Vitamin D deficiency and chronic lung disease

Mediated relationship between Vitamin D deficiency and reduced pulmonary function by copper in Taiwanese young adults

BACKGROUND

Vitamin D deficiency is prevalent worldwide and associated with worse outcomes in various lung diseases. This study examines the association between vitamin D deficiency and pulmonary function in healthy young adults.

METHODS

This prospective cohort study (2017-2019) explored the impact of vitamin D deficiency on pulmonary function in a community-based young adult population. Pulmonary function was assessed via spirometry, with serum 25-hydroxyvitamin D [25(OH)D] and urinary copper levels quantified. Multivariate regression was used to estimate the relationship between vitamin D levels and lung function, with mediation analysis evaluating copper's role.

RESULTS

The study included 1034 participants, average age 33.45 years, 41.93 % male. The median 25(OH)D level was 19.20 ng/mL (Interquartile Range: 13.48-24.90 ng/mL). Over half (54.74 %) had 25(OH)D levels below 20 ng/mL. Higher 25(OH)D levels were associated with better forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Trends suggested subgroup differences, but these were not statistically significant, indicating a consistent effect of 25(OH)D on pulmonary function across groups. SEM analysis suggested urinary copper as a mediator between 25(OH)D levels and FVC.

CONCLUSION

Vitamin D deficiency is significantly associated with reduced pulmonary function in young adults in Taiwan.

Healthcare Costs and Healthcare Utilization Outcomes of Vitamin D3 Supplementation at 5000 IU Daily during a 10.9 Month Observation Period within a Pragmatic Randomized Clinical Trial

Vitamin D insufficiency has been linked to multiple conditions including bone disease, respiratory disease, cardiovascular disease, diabetes, and cancer. Observational studies indicate lower healthcare costs and healthcare utilization with sufficient vitamin D levels. The secondary aims of our previously published pragmatic clinical trial of vitamin D3 supplementation were comparisons of healthcare costs and healthcare utilization. Comparisons were made between the vitamin D3 at 5000 IU supplementation group and a non-supplemented control group. Costs of care between the groups differed but were not statistically significant. Vitamin D3 supplementation reduced healthcare utilization in four major categories: hospitalizations for any reason (rate difference: -0.19 per 1000 person-days, 95%-CI: -0.21 to -0.17 per 1000 person-days, p < 0.0001); ICU admissions for any reason (rate difference: -0.06 per 1000 person-days, 95%-CI: -0.08 to -0.04 per 1000 person-days, p < 0.0001); emergency room visits for any reason (rate difference: -0.26 per 1000 person-days, 95%-CI: -0.46 to -0.05 per 1000 person-days, p = 0.0131; and hospitalizations due to COVID-19 (rate difference: -8.47 × 10-3 per 1000 person-days, 95%-CI: -0.02 to -1.05 × 10-3 per 1000 person-days, p = 0.0253). Appropriately powered studies of longer duration are recommended for replication of these utilization findings and analysis of cost differences.

An inverse causal association between genetically predicted vitamin D and chronic obstructive pulmonary disease risk

Aim

Observational studies have reported that levels of vitamin D were associated with the incidence of chronic obstructive pulmonary disease (COPD), but the relationship between them may have been confounded in previous studies. In this study, we aimed to determine the relationship between the levels of 25-hydroxyvitamin D (25OHD) and the risk of COPD by two-sample Mendelian randomization (MR) analysis.

Methods

Summary statistics for 25OHD and COPD in this study were obtained from the EBI (n = 496,946) consortium and Finn (n = 187,754) consortium. MR was adopted to explore the effect of the genetically predicted levels of 25OHD on the risk of COPD. Based on three assumptions of MR analysis, inverse variance weighting was used as the main analysis. To make our results more robust and reliable, MR Egger’s intercept test, Cochran’s Q test, funnel plot, and “leave-one-out” sensitivity analysis were used to assess the potential pleiotropy and heterogeneity in this study. Then, colocalization analysis and MR Steiger approaches were used to estimate the possible directions of estimates between them. Finally, we analyzed the causal associations between the four core genes (DHCR7, GC, CYP2R1, and CYP24A1) of vitamin D and the levels of 25OHD or the risk of COPD.

Results

Our results showed that each 1 standard deviation (SD) increase in the genetically predicted 25OHD level was associated with a 57.2% lower relative risk of COPD [odds ratio (OR): 0.428, 95% Cl: 0.279–0.657, p = 1.041 × 10−4], and the above association was also verified by maximum likelihood (OR: 0.427, 95% Cl: 0.277–0.657, p = 1.084 × 10−4), MR–Egger (OR: 0.271, 95% CI: 0.176–0.416, p = 2.466 × 10−4), MR-PRESSO (OR: 0.428, 95% Cl: 0.281–0.652, p = 1.421 × 10−4) and MR-RAPS (OR: 0.457, 95% Cl: 0.293–0.712, p = 5.450 × 10−4). Furthermore, colocalization analyses (rs3829251, PP.H4 = 0.99) and MR Steiger (“TRUE”) also showed a reverse association between them. Besides, the core genes of vitamin D also showed similar results except for CYP24A1.

Conclusion

Our findings provide evidence for a reverse association between genetically predicted 25OHD levels and COPD risk. Taking measures to supplement 25OHD may help reduce the incidence of COPD.

Recent advances in vitamin D implications in chronic respiratory diseases

Chronic airway inflammatory and infectious respiratory diseases are the most common medical respiratory conditions, associated with significant morbidity and mortality. Vitamin D (1,25(OH)₂D₃) deficiency has been shown to be highly prevalent in patients with chronic airway inflammatory and infectious diseases, correlated with increased disease severity. It has been established that vitamin D modulates ongoing abnormal immune responses in chronic respiratory diseases and is shown to restrict bacterial and viral colonization into the lungs. On the contrary, other studies revealed controversy findings regarding vitamin D efficacy in respiratory diseases. This review aims to update the current evidence regarding the role of vitamin D in airway inflammation and in various respiratory diseases. A comprehensive search of the last five years of literature was conducted using MEDLINE and non-MEDLINE PubMed databases, Ovid MEDLINE, SCOPUS-Elsevier, and data from in vitro and in vivo experiments, including clinical studies. This review highlights the importance of understanding the full range of implications that vitamin D may have on lung inflammation, infection, and disease severity in the context of chronic respiratory diseases.

Reduced blood circulating calcium level is an outstanding biomarker for preeclampsia among 48 types of human diseases

BACKGROUND

Calcium ion (Ca2+) is essential for human physiology by regulating various signal transduction pathways inside all cells and in the blood circulation.

AIM

We compared circulating Ca2+ levels in the healthy control against 48 different types of human diseases.

DESIGN

A total of 144 201 independent test results of Ca2+ levels from 48 clinically defined diseases and 141 679 independent test results of Ca2+ from healthy individuals who came to the hospital for annual physical examination were retrieved during the past 5 years.

METHODS

Ca2+ was determined by the standard 'Arsenazo III method' in the clinical laboratory of Affiliated Hospital of Qingdao University. We analyzed all data using RStudio V.1.3.1073 and python libraries 3.8.

RESULTS

All 48 types of diseases had decreased Ca2+ levels than the healthy control based on either mean or median values. Patients suffering from preeclampsia had the lowest Ca2+ levels among all 48 diseases. The perfect area under the curve, sensitivity, and specificity values of 1.0, 0.96 and 0.96 indicated that Ca2+ was an excellent biomarker for diagnosing preeclampsia. Extremely low Ca2+ was present in patients suffering kidney-related diseases. Since the correlation between each disease on the statistical features is proportional to their vector distance, the two-component analysis revealed that preeclampsia, sepsis and chronic obstructive pulmonary disease were closely related among 48 diseases.

CONCLUSIONS

All human diseases were associated with reduced circulating Ca2+ levels, where the decreased Ca2+ was a perfect biomarker for preeclampsia. Kidney-related conditions were related to over-down-regulation of Ca2+ levels. The resemblance of preeclampsia to sepsis and chronic obstructive pulmonary disease based on two-component analysis suggested that the three unrelated diseases might share a similar mechanism of the circulating Ca2+ regulation.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

Effects of early vitamin D supplementation on the prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a respiratory dysfunction caused by poor lung bronchial development, which may lead to long-term lung disease, threatening the lives of children. Studies have shown that premature infants with low vitamin D are highly associated with BPD. In this study, we aim to obtain insights into whether early vitamin D supplementation could prevent BPD in preterm infants.

METHODS

A total of 112 preterm infants were randomly divided into two groups: the control and vitamin D supplementation (VD) group. The VD group received vitamin D (800 IU/day) within 48 h at birth for consecutively 28 days. The serum levels of 25(OH)D₃ and C-reactive protein (CRP), IL6, and TNF-α were measured using ELISA assay. The arterial partial pressure of oxygen (PaO₂ ) and carbon dioxide (PaCO₂ ) was measured using an i-STAT analyzer.

RESULTS

The occurrence of BPD was decreased in the VD group compared with the control. The decreased serum 25(OH)D₃ was significantly elevated by supplementation with vitamin D. In addition, the serum inflammation factors (CRP, IL6, and TNF-α) were significantly reduced by vitamin D supplementation.

CONCLUSION

We demonstrated that early vitamin D supplementation could significantly reduce BPD incidence in preterm infants. We showed that early vitamin D supplementation could significantly increase serum level of 25(OH)D₃ and reduce inflammatory response thereby preventing and reducing neonatal BPD.

LIMITATION

Firstly, a larger sample size will be needed to be included to gain a comprehensive understanding of the protective effects of vitamin D and BPD mechanistically in preterm infants. Secondly, the pathophysiological process of BPD will need to be studied. In addition, the pathways that vitamin D is responsible for, need to be further researched.

Local nebulization of 1α,25(OH)2D3 attenuates LPS-induced acute lung inflammation

Background

Evidence supports a critical role of vitamin D status on exacerbation in chronic obstructive pulmonary disease, indicating the need to avoid vitamin D deficiency in these patients. However, oral vitamin D supplementation is limited by the potential risk for hypercalcemia. In this study, we investigated if local delivery of vitamin D to the lungs improves vitamin D-mediated anti-inflammatory action in response to acute inflammation without inducing hypercalcemia.

Methods

We studied vitamin D sufficient (VDS) or deficient (VDD) mice in whom 1α,25(OH)₂D₃ (0.2 μg/kg) or a vehicle followed by lipopolysaccharide (LPS 25 µg) were delivered to the lung as a micro-spray.

Results

Local 1α,25(OH)₂D₃ reduced LPS-induced inflammatory cells in bronchoalveolar lavage (BAL) in VDS (absolute number of cells: − 57% and neutrophils − 51% p < 0.01) and tended to diminish LPS-increased CXCL5 BAL levels in VDS (− 40%, p = 0.05) while it had no effect on CXCL1 and CXCL2 in BAL and mRNA in lung of VDS and VDD. It also significantly attenuated the increased IL-13 in BAL and lung, especially in VDD mice (− 41 and − 75%, respectively). mRNA expression of Claudin-18 in lung was significantly lower in VDS mice with local 1α,25(OH)₂D₃ while Claudin-3, -5 and -8 mRNA levels remained unchanged. Finally, in VDD mice only, LPS reduced lung mRNA expression of adhesion junction Zona-occludens-1, in addition to increasing uric acid and total protein in BAL, which both were prevented by local 1α,25(OH)₂D₃.

Conclusion

Under normal levels of vitamin D, local 1α,25(OH)₂D₃ nebulization into the lung efficiently reduced LPS induction of inflammatory cells in BAL and slightly attenuated LPS-increase in CXCL5. In case of severe vitamin D deficiency, although local 1α,25(OH)₂D₃ nebulization failed to significantly minimize cellular inflammation in BAL at this dose, it prevented epithelial barrier leakage and damage in lung. Additional research is needed to determine the potential long-term beneficial effects of local 1α,25(OH)2D3 nebulization on lung inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01997-9.

Vitamin D Receptor Influences Intestinal Barriers in Health and Disease

Vitamin D receptor (VDR) executes most of the biological functions of vitamin D. Beyond this, VDR is a transcriptional factor regulating the expression levels of many target genes, such as genes for tight junction proteins claudin-2, -5, -12, and -15. In this review, we discuss the progress of research on VDR that influences intestinal barriers in health and disease. We searched PubMed and Google Scholar using key words vitamin D, VDR, tight junctions, cancer, inflammation, and infection. We summarize the literature and progress reports on VDR regulation of tight junction distribution, cellular functions, and mechanisms (directly or indirectly). We review the impacts of VDR on barriers in various diseases, e.g., colon cancer, infection, inflammatory bowel disease, and chronic inflammatory lung diseases. We also discuss the limits of current studies and future directions. Deeper understanding of the mechanisms by which the VDR signaling regulates intestinal barrier functions allow us to develop efficient and effective therapeutic strategies based on levels of tight junction proteins and vitamin D/VDR statuses for human diseases.

Effects of repeated infections with non-typeable Haemophilus influenzae on lung in vitamin D deficient and smoking mice

Background

In chronic obstructive pulmonary disease (COPD), exacerbations cause acute inflammatory flare-ups and increase the risk for hospitalization and mortality. Exacerbations are common in all disease stages and are often caused by bacterial infections e.g., non-typeable Heamophilus influenzae (NTHi). Accumulating evidence also associates vitamin D deficiency with the severity of COPD and exacerbation frequency. However, it is still unclear whether vitamin D deficiency when combined with cigarette smoking would worsen and prolong exacerbations caused by repeated infections with the same bacterial strain.

Methods

Vitamin D sufficient (VDS) and deficient (VDD) mice were exposed to nose-only cigarette smoke (CS) for 14 weeks and oropharyngeally instilled with NTHi at week 6, 10 and 14. Three days after the last instillation, mice were assessed for lung function, tissue remodeling, inflammation and immunity. The impact of VDD and CS on inflammatory cells and immunoglobulin (Ig) production was also assessed in non-infected animals while serum Ig production against NTHi and dsDNA was measured in COPD patients before and 1 year after supplementation with Vitamin D3.

Results

VDD enhanced NTHi eradication, independently of CS and complete eradication was reflected by decreased anti-NTHi Ig’s within the lung. In addition, VDD led to an increase in total lung capacity (TLC), lung compliance (Cchord), MMP12/TIMP1 ratio with a rise in serum Ig titers and anti-dsDNA Ig’s. Interestingly, in non-infected animals, VDD exacerbated the CS-induced anti-NTHi Ig’s, anti-dsDNA Ig’s and inflammatory cells within the lung. In COPD patients, serum Ig production was not affected by vitamin D status but anti-NTHi IgG increased after vitamin D3 supplementation in patients who were Vitamin D insufficient before treatment.

Conclusion

During repeated infections, VDD facilitated NTHi eradication and resolution of local lung inflammation through production of anti-NTHi Ig, independently of CS whilst it also promoted autoantibodies. In COPD patients, vitamin D supplementation could be protective against NTHi infections in vitamin D insufficient patients. Future research is needed to decipher the determinants of dual effects of VDD on adaptive immunity.

Trail registration

ClinicalTrials, NCT00666367. Registered 23 April 2008, https://www.clinicaltrials.gov/ct2/show/study/NCT00666367.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01962-6.

Comparing Serum Levels of Vitamin D and Zinc in Novel Coronavirus-Infected Patients and Healthy Individuals in Northeastern Iran, 2020

BACKGROUND

COVID-19 infection has recently become a pandemic disease around the world, and its risk factors have not fully evaluated. This study aimed to compare the serum vitamin D (Vit D) and zinc levels in patients infected with novel coronavirus and healthy volunteers (HVs).

METHODS

This was a single-center, cross-sectional study conducted on 56 patients (32 severe cases and 24 nonsevere) admitted to the COVID-19 ward and 46 HVs living in Esfarayen City, North Khorasan Province of Iran. Serum levels of Vit D and zinc in admitted patients to the COVID-19 ward and HVs were measured.

RESULTS

The average levels of serum Vit D in severe cases, nonsevere cases, and HVs were 31.03 ± 15.49, 37.25 ± 18.49, and 39.33 ± 14.83, respectively (P = 0.05). Moreover, the average concentrations of serum zinc in severe cases, nonsevere cases, and HVs were 31.03 ± 15.49, 37.25 ± 18.49, and 39.33 ± 14.83, respectively (P = 0.01). Mortality rate, reinfection (for 5 months), and length of hospital stay in severe cases were higher than in nonsevere cases (P > 0.05).

CONCLUSIONS

Results showed that severe cases had lower levels of Vit D than did other groups and were marginally significant. Also, severe cases had a significantly low level of zinc when compared with nonsevere cases and HVs. Levels of Vit D and zinc can affect the incidence of COVID-19 infection.

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.

Association of lower vitamin D levels with inflammation and leucocytes parameters in patients with and without diabetes mellitus undergoing coronary angiography

BACKGROUND

Diabetes mellitus has been associated with a chronic low-grade inflammation and a higher risk of cardiovascular and infectious disease, that could be prevented by the effects of vitamin D. We aimed at evaluating the impact of vitamin D levels on the biomarkers of acute-phase response, inflammation and glucose metabolism in a large cohort of diabetic patients with cardiovascular disease.

MATERIALS AND METHODS

Consecutive patients undergoing coronary angiography were included. Diabetes mellitus was defined as previous diagnosis, specific treatment administration (oral drug or insulin), fasting glycaemia >6.99 mmol/L or HbA1c >48 mmol/L. Glucose parameters, white blood cells, Neutrophil-to-Lymphocyte Ratio (NLR), Monocyte-to-Lymphocyte Ratio (MLR), C-reactive protein (CRP) and vitamin D were measured at admission. Vitamin D levels were measured by chemiluminescence immunoassay kit LIAISON® Vitamin D assay (Diasorin Inc).

RESULTS

We included 1472 diabetic patients and 2499 non-diabetic patients that were divided according to vitamin D tertiles. Among diabetic patients, lower levels of vitamin D were associated with female gender (P = .02), obesity (P = .004), active smoking and acute presentation (P < .001) and with a more atherogenic metabolic profile. The levels of white blood cells, leucocytes subfamilies, and inflammatory parameters significantly correlated with vitamin D levels in both patients with and without diabetes (diabetic: P = .012 for WBC, P = .004 for NLR and P < .001 for MLR and C-reactive protein, non-diabetic: P < .001 for WBC; NLR, MLR and C-reactive protein, respectively). Among diabetic patients, results were confirmed at multivariate analysis with no significant interaction according to glycaemic control.

CONCLUSION

The present study demonstrates that, among patients with cardiovascular disease, vitamin D deficiency is associated with metabolic dysregulation and with an elevation of cellular and humoural inflammatory parameters, especially among diabetics, although not being dependent from glycaemic control.

Metabolic Healthy Obesity, Vitamin D Status, and Risk of COVID-19

Aging and obesity-related conditions seem to worsen the effect of Coronavirus Disease 2019 (COVID-19). This study assessed the possible roles of metabolic/obesity phenotypes and vitamin D status in increasing the greater severity of COVID-19. We studied 353,299 UK Biobank participants from England with a mean age of 67.7 years. Metabolic/obesity phenotypes were defined as a combination of metabolic components (hypertension, high cholesterol, and diabetes) and obesity. Multivariate logistic regression analysis was performed to test whether the addition of metabolic disorders and vitamin D insufficiency increased obesity associations with COVID-19 hospitalization, confirmed COVID-19, and severe COVID-19. Metabolically unhealthy obesity (MUHO) represented 12.3% of the total analytic samples, and 21.5%, 18.5%, and 19.8% of the included subpopulations with COVID-19 hospitalization, confirmed COVID-19, and severe COVID-19, respectively. Vitamin D insufficiency phenotypes represented 53.5% of the total analytic samples, and 59.5%, 61.7%, and 61.5% of the included subpopulations with COVID-19 hospitalization, confirmed COVID-19, and severe COVID-19, respectively. In multivariate logistic regression, MUHO and vitamin D insufficiency and their combination were significantly associated with COVID-19 illness severity (odds ratio [OR] for COVID-19 hospitalization = 2.33, 95% confidence interval [CI], 2.02-2.70; OR for confirmed COVID-19 = 2.06, 95% CI, 1.58-2.70; OR for severe COVID-19 = 2.06, 95% CI, 1.47-2.87). Elderly men were prone to have a higher risk of COVID-19 than women. Our findings showed that MUHO and vitamin D insufficiency are associated with a significantly increased risk of COVID-19 severity, especially for adults 65 years and older. Susceptible individuals should be aware of their conditions and avoid contact with new coronavirus.

The potential link between inherited G6PD deficiency, oxidative stress, and vitamin D deficiency and the racial inequities in mortality associated with COVID-19

There is a marked variation in mortality risk associated with COVID-19 infection in the general population. Low socioeconomic status and other social determinants have been discussed as possible causes for the higher burden in African American communities compared with white communities. Beyond the social determinants, the biochemical mechanism that predisposes individual subjects or communities to the development of excess and serious complications associated with COVID-19 infection is not clear. Virus infection triggers massive ROS production and oxidative damage. Glutathione (GSH) is essential and protects the body from the harmful effects of oxidative damage from excess reactive oxygen radicals. GSH is also required to maintain the VD-metabolism genes and circulating levels of 25-hydroxyvitamin D (25(OH)VD). Glucose-6-phosphate dehydrogenase (G6PD) is necessary to prevent the exhaustion and depletion of cellular GSH. X-linked genetic G6PD deficiency is common in the AA population and predominantly in males. Acquired deficiency of G6PD has been widely reported in subjects with conditions of obesity and diabetes. This suggests that individuals with G6PD deficiency are vulnerable to excess oxidative stress and at a higher risk for inadequacy or deficiency of 25(OH)VD, leaving the body unable to protect its 'oxidative immune-metabolic' physiological functions from the insults of COVID-19. An association between subclinical interstitial lung disease with 25(OH)VD deficiencies and GSH deficiencies has been previously reported. We hypothesize that the overproduction of ROS and excess oxidative damage is responsible for the impaired immunity, secretion of the cytokine storm, and onset of pulmonary dysfunction in response to the COVID-19 infection. The co-optimization of impaired glutathione redox status and excess 25(OH)VD deficiencies has the potential to reduce oxidative stress, boost immunity, and reduce the adverse clinical effects of COVID-19 infection in the AA population.

The possible double-edged sword effects of vitamin D on COVID-19: A hypothesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gains access to host cells by attaching to angiotensin-converting enzyme 2 (ACE2). Vitamin D (VitD) can upregulate ACE2 and has an antagonistic effect on Renin, which exerts a vasodilatation and anti-inflammatory effect against coronavirus disease (COVID-19). However, it may also facilitate viral entry by increasing ACE2 as the main SARS-CoV-2 receptor and mediates ROS production through NADPH oxidase, as a double-edged sword effect. Lung function and the immune system are also influenced by VitD through several mechanisms, including increased natural antibiotics (Defensin and Cathelicidin) and upregulated transforming growth factor-β. A higher IgA, Th2/Th1 ratio, and T-regulatory cells are attributable to VitD effects on the immune cells, while these changes may also be a double-edged sword in COVID-19. Although VitD supplementation might be highly recommended in COVID-19, the administration's dosage and route could be challenging. Furthermore, this issue has not been mentioned in various studies so far. So, the report aimed to explain the current challenges with the application of VitD in COVID-19.

The Association of Dietary Macronutrients with Lung Function in Healthy Adults Using the Ansan-Ansung Cohort Study

This study is aimed to examine the association between macronutrient intake and lung function in healthy adults (n = 5880) using the Ansan-Ansung cohort study. To identify the index of lung function, we used the percentage difference of predicted Forced Expiratory Volume (%FEV_{1_diff}) between baseline and follow-up. Based on the median %FEV_{1_diff}, subjects were classified by two groups as “decreased vs. unchanged/improved”. The dietary macronutrients were estimated and validated using the food-frequency questionnaire. Multiple logistic regression models were used to evaluate the association after adjusting for confounders. Advanced analysis examined the association after stratifying by age and obesity. The average of %FEV₁ is 114.1 and 112.5 at baseline and follow-up, respectively. The positive association of protein and fiber intake with lung function was observed in men. Low fat and high carbohydrate intake decreased the lung function in women only. After stratification by age, the association of protein, fat, and carbohydrate intake with lung function was observed in young men and old women only. Otherwise, the association of protein and fiber with lung function was influenced by abdominal obesity. In conclusion, the lung function was positively associated with high protein and fat intake, but was negatively associated with high carbohydrate intake, which could be influenced by age and obesity.

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

Evidence suggests that vitamin D supplementation could potentially be effective either in treatment or prevention of coronavirus disease 2019 (Covid-19). Indeed, several studies and trials have begun to investigate the impact of vitamin D supplementation on patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this review, we focus on the potential mechanisms of vitamin D in the pathogenesis of Covid-19. We consider whether deficiency of vitamin D may be one of the underlying biological factors that could explain the excess mortality seen among non-Caucasians. We also raise several important questions which need to be addressed to provide a clear picture of the extent to which vitamin D supplementation may benefit patients with Covid-19, particularly those with underlying risk factors.

Reduced 25(OH) Vitamin D Association with Lower Alpha-1-Antitrypsin Blood Levels in Type 2 Diabetic Patients

Introduction: Reduced circulating levels of 25(OH)VD are associated with an increased incidence of chronic lung diseases. Alpha-1-antitrypsin (AAT) is needed to maintain healthy lung function.Objective: This study examined the hypothesis that circulating levels of AAT are lower in adult type 2 diabetic patients and that a positive association exists between circulating AAT levels and 25(OH)VD levels in these patients.Methods: Fasting blood was obtained after written informed consent from type 2 diabetic patients (n = 80) and normal siblings or volunteers (n = 22) attending clinics at LSUHSC according to the protocol approved by the Institutional Review Board for Human studies. Plasma AAT and 25(OH)VD levels were determined using ELISA kits. HbA_1c levels and chemistry profiles were analyzed at the clinical laboratory of LSUHSC hospital.Results: ATT and 25(OH)VD levels were significantly lower in type 2 diabetic patients compared with those of age-matched healthy controls. There was a significant positive correlation between 25(OH)VD and ATT deficiency. AAT levels showed significant positive correlation with HDL cholesterol levels in type 2 diabetic patients. There was no correlation between AAT levels and those of HbA_1c or with the duration of diabetes of T2D patients.Conclusions: These results suggest that 25(OH)VD deficiency may predispose type 2 diabetic patients to AAT deficiency. Whether reduced levels of circulating AAT indeed contribute to the increased risk for lung dysfunction in subjects with type 2 diabetes needs further investigation.

Respiratory infections: Role of Vitamin D and surfactant proteins A and D

Respiratory tract infection is the common viral infection and the principal cause of death among children under 5 years of age. It damages lung epithelium and increases mucus production and inflammation, leading to dyspnea. The sunshine vitamin (Vitamin D) and surfactant protein (SP) A and D along with their usual function play an important role in host defense. This article reviews with immune role of Vitamin D and SP A and D which aids excessive cytokines production, boosts phagocytosis, hinders inflammatory activity, and thus acts as a first-line defense against lung pathogens.

Clinical Phenotypes, Comorbidities, and Exacerbations according to Serum 25-OH Vitamin D and Plasma Fibrinogen Levels in Chronic Obstructive Pulmonary Disease

BACKGROUND

Although vitamin D deficiency is prevalent in patients with chronic obstructive pulmonary disease (COPD), the influence of vitamin D deficiency on COPD has not been fully established. Moreover, the inflammation process is associated with vitamin D deficiency in the general population. Therefore, this study aimed to determine whether clinical phenotypes, comorbidities, and exacerbation rates are affected by the level of plasma fibrinogen, well studied by an inflammatory marker in COPD patients, and 25-hydroxy (25-OH) vitamin D.

METHODS

This retrospective study analyzed patients with COPD whose inflammatory marker levels, especially plasma fibrinogen and 25-OH vitamin D levels, had been examined. A correlation analysis was conducted for inflammatory markers and 25-OH vitamin D. Clinical characteristics, comorbidities and exacerbation rates were compared among four groups based on plasma fibrinogen concentrations (threshold, 350 mg/dL) and 25-OH vitamin D levels (threshold, 20 ng/mL).

RESULTS

Among 611 patients with COPD, 236 were included in the study. The levels of inflammatory markers had no statistical correlation with the serum 25-OH vitamin D levels. The four groups showed no statistically significant differences in age, sex, smoking history, inhaler use, and severity of comorbidities. Patients with high plasma fibrinogen concentrations and low 25-OH vitamin D levels had lower lung function, higher severity index, and higher annual rate of severe exacerbations 12 months before (0.23/year) and after (0.41/year) the measurement of 25-OH vitamin D levels than did the other patients.

CONCLUSION

Our findings suggested an interaction between vitamin D deficiency and COPD. The measurement of plasma fibrinogen concentrations could help identify a severe phenotypic group among patients with vitamin D deficiency.

Correlation between hypocalcemia and acute exacerbation of chronic obstructive pulmonary disease in the elderly

Introduction: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important disease of hospitalized elderly patients, who often have electrolyte imbalances. This study was performed to analyze total serum calcium levels in elderly patients with AECOPD and identify the correlation between hypocalcemia and AECOPD. Methods: 153 elderly patients with AECOPD served as the observation group, and 115 healthy elderly people undergoing physical examinations served as the control group. Differences in the corrected serum calcium, albumin (ALB), and neutrophil/lymphocyte ratio (NLR) were analyzed between the observation and control groups before and after treatment. The incidence of hypocalcemia was compared among patients at different ages and with different pulmonary function classifications before treatment. The relationship between hypocalcemia and respiratory infection was analyzed. Differences in the pretreatment NLR, ALB, logarithm of the serum C-reactive protein level (LogCRP), and hospital stay were compared between patients with and without hypocalcemia. Results: The corrected serum calcium level (P < 0.001), NLR (P = 0.001) and albumin level (P < 0.001) were significantly different among the pretreatment group, post-treatment group, and control group. The serum calcium level, LogCRP, and NLR were significantly lower after than before treatment (P < 0.05). Significant differences in the incidence of hypocalcemia were found among patients of different ages (P = 0.002). The respiratory infection rate (P < 0.001), hospital stay (P < 0.001), NLR (P = 0.007), and LogCRP (P < 0.001) was higher in patients with than without hypocalcemia. However, the albumin level was lower in patients with than without hypocalcemia (P < 0.001). Conclusions: In elderly patients with AECOPD, hypocalcemia may be related to the disease progression, respiratory infection rate, and hospital stay of patients with AECOPD.

Airway infection with Nontypeable Haemophilus influenzae is more rapidly eradicated in vitamin D deficient mice

Chronic obstructive pulmonary disease (COPD), which is characterized by an excessive inflammatory response of the airways, is often complicated by exacerbations. Vitamin D deficiency has been associated with an increased risk for COPD and may predispose COPD patients to a higher exacerbation rate, particularly during smoking. In the current study, we investigated the effect of vitamin D deficiency and cigarette smoke (CS)-exposure on lung inflammation and bacterial clearance after an acute infection with Nontypeable Haemophilus influenzae (NTHi). Vitamin D deficient or sufficient mice were exposed to nose-only CS or ambient air for 6 weeks and oropharyngeally instilled with 10⁶ NTHi. Residual viable NTHi were measured at different time points post-infection. Mechanisms of bacterial clearance (e.g. phagocytosis, pattern recognition receptors, antimicrobial peptides, surfactant proteins and mucin) and lung remodeling (e.g. metalloproteinases, MMP's) were assessed. Although smoking resulted in reduced phagocytosis capacity of macrophages and neutrophils, bacterial clearance was similar to control mice. By contrast and independent of smoking, bacterial clearance was significantly accelerated in vitamin D deficient mice already from 24 h post-infection (p = 0.0087). This faster and complete eradication was associated with a more rapid resolution of cytokines and neutrophils 72 h post-infection and dominated by an upregulation of cathelicidin-related antimicrobial peptide (CRAMP) mRNA during infection (p = 0.026). However, vitamin D deficiency also resulted in more MMP12 protein in broncho-alveolar lavage and a shift in mRNA expression of MMP12/TIMP1 (p = 0.038) and MMP9/TIMP1 (p = 0.024) ratio towards more protease activity. Overall, vitamin D deficient mice resolved NTHi infection faster with a faster resolution of local lung inflammation, possibly through upregulation of CRAMP. This was associated with a disruption of the protease/anti-protease balance, which may potentially scale towards a higher extracellular matrix breakdown.

Serum 25-Hydroxyvitamin D Concentrations Are Associated with Computed Tomography Markers of Subclinical Interstitial Lung Disease among Community-Dwelling Adults in the Multi-Ethnic Study of Atherosclerosis (MESA)

Background

Activated vitamin D has anti-inflammatory properties. 25-Hydroxyvitamin D [25(OH)D] deficiency might contribute to subclinical interstitial lung disease (ILD).

Objective

We examined associations between serum 25(OH)D concentrations and subclinical ILD among middle-aged to older adults who were free of cardiovascular disease at baseline.

Methods

We studied 6302 Multi-Ethnic Study of Atherosclerosis (MESA) participants who had baseline serum 25(OH)D concentrations and computed tomography (CT) imaging spanning ≤ 10 y. Baseline cardiac CT scans (2000-2002) included partial lung fields. Some participants had follow-up cardiac CT scans at exams 2-5 and a full-lung CT scan at exam 5 (2010-2012), with a mean ± SD of 2.1 ± 1.0 scans. Subclinical ILD was defined quantitatively as high-attenuation areas (HAAs) between -600 and -250 Hounsfield units. We assessed associations of 25(OH)D with adjusted HAA volumes and HAA progression. We also examined associations between baseline 25(OH)D and the presence of interstitial lung abnormalities (ILAs) assessed qualitatively (yes or no) from full-lung CT scans at exam 5. Models were adjusted for sociodemographic characteristics, lifestyle factors (including smoking), and lung volumes.

Results

The cohort's mean ± SD characteristics were 62.2 ± 10 y for age, 25.8 ± 10.9 ng/mL for 25(OH)D concentrations, and 28.3 ± 5.4 for body mass index (kg/m2); 53% were women, with 39% white, 27% black, 22% Hispanic, and 12% Chinese race/ethnicities. Thirty-three percent had replete (≥30 ng/mL), 35% intermediate (20 to <30 ng/mL), and 32% deficient (<20 ng/mL) 25(OH)D concentrations. Compared with those with replete concentrations, participants with 25(OH)D deficiency had greater adjusted HAA volume at baseline (2.7 cm3; 95% CI: 0.9, 4.5 cm3) and increased progression over a median of 4.3 y of follow-up (2.7 cm3; 95% CI: 0.9, 4.4 cm3) (P < 0.05). 25(OH)D deficiency was also associated with increased prevalence of ILAs 10 y later (OR: 1.5; 95% CI: 1.1, 2.2).

Conclusions

Vitamin D deficiency is independently associated with subclinical ILD and its progression, based on both increased HAAs and ILAs, in a community-based population. Further studies are needed to examine whether vitamin D repletion can prevent ILD or slow its progression. The MESA cohort design is registered at www.clinicaltrials.gov as NCT00005487.

Associations of Serum 25(OH)D Concentrations with Lung Function, Airway Inflammation and Common Cold in the General Population

Vitamin D is hypothesized to have a beneficial effect on lung function and respiratory infections. The aim of this study was to assess the relationship of serum 25-hydroxyvitamin D (25(OH)D) concentrations with lung function, airway inflammation and common colds. We performed a cross-sectional analysis in the Netherlands Epidemiology of Obesity (NEO) study, a population-based cohort study. We included participants with measurements of serum 25(OH)D, Forced Expiratory Volume in 1 s (FEV₁), Forced Vital Capacity (FVC), Fractional Exhaled Nitric Oxide (Fe_NO), and data on self-reported common colds (n = 6138). In crude associations, serum 25(OH)D was positively associated with FEV₁ and FVC, and negatively with Fe_NO and the occurrence of a common cold. After adjustment for confounders, however, these associations disappeared. Stratified analyses showed that Body Mass Index (BMI) was an effect modifier in the relationship between serum 25(OH)D and FEV₁, FVC and Fe_NO. In obese participants (BMI ≥ 30 kg/m²), 10 nmol/L higher 25(OH)D was associated with 0.46% predicted higher FEV₁ (95% Confidence Interval: 0.17 to 0.75), 0.46% predicted higher FVC (0.18 to 0.74), and 0.24 ppb lower Fe_NO (−0.43 to −0.04). Thus, in the total study population, 25(OH)D concentrations were not associated with lung function, airway inflammation and common colds. In obese participants, however, higher 25(OH)D concentrations were associated with a better lung function and lower airway inflammation.

Effect of high dose vitamin D3 therapy on serum vitamin D3 levels in vitamin D insufficient adults with cystic fibrosis

BACKGROUND

The effect of a high dose oral cholecalciferol repletion strategy in Vitamin D insufficient adults with CF is still unknown. Therefore, we assessed the effectiveness of our current approach, giving oral vitamin D3 supplementation at a dose of 10,000 IU from Monday to Friday for a total of 50,000 IU D3 weekly in vitamin D insufficient adult with CF.

METHODS

We performed a retrospective chart review of all 59 adult CF patients between the ages of 17 and 64 years routinely followed at the CF Adult Program of Winnipeg Health Sciences Centre. Through consultation with the endocrinologist, our clinic vitamin D repletion protocol for treating CF adult patients who have serum 25-hydroxyvitamin D (25-OHD) < 30 ng/ml (<75 nmol/L) was to prescribe vitamin D3 10,000 IU orally from Monday to Friday (or the weekly equivalent of 50,000 IU) for 12 weeks in addition to their regular CF vitamin that supplied from 800 to 2000 IU vitamin D3 daily. Cholecalciferol was conveniently administered orally as either one capsule (oil-based) 10,000 IU or one tablet (powder-based) 10,000 IU. All patients were instructed to obtain follow-up serum 25-OHD levels post completion of treatment.

RESULTS

Of the 59 adult patients at our CF Clinic, 35 patients (59%) had below optimal serum 25-OHD levels. Of the 35 patients identified, 10 patients with insufficient serum 25-OHD levels between 10 and 30 ng/ml (25-75 nmol/L) fulfilled the inclusion criteria. A significant increase in serum 25-OHD levels was observed (P < 0.01) from mean value of 21.6 ± 5.9 ng/ml (54.1 ± 14.8 nmol/L) at baseline to 31.7 ± 9.1 ng/ml (79.3 ± 22.8 nmol/L) ≥ 2 months post intervention. The current treatment approach was successful in treating Vitamin D insufficiency in 70% of the patients with low 25-OHD levels.

CONCLUSION

The results of this study demonstrate that a large number of adults attending Winnipeg Health Sciences Centre CF Clinic have serum 25-OHD levels below 30 ng/ml (75 nmol/L). This supports the need for dedicated and individualized approach to manage this condition. High dose therapy of vitamin D3, although a more aggressive treatment approach, may result in achieving optimal levels of serum 25-OHD in adults with CF.

Vitamin D Levels and Associations in Indian Patients with Primary Sjögren's Syndrome

Introduction

Vitamin D is a steroid hormone belonging to the class of secosteroids with myriad immune functions and has been implicated in aetiopathogenesis of various autoimmune diseases. Although, there have been various studies showing the association of vitamin D in rheumatoid arthritis and lupus in different populations, there have been limited studies on vitamin D and primary Sjögren's Syndrome (pSS). There are no studies on association of vitamin D and pSS from any tropical country including Indian subcontinent.

Aim

The purpose of the study was to look for any association between 25-hydroxyvitamin D (25(OH)D) levels and disease manifestations in Indian patients with pSS.

Materials and Methods

This is a retrospective cross-sectional study done at a tertiary teaching hospital in southern India in 235 patients with pSS. Patients satisfying the American European Consensus Group (AECG) or American College of Rheumatology (ACR) 2012 for pSS between 2008 and 2015 were included if baseline 25(OH)D levels using electrochemiluminescence were available in hospital's laboratory record, 25(OH)D <20 ng/ml,20-30 ng/ml and >30 ng/ml was defined as deficiency, insufficiency and normal, respectively. Clinical laboratory data and disease activity scoring by EULAR Sjögren's syndrome disease activity index (ESSDAI) were retrieved retrospectively. Latitude corresponding to residence of each patient and the season of performing the assay were recorded. Chi-square statistics was done to find associations between categorized 25(OH)D and outcomes and was reported as odds ratio(95% confidence interval).

Results

Mean 25(OH)D for 235 patients with pSS was 19.98(12.55)ng/ml. A vitamin D deficiency, insufficiency and sufficiency was seen in 141(60%), 60(25.5%) and 34.0(14.5%), respectively. No association was noted between latitude or season of performing assay and the levels. pSS with 25(OH)D ≤30ng/ml had more than two fold risk of higher grading on lip biopsy as well as Rheumatoid Factor (RF) positivity. However, low 25(OH)D seemed to be associated with lower ESSDAI and less pulmonary involvement.

Conclusion

Prevalence of 25(OH)D deficiency in Indian patients with pSS was comparable to that of general Indian population. Low 25(OH)D level ≤30ng/ml was associated with higher odds for RF positivity and positive grading on lip biopsy. Surprisingly, low 25(OH)D was associated with lower ESSDAI score.

Serum Vitamin D Level at ICU Admission and Mortality

OBJECTIVE

Vitamin D is a fat-soluble vitamin that plays a major role in the regulation of bone and calcium metabolism and has effects on the immune and cardiovascular systems. Vitamin D deficiency is commonly seen in the general population as well as in critically ill patients and is reported to be associated with increased mortality and morbidity. Our aim was to determine the relationship between vitamin D level at ICU admission and mortality.

METHODS

A total of 491 patients admitted to the ICU between January 2014 and January 2015 were evaluated retrospectively. The patients who were under 18 years old, had elective surgery, or whose serum vitamin D levels and outcomes were unknown were excluded. The patient's age, gender, APACHE II score, number of organ dysfunction, serum vitamin D level at ICU admission and outcomes were recorded.

RESULTS

Vitamin D level was low (<25 ng dL^-1) in 166 (77.1%) of the patients. In non-survivor patients, APACHE II score and the number of organ dysfunction were significantly higher than the survivor patients (p<0.001 and p<0.001). There was a negative correlation between vitamin D level and APACHE II score (r²=0.04, p=0.006). In multivariate analyses, the likelihood of mortality was increased 9.8-fold (range 4.2-17.6) and 8.9-fold (range 3.9-14.1) with an APACHE II score ≥24 and the number of organ dysfunction ≥2, respectively (p<0.001 and p<0.001).

CONCLUSION

Vitamin D deficiency is commonly seen in intensive care patients. Although it is not an independently decisive factor for mortality, it might be related with poor clinical status at ICU admission. The APACHE II score and number of organ dysfunction are still important parameters for increased mortality.

Chronic vitamin D deficiency induces lung fibrosis through activation of the renin-angiotensin system

Pulmonary fibrosis, which influences lung function and exacerbates a patient’s condition, is the ultimate stage of many lung diseases. Vitamin D deficiency is associated with pulmonary fibrosis and impaired lung function, but the underlying mechanism has not yet been fully elucidated. Moreover, vitamin D deficiency may cause over-activation of the renin-angiotensin system (RAS), which aggravates extracellular matrix (ECM) deposition and lung fibrosis. This study aims to investigate the effect of chronic vitamin D deficiency on lung fibrosis in otherwise healthy mice and to explore the role of RAS in this process. Mice were depleted of vitamin D through diet control and were compared with healthy subjects. Chronic vitamin D deficiency destructs lung structures, impairs lung development and stimulates ECM deposition. RAS components are also found to increase. These effects seem to worsen with prolonged vitamin D deficiency. By giving RAS blockers, these changes can be largely rescued. However, a smooth muscle relaxant whose regulatory effect on blood pressure is independent of RAS does not show similar effects. This study demonstrated that chronic vitamin D deficiency may induce RAS activation, which subsequently stimulates the expression of profibrotic factors and activates the fibrotic cascade. This profibrotic effect of RAS is independent of elevated blood pressure.

Emphysema is associated with thoracic vertebral bone attenuation on chest CT scan in HIV-infected individuals

BACKGROUND

Age-related chronic diseases are prevalent in HIV-infected persons in the antiretroviral therapy (ART) era. Bone mineral density (BMD) loss and emphysema have separately been shown to occur at a younger age and with lesser risk exposure in HIV-infected compared to HIV-uninfected individuals. In non-HIV infected smokers, emphysema has been shown to independently predict low BMD. We hypothesized that emphysema would independently associate with thoracic vertebral bone attenuation, a surrogate for bone mineral density, in HIV-infected individuals.

METHODS

Clinical, pulmonary function, and radiographic data were analyzed for 164 individuals from the University of Pittsburgh's HIV Lung Research Center cohort. Chest CT scans were used to quantify emphysema and compute Hounsfield Unit (HU) attenuation of the 4th, 7th, and 10th thoracic vertebrae. The association between mean HU attenuation values across the three vertebrae and radiographic emphysema, age, sex, body mass index (BMI), steroid use, viral load, CD4 count, and forced expiratory volume in the first second (FEV1) was assessed by univariate and multivariate analyses.

RESULTS

In univariate analysis, mean HU attenuation decreased with increasing age (p<0.001), pack years (p = 0.047), and percent emphysema (p<0.001). In a multivariable model, including pack years, age, sex, ART and steroid use, greater emphysema was independently associated with this surrogate marker of BMD in HIV-infected individuals (p = 0.034).

CONCLUSIONS

The association of emphysema with thoracic bone attenuation in HIV-infected individuals is consistent with previous reports in non-HIV infected smokers. These findings suggest that emphysema should be considered a potential marker of osteoporosis risk in HIV-infected individuals.

Vitamin D deficiency: What does it mean for chronic obstructive pulmonary disease (COPD)? a compherensive review for pulmonologists

OBJECTIVES

Vitamin D deficiency and Chronic Obstructive Pulmonary Disease (COPD) are both under-recognized health problems, world-wide. Although Vitamin D has long been known for calcemic effects it also has less known noncalcemic effects. Recent data have shown that Vitamin D deficiency is highly prevalent in patients with COPD and correlates with forced expiratory volume in one second (FEV₁ ) and FEV₁ decline. The objective of this work was to review the current literature on vitamin D deficiency in relation with COPD.

DATA SOURCE

A literature search, using the words "vitamin D" and "COPD", was undertaken in Pubmed database.

RESULTS

The noncalcemic effects of vitamin D relating with COPD may be summarised as increasing antimicrobial peptide production, regulation of inflammatory response and airway remodelling. Vitamin D inhibits the production of several proinflammatory cytokines and leads to suppression Th1 and Th17 responses which may be involved in the pathogenesis of COPD. Vitamin D insufficiency may also contribute to chronic respiratory infections and airway colonization so returning vitamin D concentrations to an optimal range in patients with COPD might reduce bacterial load and concomitant exacerbations.Vitamin D is also important for COPD-related comorbodities such as osteoporosis, muscle weakness and cardiovascular diseases. Data about the effect of Vitamin D supplementation on those comorbidities in relation with COPD are been scarce.

CONCLUSION

Improving the blood level of Vitamin D into the desired range may have a beneficial effect bones and muscles, but more studies are needed to test to test that hypothesis.

Identification of vitamin D sensitive pathways during lung development

BACKGROUND

We have previously shown that vitamin D deficiency has a detrimental impact on lung development. In this study, we aimed to identify the mechanisms linking vitamin D with lung development using a mouse model of dietary manipulation.

METHODS

Female offspring were euthanized at different time-points; embryonic day (E)14.5, E17.5 or postnatal day (P)7. Lung tissue was collected for mass spectrometry-based proteomic analysis. Label-free quantitation was used to identify the differentially expressed proteins and ELISA confirmed the expression of selected proteins. Lungs from separate groups of mice were fixed and processed for stereological assessment of lung structure.

RESULTS

No differences in protein expression between vitamin D deficient and replete mice were detected at E14.5 and E17.5, whereas 66 proteins were differentially expressed in P7 lungs. The expression of pulmonary surfactant-associated protein B (SP-B) and peroxiredoxin 5 (PRDX5) were reduced in P7 lungs of vitamin D deficient mice, while the production of collagen type Ι alpha 1 (COL1A1) was higher in lungs of vitamin D deficient mice. There were no differences in lung volume, parenchymal volume, volume of airspaces or surface area of airspaces between vitamin D deficient and vitamin D replete mice across three time-points.

CONCLUSIONS

The difference in protein expression during the early postnatal time-point suggests that vitamin D deficiency may induce alterations of lung structure and function in later life during alveolarization stage through impaired pulmonary surfactant production and anti-oxidative stress ability as well as enhanced collagen synthesis. These data provided a plausible mechanism linking maternal vitamin D deficiency with altered postnatal lung function.

Skeletal Implications of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with numerous comorbidities, among which osteoporosis is of high significance. Low bone mass and the occurrence of fragility fractures is a common finding in patients with COPD. Typical risk factors related directly or indirectly to these skeletal complications include systemic inflammation, tobacco smoking, vitamin D deficiency, and treatment with oral or inhaled corticosteroids. In particular, treatment with glucocorticoids appears to be a strong contributor to bone changes in COPD, but does not fully account for all skeletal complications. Additional to the effects of COPD on bone mass, there is evidence for COPD-related changes in bone microstructure and material properties. This review summarizes the clinical outcomes of low bone mass and increased fracture risk, and reports on recent observations in bone tissue and material in COPD patients.

Vitamin D and airway infections: a European perspective

Vitamin D has immuno-modulatory properties, and deficient levels of circulating 25-hydroxyvitamin D (<30 nmol/l) may contribute to increased risk of infectious illnesses. This narrative review summarises data on vitamin D status in Europe and updates results of randomised controlled trials (RCTs) regarding vitamin D and airway infections such as tuberculosis (TB) and acute upper respiratory tract infection. In Europe, the prevalence of vitamin D deficiency is up to 37% in the general population and up to 80% in nursing home residents and non-European immigrants. Half of TB patients have a migration background. While results of RCTs do not support the concept of beneficial adjunctive effects of vitamin D supplements in anti-TB treatment [odds ratio (OR) = 0.86; 95% CI 0.62-1.19], the few published RCTs on the prophylaxis of TB suggest some protective vitamin D effects in individuals with deficient circulating 25-hydroxyvitamin D levels. Regarding acute respiratory tract infection, RCTs indicate a significant risk reduction by vitamin D supplements [OR = 0.65; 95% confidence interval (CI) 0.50-0.85]. There is evidence that daily administration is more effective than high-dose bolus administration [OR = 0.48 (95% CI 0.30-0.77) vs. OR = 0.87 (95% CI 0.67-1.14)] and that individuals with deficient or insufficient (30-50 nmol/l) circulating 25-hydroxyvitamin D levels benefit most. Several vitamin D effects on innate immunity may explain these protective effects. In summary, there is possible evidence from RCTs for protective vitamin D effects on TB and likely evidence for protective effects on acute airway infection. Since vitamin D deficiency is prevalent in Europe, especially in institutionalised individuals and non-European immigrants, daily oral vitamin D intake, e.g. 1000 international units, is an inexpensive measure to ensure adequate vitamin D status in individuals at risk.

The Effects of Vitamin D Supplementation on Pulmonary Function of Chronic Obstructive Pulmonary Disease Patients, before and after Clinical Trial

Vitamin D has several extra calcemic effects. Vitamin D deficiency is highly prevalent in chronic obstructive pulmonary disease (COPD) patients but little is known about it’s association with lung function. Objective: To investigate whether supplementation with vitamin D could improve pulmonary function in COPD patients. Design: Before and after, double center, clinical trial. Setting: Hazrat Rasoul University Hospital, Tehran, and Imam Khomaini University Hospital, Ahvaz, Iran. Participants: 24 patients with mild to very severe COPD. Intervention: Loading dose of 300,000–600,000 International Units (IU) of vitamin D, then 50000 IU weekly for 12 weeks. Measurements: The outcomes included forced expiratory volume in one second (FEV1), forced vital capacity (FVC), vital capacity (VC), forced expiratory flow between 25%–75% of forced vital capacity (FEF 25%–75%), exercise capacity according to the six minute walk test(6MWT) and the saturation of oxygen during exercise. Results: The mean FEV1 (p-value = 0.866), FVC (p-value = 0.475) and VC (p-value = 0.425) were not significantly different before and after intervention. FEF 25%–75% did not improve with this intervention (p-value = 0.555). The vitamin D supplementation did not have any significant effect on the exercise capacity (p-value=0.175) or the saturation of oxygen (p-value = 0.635). Conclusion: Pulmonary function and exercise capacity did not improve with vitamin D supplementation in COPD patients.

Lung function, 25-hydroxyvitamin D concentrations and mortality in US adults

OBJECTIVE

To explore the associations between serum concentrations of vitamin D (25(OH)D) and all-cause mortality among US adults defined by lung function (LF) status, particularly among adults with obstructive LF (OLF).

METHODS

Data from 10,795 adults aged 20-79 years (685 with restrictive LF (RLF) and 1309 with OLF) who participated in the Third National Health and Nutrition Examination Survey (1988-1994), had a spirometric examination, and were followed through 2006 were included.

RESULTS

During 14.2 years of follow-up, 1792 participants died. Mean adjusted concentrations of 25(OH)D were 75.0 nmol/l (s.e. 0.7) for adults with normal LF (NLF), 70.4 nmol/l (s.e. 1.8) for adults with RLF, 75.5 nmol/l (s.e. 1.5) for adults with mild obstruction and 71.0 nmol/l (s.e. 1.9) among adults with moderate or worse obstruction (P=0.030). After adjustment for sociodemographic factors, lifestyle factors, clinical variables and prevalent chronic conditions, a concentration of <25 nmol/l compared with ⩾ 75 nmol//l was associated with mortality only among adults with NLF (hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.03, 3.00). Among participants with OLF, adjusted HRs were 0.65 (95% CI 0.29, 1.48), 1.21 (95% CI 0.89, 1.66) and 0.97 (95% CI 0.78, 1.19) among those with concentrations <25, 25-<50 and 50-<75 nmol/l, respectively.

CONCLUSIONS

Baseline concentrations of 25(OH)D did not significantly predict mortality among US adults with impaired LF.

Association Between Vitamin D Status and Weaning From Prolonged Mechanical Ventilation in Survivors of Critical Illness

BACKGROUND

In this study, we examined the association between 25-hydroxyvitamin D (25(OH)D) concentration and successful weaning from mechanical ventilation in a cohort of ICU survivors requiring prolonged mechanical ventilation.

METHODS

This was a retrospective cohort study of ICU survivors admitted to a long-term acute care hospital. Demographic data were extracted from medical records, including 25(OH)D concentrations drawn on admission. Subjects were divided into 2 groups based on their 25(OH)D concentrations (deficient, < 20 ng/mL; not deficient, ≥ 20 ng/mL), and associations between 25(OH)D concentration and successful weaning were calculated.

RESULTS

A total of 183 subjects were studied. A high prevalence of 25(OH)D deficiency was found (61%, 111/183). No association was found between 25(OH)D concentration and weaning from mechanical ventilation. Increased comorbidity burden (Charlson comorbidity index) was associated with decreased odds of weaning (odds ratio of 0.50, 95% CI 0.25-0.99, P = .05).

CONCLUSIONS

Vitamin D deficiency is common in ICU survivors requiring prolonged mechanical ventilation. Surprisingly, there was no significant relationship between 25(OH)D concentration and successful weaning. This finding may be due to the low 25(OH)D concentrations seen in our subjects. Given what is known about vitamin D and lung function and given the low vitamin D concentrations seen in patients requiring long-term ventilatory support, interventional studies assessing the effects of 25(OH)D supplementation in these patients are needed.

Vitamin D status and distribution in patients with chronic obstructive pulmonary disease versus healthy controls

BACKGROUND

Vitamin D has a potential to modulate inflammatory response against noxious particles in patients with chronic obstructive pulmonary disease (COPD). The present study was conducted to determine the status of serum vitamin D in COPD versus healthy group.

METHODS

The patients presented to the outpatient pulmonary clinic of Ayatollah Rouhani Hospital, Babol Iran. Diagnosis of COPD was confirmed based on airflow limitation defined as FEV1/FVC ratio <70% and FEV1< 80% of predicted. All eligible patients aged ≥ 40 years old entered the study. Pulmonary infection, tuberculosis, pleural effusion, congestive heart failure, pulmonary hypertension and embolism, restrictive airway disease, conditions leading changes in vitamin D metabolism and absorption were excluded. Serum 25-hydroxyvitamin D (25-OHD) was determined by electrocheminluminescence method and levels <20, 20-29, and ≥30ng/ml were considered as deficiency, insufficiency, and sufficiency. In statistical analysis, the frequency of serum 25-OHD deficiency and insufficiency in patients were compared regarding age of ≤ 50 or >50 years old. All patients were males and age and sex-matched controls were selected among healthy subjects accompanied COPD patients.

RESULTS

Ninety patients and 100 controls with respective mean (±SD) age of 64.8±11.7 and 62.6±11.7 years old (P=0.19) were studied. Compared with control, proportions of serum 25-OHD deficiency and insufficiency in patients >50 years were higher and deficiency was lower (61.5% vs 87.5%, P=0.11).

CONCLUSION

These findings indicate that a significant proportion of young COPD patients have insufficient serum 25-OHD. Regarding a positive relationship between 25-OHD and FEV1 in COPD, these findings highlight serum 25-OHD assessment in COPD for recognizing high risk patients.

Vitamin D Inhibits Expression and Activity of Matrix Metalloproteinase in Human Lung Fibroblasts (HFL-1) Cells

BACKGROUND

Low levels of serum vitamin D is associated with several lung diseases. The production and activation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis of emphysema. The aim of the current study therefore is to investigate if vitamin D modulates the expression and activation of MMP-2 and MMP-9 in human lung fibroblasts (HFL-1) cells.

METHODS

HFL-1 cells were cast into three-dimensional collagen gels and stimulated with or without interleukin-1β (IL-1β) in the presence or absence of 100 nM 25-hydroxyvitamin D (25(OH)D) or 1,25-dihydroxyvitamin D (1,25(OH)2D) for 48 hours. Trypsin was then added into the culture medium in order to activate MMPs. To investigate the activity of MMP-2 and MMP-9, gelatin zymography was performed. The expression of the tissue inhibitor of metalloproteinase (TIMP-1, TIMP-2) was measured by enzyme-linked immunosorbent assay. Expression of MMP-9 mRNA and TIMP-1, TIMP-2 mRNA was quantified by real time reverse transcription polymerase chain reaction.

RESULTS

IL-1β significantly stimulated MMP-9 production and mRNA expression. Trypsin converted latent MMP-2 and MMP-9 into their active forms of MMP-2 (66 kDa) and MMP-9 (82 kDa) within 24 hours. This conversion was significantly inhibited by 25(OH)D (100 nM) and 1,25(OH)2D (100 nM). The expression of MMP-9 mRNA was also significantly inhibited by 25(OH)D and 1,25(OH)2D.

CONCLUSION

Vitamin D, 25(OH)D, and 1,25(OH)2D play a role in regulating human lung fibroblast functions in wound repair and tissue remodeling through not only inhibiting IL-1β stimulated MMP-9 production and conversion to its active form but also inhibiting IL-1β inhibition on TIMP-1 and TIMP-2 production.

Vitamin D modulates prostaglandin E2 synthesis and degradation in human lung fibroblasts

Vitamin D insufficiency has been increasingly recognized in the general population worldwide and has been associated with several lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), and respiratory tract infections. Fibroblasts play a critical role in tissue repair and remodeling, which is a key feature of COPD and asthma. Fibroblasts modulate tissue repair by producing and modifying extracellular matrix components and by releasing mediators that act as autocrine or paracrine modulators of tissue remodeling. The current study was designed to investigate if vitamin D alters fibroblast release of key autocrine/paracrine repair factors. First, we demonstrated that human fetal lung (HFL)-1 cells express the vitamin D receptor (VDR) and that vitamin D, 25-hydroxyvitamin D [25(OH)D], or 1,25-dihydroxyvitamin D [1,25(OH)2D] induce VDR nuclear translocation and increase VDR-DNA binding activity. We next demonstrated that vitamin D, 25(OH)D, and 1,25(OH)2D significantly reduced prostaglandin (PG)E2 production by human lung fibroblasts (HFL-1) but had no effect on transforming growth factor β1, vascular endothelial growth factor, or fibronectin production. Vitamin D, 25(OH)D, and 1,25(OH)2D significantly inhibited IL-1β-induced microsomal PGE synthase (mPGES)-1 expression; in contrast, all three forms of vitamin D stimulated 15-hydroxy PG dehydrogenase, an enzyme that degrades PGE2. Cyclooxygenase-1 and -2 and the other two PGE2 synthases (mPGES-2 and cytosolic PGE synthase) were not altered by vitamin D, 25(OH)D, or 1,25(OH)2D. Finally, the effect of PGE2 inhibition by 25(OH)D was observed in adult lung fibroblasts. These findings suggest that vitamin D can regulate PGE2 synthesis and degradation and by this mechanism can modulate fibroblast-mediated tissue repair function.

The role of vitamin D in chronic obstructive pulmonary disease, asthma and other respiratory diseases

There has been growing interest in recent years in the extraosseous effects of vitamin D. In this article, we review the physiology of vitamin D, the physiopathological effects associated with vitamin D deficit and the available evidence on its etiopathogenic role in respiratory diseases. Given the pleiotropic actions of vitamin D, it is biologically plausible that the deficit of this vitamin could play a pathogenic role of in the development of various respiratory diseases. However, the many epidemiological studies that have shown an association between low vitamin D levels and a higher risk of developing various respiratory diseases or a poorer prognosis if they do appear, were unable to show causality. Post-hoc analyses of some clinical trials, particularly in chronic obstructive pulmonary disease (COPD) and asthma, appear to suggest that some patient subtypes may benefit from correction of a vitamin D deficit. In this respect, it would be interesting to determine if the interindividual differences found in the effect of vitamin D deficit and responses to correcting this deficit could be explained by the genetic variants involved in vitamin D metabolism. Ultimately, only appropriately designed clinical trials will determine whether 25-OHD supplements can prevent or improve the course of the various respiratory diseases in which an epidemiological association between prognosis and vitamin D deficit has been described.

Vitamin D treatment improves survival and infant lung structure after intra-amniotic endotoxin exposure in rats: potential role for the prevention of bronchopulmonary dysplasia

Vitamin D (vit D) has anti-inflammatory properties and modulates lung growth, but whether vit D can prevent lung injury after exposure to antenatal inflammation is unknown. We hypothesized that early and sustained vit D treatment could improve survival and preserve lung growth in an experimental model of bronchopulmonary dysplasia induced by antenatal exposure to endotoxin (ETX). Fetal rats (E20) were exposed to ETX (10 μg), ETX + Vit D (1 ng/ml), or saline (control) via intra-amniotic (IA) injections and delivered 2 days later. Newborn pups exposed to IA ETX received daily intraperitoneal injections of vit D (1 ng/g) or saline for 14 days. Vit D treatment improved oxygen saturations (78 vs. 87%; P < 0.001) and postnatal survival (84% vs. 57%; P < 0.001) after exposure to IA ETX compared with IA ETX alone. Postnatal vit D treatment improved alveolar and vascular growth at 14 days by 45% and 25%, respectively (P < 0.05). Vit D increased fetal sheep pulmonary artery endothelial cell (PAEC) growth and tube formation by 64% and 44%, respectively (P < 0.001), and prevented ETX-induced reductions of PAEC growth and tube formation. Vit D directly increased fetal alveolar type II cell (ATIIC) growth by 26% (P < 0.001) and enhanced ATIIC growth in the presence of ETX-induced growth suppression by 73% (P < 0.001). We conclude that antenatal vit D therapy improved oxygenation and survival in newborn rat pups and enhanced late lung structure after exposure to IA ETX in vivo, which may partly be due to direct effects on vascular and alveolar growth.

The role of vitamin D in critical illness

The role of vitamin D in critical illness is under investigation. Recent data indicate declining levels of serum vitamin D in multiple adult populations. Deficiencies have been strongly linked to infectious processes and certain chronic disorders. Vitamin D deficiency that is present at the onset of critical illness may impact the severity of illness and contribute to less-than-optimal outcomes. This article describes the function of vitamin D, the effects that deficiencies have on body systems, and the emerging role of vitamin D deficiency for critically ill patients.

Should vitamin D supplementation be a regular part of asthma care?

Vitamin D (vitD3) deficiency occurs frequently and has profound effects on health, especially asthma. This article examines how current knowledge of vitD3 actions and the worldwide distribution of vitD3 deficiency influences everyday clinical allergy practice. Within the limits of current knowledge, the article concisely explains the molecular nature of vitD3 actions, reviews key vitD3 research as it applies to clinical care, answers questions about the potential clinical impact of low vitD3 levels, and discusses use and safety of vitD3 supplements.

Plasma 25-hydroxyvitamin D associated with pulmonary function in Canadian adults with excess adiposity

BACKGROUND

Vitamin D deficiency is an important health issue, particularly among people residing in northern countries. Low concentrations of 25-hydroxyvitamin D [25(OH)D] have been linked to several health conditions.

OBJECTIVE

The objective was to determine the association between plasma 25(OH)D and pulmonary function and the effect modifications of sex and body mass index (BMI) in adults.

DESIGN

A cross-sectional study included 3359 adults aged ≥18 y who participated in the Canadian Health Measures Survey, and a 2-stage multiple linear regression analysis was conducted.

RESULTS

Overall, 26% of the adults had a plasma 25(OH)D concentration <50 nmol/L, which is considered deficient (ie, hypovitaminosis D). This deficiency was more prevalent among men than among women (30% compared with 23%). Regression analysis showed that deficient plasma 25(OH)D was associated with lower mean residual forced vital capacity and forced expiratory volume in 1 s in men after adjustment for covariates. When further stratified by BMI, the associations were more marked in overweight and obese men. Vitamin D deficiency associated with pulmonary function was not statistically significant in normal-weight men or in women, regardless of BMI categories. Similar results were obtained when plasma 25(OH)D was examined as a continuous variable in the models.

CONCLUSIONS

Hypovitaminosis D may be a risk factor for lung dysfunction, especially for overweight and obese men. Further research is necessary to determine the mechanism of the interrelation between vitamin D, adiposity, and pulmonary function.

Effects of vitamin D on immune disorders with special regard to asthma, COPD and autoimmune diseases: a short review

This paper reviews the recent data on the role of vitamin D (VD) in the genesis of various immunological disorders. It inhibits immune reactions in general, but it enhances the transcription of 'endogenous antibiotics' such as cathelicidin and defensins. VD inhibits the genesis of both Th1- and Th2-cell mediated diseases. The pleiotropic character VD-induced effects are due to the altered transcription of hundreds of genes. VD supplementation in most related studies reduced the prevalence of asthma. Th1-dependent autoimmune diseases (e.g., multiple sclerosis, Type 1 diabetes, Crohn's disease, rheumatoid arthritis and so on) are also inhibited by VD due to inhibition of antigen presentation, reduced polarization of Th0 cells to Th1 cells and reduced production of cytokines from the latter cells. VD seems to also be a useful adjunct in the prevention of allograft rejection. Last but not least, VD supplementation may be useful in the prevention or adjunct treatment of chronic obstructive pulmonary disease.

Role of vitamin D-binding protein in isocyanate-induced occupational asthma

The development of a serological marker for early diagnosis of isocyanate-induced occupational asthma (isocyanate-OA) may improve clinical outcome. Our previous proteomic study found that expression of vitamin D-binding protein (VDBP) was upregulated in the patients with isocyanate-OA. In the present study, we evaluated the clinical relevance of VDBP as a serological marker in screening for isocyanate-OA among exposed workers and its role in the pathogenesis of isocyanate-OA. Three study groups including 61 patients with isocyanate-OA (group I), 180 asymptomatic exposed controls (AECs, group II), 58 unexposed healthy controls (NCs, group III) were enrolled in this study. The baseline serum VDBP level was significantly higher in group I compared with groups II and III. The sensitivity and specificity for predicting the phenotype of isocyanate-OA with VDBP were 69% and 81%, respectively. The group I subjects with high VDBP (≥ 311 µg/ml) had significantly lower PC₂₀ methacholine levels than did subjects with low VDBP. The in vitro studies showed that TDI suppressed the uptake of VDBP into RLE-6TN cells, which was mediated by the downregulation of megalin, an endocytic receptor of the 25-hydroxycholecalciferol-VDBP complex. Furthermore, toluene diisocyanate (TDI) increased VEGF production and secretion from this epithelial cells by suppression of 1,25-dihydroxycholecalciferol [1,25(OH)₂D₃] production. The findings of this study suggest that the serum VDBP level may be used as a serological marker for the detection of isocyanate-OA among workers exposed to isocyanate. The TDI-induced VEGF production/secretion was reversed by 1,25(OH)₂D₃ treatment, which may provide a potential therapeutic strategy for patients with isocyanate-OA.