Vitamin D and Covid-19: From potential therapeutic effects to unanswered questions

Effect of vitamin D supplementation on clinical outcomes in adult patients with COVID-19: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials

The COVID-19 pandemic has emerged as a major global health crisis. Vitamin D, a crucial fat-soluble vitamin, has been recommended for COVID-19 patients, though evidence of its effectiveness is inconsistent. This systematic literature review and meta-analysis aimed to evaluate the impact of vitamin D supplementation on COVID-19-related outcomes. A comprehensive search was conducted across PubMed, Scopus, Web of Science, Embase, and Cochrane databases. Primary outcomes included mortality and hospital length of stay, while secondary outcomes encompassed C-reactive protein (CRP), ferritin, D-dimer, hemoglobin (Hb) concentrations, and lymphocyte, neutrophil, and platelet counts. Data analysis was performed using Stata™ Version 14. A total of 16 trials were analyzed. The meta-analysis revealed that vitamin D supplementation significantly reduced hospital length of stay (mean difference = -1.16; 95% confidence interval [CI]: -2.23, -0.09; p = .033) with significant heterogeneity (I2 = 69.2%, p = .002). Subgroup analysis showed a more pronounced reduction in studies with vitamin D dosages ≤10 000 international units (IU) (mean difference = -1.27; 95% CI: -1.96, -0.57; p < .001) and in patients over 60 years old (mean difference = -1.84; 95% CI: -2.53, -1.14; p < .001). Additionally, vitamin D significantly reduced CRP concentrations in older adults (>60 years) (mean difference = -1.13; 95% CI: -2.07, -0.18; p = .019). No significant changes were found in ferritin, D-dimer, Hb concentrations, or in lymphocyte, neutrophil, and platelet counts (p > .05). In conclusion, while vitamin D supplementation did not significantly affect most COVID-19-related biomarkers, however, it reduces the length of hospital stay.

Exploration of blood−derived coding and non-coding RNA diagnostic immunological panels for COVID-19 through a co-expressed-based machine learning procedure

Severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) is the causative virus of the pandemic coronavirus disease 2019 (COVID-19). Evaluating the immunological factors and other implicated processes underlying the progression of COVID-19 is essential for the recognition and then the design of efficacious therapies. Therefore, we analyzed RNAseq data obtained from PBMCs of the COVID-19 patients to explore coding and non-coding RNA diagnostic immunological panels. For this purpose, we integrated multiple RNAseq data and analyzed them overall as well as by considering the state of disease including severe and non-severe conditions. Afterward, we utilized a co-expressed-based machine learning procedure comprising weighted-gene co-expression analysis and differential expression gene as filter phase and recursive feature elimination-support vector machine as wrapper phase. This procedure led to the identification of two modules containing 5 and 84 genes which are mostly involved in cell dysregulation and innate immune suppression, respectively. Moreover, the role of vitamin D in regulating some classifiers was highlighted. Further analysis disclosed the role of discriminant miRNAs including miR-197-3p, miR-150-5p, miR-340-5p, miR-122-5p, miR-1307-3p, miR-34a-5p, miR-98-5p and their target genes comprising GAN, VWC2, TNFRSF6B, and CHST3 in the metabolic pathways. These classifiers differentiate the final fate of infection toward severe or non-severe COVID-19. The identified classifier genes and miRNAs may help in the proper design of therapeutic procedures considering their involvement in the immune and metabolic pathways.

Positive Effects of Vitamin D Supplementation in Patients Hospitalized for COVID-19: A Randomized, Double-Blind, Placebo-Controlled Trial

Retrospective studies showed a relationship between vitamin D status and COVID-19 severity and mortality, with an inverse relation between SARS-CoV-2 positivity and circulating calcifediol levels. The objective of this pilot study was to investigate the effect of vitamin D supplementation on the length of hospital stay and clinical improvement in patients with vitamin D deficiency hospitalized with COVID-19. The study was randomized, double blind and placebo controlled. A total of 50 subjects were enrolled and received, in addition to the best available COVID therapy, either vitamin D (25,000 IU per day over 4 consecutive days, followed by 25,000 IU per week up to 6 weeks) or placebo. The length of hospital stay decreased significantly in the vitamin D group compared to the placebo group (4 days vs. 8 days; p = 0.003). At Day 7, a significantly lower percentage of patients were still hospitalized in the vitamin D group compared to the placebo group (19% vs. 54%; p = 0.0161), and none of the patients treated with vitamin D were hospitalized after 21 days compared to 14% of the patients treated with placebo. Vitamin D significantly reduced the duration of supplemental oxygen among the patients who needed it (4 days vs. 7 days in the placebo group; p = 0.012) and significantly improved the clinical recovery of the patients, as assessed by the WHO scale (p = 0.0048). In conclusion, this study demonstrated that the clinical outcome of COVID-19 patients requiring hospitalization was improved by administration of vitamin D.

Vitamin D Regulation of Immune Function

PURPOSE OF REVIEW

To review the mechanisms by which vitamin D and its metabolites regulate the immune system to facilitate the ability of the body to prevent and/or treat SARS-CoV2 and other respiratory infections and encourage further research into the role that vitamin D supplementation plays in preventing/treating such infections.

RECENT FINDINGS

Vitamin D deficiency is associated with an increased risk of SARS-CoV2 and other respiratory infections. Clinical trials in general demonstrate that correction of vitamin D deficiency reduces the risk of hospitalization, ICU admission, and death from SARS-CoV2 infection. The airway epithelium and alveolar macrophages express the enzyme, CYP27B1, that produces the active metabolite of vitamin D, 1,25(OH)2D, and the vitamin D receptor, VDR. Vitamin D and its metabolites promote the innate immune response, which provides the first line of defense against viral and bacterial infections while restricting the adaptive immune response, which if unchecked promotes the inflammatory response leading to the acute respiratory distress syndrome and death. The rationale for treating vitamin D deficiency to reduce the risk of SARS-CoV2 infection and supplementing patients with vitamin D early in the course of SARS-CoV2 infection rests primarily on the ability of vitamin D metabolites to promote an effective immune response to the infection.

Association of vitamin D status with COVID-19 disease severity in pediatric patients: A retrospective observational study

Background and Aims

Vitamin D deficiency is associated with increased vulnerability to respiratory infections. This study aimed to determine the potential relationships between coronavirus disease 2019 (COVID-19) severity, serum vitamin D concentrations, and some inflammatory markers among pediatric COVID-19 patients in Iran.

Methods

A retrospective study was conducted among hospitalized pediatric COVID-19 cases in Abuzar Hospital (Ahvaz, Iran) for 6 months. The COVID-19 diagnosis was based on the real-time reverse transcription-polymerase chain reaction technique. Demographic and clinical data of patients were recorded. Patients with serum vitamin D levels lower than 20 ng/ml were assigned as Group 1 and those with serum vitamin D concentrations equal to or more than 20 ng/ml were considered as Group 2.

Results

A total of 144 patients were enrolled. Their mean age was 80  ±  49 months (range: 1-16 years). Patients in Group 1 had significantly lower levels of serum vitamin D, calcium, and lymphocytes, as well as higher fibrinogen, d-dimer, and C-reactive protein (CRP) levels compared with those in Group 2 (p < 0.001). In addition, they had a significantly higher dry cough, fever, chest radiographic findings, respiratory rate, and longer hospital length of stay than patients in Group 2. Serum concentrations of vitamin D were positively correlated with levels of serum calcium, lymphocytes, and neutrophils but negatively correlated with CRP, fibrinogen, and d-dimer values. Furthermore, patients with moderate or severe courses of COVID-19 had significantly higher inflammatory markers (CRP, d-dimer, and fibrinogen), as well as lower levels of serum calcium, vitamin D, lymphocytes, and neutrophils than those with mild COVID-19 (p < 0.001). In the multivariate analysis, fibrinogen level on admission was detected as the independent predictor of severe COVD-19 (odds ratio = 1.06, 95% confidence interval: 1.03-1.09; p < 0.001).

Conclusion

This study indicated associations between the severity of COVID-19, serum vitamin D concentrations, and some inflammatory markers in pediatric COVID-19 patients.

SARS-CoV-2 and Coronavirus Disease Mitigation: Treatment Options, Vaccinations and Variants

COVID-19 is caused by a novel coronavirus (2019-nCoV), which was declared as a pandemic after it emerged in China 2019. A vast international effort has been conducted to prevent and treat COVID-19 due to its high transmissibility and severe morbidity and mortality rates, particularly in individuals with chronic co-morbidities. In addition, polymorphic variants increased the need for proper vaccination to overcome the infectivity of new variants that are emerging across the globe. Many treatment options have been proposed and more than 25 vaccines are in various stages of development; however, the infection peaks are oscillating periodically, which raises a significant question about the effectiveness of the prevention measures and the persistence of this pandemic disease. In this review, we are exploring the most recent knowledge and advances in the treatment and vaccination options as well as the new emerging variants of 2019-nCoV and the possible mitigation of one of the most aggressive pandemics in the last centuries.

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.

COVID-19 and Vitamin D Misinformation on YouTube: Content Analysis

Background

The "infodemic" accompanying the SARS-CoV-2 virus pandemic has the potential to increase avoidable spread as well as engagement in risky health behaviors. Although social media platforms, such as YouTube, can be an inexpensive and effective method of sharing accurate health information, inaccurate and misleading information shared on YouTube can be dangerous for viewers. The confusing nature of data and claims surrounding the benefits of vitamin D, particularly in the prevention or cure of COVID-19, influences both viewers and the general "immune boosting" commercial interest.

Objective

The aim of this study was to ascertain how information on vitamin D and COVID-19 was presented on YouTube in 2020.

Methods

YouTube video results for the search terms "COVID," "coronavirus," and "vitamin D" were collected and analyzed for content themes and deemed useful or misleading based on the accuracy or inaccuracy of the content. Qualitative content analysis and simple statistical analysis were used to determine the prevalence and frequency of concerning content, such as confusing correlation with causation regarding vitamin D benefits.

Results

In total, 77 videos with a combined 10,225,763 views (at the time of data collection) were included in the analysis, with over three-quarters of them containing misleading content about COVID-19 and vitamin D. In addition, 45 (58%) of the 77 videos confused the relationship between vitamin D and COVID-19, with 46 (85%) of 54 videos stating that vitamin D has preventative or curative abilities. The major contributors to these videos were medical professionals with YouTube accounts. Vitamin D recommendations that do not align with the current literature were frequently suggested, including taking supplementation higher than the recommended safe dosage or seeking intentional solar UV radiation exposure.

Conclusions

The spread of misinformation is particularly alarming when spread by medical professionals, and existing data suggesting vitamin D has immune-boosting abilities can add to viewer confusion or mistrust in health information. Further, the suggestions made in the videos may increase the risks of other poor health outcomes, such as skin cancer from solar UV radiation.

Diet, Probiotics and Their Impact on the Gut Microbiota during the COVID-19 Pandemic

SARS-CoV-2 infection is associated with diverse clinical manifestations, immune dysfunction, and gut microbiota alterations. The nutritional and biochemical quality of one's diet can influence the intestinal microbiota, which may play a role in the defense mechanisms against potential pathogens, by promoting a wide variety of immune-host interactions. In the COVID-19 pandemic, besides the development of pharmacological therapies, a healthy balanced diet, rich with food-derived antioxidants, may be a useful strategy. Many studies demonstrated that vitamins and probiotic therapies have positive effects on the treatment and prevention of oxidative stress and inflammation in COVID-19. The ecology of the gut microbiota in the digestive tract has been linked to the transport function of the host receptor known as angiotensin converting enzyme 2 (ACE2), suggesting that COVID-19 may be related to the gut microbiota. The angiotensin converting enzyme (ACE), and its receptor (ACE2), play central roles in modulating the renin-angiotensin system (RAS). In addition, ACE2 has functions that act independently of the RAS. ACE2 is the receptor for the SARS coronavirus, and ACE2 is essential for the expression of neutral amino acid transporters in the gut. In this context, ACE2 modulates innate immunity and influences the composition of the gut microbiota. Malnutrition is one of the leading underlying causes of morbidity and mortality worldwide and, including comorbidities, may be a major cause of worse outcomes and higher mortality among COVID-19 patients. This paper reviews the research on dietary components, with particular emphasis on vitamins, antioxidants, and probiotic therapies, and their impacts on the intestinal microbiota's diversity during the SARS-CoV-2 pandemic.

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.

COVID-19-related thyroid conditions (Review)

In patients who were not previously diagnosed with any thyroid conditions, the scenario of COVID-19-related anomalies of the hypothalamus-pituitary-thyroid axes may include either: A process of central thyroid stimulating hormone (TSH) disturbances via virus-related hypophysitis; an atypical type of subacute thyroiditis which is connected to the virus spread or to excessive cytokine production including a destructive process with irreversible damage of the gland or low T3 (triiodothyronine) syndrome (so called non-thyroid illness syndrome) which is not specifically related to the COVID-19 infection, but which is associated with a very severe illness status. Our objective here was to briefly review thyroid changes due to the COVID-19 infection. Ongoing assessment of the effects of the COVID-19 pandemic will reveal more information on coronavirus-induced thyroid conditions. Routine thyroid assays performed in patients with severe infection/at acute phase of COVID-19 are encouraged in order to detect thyrotoxicosis. After recovery, thyroid function should be assessed to identify potential hypothyroidism. There remain unanswered questions related to the prognostic value of interleukin-6 in infected patients, especially in cases with cytokine storm, and the necessity of thyroid hormone replacement in subjects with hypophysitis-related central hypothyroidism.

Bad Prognosis in Critical Ill Patients with COVID-19 during Short-Term ICU Stay regarding Vitamin D Levels

BACKGROUND AND AIMS

Vitamin D inadequacy may be involved in the mechanisms of SARS-CoV-2 infection and in potential risk factors for disease propagation or control of coronavirus disease 2019 (COVID-19). This study assessed a short-term evolution of vitamin D status and its influence upon different clinical parameters in critically ill patients with COVID-19.

METHODS

A prospective analytical study in which 37 critically ill volunteers between 41 and 71 years of age with COVID-19 were evaluated at baseline and three days of intensive care unit (ICU) stay. 25-OH-D₃ and 25-OH-D₂ were analyzed by liquid chromatography-tandem mass spectrometry and total 25-OH-D levels were calculated as the sum of both.

RESULTS

All patients presented low 25-OH-D levels at baseline, decreasing total 25-OH-D (p = 0.011) mainly through 25-OH-D₂ (p = 0.006) levels during ICU stay. 25-OH-D₂ levels decreased a mean of 41.6% ± 89.6% versus 7.0% ± 23.4% for the 25-OH-D₃ form during the ICU stay. Patients who did not need invasive mechanical ventilation presented higher levels of 25-OH-D₂ at baseline and follow-up. Lower 25-OH-D and 25-OH-D₃ levels were associated with higher D-dimer at baseline (p = 0.003; p = 0.001) and at follow up (p = 0.029), higher procalcitonin levels (p = 0.002; p = 0.018) at follow up, and lower percentage lymphocyte counts (p = 0.044; p = 0.040) during ICU stay.

CONCLUSIONS

Deficient vitamin D status in critical patients was established at the admission and further worsened after three days of stay. Lower vitamin D levels were related to key altered clinical and biochemical parameters on patients with SARS-CoV-2 infection. Given the different response of the 25-OH-D₃ and 25-OH-D₂ forms, it would be useful to monitor them on the evolution of the critically ill patient.

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.

Pharmacological Effects of Selected Medicinal Plants and Vitamins Against COVID-19

The coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is a serious disease that has caused multiple deaths in various countries in the world. Globally, as of May 23, 2021, the total confirmed cases of COVID-19 have reach 166,346,635 with a total of 3,449,117 deaths. Several recent scientific studies have shown that medicinal plants and vitamins can benefit and improve the health of COVID-19 patients. However, the benefits of medicinal plants and vitamins in the treatment of COVID-19 remain unproven. Therefore, the objective of this article is to expounds the benefits of using medicinal plants (Allium sativum, curcumin, Nigella sativa, Zingiber officitale) and vitamins (vitamin C and vitamin D) that possess the antiviral properties for the prevention and/or control of COVID-19. To reach our objective, we searched scientific databases of ongoing trials in the Centers for Disease Control and Prevention websites, PubMed Central, Medline databases, and Google Scholar websites. We also searched databases on World Health Organization International Clinical Trials Registry Platform to collect relevant papers. We found that all of the selected medicinal plants and vitamins possess antiviral activities, and their individual intake shows promise for the prevention and/or control of COVID-19. We conclude that, the selected medicinal plants and vitamins possess anti-viral properties that are more likely to prevent and/or disrupt the SARS-CoV-2 replication cycle, enhance the human immune system and promote good health.

Association of Calcitriol Supplementation with Reduced COVID-19 Mortality in Patients with Chronic Kidney Disease: A Population-Based Study

Treatment with calcitriol, the hormonal form of vitamin D, has shown beneficial effects in experimental models of acute lung injury. In this study, we aimed to analyze the associations between calcitriol supplementation and the risk of SARS-CoV2 infection or COVID-19 mortality. Individuals ≥18 years old living in Catalonia and supplemented with calcitriol from April 2019 to February 2020 were compared with propensity score matched controls. Outcome variables were SARS-CoV2 infection, severe COVID-19 and COVID-19 mortality. Associations between calcitriol supplementation and outcome variables were analyzed using multivariable Cox proportional regression. A total of 8076 patients were identified as being on calcitriol treatment. Advanced chronic kidney disease and hypoparathyroidism were the most frequent reasons for calcitriol supplementation in our population. Calcitriol use was associated with reduced risk of SARS-CoV2 infection (HR 0.78 [CI 95% 0.64-0.94], p = 0.010), reduced risk of severe COVID-19 and reduced COVID-19 mortality (HR 0.57 (CI 95% 0.41-0.80), p = 0.001) in patients with advanced chronic kidney disease. In addition, an inverse association between mean daily calcitriol dose and COVID-19 severity or mortality was observed in treated patients, independently of renal function. Our findings point out that patients with advanced chronic kidney disease could benefit from calcitriol supplementation during the COVID-19 pandemic.

COVID-19: Characteristics and Therapeutics

Novel coronavirus (COVID-19 or 2019-nCoV or SARS-CoV-2), which suddenly emerged in December 2019 is still haunting the entire human race and has affected not only the healthcare system but also the global socioeconomic balances. COVID-19 was quickly designated as a global pandemic by the World Health Organization as there have been about 98.0 million confirmed cases and about 2.0 million confirmed deaths, as of January 2021. Although, our understanding of COVID-19 has significantly increased since its outbreak, and multiple treatment approaches and pharmacological interventions have been tested or are currently under development to mitigate its risk-factors. Recently, some vaccine candidates showed around 95% clinical efficacy, and now receiving emergency use approvals in different countries. US FDA recently approved BNT162 and mRNA-1273 vaccines developed by Pfizer/BioNTech and Moderna Inc. for emergency use and vaccination in the USA. In this review, we present a succinct overview of the SARS-CoV-2 virus structure, molecular mechanisms of infection, COVID-19 epidemiology, diagnosis, and clinical manifestations. We also systematize different treatment strategies and clinical trials initiated after the pandemic outbreak, based on viral infection and replication mechanisms. Additionally, we reviewed the novel pharmacological intervention approaches and vaccine development strategies against COVID-19. We speculate that the current pandemic emergency will trigger detailed studies of coronaviruses, their mechanism of infection, development of systematic drug repurposing approaches, and novel drug discoveries for current and future pandemic outbreaks.

Micronutrient therapy and effective immune response: a promising approach for management of COVID-19

The escalating prevalence of coronavirus disease 2019 (COVID-19) worldwide, with an increased rate of morbidity and mortality, highlights an urgent need to develop more effective therapeutic interventions. Despite the authorized treatment against COVID-19 by the European Union (EU), the safety and effectiveness of this therapeutic strategy for a wide variety of patients have remained a significant challenge. In this respect, micronutrients such as vitamins and minerals, as essential factors, can be considered for improving the function of the immune system and accelerating the treatment procedure. Dietary supplements can attenuate vascular and inflammatory manifestations related to infectious diseases in large part due to their anti-inflammatory and antioxidant properties. Recently, it has been revealed that poor nutritional status may be one of the notable risk factors in severe COVID-19 infections. In the current review, we focus on the micronutrient therapy of COVID-19 patients and provide a comprehensive insight into the essential vitamins/minerals and their role in controlling the severity of the COVID-19 infection. We also discuss the recent advancements, challenges, negative and positive outcomes in relevance to this approach.

Lower levels of vitamin D are associated with SARS-CoV-2 infection and mortality in the Indian population: An observational study

•

Differential distributions of vitamin D were observed in the Indian population.

•

Vitamin D levels was inversely correlated with SARS-CoV-2 infection rate.

•

COVID-19 mortality rate was negatively associated with mean vitamin D levels.

Background

The role of vitamin D in the susceptibility and severity of various viral diseases has been well documented. Recently, some reports highlighted the possible importance of vitamin D in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although India receives adequate sunlight throughout the year, the majority of Indians are deficient in vitamin D levels. In the present study, we hypothesized that vitamin D deficiency would be associated with the SARS-CoV-2 infection rate and mortality in the Indian population.

Materials and methods

SARS-CoV-2 infection and mortality data were obtained from the Government of India's official website (accessed on 16th August 2020). Various literature databases like PubMed and Google Scholar were searched to find the mean of 25-hydroxyvitamin D [25(OH)D] levels in different states and union territories of India, Pearson correlation was carried out to investigate the possible link between mean 25(OH)D levels and SARS-CoV-2 infection and mortality per million of the population.

Results

An inverse correlation was observed between the mean level of 25(OH)D and SARS-CoV-2 infection rate (r = −0.43, p = 0.02) and mortality rate (r = −0.42, p = 0.02).

Conclusions

The present observational study revealed an association of vitamin D with SARS-CoV-2 infection and related mortality. Further studies are required to validate our observations.