Low Vitamin D Levels Are Associated With the Development of Deep Venous Thromboembolic Events in Patients With Ischemic Stroke

Vitamin D Levels as a Marker of Severe SARS-CoV-2 Infection

The SARS-CoV-2 virus may cause severe infection, which is associated with diverse clinical manifestations. Vitamin D has immunomodulating properties and may enhance the body's defense system against invading pathogenic organisms. The aim was to assess 25(OH)D3 levels in patients hospitalized for severe infection from the SARS-CoV-2 virus and explore the relationship between 25(OH)D3 and outcomes. In a group of 88 patients hospitalized for severe infection from the SARS-CoV-2 virus and a control group matched for age and sex, the levels of 25(OH)D3 were analyzed. Levels of 25(OH)D3 were 17.36 ± 8.80 ng/mL (mean ± SD) compared with 24.34 ± 10.34 ng/mL in patients with severe SARS-CoV-2 infection and the control group, respectively, p < 0.001 (Student's t-test). 25(OH)D3 levels were significantly related to outcomes, i.e., survival as opposed to non-survival, as more patients with 25(OH)D3 deficiency (0-10 ng/mL) and insufficiency (10-20 ng/mL) had a fatal outcome as compared with those with vitamin D sufficiency (p < 0.001, chi-square test, p < 0.001, Fisher's exact test). Levels of 25(OH)D3 were inversely related to C-reactive protein (CRP), ferritin, d-dimer, and fibrinogen levels (p < 0.001, linear regression analysis, beta coefficient of variation, -0.176, -0.160, -0.178, and -0.158, respectively). Vitamin D deficiency observed in severe SARS-CoV-2 infection was related to disease outcomes.

Plasminogen Activator Inhibitor-1 and Vitamin D Association in the Overweight and Obese Pediatric Population

BACKGROUND

Childhood overweight and obesity have been described by the World Health Organization as noncommunicable diseases and among the greatest public health threats since they have reached epidemic proportions. A child with obesity risks becoming an adult with obesity and developing metabolic and hemostatic disorders which are the basis for the development of coronary heart diseases. Recently, a number of clinical reports have demonstrated that both an increase in plasminogen activator inhibitor-1 (PAI-1) and a deficiency in 25OH-vitamin D3 (VD) are associated with an increase in thrombotic episodes.

METHODS

PAI-1 and VD levels were measured in 259 clinically overweight and obese children aged between 2 and 18 years enrolled in the Nutritional Education Program of the Bambino Gesù Children's Hospital and Research Institute of Rome (Italy) and 80 normal-weight subjects.

RESULTS

We observed increased HOMA-IR, PAI-1, and other inflammation indices associated with decreased VD levels when compared to normal-weight children.

CONCLUSIONS

Our results demonstrated that overweight and obesity are correlated with higher levels of the inflammation index. Moreover, our patients show high PAI-1 and low VD levels, confirming the high thrombotic risk in our pediatric population.

A Retrospective Analysis of Vitamin D Levels in Hospitalized COVID-19 Patients With Suspected Pulmonary Embolism

Introduction Despite using anti-coagulation therapy in hospitalized coronavirus disease 2019 (COVID-19) patients, they have high rates of pulmonary embolism (PE) and deep vein thrombosis (DVT). The main objective of this study was to evaluate the association between vitamin D deficiency and thrombotic events (defined as the occurrence of a new PE or DVT) in hospitalized COVID-19 patients. Materials and Methods This was a retrospective, cross-sectional study of 208 hospitalized COVID-19 patients who received a computed tomographic pulmonary angiography (CTPA) based on clinical suspicion of PE between January 1, 2020, and February 5, 2021. A <20 ng/mL serum vitamin D level was used to categorize vitamin D deficiency. Nonparametric tests and multivariate binary logistic regression were used to evaluate the association between serum vitamin D levels and clinical outcomes. Results The mean vitamin D level was 26.7±13.0 ng/mL (n=208), and approximately one-third of patients were vitamin D deficient (n=68, 32.7%). No association was found between vitamin D deficiency and the occurrence of thrombotic events. The incidence of PE was 19.1% in vitamin D deficient patients compared to 11.4% in vitamin D sufficient patients (p=0.13). Vitamin D deficiency was positively associated with ICU admission (OR 3.047, 95%CI 1.57-5.91, p=0.001) and mortality (OR 3.76, 95%CI 1.29-11.01, p=0.016). Conclusions This study found no association between vitamin D deficiency and the occurrence of a new PE or DVT in hospitalized COVID-19 patients. Patients with vitamin D deficiency were more likely to be admitted to the ICU and had increased overall mortality.

The interplay between hypovitaminosis D and the immune dysfunction in the arteriovenous thrombotic complications of the sever coronavirus disease 2019 (COVID-19) infection

Thromboembolic complications including cerebrovascular accidents, pulmonary embolism, myocardial infarction, deep vein thrombosis and disseminating intravascular coagulopathy are serious encounters in sever coronavirus disease 2019 (COVID-19) infected patients. This worsens the prognosis and may lead to death or life long morbidities. The laboratory finding of the disturbed haemostasias and the hyperinflammatory response are almost invariably present in COVID-19 patients. Multiple treatment modalities are utilized by the healthcare professionals to overcome the cytokine storm, oxidative stress, endothelial dysfunction, and coagulopathy in these patients. The combined actions of vitamin D (VitD) as a steroid hormone with anti-inflammatory, immunomodulatory, and antithrombotic properties increase the potential of the possible involvement of hypovitaminosis D in the thromboembolic complications of COVID-19 infection, and stimulated researchers and physicians to administer VitD therapy to prevent the infection and/or overcome the disease complications. The current review highlighted the immunomodulatory, anti-inflammatory, antioxidative and hemostatic functions of VitD and its interrelation with the renin-angiotensin-aldosterone system (RAAS) pathway and the complement system. Additionally, the association of VitD deficiency with the incidence and progression of COVID-19 infection and the associated cytokine storm, oxidative stress, hypercoagulability, and endothelial dysfunction were emphasized. Normalizing VitD levels by daily low dose therapy in patients with hypovitaminosis D below (25 nmol/l) is essential for a balanced immune response and maintaining the health of the pulmonary epithelium. It protects against upper respiratory tract infections and decreases the complications of COVID-19 infections. Understanding the role of VitD and its associated molecules in the protection against the coagulopathy, vasculopathy, inflammation, oxidative stress and endothelial dysfunction in COVID-19 infection could lead to new therapeutic strategies to prevent, treat, and limit the complications of this deadly virus infection.

Is Circulating Vitamin D Status Associated with the Risk of Venous Thromboembolism? A Meta-Analysis of Observational Studies

BACKGROUND

Although vitamin D is antithrombotic, associations between serum vitamin D status and the risk of venous thromboembolism (VTE) remain inconsistent.

METHODS

We searched the EMBASE, MEDLINE, Cochrane Library, and Google Scholar databases from inception to June 2022 to identify observational studies examining associations between vitamin D status and VTE risk in adults. The primary outcome presented as odds ratio (OR) or hazard ratio (HR) was the association of vitamin D levels with the risk of VTE. Secondary outcomes included the impacts of vitamin D status (i.e., deficiency or insufficiency), study design, and the presence of neurological diseases on the associations.

RESULTS

Pooled evidence from a meta-analysis of sixteen observational studies, including 47648 individuals published from 2013 to 2021, revealed a negative relationship between vitamin D levels and the risk of VTE either based on OR (1.74, 95% confidence interval (CI): 1.37 to 2.20, p < 0.00001; I² = 31%, 14 studies, 16074 individuals) or HR (1.25, 95% CI: 1.07 to 1.46, p = 0.006; I² = 0%, 3 studies, 37,564 individuals). This association remained significant in subgroup analyses of the study design and in the presence of neurological diseases. Compared to individuals with normal vitamin D status, an increased risk of VTE was noted in those with vitamin D deficiency (OR = 2.03, 95% CI: 1.33 to 3.11) but not with vitamin D insufficiency.

CONCLUSIONS

This meta-analysis demonstrated a negative association between serum vitamin D status and the risk of VTE. Further studies are required to investigate the potential beneficial effect of vitamin D supplementation on the long-term risk of VTE.

Risk factors and predictors for venous thromboembolism in people with ischemic stroke: A systematic review

Identification of individuals with ischemic stroke at particularly high risk of venous thromboembolism (VTE) is crucial for targeted thromboprophylaxis. To guide clinical decision-making and development of risk prediction models, increased knowledge on risk factors and biomarkers is needed. Therefore, we set out to identify risk factors and predictors for VTE in people with ischemic stroke by conducting a systematic review of the literature. Medline and Embase were searched from January 1990 and onwards. Studies investigating demographic, clinical, and/or laboratory factors for stroke-related VTE were considered. Two reviewers screened all retrieved records, independently and in duplicate. Risk of bias assessments were guided by a structured framework (PROSPERO-ID: CRD42020176361). Of 4674 identified records, 26 studies were included. Twenty-six demographic, clinical, and laboratory factors associated with increased risk of stroke-related VTE after multivariable adjustments were identified. The following factors were reported by ≥2 studies: prior VTE, cancer, prestroke disability, leg weakness, increasing lesion volume of the brain infarct, infection, low Barthel Index, increasing length of hospital stay, biochemical indices of dehydration, as well as elevated levels of D-dimer, C-reactive protein, and homocysteine. The majority of the studies were of poor quality with moderate or high risk of bias. In conclusion, this systematic review informs on several potential risk factors and predictors for VTE in people with ischemic stroke. To improve risk stratification and guide development of risk prediction models, further confirmation is needed because there were few high-quality studies on each factor.

Antiphospholipid antibodies and vitamin D deficiency in COVID-19 infection with and without venous or arterial thrombosis: A pilot case-control study

Background

Coronavirus disease-2019 (COVID-19) is associated with thromboembolism. Antiphospholipid antibody (APLa) formation is one of the mechanisms. Vitamin D deficiency has been associated with thrombosis in antiphospholipid antibody syndrome.

Objective

Measure APLa and vitamin D in hospitalized COVID-19 patients with and without thrombosis to evaluate if thromboembolism is associated with concomitant APLa and vitamin D deficiency.

Methods

Case-control study. Hospitalized COVID-19 patients with a thromboembolic event (ischemic stroke, myocardial infarction, deep venous thrombosis/pulmonary embolism, Cases n = 20). Controls (n = 20): Age, sex-matched without thromboembolic events. Patients with autoimmune disorders, antiphospholipid antibody syndrome, thrombophilia, anticoagulation therapy, prior thromboembolism, chronic kidney disease 3b, 4, end-stage renal disease, and malignancy were excluded. Given the limited current literature on the role of concomitant antiphospholipid antibodies and vitamin D deficiency in causing venous and/or arterial thrombosis in hospitalized COVID-19 patients, we enrolled 20 patients in each arm. Anti-cardiolipin IgG/IgM, beta-2 glycoprotein-1 IgG/IgM, lupus anticoagulant and vitamin D levels were measured in both groups.

Results

Cases were 5.7 times more likely to be vitamin D deficient (OR:5.7, 95% CI:1.3–25.6) and 7.4 times more likely to have any one APLa (OR:7.4, 95% CI: 1.6–49.5) while accounting for the effects of sex. Patients with both APLa and vitamin D deficiency had significantly more thrombosis compared to patients who were antibody positive without vitamin D deficiency (100% vs 47.4%; p = 0.01).

Conclusions

Thrombosis in COVID-19 was associated with concomitant APLa and vitamin D deficiency. Future studies in COVID-19 should assess the role of vitamin D in reducing thrombosis.

Vitamin D Endocrine System and COVID-19: Treatment with Calcifediol

The COVID-19 pandemic is the greatest challenge facing modern medicine and public health systems. The viral evolution of SARS-CoV-2, with the emergence of new variants with in-creased infectious potential, is a cause for concern. In addition, vaccination coverage remains in-sufficient worldwide. Therefore, there is a need to develop new therapeutic options, and/or to optimize the repositioning of drugs approved for other indications for COVID-19. This may include the use of calcifediol, the prohormone of the vitamin D endocrine system (VDES) as it may have potential useful effects for the treatment of COVID-19. We review the aspects associating COVID-19 with VDES and the potential use of calcifediol in COVID-19. VDES/VDR stimulation may enhance innate antiviral effector mechanisms, facilitating the induction of antimicrobial peptides/autophagy, with a critical modulatory role in the subsequent host reactive hyperinflammatory phase during COVID-19: By decreasing the cytokine/chemokine storm, regulating the renin–angiotensin–bradykinin system (RAAS), modulating neutrophil activity and maintaining the integrity of the pulmonary epithelial barrier, stimulating epithelial repair, and directly and indirectly decreasing the increased coagulability and prothrombotic tendency associated with severe COVID-19 and its complications. Available evidence suggests that VDES/VDR stimulation, while maintaining optimal serum 25OHD status, in patients with SARS-CoV-2 infection may significantly reduce the risk of acute respiratory distress syndrome (ARDS) and severe COVID-19, with possible beneficial effects on the need for mechanical ventilation and/or intensive care unit (ICU) admission, as well as deaths in the course of the disease. The pharmacokinetic and functional characteristics of calcifediol give it superiority in rapidly optimizing 25OHD levels in COVID-19. A pilot study and several observational intervention studies using high doses of calcifediol (0.532 mg on day 1 and 0.266 mg on days 3, 7, 14, 21, and 28) dramatically decreased the need for ICU admission and the mortality rate. We, therefore, propose to use calcifediol at the doses described for the rapid correction of 25OHD deficiency in all patients in the early stages of COVID-19, in association, if necessary, with the new oral antiviral agents.

Influence of Vitamin D Status on the Maintenance Dose of Warfarin in Patients Receiving Chronic Warfarin Therapy

INTRODUCTION

Considering the anticoagulant actions of vitamin D, we hypothesize that vitamin D status might affect the required dose of warfarin for maintaining the therapeutic international normalized ratio (INR).

METHODS

In a retrospective single-center cohort study, serum levels of 25-hydroxyvitamin D were assessed for 89 subjects receiving a stable dose of warfarin for 3 months or longer and had a stable INR between 2 and 3.5 for at least three consecutive visits. A warfarin sensitivity index (WSI), defined as the steady-state INR divided by the mean daily warfarin dose, was used for measuring the warfarin dose response. The relation between the serum level of 25-hydroxyvitamin D and WSI value and the difference in the mean WSI value between the subjects with different vitamin D status categories (sufficient, insufficient, and deficient) were assessed.

RESULTS

Twenty-one subjects had vitamin D deficiency, 43 had vitamin D insufficiency, and only 25 had normal levels of 25-hydroxyvitamin D. Based on the multiple linear regression analysis, there was a significant but weakly positive correlation between WSI and 25-hydroxyvitamin D serum levels, as the value of WSI increases by almost 0.0027434 for every unit increase in 25-hydroxyvitamin D serum level (p value = 0.041). Using one-way ANOVA analysis, there was a trend in a significant difference between the groups with different vitamin D status categories regarding the mean WSI value (F = 2.95, p value = 0.057), as subjects with sufficient vitamin D state compared to those with vitamin D deficiency had a higher WSI value.

CONCLUSIONS

Although the study's limitations limit our ability to draw definite conclusions, the present data suggest that in addition to other traditional factors, vitamin D status might also affect warfarin sensitivity and maintenance dose requirement. However, to more clearly explain this link, further studies with high involvement subjects are required.

Calcifediol for Use in Treatment of Respiratory Disease

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

The Association between Vitamin D Levels and Thrombus Burden in Patients with ST-Elevation Myocardial Infarction

Background: In current practice, establishing the potential predictors of high thrombus burden (HTB) before primary percutaneous coronary intervention (PCI) is crucial for its management. In this research, we aimed to investigate the association between vitamin D levels and HTB in patients with ST-elevation myocardial infarction (STEMI). Methods: This prospective, observational study was conducted on 257 STEMI patients undergoing primary PCI in Van Education and Research Hospital between March 2020 and March 2021. The thrombus burden grade was determined for each subject. The study population was divided into 2 groups: patients with HTB and those with low thrombus burden (LTB) based on the thrombus burden grade. Demographic, laboratory, and angiographic features were compared between the groups. Results: In total, 154 patients (mean age±SD=63.42±11.53 y, 65.6% male) had HTB and 103 patients had LTB (mean age±SD=61.50±10.23 y, 70.9% male). The patients stratified into the HTB group had lower vitamin D levels than those in the LTB group (8.0 ng/mL vs 17.9 ng/mL, respectively; P<0.001). The patients with HTB and low vitamin D levels had lower post-PCI thrombolysis in myocardial infarction (TIMI) flow, TIMI myocardial perfusion grade, and post-PCI ST resolution. In a multivariable analysis, vitamin D was an independent predictor of HTB among the STEMI patients (OR: 0.76, 95%CI: 0.70-0.82; P<0.001). The ideal value of vitamin D to predict HTB was >17.6 ng/mL with a sensitivity of 81.8% and a specificity of 90.3%. Conclusion: The study results showed that vitamin D levels were an independent predictor of HTB in STEMI patients treated by primary PCI.

The role of vitamin D in cardiovascular disease and COVID-19

Patients with pre-existing cardiovascular disease (CVD) are at high risk for adverse outcomes with coronavirus disease 2019 (COVID-19). Further, COVID-19 infection is associated with numerous cardiovascular (CV) complications including arrhythmia, myocardial injury, cardiomyopathy, and thrombotic events. Increased susceptibility to COVID-19 and CV complications related to COVID-19 may be in part related to immune dysregulation and inflammation associated with CV disease which is exacerbated with viral infection. Vitamin D plays a major role in immune function and exerts anti-inflammatory effects, which may prove important in the context of CVD and COVID-19. To date, studies have shown minimal benefit for vitamin D supplementation in patients with COVID-19, though there are no studies specific to patients with CVD and related complications. Further, given that vitamin D has important protective effects on the CV system, including augmentation of myocardial contractility and anti-thrombotic effects, it is unknown if supplementation with vitamin D can mitigate CVD complications associated with COVID-19.

Vitamin D, infections and immunity

Vitamin D, best known for its role in skeletal health, has emerged as a key regulator of innate immune responses to microbial threat. In immune cells such as macrophages, expression of CYP27B1, the 25-hydroxyvitamin D 1α-hydroxylase, is induced by immune-specific inputs, leading to local production of hormonal 1,25-dihydroxyvitamin D (1,25D) at sites of infection, which in turn directly induces the expression of genes encoding antimicrobial peptides. Vitamin D signaling is active upstream and downstream of pattern recognition receptors, which promote front-line innate immune responses. Moreover, 1,25D stimulates autophagy, which has emerged as a mechanism critical for control of intracellular pathogens such as M. tuberculosis. Strong laboratory and epidemiological evidence links vitamin D deficiency to increased rates of conditions such as dental caries, as well as inflammatory bowel diseases arising from dysregulation of innate immune handling intestinal flora. 1,25D is also active in signaling cascades that promote antiviral innate immunity; 1,25D-induced expression of the antimicrobial peptide CAMP/LL37, originally characterized for its antibacterial properties, is a key component of antiviral responses. Poor vitamin D status is associated with greater susceptibility to viral infections, including those of the respiratory tract. Although the severity of the COVID-19 pandemic has been alleviated in some areas by the arrival of vaccines, it remains important to identify therapeutic interventions that reduce disease severity and mortality, and accelerate recovery. This review outlines of our current knowledge of the mechanisms of action of vitamin D signaling in the innate immune system. It also provides an assessment of the therapeutic potential of vitamin D supplementation in infectious diseases, including an up-to-date analysis of the putative benefits of vitamin D supplementation in the ongoing COVID-19 crisis.

Is There a Crucial Link Between Vitamin D Status and Inflammatory Response in Patients With COVID-19?

Background

Hypovitaminosis D has been suggested to play a possible role in coronavirus disease 2019 (COVID-19) infection.

Methods

The aim of this study is to analyze the relationship between vitamin D status and a biochemical panel of inflammatory markers in a cohort of patients with COVID-19. A secondary endpoint was to evaluate the correlation between 25OHD levels and the severity of the disease. Ninety-three consecutive patients with COVID-19-related pneumonia were evaluated from March to May 2020 in two hospital units in Pisa, in whom biochemical inflammatory markers, 25OHD levels, P/F ratio at nadir during hospitalization, and complete clinical data were available.

Results

Sixty-five percent of patients presented hypovitaminosis D (25OHD ≤ 20 ng/ml) and showed significantly higher IL-6 [20.8 (10.9-45.6) vs. 12.9 (8.7-21.1) pg/ml, p = 0.02], CRP [10.7 (4.2-19.2) vs. 5.9 (1.6-8.1) mg/dl, p = 0.003], TNF-α [8.9 (6.0-14.8) vs. 4.4 (1.5-10.6) pg/ml, p = 0.01], D-dimer [0.53 (0.25-0.72) vs. 0.22 (0.17-0.35) mg/l, p = 0.002], and IL-10 [3.7 (1.8-6.9) vs. 2.3 (0.5-5.8) pg/ml, p = 0.03]. A significant inverse correlation was found between 25OHD and all these markers, even adjusted for age and sex. Hypovitaminosis D was prevalent in patients with severe ARDS, compared with the other groups (75% vs. 68% vs. 55%, p < 0.001), and 25OHD levels were lower in non-survivor patients.

Conclusions

The relationship between 25OHD levels and inflammatory markers suggests that vitamin D status needs to be taken into account in the management of these patients. If vitamin D is a marker of poor prognosis or a possible risk factor with beneficial effects from supplementation, this still needs to be elucidated.

The Evaluation of the Neuroprotective Effect of a Single High-Dose Vitamin D3 in Patients with Moderate Ischemic Stroke

INTRODUCTION

Vitamin D insufficiency is highly prevalent and is a negative predictor for survival in ischemic stroke patients. We evaluated the effect of a high dose of vitamin D3 on the Neuron-Specific Enolase (NSE) level, National Institute of Health Stroke Scale (NIHSS), and Barthel Index (BI) scoring system in moderate ischemic stroke patients.

METHODS

This prospective, double-blind, randomized clinical trial (RCT) study was conducted from April 2020 to March 2021. Patients with moderate ischemic stroke (NIHSS 5 to 15) who had vitamin D deficiency (serum 25-OH vitamin D ≤30 ng/mL) were recruited and randomized into intervention and control groups. Subjects in the intervention group received a single dose, intramuscular (IM) injection of 600000 international unit (IU) vitamin D3, in addition to the standard treatment. NSE level and NIHSS were evaluated at baseline and 48 hours after the intervention. The BI was monitored three months after discharge.

RESULTS

During the study period, 570 patients were assessed; finally, forty-one patients completed the study. Except for the age which was higher in the control group (p = 0.04), there were no statistically significant differences in other baseline characteristics between the two groups. After 48 hours, the NIHSS score was significantly lower in the intervention group (median 8 vs. 6.5, p = 0.008 in the control and intervention groups, respectively), but there was no significant difference in the NSE level (p = 0.80). Three months after discharge, the BI was significantly higher in the intervention group (median 8 vs. 9, p = 0.03 in the control and intervention groups, respectively).

CONCLUSIONS

Administration of a single 600000 IU of vitamin D3 could have neuroprotective effects in patients with moderate ischemic stroke, according to its significantly positive effects on functional clinical outcomes (NIHSS and BI), but this effect on the biomarker related to neural damage (NSE) was not significant.

The Role of Vitamin D in the Relationship Between Gender and Deep Vein Thrombosis Among Stroke Patients

Introduction: Accumulating evidence had demonstrated that females had a higher risk of deep vein thrombosis (DVT) than males, but the mechanism was still unknown. Vitamin D was found to play an essential role in DVT, and gender may influence the serum vitamin D levels. This study aimed to explore whether vitamin D played a role in the gender difference in DVT.

Materials and Methods: A total of 444 patients with acute stroke were recruited, which were divided into the DVT group (n = 222) and the non-DVT group (n = 222). Serum vitamin D levels were measured after admission and were split into three categories, including deficiency (<50 nmol/L), insufficiency (52.5–72.5 nmol/L), and sufficiency (more than 75 nmol/L). Hierarchical regression analysis was adopted to analyze the relationship between gender and DVT, controlling the confounding factors.

Results: Females showed a higher proportion of DVT than males (60.7 vs. 42.5%, p < 0.001), and lower serum vitamin D levels than males (53.44 ± 16.45 vs. 69.43 ± 23.14, p < 0.001). Moreover, serum vitamin D levels were lower in the DVT group than in the non-DVT group (59.44 ± 19.61 vs. 66.24 ± 23.86, p < 0.001). Besides, the DVT group showed a lower proportion of vitamin D sufficiency than the non-DVT group (21.2 vs. 32.9%, p < 0.05). Hierarchical regression analysis showed that females had 2.083-fold (p < 0.001, unadjusted model) and 1.413-fold (p = 0.155, adjusted model) risk to develop DVT. In addition, the sufficiency status of vitamin D showed an independent protective effect on DVT (unadjusted model OR, 0.504, p = 0.004; adjusted model OR, 0.686, p = 0.011).

Conclusion: Females had a higher risk of DVT than males, and vitamin D may play an essential role in this relationship. Further studies are needed to explore whether vitamin D supplementation could reduce DVT risk in stroke patients, especially females.

Retrospective analysis of vitamin D status on ınflammatory markers and course of the disease in patients with COVID-19 infection

PURPOSE

The aim of the study was to investigate the association between serum 25-hydroxyvitamin D status within the last 6 months prior to COVID-19 infection and parameters of immune function and clinical outcomes.

METHODS

Fifty-six patients, who were admitted to the emergency clinic and diagnosed with COVID-19 infection, were included in the study. Data on clinical characteristics, inflammatory parameters and vitamin D status were recorded for each patient. All the participants had data on 25-hydroxyvitamin D status within the last 6 months prior to COVID-19 infection.

RESULTS

The patients were stratified as those with vitamin D status less than 20 ng/mL and higher than 20 ng/mL. A group with vitamin D status less than 20 ng/mL had lower lymphocyte counts and lower haemoglobin levels that was statistically significant (respectively; p = 0.021, p = 0.035). Higher C-reactive protein (CRP) levels were seen in the vitamin D-deficient group (p = 0.013). It was observed that vitamin D status of the patients who required oxygen therapy were lower than those who did not require oxygen therapy, not statistically significant (p = 0.05). Patients who did not use vitamin D supplementation within 6 months prior to COVID-19 infection had more likely to be diagnosed with pneumonia (p = 0.004).

CONCLUSION

Cases with lower vitamin D status had increased inflammatory markers and worse clinical outcomes than patients with higher vitamin D status. This study suggests that vitamin D status can be used as a prognostic factor in COVID-19 patients, and vitamin D supplementation can be recommended to improve the clinical outcomes in COVID-19 infection.

Vitamin D Endocrine System and COVID-19

Preclinical data strongly suggest that the vitamin D endocrine system (VDES) may have extraskeletal effects. Cells of the immune and cardiovascular systems and lungs can express the vitamin D receptor, and overall these cells respond in a coherent fashion when exposed to 1,25-dihydroxyvitamin D, the main metabolite of the VDES. Supplementation of vitamin D-deficient subjects may decrease the risk of upper respiratory infections. The VDES also has broad anti-inflammatory and anti-thrombotic effects, and other mechanisms argue for a potential beneficial effect of a good vitamin D status on acute respiratory distress syndrome, a major complication of this SARS-2/COVID-19 infection. Activation of the VDES may thus have beneficial effects on the severity of COVID-19. Meta-analysis of observational data show that a better vitamin D status decreased the requirement of intensive care treatment or decreased mortality. A pilot study in Cordoba indicated that admission to intensive care was drastically reduced by administration of a high dose of calcifediol early after hospital admission for COVID-19. A large observational study in Barcelona confirmed that such therapy significantly decreased the odds ratio (OR) of mortality (OR = 0.52). This was also the conclusion of a retrospective study in five hospitals of Southern Spain. A retrospective study on all Andalusian patients hospitalized because of COVID-19, based on real-world data from the health care system, concluded that prescription of calcifediol (hazard ratio [HR] = 0.67) or vitamin D (HR = 0.75), 15 days before hospital admission decreased mortality within the first month. In conclusion, a good vitamin D status may have beneficial effects on the course of COVID-19. This needs to be confirmed by large, randomized trials, but in the meantime, we recommend (rapid) correction of 25 hydroxyvitamin D (25OHD) deficiency in subjects exposed to this coronavirus. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Rays of immunity: Role of sunshine vitamin in management of COVID-19 infection and associated comorbidities

The catastrophic pandemic engendered due to the Novel coronavirus (COVID-19) outbreak which causes severe clinical afflictions on the respiratory system has severely high morbidity and mortality rates. The requirement of novel compounds is at utmost importance due to lack of targeted drug molecule to treat the afflictions and restrict the viral infection and for the usage of prophylactic treatment to avoid the spread of the infection is of utmost importance. Vitamin D is one such naturally available multifunctional molecule, which plays an eminent role in the immune system and instigation of numerous cellular pathways further promoting health benefits and enhancing the human quality of life. This article reviews the current standpoint scenario and future prevalence of vitamin D supplementation in the management of covid-19 patients. Novel findings of Vitamin D suggest that along with regulation of cell growth, neuroprotective and mood-stabilizing effects, it regulates the immune response also modulate cytokine Interleukin-6 (IL-6) by inducing progesterone-induced blocking factor (PIBF), given the IL-6 levels are considerably high in COVID-19 patients which increases the further complications. Vitamin D also have its effect on angiotensin converting enzyme (ACEII) inhibitor through which the COVID-19 virus makes cell entry. Numerous research data elucidate the play of Vitamin D, in complications of COVID-19 including the most common comorbid conditions, neurological manifestations and immunological aspects makes it an ideal molecule for adjuvant therapy. Including Vitamin D as add-on therapy in the management of COVID-19 might aid the arrest of infection and helps fight this arduous epidemic.

Association between Serum 25-Hydroxyvitamin D Level and Stroke Risk: An Analysis Based on the National Health and Nutrition Examination Survey

Background

To analyze the association between serum 25-hydroxyvitamin D level (25(OH)D) and stroke risk based on the National Health and Nutrition Examination Survey (NHANES).

Methods

Between 2007 and 2018, the baseline information of participants from NHNES was collected. Univariate analysis was used to identify the covariates. Multivariate logistic regression model was used to analyze the association between serum 25(OH)D level and the stroke risk.

Results

Of the 8,523 participants, there were 310 participants with stroke and 8,213 participants without stroke. The multivariate logistic analysis showed that serum 25(OH)D deficiency (odds ratio (OR): 1.993, 95% confidence intervals (CI): 1.141-3.481, and P = 0.012) was the significant risk factors for stroke. Subgroup analysis showed that non-Hispanic whites with serum 25(OH)D deficiency (OR: 2.501, 95% CI: 1.094-5.720, and P = 0.001) and insufficiency (OR: 1.853, 95% CI: 1.170-2.934, and P = 0.006) were associated with a higher risk of stroke than those with normal 25(OH)D levels.

Conclusions

Serum 25(OH)D deficiency may be associated with an increased risk of stroke.

Vitamin D levels and C-reactive protein/albumin ratio in pregnant women with cerebral venous sinus thrombosis

Changes in coagulation system during pregnancy have been put forth as risk factors for cerebral venous sinus thrombosis (CVT), yet we still have limited knowledge on markers for predicting the risk of CVT in pregnant women. Therefore, we aimed to investigate the significance of vitamin D (VD) levels and C-reactive protein (CRP)/albumin ratio (CAR), an inflammation marker, as risk factors for CVT in pregnant women. 23 pregnant women who were followed up for CVT, 26 healthy pregnant women who had no pregnancy complications, and 31 non-pregnant fertile women were included in the study. CAR and VD levels were compared between groups. CAR was significantly higher in the pregnant CVT group compared to the other two groups (p < 0.001). CAR was also significantly higher in the healthy pregnant group than the non-pregnant fertile group (p < 0.001). VD levels were determined to be statistically significantly lower in the pregnant CVT group compared to the other two groups (p < 0.001). However, VD levels did not significantly differ between healthy pregnant group and non-pregnant fertile group (p > 0.05). We found no significant correlation between CAR and VD levels in any of the three groups. Pregnant women with CVT were found to have a high rate of severe VD deficiency. Low VD levels and high CAR levels in pregnant women may be associated with an increased risk of CVT.

Low Circulating Vitamin D in Intensive Care Unit-Admitted COVID-19 Patients as a Predictor of Negative Outcomes

BACKGROUND

Vitamin D deficiency has been associated with an increased risk of respiratory infections.

OBJECTIVES

The study aimed to evaluate the serum 25-hydroxyvitamin D [25(OH)D] concentration in patients admitted to the intensive care unit (ICU) as a predictor of coronavirus disease 2019 (COVID-19) mortality.

METHODS

A single-center retrospective observational study was conducted. Forty adult patients (50% men) with confirmed COVID-19 who were admitted to the ICU were enrolled. The primary endpoint was mortality at day 60. Serum 25(OH)D concentration was measured on the day of admission to the ICU. We used the Mann-Whitney test, Fisher's exact test, Kaplan-Meier analysis, and receiver operator characteristic (ROC) analysis to assess serum 25(OH)D concentration as a predictor of COVID-19 mortality.

RESULTS

All 40 patients had a low median (IQR) serum 25(OH)D concentration at admission [12 (9-15) ng/mL]. The median (IQR) serum 25(OH)D concentration was greater in survivors [13.3 (10.0-17.1) ng/mL, n = 22] than in nonsurvivors [9.6 (7.9-14.2) ng/mL; n = 18], P = 0.044. The area under the ROC curve was 0.69 (95% CI: 0.52, 0.86; P = 0.044). The 60-d mortality rate of those with serum 25(OH)D concentrations ≤9.9 ng/mL (n = 14, 71%) tended to be greater than that of those with concentrations >9.9 ng/mL (n = 26, 31%) (P = 0.065), and they had a 5.6-fold higher risk of death (OR: 5.63; 95% CI: 1.35, 23.45; P = 0.018).

CONCLUSIONS

The ICU patients had a low serum 25(OH)D concentration. Serum 25(OH)D concentrations ≤9.9 ng/mL on admission can be used to predict in-hospital mortality in patients with COVID-19.This trial was registered at clinicaltrials.gov as NCT04450017.

The Effects of Vitamin D Supplementation and 25-Hydroxyvitamin D Levels on the Risk of Myocardial Infarction and Mortality

Objective

The aim of the study was to examine the effects of the vitamin D (Vit-D) treatment and nontreatment on Vit-D–deficient patients without a prior history of myocardial infarction (MI).

Materials and Methods

This was a retrospective, observational, nested case–control study of patients (N = 20 025) with low 25-hydroxyvitamin D ([25-OH]D) levels (<20 ng/mL) who received care at the Veterans Health Administration from 1999 to 2018. Patients were divided into 3 groups: Group A (untreated, levels ≤20 ng/mL), Group B (treated, levels 21-29 ng/mL), and Group C (treated, levels ≥30 ng/mL). The risk of MI and all-cause mortality were compared utilizing propensity score–weighted Cox proportional hazard models.

Results

Among the cohort of 20 025 patients, the risk of MI was significantly lower in Group C than in Group B (hazard ratio [HR] 0.65, 95% CI 0.49-0.85, P = .002) and Group A (HR 0.73, 95% CI 0.55-0.96), P = .02). There was no difference in the risk of MI between Group B and Group A (HR 1.14, 95% CI 0.91-1.42, P = 0.24). Compared with Group A, both Group B (HR 0.59, 95% CI 0.54-0.63, P < .001) and Group C (HR 0.61, 95% CI 0.56-0.67, P < .001) had significantly lower all-cause mortality. There was no difference in all-cause mortality between Group B and Group C (HR 0.99, 95% CI 0.89-1.09, P = .78).

Conclusions

In patients with Vit-D deficiency and no prior history of MI, treatment to the (25-OH)D level of >20 ng/mL and >30 ng/mL was associated with a significantly lower risk of all-cause mortality. The lower risk of MI was observed only in individuals maintaining (25-OH)D levels ≥30 ng/mL.

Relevance of vitamin D3 in COVID-19 infection

SARS-CoV-2 virus, the main culprit for COVID-19 disaster, has triggered a gust of curiosity both in the mechanism of action of this infection as well as potential risk factors for disease generation and regimentation. The prime focus of the present review, which is basically a narrative one, is in utilizing the current concepts of vitamin D₃ as an agent with myriad functions, one of them being immunocompetence and a promising weapon for both innate and adaptive immunity against COVID-19 infection. Some of the manifestations of SARS-CoV-2 virus such as Acute Respiratory Distress Syndrome (ARDS) overlap with the pathophysiological effects that are overcome due to already established role of vitamin D₃ e.g., amelioration of cytokine outburst. Additionally, the cardiovascular complications due to COVID-19 infection may also be connected to vitamin D₃ levels and the activity of its active forms. Eventually, we summarise the clinical, observational and epidemiological data of the respiratory diseases including COVID-19 disease and try to bring its association with the potential role of vitamin D₃, in particular, the activity of its active forms, circulating levels and its supplementation, against dissemination of this disease.

Low Vitamin D Level Is Associated with Acute Deep Venous Thrombosis in Patients with Traumatic Brain Injury

Vitamin D and its association with venous thromboembolism (VTE) have been studied in common rehabilitation populations, such as spinal cord injury and ischemic stroke groups. This study explores the relationship between vitamin D levels and acute deep venous thrombosis (DVT) in the traumatic brain injury (TBI) population. This is a retrospective cohort study that analyzes the relationship between vitamin D levels and the prevalence of DVT during acute inpatient rehabilitation. In this population, 62% (117/190) of patients had low vitamin D levels upon admission to acute rehabilitation. Furthermore, 21% (24/117) of patients in the low vitamin D group had acute DVT during admission to acute rehabilitation. In contrast, only 8% (6/73) of patients in the normal vitamin D group had acute DVT during admission to acute rehabilitation. Fisher’s exact tests revealed significant differences between individuals with low and normal vitamin D levels (p = 0.025). In conclusion, a vitamin D level below 30 ng/mL was associated with increased probability of the occurrence of acute DVT in individuals with moderate–severe TBI.

Health implication of vitamin D on the cardiovascular and the renal system

Vitamin D regulates the calcium and phosphorus balance in the body. The activated form of vitamin D (1 α,25-dihydroxyvitamin D) binds to vitamin D receptor which regulates genes that control cell proliferation, differentiation and apoptosis. In the cardiovascular system, the vitamin D receptor is present in cardiomyocytes and the arterial wall. A clear correlation between vitamin D level and cardiovascular diseases is established. Vitamin D deficiency affects the renin-angiotensin system leading to ventricular hypertrophy and eventually to stroke. While clinical trials highlighted the positive effects of vitamin D supplements on cardiovascular disease these still need to be confirmed. This review outlines the association between vitamin D and cardiovascular and renal disease summarising the experimental data of selective cardiovascular disorders.

Exploring the link between vitamin D and clinical outcomes in COVID-19

The immunomodulating role of vitamin D might play a role in COVID-19 disease. We studied the association between vitamin D and clinical outcomes in COVID-19 patients. This is a retrospective cohort study on COVID-19 patients with documented vitamin D levels within the last year. Vitamin D levels were grouped as ≥ 20 ng/mL or < 20 ng/mL. Main outcomes were mortality, need for mechanical ventilation, new DVT or pulmonary embolism, and ICU admission. A total of 270 patients (mean ± SD) age, 63.81 (14.69) years); 117 (43.3%) males; 216 (80%) Blacks; 139 (51.5%) in 65 and older age group were included. Vitamin D levels were less than 20 ng/mL in 95 (35.2%) patients. During admission, 72 patients (26.7%) died, 59 (21.9%) needed mechanical ventilation, and 87 (32.2%) required ICU. Vitamin D levels showed no significant association with mortality (OR = 0.69; 95% CI, 0.39-1.24; P = 0.21), need for mechanical ventilation (OR = 1.23; 95% CI, 0.68-2.24; P = 0.49), new DVT or PE(OR= 0.92; 95% CI, 0.16-5.11; P = 1.00) or ICU admission (OR = 1.38; 95% CI, 0.81-2.34; P = 0.23). We did not find any significant association of vitamin D levels with mortality, the need for mechanical ventilation, ICU admission and the development of thromboembolism in COVID-19 patients.NEW & NOTEWORTHY Low vitamin D has been associated with increased frequency and severity of respiratory tract infections in the past. Current literature linking clinical outcomes in COVID-19 with low vitamin D is debatable. This study evaluated the role of vitamin D in severe disease outcomes among COVID-19 patients and found no association of vitamin D levels with mortality, the need for mechanical ventilation, ICU admission, and thromboembolism in COVID-19.

Role of vitamin D in treating COVID-19-associated coagulopathy: problems and perspectives

Aggressive inflammatory response leading to hypercoagulability has been found to be associated with disease severity in COVID-19 patients and portends bad treatment outcome. A state of acute disseminated intravascular coagulation (DIC), along with pulmonary embolism and/or deep vein thrombosis, has been observed in critically ill ICU patients. Autopsy reports of COVID-19 patients demonstrated microthrombi in lungs and in other organs, as well as marked inflammatory changes, characteristic clinicopathological features that exacerbate disease severity. Vitamin D supplementation was recommended by many clinicians across the globe to improve clinical symptoms of COVID-19 patients, mainly because of its immunomodulatory roles on immune cells. Furthermore, vitamin D and its associated molecules are also known to directly or indirectly regulate various thrombotic pathways. We propose that vitamin D supplementation not only attenuates the risk of Acute Respiratory Disease Syndrome (ARDS) but it also may have a role in reducing coagulation abnormalities in critically ill COVID-19 patients. The overarching goal of this review is to discuss the effects of vitamin D on coagulation pathways and other intertwined processes leading to thrombosis. Many clinical trials are currently investigating the efficacy of vitamin D supplementation in reducing the risk of COVID-19 infection. However, randomized placebo control clinical trials are also necessary to ascertain the effect of vitamin D supplementation on reducing the risk of coagulopathy in COVID-19 patients.

Risk Factors of Vitamin D Deficiency in Chinese Ischemic Stroke Patients: A Cross-Sectional Study

Purpose

Lower serum vitamin D has been reported to be associated with stroke. This study aimed to analyze the risk factors of vitamin deficiency in Chinese stroke patients, and further analyze its impact in different gender and their clinical variables.

Methods

982 stroke patients were enrolled. Laboratory parameters such as serum vitamin D, apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB), ApoA-I/ApoB, cholesterol (CH), fibrinogen (FIB), blood glucose (Glu), high-density lipoprotein (HDL), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were collected and recorded. The severity of stroke was assessed by National Institute of Health Stroke Scale (NIHSS) score. Based on their serum vitamin D level, patients were divided into three groups: Vitamin D deficiency (<50 nmol/L), vitamin D insufficiency (≥50–75 nmol/L) and vitamin D sufficiency (≥75 nmol/L) and differences were compared among the three groups. Statistical analyses were done to assess the risk factors for serum vitamin D deficiency in our ischemic stroke patients.

Results

Gender, NIHSS, and FIB showed significant differences among the vitamin D groups (P < 0.001 ∼ P = 0.002). The female gender (OR = 2.422, P < 0.001), severity of stroke using NIHSS (OR = 1.055, P = 0.008) and FIB (OR = 1.256, P = 0.005) were risk factors of vitamin D deficiency in ischemic stroke patients. In subgroup analysis, NIHSS was significantly associated with vitamin D deficiency in the male group (OR = 1.087, P = 0.002) and higher FIB group (OR = 1.078, P = 0.001).

Conclusions

The female gender, severity of stroke using NIHSS and FIB were risk factors for vitamin D deficiency in our incident stroke patients. NIHSS was more sensitive to vitamin D deficiency in male ischemic stroke patients. Besides, under higher FIB circumstance, the increasing NIHSS score was more related to the vitamin D deficiency. Levels of vitamin D in patients with ischemic stroke should be well monitored during the disease cascade.

A brief discussion of the benefit and mechanism of vitamin D supplementation on coronavirus disease 2019

PURPOSE OF REVIEW

Vitamin D exerts extraskeletal functions, including immunomodulatory activity, protection against respiratory tract infections and pleiotropic effects on the cardiovascular system. Since the outbreak of the coronavirus disease-2019 (COVID-19) pandemic, several articles have suggested the potential involvement of vitamin D in reducing the risk and severity of the disease.

RECENT FINDINGS

Epidemiological and observational studies support the hypothesis of a protective role of vitamin D but most studies are retrospective or based on small samples. However, the pandemic progression and the increased knowledge on the pathogenesis of COVID-19 have challenged the first evidence, suggesting also potential negative consequences derived by adequate vitamin D status. A cautious interpretation of the significance of low vitamin D25OH levels is advisable. The balance between over-activation of innate immunity and the exhaustibility of the adaptive immune response still needs to be clarified. In addition, the modulation of endothelial function, the down-regulation of renin, angiotensin-converting-enzyme (ACE) and angiotensin genes and the up-regulation of ACE2 expression is still an area of research.

SUMMARY

Speculative hypotheses and observational data have suggested a protective role of vitamin D in COVID-19. However, many unanswered questions remain, aberrant detrimental effects of adequate vitamin D25OH levels cannot be excluded and whether its adequacy may prevent the infection or improve clinical outcomes needs to be assessed by adequately sized and designed population-based studies and intervention trials.

Association between vitamin D levels and lower-extremity deep vein thrombosis: a case-control study

BACKGROUND

Vitamin D has relationships with pathogenesis and inflammation pathways in many diseases. Its deficiency may make clinicians think not only of supplementation but also of presence of other diseases.

OBJECTIVE

To investigate the relationship between vitamin D levels and deep vein thrombosis (DVT), given that reduced levels are related to increased risk of cardiovascular diseases.

DESIGN AND SETTING

Case-control study conducted in the cardiovascular surgery and family medicine departments of a hospital in Turkey.

METHODS

A total of 280 participants were included: 140 each in the DVT and control groups. Basic clinical characteristics, comorbidities and serum 25-hydroxyvitamin D (25(OH)D) levels were recorded and then compared between the groups. Serum 25(OH)D levels were also evaluated separately in three subgroups (sufficient, insufficient and deficient).

RESULTS

Serum 25(OH)D levels were significantly lower in the DVT group than in the controls (P < 0.001). Females in the DVT group had lower 25(OH)D levels than those in the control group (P = 0.002). Nonetheless, the median 25(OH)D level (16.41 ng/ml) of the control group was still below the reference value. Logistic regression analysis showed that 25(OH)D was a significant predictor of DVT. Weight, height and body mass index, which all presented interaction, were significant in the logistic regression analysis but not in individual analyses.

CONCLUSION

The serum vitamin D levels of DVT patients were lower than those of controls. If the results obtained from our study are supported by further large-scale randomized controlled trials, vitamin D replacement may be brought into the agenda for protection against DVT.

MECHANISMS IN ENDOCRINOLOGY: Vitamin D and COVID-19

The SARS-CoV-2 virus responsible for the COVID-19 pandemic has generated an explosion of interest both in the mechanisms of infection leading to dissemination and expression of this disease, and in potential risk factors that may have a mechanistic basis for disease propagation or control. Vitamin D has emerged as a factor that may be involved in these two areas. The focus of this article is to apply our current understanding of vitamin D as a facilitator of immunocompetence both with regard to innate and adaptive immunity and to consider how this may relate to COVID-19 disease. There are also intriguing potential links to vitamin D as a factor in the cytokine storm that portends some of the most serious consequences of SARS-CoV-2 infection, such as the acute respiratory distress syndrome. Moreover, cardiac and coagulopathic features of COVID-19 disease deserve attention as they may also be related to vitamin D. Finally, we review the current clinical data associating vitamin D with SARS-CoV-2 infection, a putative clinical link that at this time must still be considered hypothetical.

Association between serum vitamin D levels and venous thromboembolism (VTE): A systematic review and meta-analysis of observational studies

OBJECTIVE

Although many studies have attempted to unravel the relationship between vitamin D deficiency and the incidence of VTE, the results remained inconsistent. To address this discrepancy, we performed a systematic review and meta-analysis to precisely disentangle the relationship between serum vitamin D levels and VTE risk.

METHODS

The Web of Science, Scopus, PubMed/Medline, Embase, and Google Scholar databases were searched for all available observational studies that reported the risk of venous thromboembolism (VTE) based on serum vitamin D levels categories. The search was performed up to March 2020.

RESULTS

Seven studies were included. The overall analysis showed a significantly increased risk of VTE in subjects with low levels of serum vitamin D compared with those with normal vitamin D levels (RR = 1.34; 95% CI: 1.07-1.69; P = 0.011). In a sensitivity analysis, we did not observe a significant effect of any individual study on the combined effect sizes. Nevertheless, significant heterogeneity was present among the studies (Cochrane Q test, p = 0.018, I² = 61%). In the stratified analysis, low vitamin D levels were positively associated with an increased risk of VTE in prospective population-based studies (RR = 1.31; 95% CI: 1.06-1.61; P = 0.010) and in subjects below 60 years old (RR = 1.28; 95% CI: 1.07-1.54; P = 0.060).

CONCLUSION

our systematic review and meta-analysis showed that a low serum vitamin D level was indeed associated with an increased risk of VTE.

Vitamin D receptor stimulation to reduce acute respiratory distress syndrome (ARDS) in patients with coronavirus SARS-CoV-2 infections: Revised Ms SBMB 2020_166

Coronavirus infection is a serious health problem awaiting an effective vaccine and/or antiviral treatment. The major complication of coronavirus disease 2019 (COVID-19), the Acute Respiratory Distress syndrome (ARDS), is due to a variety of mechanisms including cytokine storm, dysregulation of the renin-angiotensin system, neutrophil activation and increased (micro)coagulation. Based on many preclinical studies and observational data in humans, ARDS may be aggravated by vitamin D deficiency and tapered down by activation of the vitamin D receptor. Several randomized clinical trials using either oral vitamin D or oral Calcifediol (25OHD) are ongoing. Based on a pilot study, oral calcifediol may be the most promising approach. These studies are expected to provide guidelines within a few months.

Vitamin D and Stroke: Effects on Incidence, Severity, and Outcome and the Potential Benefits of Supplementation

Vitamin D serum level has been positively associated with improved cardiovascular health, especially with reduction of stroke risk. This systemic review summarizes and synthesizes findings from studies relevant to the relationship between vitamin D and stroke risk, severity, and outcome; potential mechanisms explaining such a relationship; and outcomes from vitamin D supplementation. The literature shows that vitamin D deficiency is a significant risk factor for ischemic stroke, with sun exposure, sex, age, race, diabetes, and genetics playing a role as well. Stroke severity and short- and long-term outcomes also worsen with vitamin D deficiency. The neuroprotective mechanisms by which vitamin D operates to mitigate stroke onset and outcomes have yet to be fully studied, but researchers have proposed several pathways, including promotion of certain neuroprotective growth factors, reduction of arterial pressure through vasodilation, and inhibition of reactive oxygen species. There is some evidence that vitamin D supplementation could lower stroke risk and improve recovery, though outcomes can also be negligible or negative. Although results are mixed and the limitations of vitamin D supplementation merit some caution, vitamin D overall plays a significant role in stroke health. Future research should further develop understanding of the neuroprotective mechanisms of vitamin D and study how supplementation could be administered effectively in stroke treatment.

Emerging Role of Vitamin D and its Associated Molecules in Pathways Related to Pathogenesis of Thrombosis

Vitamin D, besides having an essential role in calcium and bone metabolism, also acts as a mediator of many non-calcemic effects through modulations of several biological responses. Vitamin D exists in its two major forms, vitamin D₂, or commonly known as ergocalciferol, and vitamin D₃, or commonly known as cholecalciferol. Both of these forms bind to vitamin D-binding protein to get transported to all vital target organs, where it serves as a natural ligand to vitamin D receptors for enabling their biological actions. Clinical reports corroborating vitamin D deficiency with an increase in thrombotic episodes implicate the role of vitamin D and its associated molecule in the regulation of thrombosis-related pathways. Thrombosis is the formation and propagation of a blood clot, known as thrombus. It can occur either in the arterial or the venous system resulting in many severe complications, including myocardial infarction, stroke, ischemia, and venous thromboembolism. Vitamin D, directly or indirectly, controls the expression of several genes responsible for the regulation of cellular proliferation, differentiation, apoptosis, and angiogenesis. All of these are the processes of potential relevance to thrombotic disorders. This review, thus, discussed the effects of vitamin D on pathways involved in thrombosis, such as hemostatic process, inflammatory pathway, and endothelial cell activation, with a focus on the molecular mechanisms associated with them.