can perform a variety of cellular processes, including cellular proliferation; differentiation; wound repair; healing; and regulatory systems, such as the immune response, immunological, and inflammation. The actions of vitamin D on inflammatory cells are dissected in this review, as well as their clinical significance in respiratory illnesses.

Vitamin D: Bolus Is Bogus-A Narrative Review

In this review we summarize the impact of bolus versus daily dosing of vitamin D on 25(OH)D and 1,25(OH)2D levels, as well as on key countervailing factors that block vitamin D functions at the cellular level. Further, we discuss the role of bolus versus daily dosing of vitamin D for several health outcomes, including respiratory infections and coronavirus disease 2019 (COVID-19), rickets, falls and fractures, any cancer, and cancer-related mortality. This discussion appears timely because bolus doses continue to be tested for various disease outcomes despite a growing amount of evidence suggesting lack of efficacy or even detrimental effects of bolus dosing of vitamin D for outcomes where daily dosing at modest levels was effective in the vitamin D deficient. As a result, these discordant results may bias health recommendations for vitamin D if the recommendations are based on meta-analyses combining both daily and bolus dosing trials. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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.].

COVID-19 Mortality Risk Correlates Inversely with Vitamin D3 Status, and a Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3: Results of a Systematic Review and Meta-Analysis

BACKGROUND

Much research shows that blood calcidiol (25(OH)D3) levels correlate strongly with SARS-CoV-2 infection severity. There is open discussion regarding whether low D3 is caused by the infection or if deficiency negatively affects immune defense. The aim of this study was to collect further evidence on this topic.

METHODS

Systematic literature search was performed to identify retrospective cohort as well as clinical studies on COVID-19 mortality rates versus D3 blood levels. Mortality rates from clinical studies were corrected for age, sex, and diabetes. Data were analyzed using correlation and linear regression.

RESULTS

One population study and seven clinical studies were identified, which reported D3 blood levels preinfection or on the day of hospital admission. The two independent datasets showed a negative Pearson correlation of D3 levels and mortality risk (r(17) = -0.4154, p = 0.0770/r(13) = -0.4886, p = 0.0646). For the combined data, median (IQR) D3 levels were 23.2 ng/mL (17.4-26.8), and a significant Pearson correlation was observed (r(32) = -0.3989, p = 0.0194). Regression suggested a theoretical point of zero mortality at approximately 50 ng/mL D3.

CONCLUSIONS

The datasets provide strong evidence that low D3 is a predictor rather than just a side effect of the infection. Despite ongoing vaccinations, we recommend raising serum 25(OH)D levels to above 50 ng/mL to prevent or mitigate new outbreaks due to escape mutations or decreasing antibody activity.

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.

Conundrum of vitamin D on glucose and fuel homeostasis

As an endocrine hormone, vitamin D plays an important role in bone health and calcium homeostasis. Over the past two decades, the non-calcemic effects of vitamin D were extensively examined. Although the effect of vitamin D on beta cell function were known for some time, the effect of vitamin D on glucose and fuel homeostasis has attracted new interest among researchers. Yet, to date, studies remain inconclusive and controversial, in part, due to a lack of understanding of the threshold effects of vitamin D. In this review, a critical examination of interventional trials of vitamin D in prevention of diabetes is provided. Like use of vitamin D for bone loss, the benefits of vitamin D supplementation in diabetes prevention were observed in vitamin D-deficient subjects with serum 25-hydroxyvitamin D < 50 nmol/L (20 ng/mL). The beneficial effect from vitamin D supplementation was not apparent in subjects with serum 25-hydroxyvitamin D > 75 nmol/L (30 ng/mL). Furthermore, no benefit was noted in subjects that achieved serum 25-hydroxyvitamin D > 100 nmol/L (40 ng/mL). Further studies are required to confirm these observations.

Vitamin D in infectious complications in critically ill patients with or without COVID-19

25-hydroxyvitamin D [25(OH)D] is an important immunomodulator, whose deficiency may aggravate the incidence and outcome of infectious complications in patients admitted to the intensive care unit. The most recognized extra-skeletal action of vitamin D is the regulation of immune function. Host defense against intracellular pathogens depends upon both innate and adaptive immunity. It has been suggested that vitamin D regulates the pro-inflammatory endothelial response to lipopolysaccharide, rendering it a role in the sepsis cascade. Recent studies have indicated that vitamin D deficiency may be associated with worse outcomes in patients with coronavirus disease 2019 (COVID-19), such as more severe disease and higher mortality rates. To this end, clinical trials with vitamin D supplementation are being carried out in an effort to improve COVID-19 outcomes. In this review, we will discuss the role of vitamin D in the immune response, and more specifically its effect on immune cells. Subsequently, we will provide an overview of the studies that have investigated the predictive value of vitamin D in critical illness outcomes, and its therapeutic value as a supplement in critically ill patients. Finally, the emerging role of vitamin D deficiency in COVID-19 infection risk, and worse outcomes will be discussed.

Association between Vitamin D Status and Risk of Developing Severe COVID-19 Infection: A Meta-Analysis of Observational Studies

OBJECTIVE

The relationship between 25-hydroxyvitamin D3 (25(OH)D), the surrogate marker for vitamin D₃, serum concentration and COVID-19 has come to the forefront as a potential pathway to improve COVID-19 outcomes. The current evidence remains unclear on the impact of vitamin D status on the severity and outcomes of COVID-19 infection. To explore possible association between low 25(OH)D levels and risk of developing severe COVID-19 (i.e. need for invasive mechanical ventilation, the length of hospital stay, total deaths). We also aimed to understand the relationship between vitamin D insufficiency and elevated inflammatory and cardiac biomarkers.

METHODS

We conducted a comprehensive electronic literature search for any original research study published up to March 30, 2021. For the purpose of this review, low vitamin D status was defined as a range of serum total 25(OH)D levels of <10 to <30 ng/ml. Two independent investigators assessed study eligibility, synthesized evidence, analyzed, critically examined, and interpreted herein.

RESULTS

Twenty-four observational studies containing 3637 participants were included in the meta-analysis. The mean age of the patients was 61.1 years old; 56% were male. Low vitamin D status was statistically associated with higher risk of death (RR, 1.60 (95% CI, 1.10-2.32), higher risk of developing severe COVID-19 pneumonia (RR: 1.50; 95% CI, 1.10-2.05). COVID-19 patients with low vitamin D levels had a greater prevalence of hypertension and cardiovascular diseases, abnormally high serum troponin and peak D-dimer levels, as well as elevated interleukin-6 and C-reactive protein than those with serum 25(OH)D levels ≥30 ng/ml.

CONCLUSIONS

In this meta-analysis, we found a potential increased risk of developing severe COVID-19 infection among patients with low vitamin D levels. There are plausible biological mechanisms supporting the role of vitamin D in COVID-19 severity. Randomized controlled trials are needed to test for potential beneficial effects of vitamin D in COVID-19 outcomes.

Vitamin D deficiency as a predictor of severity in patients with COVID-19 infection

BACKGROUND

As an immune modulator, vitamin D has been implicated in the coronavirus disease 2019 (COVID-19) severity. This study aimed to investigate the association between vitamin D levels and the severity of COVID-19 infection.

METHODS

A cross-sectional study, which included 124 patients diagnosed with COVID-19 and were selected from Ain Shams University Hospitals and assigned to two groups; mild and severe COVID-19. All patients underwent detailed history taking, clinical data, and different laboratory investigations as complete blood count, blood urea nitrogen, serum creatinine, liver enzymes, C-reactive protein, D-dimer, ferritin and serum vitamin D concentration. In addition to findings of initial chest computed tomography (CT) were recorded. COVID-19 Reporting and Data System (CO-RADS) and CT chest severity scores (CT SS) were reported.

RESULTS

In this study of 124 COVID-19-positive individuals, a high prevalence of hypovitaminosis D was found (97.6%). Lower vitamin D levels were significantly associated with more severe COVID-19 cases (p-value < 0.001), higher blood levels of inflammatory markers including (D-dimer, CRP, and ferritin), a higher CT SS and longer disease duration. Serum vitamin D can be used as a predictor for the severity of COVID-19 infection with a specificity of 96.6%, and sensitivity of 45.5%.

CONCLUSION

The high frequency of hypovitaminosis D in severe COVID-19 patients provides further evidence of a potential link to poor prognosis and severity of the disease, so vitamin D deficiency may be a marker of poor prognosis in these patients.

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.

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.

COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D's plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.

Severe vitamin D deficiency is not related to SARS-CoV-2 infection but may increase mortality risk in hospitalized adults: a retrospective case-control study in an Arab Gulf country

Purpose

As the world continues to cautiously navigate its way through the coronavirus disease 2019 (COVID-19) pandemic, several breakthroughs in therapies and vaccines are currently being developed and scrutinized. Consequently, alternative therapies for severe acute respiratory coronavirus 2 (SARS-CoV-2) prevention, such as vitamin D supplementation, while hypothetically promising, require substantial evidence from countries affected by COVID-19. The present retrospective case–control study aims to identify differences in vitamin D status and clinical characteristics of hospitalized patients screened for SARS-CoV-2, and determine associations of vitamin D levels with increased COVID-19 risk and mortality.

Methods

A total of 222 [SARS-CoV-2 (+) N = 150 (97 males; 53 females); SARS-CoV-2 (−) N = 72 (38 males, 34 females)] out of 550 hospitalized adult patients screened for SARS-CoV-2 and admitted at King Saud University Medical City-King Khalid University Hospital (KSUMC-KKUH) in Riyadh, Saudi Arabia from May–July 2020 were included. Clinical, radiologic and serologic data, including 25(OH)D levels were analyzed.

Results

Vitamin D deficiency (25(OH)D < 50 nmol/l) was present in 75% of all patients. Serum 25(OH)D levels were significantly lower among SARS-CoV-2 (+) than SARS-CoV-2 (−) patients after adjusting for age, sex and body mass index (BMI) (35.8 ± 1.5 nmol/l vs. 42.5 ± 3.0 nmol/l; p = 0.037). Multivariate regression analysis revealed that significant predictors for SARS-CoV-2 include age > 60 years and pre-existing conditions (p < 0.05). Statistically significant predictors for mortality adjusted for covariates include male sex [Odds ratio, OR 3.3 (95% confidence interval, CI 1.2–9.2); p = 0.02], chronic kidney disease [OR 3.5 (95% CI 1.4–8.7); p = 0.008] and severe 25(OH)D deficiency (< 12.5 nmol/l), but at borderline significance [OR 4.9 (95% CI (0.9–25.8); p = 0.06].

Conclusion

In hospital settings, 25(OH)D deficiency is not associated with SARS-CoV-2 infection, but may increase risk for mortality in severely deficient cases. Clinical trials are warranted to determine whether vitamin D status correction provides protective effects against worse COVID-19 outcomes.

Letter to the editor: Vitamin D levels in acute illness and clinical severity in COVID-19 patients

We would like to comment on the recently published article titled: “Circulating Vitamin D levels status and clinical prognostic indices in COVID-19 patients” by Ricci et al. The authors grouped the patients into two groups according to the vitamin D levels measured at the time of admission into the hospital and reported that lower vitamin D levels are associated with elevated D-dimer and IL-6 levels, low CD4/CD8 ratio and compromised clinical findings with elevated LIPI and SOFA scores. However, review of recent literature shows this association to be debatable. The 25-hydroxyvitamin D levels in the initial phase of critical illness have been reported to drop rapidly and hence consideration of the time of measurement from symptom onset would have enhanced the clinical relevance of these findings. Inferred association between vitamin D levels and disease severity based on SOFA score in COVID-19 patients, needs to be further explored in the light of the recent literature which casts doubt on using SOFA score at admission to predict mortality in COVID-19.

Pleiotrope Wirkung von Vitamin D mit Berücksichtigung von COVID-19

Vitamin D wird aus der Nahrung aufgenommen oder in der Haut unter Einwirkung von UV-Licht gebildet. In der Leber wird 25(OH)-Vitamin D gebildet und in der Niere 1,25(OH)2-Vitamin D, welches als Hormon den Knochen- und Mineralstoffwechsel reguliert.

Außerhalb der Niere besitzen viele Organe Enzyme, um 1,25(OH)2-Vitamin D zu bilden für autokrine und parakrine Wirkungen. Für diese pleiotropen Effekte erscheint eine gleichmäßige Vitamin-D-Versorgung (tägliche Vitamin-D-Supplementation) mit mäßiger Dosierung besser wirksam als hoch dosierte Bolusapplikationen. Neben der klassischen Wirkung von 1,25(OH)2-Vitamin D auf das muskuloskelettale System sind unter den extraskelettalen Wirkungen insbesondere die immunregulatorischen Effekte mittlerweile sehr gut belegt. So kann durch eine gute Vitamin-D-Versorgung das Risiko für respiratorische Infekte vermindert werden, was gerade im Hinblick auf die aktuelle COVID-19(Coronavirus-Erkrankung-19)-Pandemie von Bedeutung erscheint.

New Roles for Vitamin D Superagonists: From COVID to Cancer

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

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.

An Evaluation of Serum 25-Hydroxy Vitamin D Levels in Patients with COVID-19 in New York City

AIM

Deterioration of patients from COVID-19 is associated with cytokine release syndrome attributed to an elevation in pro-inflammatory cytokines. Vitamin D reduces proinflammatory cytokines, and has the possibility of reducing complications from respiratory tract illnesses.

METHOD

This was a retrospective, observational, cohort study of patients with COVID-19 disease within a New York City Health System. Adult patients were included if they tested positive for SARS-CoV-2, and had a serum 25-hydroxy vitamin D level (25(OH)D) within the three previous months prior to their detected SARS-CoV-2 test. Patients were compared and evaluated based upon their 25(OH)D levels. The primary endpoints were hospitalization, need for oxygen support, and 90-day mortality.

RESULTS

437 COVID-19 patients were included [67 (IQR: 56-79) years] within this cohort. Deficient plasma 25(OH)D levels (<20 ng/ml) were associated with an increased likelihood of oxygen support [OR:2.23 (95% CI: 1.46-3.44, p = 0.0002)] from COVID-19. Deficient plasma 25(OH)D levels were not independently associated with 90-day mortality or risk of hospitalization. Hospitalization rates (98%), oxygen support (93%), and mortality rates (49%) were highest in patients who had 25(OH)D levels less than 10 ng/ml when compared to other 25(OH)D levels.

CONCLUSION

Serum 25-hydroxy vitamin D levels may affect the need for oxygen support therapy in patients with COVID-19.

Potential immunomodulatory effects of vitamin D in the prevention of severe coronavirus disease 2019: An ally for Latin America (Review)

Currently, the world is under a pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVID-19). This disease is characterized by a respiratory syndrome that can progress to an acute respiratory distress syndrome. To date, limited effective therapies are available for the prevention or treatment of COVID-19; therefore, it is necessary to propose novel treatment options with immunomodulatory effects. Vitamin D serves functions in bone health and has been recently reported to exert protective effects against respiratory infections. Observational studies have demonstrated an association between vitamin D deficiency and a poor prognosis of COVID-19; this is alarming as vitamin D deficiency is a global health problem. In Latin America, the prevalence of vitamin D deficiency is unknown, and currently, this region is in the top 10 according to the number of confirmed COVID-19 cases. Supplementation with vitamin D may be a useful adjunctive treatment for the prevention of COVID-19 complications. The present review provides an overview of the current knowledge of the potential immunomodulatory effects of vitamin D in the prevention of COVID-19 and sets out vitamin D recommendations for the Latin American population.