Serum vitamin D levels and markers of severity of childhood asthma in Costa Rica

Folate Deficiency, Atopy, and Severe Asthma Exacerbations in Puerto Rican Children

BACKGROUND

Little is known about folate and atopy or severe asthma exacerbations. We examined whether folate deficiency is associated with number of positive skin tests to allergens or severe asthma exacerbations in a high-risk population and further assessed whether such association is explained or modified by vitamin D status.

METHODS

Cross-sectional study of 582 children aged 6 to 14 years with (n = 304) and without (n = 278) asthma in San Juan, Puerto Rico. Folate deficiency was defined as plasma folate less than or equal to 20 ng/ml. Our outcomes were the number of positive skin tests to allergens (range, 0-15) in all children and (in children with asthma) one or more severe exacerbations in the previous year. Logistic and negative binomial regression models were used for the multivariate analysis. All multivariate models were adjusted for age, sex, household income, residential proximity to a major road, and (for atopy) case/control status; those for severe exacerbations were also adjusted for use of inhaled corticosteroids and vitamin D insufficiency (a plasma 25[OH]D < 30 ng/ml).

MEASUREMENTS AND MAIN RESULTS

In a multivariate analysis, folate deficiency was significantly associated with an increased degree of atopy and 2.2 times increased odds of at least one severe asthma exacerbation (95% confidence interval for odds ratio, 1.1-4.6). Compared with children who had normal levels of both folate and vitamin D, those with both folate deficiency and vitamin D insufficiency had nearly eightfold increased odds of one or more severe asthma exacerbation (95% confidence interval for adjusted odds ratio, 2.7-21.6).

CONCLUSIONS

Folate deficiency is associated with increased degree of atopy and severe asthma exacerbations in school-aged Puerto Ricans. Vitamin D insufficiency may further increase detrimental effects of folate deficiency on severe asthma exacerbations.

Vitamin D Status in Infants with Two Different Wheezing Phenotypes

OBJECTIVE

To investigate vitamin D levels in patients with recurrent wheeze at early ages of childhood.

METHODS

In the present cross-sectional study, serum 25-hydroxy vitamin D [25 (OH)D], levels which is known as an indicator of vitamin D adequacy, was examined in infants with three or more wheezing attacks.

RESULTS

A total of 186 infants with recurrent wheezing were included in the study along with 118 healthy control peers. The recurrent wheezing study participants were classified into two groups according to Asthma Predictive Index (API) positivity and compared to control subjects regarding their serum vitamin D status. The API negative group had the lowest mean serum 25 (OH)D level (n = 121; 22.71 ± 10.76 ng/ml) followed by API positive group (n = 65; 24.08 ± 9.02 ng/ml) compared to healthy group (26.24 ± 11.88 ng/ml) (p < 0.05). In addition, higher vitamin D deficiency was observed in infants in API negative group (52.1 %; p < 0.01) and API positive group (38.5 %; p < 0.05) than control group (31.4 %).

CONCLUSIONS

Low levels of 25 (OH)D were detected in infants with two different phenotypes of recurrent wheeze. Vitamin D deficiency may play a role in the pathogenesis of infants with recurrent wheezing.

The relationship between serum levels of vitamin D with asthma and its symptom severity: A case-control study

BACKGROUND

Asthma is a heterogeneous disease characterised by chronic inflammatory airways, and is affected by several immunological factors. One of the most discussed and researched hypotheses is the relationship between vitamin D serum levels with asthma. This study aimed to investigate the relationship between vitamin D serum levels with asthma and pulmonary functions in children in Kurdistan province, Iran.

MATERIALS AND METHODS

In this case-control study, 120 children ranging from 6 to 18 years were referred in summer for investigation. Participants were divided into two groups: asthma group, N=60; and control group, N=60. After serum separation, samples were analysed using vitamin D ELISA kit. Additionally, pulmonary function test and serum IgE levels were measured in both groups. Data were analysed using Chi-square test and multiple regression analysis in SPSS15.

RESULTS

No difference was shown between the groups in terms of gender composition (male: 57.5; female: 42.5) (P>0.05). Average Vitamin D serum level in the case group (17.98±8.68) was less than in control group (22.35±6.26) (P<0.01). In addition, the difference of vitamin D deficiency in level of suboptimal between the asthma (17.77±6.41) and the control group (24.9±3.18) was statistically significant (P<0.0001). Positive correlation existed between vitamin D levels with FEV1, FVC, and FEV1/FVC. Multiple regression analysis showed a reverse relationship between vitamin D levels with IgE serum levels; this remained after adjustment for potential confounders (e.g. age, sex, BMI, FEV1, and FVC).

CONCLUSION

The results showed that serum levels of vitamin D in asthma patients were less than in healthy people, and also reduced lung function in these patients. So, the serum levels of vitamin D in asthma patients must be checked continuously.

Serum Magnesium and Vitamin D Levels as Indicators of Asthma Severity

Background. Serum magnesium levels affect the concentration of circulating vitamin D in blood and subsequently it affects the immunity; thus it plays significant role in the pathogenesis of asthma. Asthma, in adults, is less studied and hypomagnesemia along with vitamin D deficiency and insufficiency is common in asthmatic individuals, which causes frequent asthma attacks, respiratory infections, severe exacerbations, and poor response to bronchodilators. Objective. To detect the magnitude of vitamin D insufficiency and deficiency and serum magnesium levels among asthmatic patients and to correlate them with the severity of asthma. Materials and Methods. This is a cross-sectional case-control study which includes 60 patients of chronic stable asthma and 60 healthy controls. After taking clinical history and systemic examination, pulmonary function test was done. Serum levels of magnesium, 25-hydroxycholecalciferol [25(OH)D], and calcium were measured in all the subjects. Results. Significant correlation was found between vitamin D deficiency, hypomagnesemia, and asthma severity. Serum calcium levels were unaffected by that. Conclusion. Vitamin D and serum magnesium deficiency are highly prevalent in patients with asthma. Increased asthma severity, frequency of attacks, and exacerbation are associated with lower levels of one or both. Serum 25(OH)D and magnesium levels may serve as important markers of asthma severity.

Vitamin D modulation of innate immune responses to respiratory viral infections

Vitamin D, in addition to its classical functions in bone homeostasis, has a modulatory and regulatory role in multiple processes, including host defense, inflammation, immunity, and epithelial repair. Patients with respiratory disease are frequently deficient in vitamin D, implying that supplementation might provide significant benefit to these patients. Respiratory viral infections are common and are the main trigger of acute exacerbations and hospitalization in children and adults with asthma and other airways diseases. Respiratory monocytes/macrophages and epithelial cells constitutively express the vitamin D receptor. Vitamin D, acting through this receptor, may be important in protection against respiratory infections. Whether the in vitro findings can be translated into a substantial in vivo benefit still remains uncertain. Here we review the in vitro data on the role of vitamin D in antiviral innate immunity, the data concerning the deficient levels of vitamin D in lung diseases, and the in vivo role of supplementation as protection against respiratory viral infections in healthy individuals and in patients with chronic respiratory diseases. Finally, we suggest ways of improving the effectiveness of vitamin D as an adjuvant in the prevention and treatment of acute respiratory infections.

Vitamin D and bronchopulmonary dysplasia in preterm infants

OBJECTIVE

Vitamin D deficiency is associated with asthma and reactive airway disease in childhood but its potential contribution to bronchopulmonary dysplasia (BPD) in preterm infants is unknown. Preterm infants have lower levels of 25-hydroxyvitamin D (25(OH)D) at birth and are at risk for nutritional deficiencies after birth. The objective of the study was to evaluate the association of 25(OH)D concentrations at birth and at 36 weeks' corrected gestational age with BPD in preterm infants born before 29 completed weeks of gestation.

STUDY DESIGN

We collected umbilical cord blood samples from 44 preterm infants (gestational age <29 weeks) delivered at Brigham and Women's Hospital in Boston. In addition, with parental consent we collected venous samples at 36 weeks' corrected age from 20 preterm infants born before 29 weeks' gestation (including 6 infants with previously collected cord blood). Samples were frozen at -80 °C until subsequent measurement of 25(OH)D levels by chemiluminescence. We used multivariable logistic models to adjust for gestational age and considered other confounding variables, including maternal race, age, mode of delivery and infant sex.

RESULTS

Among 44 infants, 41 (93.2%) survived and 3 (6.8%) died before 36 weeks' corrected age. Median 25(OH)D levels at birth were 30.4 ng ml(-1) in preterm infants who subsequently died or developed BPD and 33.8 ng ml(-1) in infants who survived without BPD (P=0.6). Median 25(OH)D levels at corrected age of 36 weeks were 59.0 ng ml(-1) among survivors without BPD and 64.2 ng ml(-1) among survivors with BPD (P=0.9). Neither cord blood nor 36 weeks' corrected 25(OH)D levels were associated with odds of death or BPD (adjusted odds ratio (OR) 1.00, 95% confidence interval (CI): 0.73 to 1.37; and OR 0.93, 95% CI: 0.61 to 1.43, respectively).

CONCLUSIONS

Among this population of extremely preterm infants neither cord blood nor the 36 weeks' corrected age 25(OH)D levels were associated with development of BPD. Notably, at the current level of supplementation, all extremely preterm infants in our cohort had achieved 25(OH)D levels >30 ng ml(-1) by 36 weeks' corrected age, which is thought to represent sufficiency in adult and pediatric populations.

Vitamin D pathway regulatory genes encoding 1α-hydroxylase and 24-hydroxylase are dysregulated in sinonasal tissue during chronic rhinosinusitis

BACKGROUND

Vitamin D deficiency is associated with many inflammatory respiratory disease states. However, serum vitamin D concentrations may not reflect tissue-specific availability. In this study we sought to assess the local expression of genes essential in vitamin D regulation in chronic rhinosinusitis (CRS).

METHODS

A cross-sectional study of adult patients undergoing endoscopic sinus surgery was performed. Patients were defined as having CRS with polyps (CRSwNP) or without polyps (CRSsNP), or normal sinus mucosa. Sinus mucosal biopsies were assessed using quantitative polymerase chain reaction to determine expression of genes encoding the vitamin D receptor (VDR), 25-hydroxylase (CYP2R1), 1α-hydroxylase (CYP27B1), and 24-hydroxylase (CYP24A1). Expression levels correlated with serum 25(OH)D [sum 25(OH)D₂  and 25(OH)D₃ ], the 22-item Sinonasal Outcome Test (SNOT-22), and Nasal Symptom Score (NSS). Separate analyses were performed for patients grouped by tissue eosinophilia.

RESULTS

Thirty-one patients were assessed (age 49.47 ± 18.14 years, 48.4% female), including 8 CRSsNP, 10 CRSwNP, and 13 controls. CRSsNP and CRSwNP mucosa exhibited decreased CYP27B1 compared with controls (0.0437 [Interquartile range (IQR) 0.0999] vs 0.3260 [IQR 2.9384] vs 0.6557 [IQR 1.1005], p = 0.039), whereas CYP24A1 was upregulated (0.8522 [IQR 1.3170] vs 1.2239 [IQR 4.4197] vs 0.1076 [IQR 0.1791], p = 0.025). CYP24A1 was upregulated in both non-eosinophilic CRS and eosinophilic CRS (1.1337 [IQR 2.3790] vs 0.9555 [IQR 3.2811] vs 0.1076 [IQR 0.1791], p = 0.033). Significant correlations were observed between NSS and CYP2R1 (r = -0.432, p = 0.022), CYP24A1 (r = 0.420, P = 0.026), and VDR (r = 0.425, p = 0.024), although no correlations with serum 25(OH)D were observed.

CONCLUSIONS

The local regulation of vitamin D in sinonasal tissue during CRS may be independent of serum 25(OH)D levels. Vitamin D may be dysregulated at multiple levels, with decreased transcription of the metabolic gene CYP27B1 and increased transcription of the catabolic gene CYP24A1 observed.

The effect of vitamin D on COPD exacerbation: a double blind randomized placebo-controlled parallel clinical trial

Background

To investigate the effect of supplementation of standard treatment (inhaled long-acting β2 agonists, anticholinergics and corticosteroids) with vitamin D on C reactive protein and pulmonary function tests in patients with COPD exacerbation.

Methods

Design: Randomized, single-center, double-blind, placebo-controlled parallel trial. One teaching hospital Participants: 135 patients in pulmonary ward with moderate to severe COPD and exacerbations.120 patients fulfilled the study protocol. Interventions: Patients were randomly divided into three groups receiving 7 day treatment with 0.25 μg calcitriol daily (n = 45), 50000 IU daily of vitamin D (n = 45) or placebo (n = 45). An independent nurse was responsible for allocation, preparation, and accounting of trial medications. Main Outcome measures: Maximal expiratory flow volume (FEV1) and forced volume capacity curves (FVC) and Modified Medical Research Council (MMRC) scale.

Results

Out of 135 patients who were recruited consecutively, 45 patients randomly were randomly assigned in three groups (balance blocked randomization.15 patients were dropped out due to non-compliance for second PFT. Intention to treat analysis was carried out for 120 participants. The difference between before and after treatment FEV1 and FEV1/FVC ratio had no significant difference between treatment groups and placebo. (P = 0.43, P = 0.51, respectively)but clinical improvement was significant in patients who received calcitriol. No side effects were reported.

Conclusions

Short term treatment with either calcitriol or 25(OH) ₂Vit D didn’t changed FEV1 or FVC in vitamin D sufficient patients with COPD exacerbation; nevertheless it can provide clinical benefit.

Trial registration

Trial registration: Iranian Registry of Clinical Trials no. IRCT138712271774N1. Registered 10 April 2011.

The use of inhaled corticosteroids in pediatric asthma: update

Despite the availability of several formulations of inhaled corticosteroids (ICS) and delivery devices for treatment of childhood asthma and despite the development of evidence-based guidelines, childhood asthma control remains suboptimal. Improving uptake of asthma management plans, both by families and practitioners, is needed. Adherence to daily ICS therapy is a key determinant of asthma control and this mandates that asthma education follow a repetitive pattern and involve literal explanation and physical demonstration of the optimal use of inhaler devices. The potential adverse effects of ICS need to be weighed against the benefit of these drugs to control persistent asthma especially that its safety profile is markedly better than oral glucocorticoids. This article reviews the key mechanisms of inhaled corticosteroid action; recommendations on dosage and therapeutic regimens; potential optimization of effectiveness by addressing inhaler technique and adherence to therapy; and updated knowledge on the real magnitude of adverse events.

Particularities of allergy in the Tropics

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

Pediatric Obesity-Related Asthma: The Role of Metabolic Dysregulation

The burden of obesity-related asthma among children, particularly among ethnic minorities, necessitates an improved understanding of the underlying disease mechanisms. Although obesity is an independent risk factor for asthma, not all obese children develop asthma. Several recent studies have elucidated mechanisms, including the role of diet, sedentary lifestyle, mechanical fat load, and adiposity-mediated inflammation that may underlie the obese asthma pathophysiology. Here, we review these recent studies and emerging scientific evidence that suggest metabolic dysregulation may play a role in pediatric obesity-related asthma. We also review the genetic and epigenetic factors that may underlie susceptibility to metabolic dysregulation and associated pulmonary morbidity among children. Lastly, we identify knowledge gaps that need further exploration to better define pathways that will allow development of primary preventive strategies for obesity-related asthma in children.

Essential vitamins for an effective T cell response

Effective adaptive immune responses rely upon appropriate activation of T cells by antigenic peptide-major histocompatibility complex on the surface of antigen presenting cells (APCs). Activation relies on additional signals including co-stimulatory molecules on the surface of the APCs that promote T cell expansion. The immune response is further sculpted by the cytokine environment. However, T cells also respond to other environmental signals including hormones, neurotransmitters, and vitamins. In this review, we summarize the mechanisms through which vitamins A and D impact immune responses, particularly in the context of T cell responses.

A review of Vitamin D effects on common respiratory diseases: Asthma, chronic obstructive pulmonary disease, and tuberculosis

Despite the classic role of Vitamin D in skeletal health, new aspects of Vitamin D have been discovered in tissues and organs other than bones. Epidemiological and observational studies demonstrate a link between Vitamin D deficiency and risk of developing respiratory diseases including asthma, chronic obstructive pulmonary disease (COPD), and tuberculosis (TB). To review the literature, we searched the terms "Vitamin D" (using the set operator) and "asthma," "COPD" and "TB" in electronic databases, including PubMed/MEDLINE, Scopus, and Google Scholar until July 2015. Non-English articles or articles with unavailable full text were excluded. Both in vivo and in vitro studies were included. All the reviewed articles state that Vitamin D deficiency is very common among patients with respiratory diseases. The present data regarding Vitamin D and asthma is still controversial, but data about COPD and TB are more encouraging. The relevant studies have been conducted in different populations therefore it is not particularly possible to compare the data due to genetic variations. In order to point out a role for Vitamin D, large clinical trials with Vitamin D deficient subjects and sufficient Vitamin D supplementation are needed.

Prenatal, perinatal, and childhood vitamin D exposure and their association with childhood allergic rhinitis and allergic sensitization

BACKGROUND

The role of early-life vitamin D in childhood allergy is controversial.

OBJECTIVE

We sought to assess vitamin D exposure in early life by multiple modalities and ascertain its association with childhood allergic rhinitis and allergic sensitization.

METHODS

One thousand two hundred forty-eight mother-child pairs from a US prebirth cohort unselected for any disease were studied. Vitamin D exposure was assessed by measures of maternal intake during the first and second trimesters of pregnancy and serum 25-hydroxyvitamin D (25[OH]D) levels in mothers during pregnancy, cord blood, and children at school age (median age, 7.7 years; interquartile range, 1.0 years). Tests for associations between vitamin D exposure with ever allergic rhinitis, serum total IgE level, and allergen sensitization at school age were conducted.

RESULTS

The correlations between maternal intake of vitamin D during pregnancy and serum 25(OH)D levels in pregnant mothers, cord blood, and children at school age were weak to moderate (r = -0.03 to 0.53). Each 100 IU/d of food-based vitamin D intake during the first and second trimesters (equivalent to the amount of vitamin D in an 8-ounce serving of milk) was associated with 21% and 20% reduced odds of ever allergic rhinitis at school age (odds ratios of 0.79 [95% CI, 0.67-0.92] and 0.80 [95% CI, 0.68-0.93]), respectively. There were no associations between maternal supplemental vitamin D intake or serum 25(OH)D levels at any time point with ever allergic rhinitis. There were no associations between any vitamin D exposure and serum total IgE level or allergen sensitization at school age.

CONCLUSIONS

Inclusion of foods containing vitamin D in maternal diets during pregnancy may have beneficial effects on childhood allergic rhinitis.

Vitamin D deficiency is associated with increased human sinonasal fibroblast proliferation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Vitamin D3 (VD3) is a steroid hormone with known antiproliferative properties. Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have been shown to be VD3-deficient. Moreover, VD3 deficiency is associated with worse disease in patients with CRSwNP. One cell type thought to play a role in chronic rhinosinusitis (CRS) is the human sinonasal fibroblast (HSNF). The aim of this study was to investigate VD3 deficiency and HSNF proliferation in CRSwNP.

METHODS

Blood and sinus tissue explants were collected at the time of surgery from patients with CRSwNP (n = 15). Control subjects (n = 12) were undergoing surgery for cerebrospinal fluid leak repair or to remove non-hormone-secreting pituitary tumors. Ex vivo HSNF proliferation was analyzed with flow cytometry using expression of fibroblast-specific protein (FSP) and the proliferation marker Ki67. Plasma levels of 25-hydroxyvitamin D3 (25VD3) were measured by enzyme-linked immunosorbent assay. In vitro analysis of HSNF proliferation after treatment with calcitriol (1,25VD3) was performed using carboxyfluorescein succinimidyl ester (CFSE) and analyzed with flow cytometry.

RESULTS

In CRSwNP patients there was an inverse correlation between 25VD3 and proliferating HSNFs (p = 0.0135). This correlation was not seen for control patients (p = 0.3869). In vitro analysis showed that HSNFs from patients with CRSwNP had a higher proliferation index at baseline than HSNFs from control patients (p < 0.01). When treated with 1,25VD3, there was a significant decrease in HSNF proliferation index in patients with CRSwNP (p < 0.01), but not control patients.

CONCLUSION

VD3 deficiency is associated with increased HSNF proliferation in CRSwNP. Further investigation into how HSNFs and VD3 impact CRSwNP pathophysiology is warranted.

[Impact of obesity on response to therapy and pulmonary function in children with asthma]

OBJECTIVE

To investigate the effects of obesity on response to therapy and pulmonary function in children with asthma who receive inhaled corticosteroid (ICS) treatment.

METHODS

A total of 129 children with asthma were divided into two groups according to their body mass index: normal weight group (n=64) and obese group (n=65). The asthma control status and pulmonary function were compared between the two groups after one year of ICS treatment. The pulmonary function was expressed as percent forced expiratory volume in 1 second (FEV1%), percent predicted forced vital capacity (FVC%), peak expiratory flow (PEF), peak expiratory flow at 25% of vital capacity (PEF25), and peak expiratory flow at 50% of vital capacity (PEF50). The asthma control status was expressed as complete control rate, partial control rate, and uncontrolled rate. Sixty-eight healthy children were selected as the healthy control group.

RESULTS

There were significant differences in the indices of pulmonary function between the three groups before treatment (P<0.01); the healthy control group had the best values of pulmonary function, while the obese group had the worst values. After 1 year of treatment, the normal weight group showed significantly more improvements in FEV1% and FVC% than the obese group (P<0.01). However, there were no significant differences in improvements in PEF, PEF25, and PEF50 between the two groups. The complete control rate, partial control rate, and uncontrolled rate in the normal weight group were 72%, 19%, and 9%, respectively, while the rates in the obese group were 28%, 51%, and 22%, respectively; the normal weight group had a significantly better asthma control status than the obese group (P<0.01).

CONCLUSIONS

The asthmatic children with obesity have a significantly less improvement in large airway function and a poorer asthma control status after ICS treatment than those with the normal weight.

Evaluation of vitamin D levels in allergic and non-allergic asthma

BACKGROUND AND OBJECTIVE

Some researches show that low vitamin D may play a role in asthma pathogenesis. The aim of this study was to evaluate the serum vitamin D level in asthmatics with different phenotypes and to determine its associations with lung function, IgE, eosinophil count and body mass index (BMI).

MATERIALS AND METHODS

The study population comprised 85 patients with asthma and 73 healthy persons. Patients with asthma were divided into groups according to phenotypes. Allergy was assessed using a skin prick test and measuring eosinophil count in peripheral blood and total IgE in serum. Lung function was evaluated by spirometry. Concentration of vitamin D (25(OH)D3) was measured using a commercial ELISA kit. Smoking history was assessed and BMI was calculated for all individuals.

RESULTS

The vitamin D level was lower in asthmatics than in the control group (14.36±0.57 vs. 22.13±0.84 ng/mL, P<0.01). There were no significant differences in the vitamin D level between the groups with allergic and non-allergic asthma (14.36±0.77 vs. 14.35±0.74 ng/mL). The low vitamin D level increased the risk of asthma 1.2 times (OR, 1.194; 95% CI, 1.109-1.286, P<0.01). The vitamin D level did not correlate with lung function and markers of allergy in asthmatic patients. The vitamin D level correlated with FEV1/FVC (rs=0.72, P<0.05) in smoking patients with asthma. Correlation between the vitamin D level and BMI was found in all studied subjects (rs=-0.18, P<0.05).

CONCLUSIONS

The vitamin D level was lower in asthmatic patients than in healthy individuals despite their hypersensitivity and increase risk of asthma. There was no relation between the vitamin D level and lung function, eosinophil count and total IgE level, whereas the lower vitamin D level was associated with higher BMI.

Reduced sinonasal levels of 1α-hydroxylase are associated with worse quality of life in chronic rhinosinusitis with nasal polyps

BACKGROUND

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have deficiencies in circulating and sinonasal levels of the inactive form of vitamin D3, 25-hydroxycholecalciferol (25VD3). Moreover, CRSwNP patients have reduced epithelial cell-specific expression of 1α-hydroxylase; the enzyme responsible for the conversion of 25VD3 to its metabolically active form, 1α,25-dihydroxyvitamin D3 (1,25VD3). The objective of this work was to determine the impact of sinonasal 1α-hydroxylase levels combined from all cellular sources on subjective disease severity and to identify variables influencing its expression.

METHODS

Blood and sinus tissue explants were collected at the time of surgery from control, chronic rhinosinusitis without nasal polyps (CRSsNP), CRSwNP, and allergic fungal rhinosinusitis (AFRS) patients. 1α-Hydroxylase was measured by immunostaining with flow cytometric analysis. Subjective disease severity was measured by the 22-item Sino-Nasal Outcomes Test (SNOT-22). 1,25VD3 and 25VD3 were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Patients with CRSwNP or AFRS have reduced 1α-hydroxylase and 1,25VD3 compared to controls or CRSsNP. Circulating 1,25VD3 levels were the same among all groups. No differences in sinonasal 1α-hydroxylase or 1,25VD3 were found between CRSwNP and AFRS. Gender, age, race, atopy, and systemic 25VD3 had no impact on sinonasal 1α-hydroxylase levels in any group. However, CRSwNP patients with asthma had higher 1α-hydroxylase than those without asthma. Total 1α-hydroxylase levels inversely correlated with SNOT-22 in CRSwNP, but not CRSsNP.

CONCLUSION

Patients with CRSwNP and AFRS both have reduced sinonasal 1α-hydroxylase and 1,25VD3 compared to controls or CRSsNP. Reductions in intracellular 1α-hydroxylase combined from all sinonasal cell types were associated with more severe subjective disease severity in CRSwNP.

Vitamin D and the development of allergic disease: how important is it?

Vitamin D has known effects on lung development and the immune system that may be important in the development, severity, and course of allergic diseases (asthma, eczema, and food allergy). Vitamin D deficiency is prevalent worldwide and may partly explain the increases in asthma and allergic diseases that have occurred over the last 50-60 years. In this review, we explore past and current knowledge on the effect of vitamin D on lung development and immunomodulation and present the evidence of its role in allergic conditions. While there is growing observational and experimental evidence for the role of vitamin D, well-designed and well-powered clinical trials are needed to determine whether supplementation of vitamin D should be recommended in these disorders.

Antenatal endotoxin disrupts lung vitamin D receptor and 25-hydroxyvitamin D 1α-hydroxylase expression in the developing rat

Vitamin D [vit D; 1,25-(OH)2D] treatment improves survival and lung alveolar and vascular growth in an experimental model of bronchopulmonary dysplasia (BPD) after antenatal exposure to endotoxin (ETX). However, little is known about lung-specific 1,25-(OH)2D3 regulation during development, especially regarding maturational changes in lung-specific expression of the vitamin D receptor (VDR), 1α-hydroxylase (1α-OHase), and CYP24A1 during late gestation and the effects of antenatal ETX exposure on 1,25-(OH)2D3 metabolism in the lung. We hypothesized that vit D regulatory proteins undergo maturation regulation in the late fetal and early neonatal lung and that prenatal exposure to ETX impairs lung growth partly through abnormal endogenous vit D metabolism. Normal fetal rat lungs were harvested between embryonic day 15 and postnatal day 14. Lung homogenates were assayed for VDR, 1α-OHase, and CYP24A1 protein contents by Western blot analysis. Fetal rats were injected on embryonic day 20 with intra-amniotic ETX, ETX + 1,25-(OH)2D3, or saline and delivered 2 days later. Pulmonary artery endothelial cells (PAECs) from fetal sheep were assessed for VDR, 1α-OHase, and CYP24A1 expression after treatment with 25-(OH)D3, 1,25-(OH)2D3, ETX, ETX + 25-(OH)D3, or ETX + 1,25-(OH)2D3. We found that lung VDR, 1α-OHase, and CYP2741 protein expression dramatically increase immediately before birth (P < 0.01 vs. early fetal values). Antenatal ETX increases CYP24A1 expression (P < 0.05) and decreases VDR and 1α-OHase expression at birth (P < 0.001), but these changes are prevented with concurrent vit D treatment (P < 0.001). ETX-induced reduction of fetal PAEC growth and tube formation and lung 1α-OHase expression are prevented by vit D treatment (P < 0.001). We conclude that lung VDR, 1α-OHase, and CYP24A1 protein content markedly increase before birth and that antenatal ETX disrupts lung vit D metabolism through downregulation of VDR and increased vit D catabolic enzyme expression, including changes in developing endothelium. We speculate that endogenous vitamin D metabolism modulates normal fetal lung development and that prenatal disruption of vit D signaling may contribute to impaired postnatal lung growth at least partly through altered angiogenic signaling.

Vitamin D Levels Are Unrelated to the Severity of Respiratory Syncytial Virus Bronchiolitis Among Hospitalized Infants

BACKGROUND

Vitamin D deficiency at birth has been reported as a risk factor for respiratory syncytial virus (RSV) lower respiratory tract infection during the first year of life. Limited data are available on whether an infant's vitamin D status is associated with the severity of acute RSV bronchiolitis.

METHODS

Infants < 1 year of age and hospitalized with their first episode of RSV bronchiolitis were enrolled into the RSV Bronchiolitis in Early Life II cohort. We investigated the relationships between vitamin D status at enrollment and the following indicators of bronchiolitis severity: duration of hospitalization, lowest oxygen saturation measured during hospitalization, and bronchiolitis severity score.

RESULTS

Among the 145 enrolled infants, the median (quartile 1 [Q1], Q3) serum 25-OH-VitD level was 36.8 (29.8, 42.3) ng/mL, with 14 infants (9.7%) having deficient serum vitamin D levels (25-OH-VitD <20 ng/mL). Vitamin D-deficient infants were younger than infants with 25-OH-VitD ≥ 20 ng/mL (2.8 vs 4.5 months, respectively; P = .04) and were less likely to consume infant's formula (42.9% vs 87.0%, respectively; P < .01). The following indicators of acute bronchiolitis severity did not differ between infants who were vitamin D-deficient and nondeficient: duration of hospitalization (P = .53), lowest oxygen saturation (P = .45), and bronchiolitis severity score (P = .97), even after adjusting for age, and for infant's formula consumption.

CONCLUSIONS

Among this cohort of infants that were hospitalized for RSV bronchiolitis, vitamin D status at the time of bronchiolitis was not associated with indicators of acute bronchiolitis severity.

Vitamin D Supplementation for Childhood Asthma: A Systematic Review and Meta-Analysis

Importance

There is growing evidence that vitamin D plays a role in the pathogenesis of asthma but it is unclear whether supplementation during childhood may improve asthma outcomes.

Objectives

The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of vitamin D supplementation as a treatment or adjunct treatment for asthma.

Data Sources

We searched MEDLINE, Embase, CENTRAL, and CINAHL through July 2014.

Study Selection

We included RCTs that evaluated vitamin D supplementation in children versus active control or placebo for asthma.

Data Extraction and Synthesis

One reviewer extracted data and one reviewer verified data accuracy. We qualitatively summarized the main results of efficacy and safety and meta-analyzed data on comparable outcomes across studies. We used GRADE for strength of evidence.

Main Outcome Measures

Main planned outcomes measures were ED visits and hospitalizations. As secondary outcomes, we examined measures of asthma control, including frequency of asthma exacerbations, asthma symptom scores, measures of lung function, β₂-agonist use and daily steroid use, adverse events and 25-hydroxyvitamin D levels.

Results

Eight RCTs (one parallel, one crossover design) comprising 573 children aged 3 to 18 years were included. One study (moderate-quality, n = 100) reported significantly less ED visits for children treated with vitamin D. No other studies examined the primary outcome (ED visits and hospitalizations). There was a reduced risk of asthma exacerbations in children receiving vitamin D (low-quality; RR 0.41, 95% CI 0.27 to 0.63, 3 studies, n = 378). There was no significant effect for asthma symptom scores and lung function. The serum 25(OH)D level was higher in the vitamin D group at the end of the intervention (low-quality; MD 19.66 nmol/L, 95% CI 5.96 nmol/L to 33.37 nmol/L, 5 studies, n = 167).

Limitations

We identified a high degree of clinical diversity (interventions and outcomes) and methodological heterogeneity (sample size and risk of bias) in included trials.

Conclusions and Relevance

Randomized controlled trials provide some low-quality evidence to support vitamin D supplementation for the reduction of asthma exacerbations. Evidence on the benefits of vitamin D supplementation for other asthma-related outcomes in children is either limited or inconclusive. We recommend that future trials focus on patient-relevant outcomes that are comparable across studies, including standardized definitions of asthma exacerbations.

The effect of vitamin D on airway reactivity and inflammation in asthmatic children: A double-blind placebo-controlled trial

BACKGROUND

Cross-sectional studies have reported an association of vitamin D deficiency with increased asthma prevalence and severity, and with allergies. The effect of vitamin D as sole therapy on airway hyper-reactivity (AHR) and airway inflammation has not been reported.

AIM

To evaluate the effect of vitamin D therapy on AHR as assessed by methacholine concentration, causing a 20% reduction in FEV1 (PC20 -FEV1 ) and fractional exhaled nitric oxide (FeNO), systemic markers of allergy and inflammation, and exhaled breath condensate cytokines.

PATIENTS AND METHODS

Children aged 6-18 years with a clinical diagnosis of mild asthma currently not receiving anti-inflammatory therapy and with low vitamin D levels were included in this randomized, double-blind, placebo-controlled study assessing the effect of 6 weeks of treatment with oral vitamin D 14,000 units once weekly or placebo.

RESULTS

Of the 39 patients included, 20 received vitamin D treatment and 19 received a placebo. Vitamin D replacement resulted in a significant increase in vitamin levels, which remained unchanged in the placebo group (P < 0.0001). There was no change in IgE, eosinophil count, high sensitivity C-reactive protein, FeNO levels or PC20 -FEV1 following treatment. Similar values of exhaled breath condensate cytokines (IL4, IL5, IL10, IL17, and γ interferon) were observed in both groups.

CONCLUSIONS

In our small group of children with mild asthma, no difference could be demonstrated between the effect of vitamin D and placebo, despite significant increases in vitamin D blood levels. Larger interventional studies are needed to fully explore the possible effect of vitamin D in asthma.

Vitamin D as a Marker for Disease Severity in Chronic Urticaria and Its Possible Role in Pathogenesis

BACKGROUND

Chronic urticaria is defined as repeated episodes of wheals lasting for 6 weeks or longer. Nowadays, the role of vitamin D in various chronic diseases is a matter of great interest, but limited data is available on the vitamin D status in patients with chronic urticaria.

OBJECTIVE

The goal of this study was to investigate the relationship between vitamin D status and clinical characteristics of chronic urticaria.

METHODS

The clinical records of 72 patients with chronic urticaria, 26 with acute urticaria and 26 with atopic dermatitis, along with 72 healthy controls, were retrospectively reviewed.

RESULTS

The serum 25-(OH)D3 level was found to be significantly reduced in patients with chronic urticaria compared to those in the other groups. In particular, the proportion of patients with critically low vitamin D levels (<10 ng/ml) was significantly higher in the chronic urticaria group than in the other groups. The serum vitamin D levels showed significant negative associations with urticaria activity score and disease duration. In addition, serum vitamin D levels were significantly lower in subjects with a positive autologous serum skin test than in subjects with a negative result.

CONCLUSION

In conclusion, the serum vitamin D level was more likely to be critically low in patients with chronic urticaria, and an inverse relationship with disease severity and disease duration was observed. These findings may open up the possibility of the clinical use of vitamin D as a contributing factor in the pathogenesis of chronic urticaria and a predictive marker for disease activity in chronic urticaria.

Asthma in Latin America

Consistent with the diversity of Latin America, there is profound variability in asthma burden among and within countries in this region. Regional variation in asthma prevalence is likely multifactorial and due to genetics, perinatal exposures, diet, obesity, tobacco use, indoor and outdoor pollutants, psychosocial stress and microbial or parasitic infections. Similarly, non-uniform progress in asthma management leads to regional variability in disease morbidity. Future studies of distinct asthma phenotypes should follow-up well-characterised Latin American subgroups and examine risk factors that are unique or common in Latin America (eg, stress and violence, parasitic infections and use of biomass fuels for cooking). Because most Latin American countries share the same barriers to asthma management, concerted and multifaceted public health and research efforts are needed, including approaches to curtail tobacco use, campaigns to improve asthma treatment, broadening access to care and clinical trials of non-pharmacological interventions (eg, replacing biomass fuels with gas or electric stoves).

Asthma and obesity: mechanisms and clinical implications

Obesity is the most common asthma co-morbidity; it has been associated with increased risk for asthma exacerbations, worse respiratory symptoms and poor control. The exact mechanisms remain elusive and are probably multifactorial, stemming from mechanical alterations of the airways and lung parenchyma, to systemic and airway inflammatory and metabolic dysregulation that adversely influences lung function and or response to therapy. However, the fact that not every obese asthmatic is equally affected by weight gain highlights the many challenges and complexities in understanding this association. The factors that determine susceptibility may not depend on being obese alone, but rather the interactions with other phenotypical characteristics, such as age of asthma onset, gender and race to name a few. Inability to account for asthma phenotypes that are differentially affected by increasing body mass index (BMI) may contribute to the lack of consistent results across studies. This review will provide a succinct summary of obesity-related mechanisms and the clinical impact on asthma including highlights on recent progress.

Vitamin D supplementation decreases Aspergillus fumigatus specific Th2 responses in CF patients with aspergillus sensitization: a phase one open-label study

BACKGROUND

Patients with cystic fibrosis (CF) complicated by allergic bronchopulmonary aspergillosis (ABPA) are vitamin D deficient and in vitro treatment with 1,25 (OH)2 vitamin D3 of CD4+ cells from CF patients with ABPA decreases Aspergillus fumigatus(Af)-induced Th2 responses. This Phase I clinical trial investigated the safety and effectiveness of daily vitamin D3 supplementation in CF patients with ABPA to reduce allergic responses and ABPA symptoms, and increase serum vitamin D levels.

METHODS

Seven patients ages 12 years and older with a clinical diagnosis of CF and ABPA with current evidence of Af sensitization received 4000 IU vitamin D3 (cholecalciferol) daily for 24 weeks. The primary outcome of the study was safety followed by the Aspergillus induced IL-13 response in CD4+ T cells to test the hypothesis that vitamin D supplementation is safe and reduces Aspergillus induced IL-13 responses in CD4+ T cells. Secondary outcomes included total IgE, Aspergillus-specific IgE, vitamin D levels, FEV1, urinary calcium/creatinine ratio, and cytokine production by Aspergillus-stimulated peripheral blood T cells.

RESULTS

Six months of vitamin D3 supplementation resulted in significant increases in serum 25-(OH) vitamin D level, and the treatment was well tolerated without evidence of vitamin D toxicity or hypercalcemia. There were no serious adverse events. Daily vitamin D supplementation led to significantly decreased Aspergillus induced IL-13 responses between the baseline visit and that at 24 weeks (p = 0.04). Aspergillus-specific IgE level was also significantly decreased after 8 (p = 0.035) and 24 weeks of daily vitamin D supplementation (p = 0.04).

CONCLUSIONS

4000 IU vitamin D3 daily over a 24-week period is well tolerated in CF patients with a history ABPA and current evidence of Th2 immunity to Af. . Daily vitamin D supplementation was associated with reduced Aspergillus induced IL-13 responses from peripheral. . CD4+ T cells and Aspergillus-specific IgE levels, as well as increased serum vitamin D levels. This treatment was well tolerated and the study supports further investigation of the use of vitamin D supplementation in Th2 mediated diseases.

TRIAL REGISTRATION

This trial was registered at www.clinicaltrials.gov as NCT01222273.

Serum vitamin D levels in a cohort of adult and pediatric patients with eosinophilic esophagitis

BACKGROUND

Vitamin D deficiency has been associated with increased risk for severe asthma, challenge-proven food allergy, and severe atopic dermatitis. Vitamin D levels have not been reported in patients with eosinophilic esophagitis (EoE).

OBJECTIVE

To determine levels of 25-hydroxyvitamin D in a cohort of patients with EoE.

METHODS

Total serum 25-hydroxyvitamin D was measured using liquid chromatography with tandem mass spectroscopy in adults (n = 35) and children (n = 34) with EoE. Results were compared with patient demographics, EoE-specific disease parameters, markers of sensitization, and features of severity using multivariable logistic regression.

RESULTS

The median vitamin D level was 28.9 ng/mL. Patients with insufficient vitamin D (<30 ng/mL) were older (median 25.5 vs 16.2 years) and had a higher body mass index (median 25.2 vs 19.8 kg/m(2)). Peak median esophageal eosinophil counts were not significantly different for vitamin D insufficient and sufficient patient groups; however, higher vitamin D levels correlated with higher histologic eosinophil counts (R = 0.61, P = .03). Although there were no statistical differences in total IgE or levels of specific IgE between patients with vitamin D insufficiency and those with sufficiency, a positive skin prick test reaction to peanut was more common in patients who had vitamin D insufficiency (adjusted odds ratio 7.57, P = .009). Vitamin D insufficiency was not associated with surrogate markers of severity (dilation in adults or hospitalization or emergency visits in children).

CONCLUSION

In these patients with EoE, vitamin D levels were low overall (median <30 ng/mL). The only marker of sensitization associated with insufficient vitamin D in these patients with EoE was a positive skin prick test reaction to peanut.

Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE)

An increasing recognition has emerged of the complexities of the global health agenda—specifically, the collision of infections and noncommunicable diseases and the dual burden of over- and undernutrition. Of particular practical concern are both 1) the need for a better understanding of the bidirectional relations between nutritional status and the development and function of the immune and inflammatory response and 2) the specific impact of the inflammatory response on the selection, use, and interpretation of nutrient biomarkers. The goal of the Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE) is to provide guidance for those users represented by the global food and nutrition enterprise. These include researchers (bench and clinical), clinicians providing care/treatment, those developing and evaluating programs/interventions at scale, and those responsible for generating evidence-based policy. The INSPIRE process included convening 5 thematic working groups (WGs) charged with developing summary reports around the following issues: 1) basic overview of the interactions between nutrition, immune function, and the inflammatory response; 2) examination of the evidence regarding the impact of nutrition on immune function and inflammation; 3) evaluation of the impact of inflammation and clinical conditions (acute and chronic) on nutrition; 4) examination of existing and potential new approaches to account for the impact of inflammation on biomarker interpretation and use; and 5) the presentation of new approaches to the study of these relations. Each WG was tasked with synthesizing a summary of the evidence for each of these topics and delineating the remaining gaps in our knowledge. This review consists of a summary of the INSPIRE workshop and the WG deliberations.

Bronchial asthma and hypovitaminosis D in Saudi children

BACKGROUND

Asthma, a common lung disease in children, is caused by excessive immune responses to environmental antigens.

OBJECTIVE

Given the immuno-modulatory properties of vitamin D, the aim of the current study was to investigate the relationship between vitamin D levels and markers of asthma severity.

METHODS

This was investigated in a 70 Saudi children with and without asthma and were recruited from the King Abdul Aziz University Hospital, Jeddah, Saudi Arabia, over the period of 11 months (May 2011-April 2012). Childhood asthma control test instrument was employed to assess the level of asthma control among asthmatic patients. Anthropometric measurements were taken and interviewer-administrated questionnaire was completed for all study participants. Pulmonary function test was performed by recording changes in the peak expiratory flow. Venous blood samples were withdrawn for measurements of vitamin D, bone profile, cytokines profile (interleukin-10, tumor necrosis factor-alpha, platelets derived growth factor), and atopy markers (IgE and eosinophil count).

RESULTS

Hypovitaminosis D is highly prevalent among asthmatic children with highly significant increase in several markers of allergy and asthma severity as compared with healthy control children. Significant correlations between several inflammatory and immunological markers and vitamin D levels were also found. Finally, lower 25-hydroxyvitamin D levels were associated with a higher asthma prevalence in multivariable analysis.

CONCLUSION

Our study showed that hypovitaminosis D is highly prevalent in the whole population in addition to a highly significant increase in several markers of allergy and asthma severity among asthmatic children as compared with healthy control children.

Association between vitamin D deficiency and insufficiency and the risk of childhood asthma: evidence from a meta-analysis

OBJECTIVE

Whether vitamin D deficiency and insufficiency are associated with childhood asthma remains unclear. Thus, we conducted a meta-analysis to summarize the evidence from epidemiological studies of vitamin D deficiency and insufficiency and the risk of childhood asthma.

METHODS

Pertinent studies were identified by searching of PubMed and Web of Knowledge. The random effect model was used to combine the results. Meta-regression and subgroups analyses were used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Egger's regression asymmetry test.

RESULTS

Finally, 14 articles with 15 studies including 3424 cases for vitamin D deficiency and 9 articles with 10 studies including 2756 cases for vitamin D insufficiency were included in this meta-analysis. The relative risk (95% confidence interval) of childhood asthma risk for vitamin D deficiency was 1.684 (1.321-2.148), and the associations were significant in America and Europe. Significant association of childhood asthma between vitamin D insufficiency and childhood asthma risk was found overall [1.577 (1.230-2.023)] and the subgroups of America, Europe and Asia. No evidence of significant publication bias between vitamin D deficiency and insufficiency and childhood asthma risk were found.

CONCLUSIONS

Results from this meta-analysis suggested that vitamin D deficiency and insufficiency might increase the risk of childhood asthma.

The role of circulating 25 hydroxyvitamin D in asthma: a systematic review

Asthma is a major public health issue. The co-occurrence of the high prevalence of asthma and vitamin D deficiency documented globally in recent decades has prompted several investigations into a possible association between the two conditions. The objective of this paper was to synthesize the evidence from studies that have measured the association between serum vitamin D and asthma incidence, prevalence, severity and exacerbations. A systematic search of the literature was performed in PubMed, and the available evidence was summarized both qualitatively and by meta-analysis. Only English language, observational studies measuring serum levels of 25(OH)D as the exposure were included, as this is the most robust measure of vitamin D levels. The search identified 23 manuscripts: two case-control, 12 cohort and nine cross-sectional studies. Collectively, the evidence suggests that higher serum levels of 25(OH)D are associated with a reduced risk of asthma exacerbations, but there was little evidence to suggest an association with asthma incidence, prevalence or severity. A significant amount of heterogeneity between study methodology and results restricted the scope for meta-analysis. These results suggest that vitamin D supplementation may be effective for the prevention of asthma exacerbations, but the findings need to be confirmed by clinical trials.

Vitamin D deficiency and acute vaso-occlusive complications in children with sickle cell disease

BACKGROUND

Vitamin D is increasingly recognized for its roles in non-skeletal disorders. Patients with sickle cell disease (SCD) have a high prevalence of vitamin D deficiency but data are limited with respect to possible associations between low vitamin D and acute vaso-occlusive complications. We examined whether vitamin D deficiency is associated with acute pain and acute chest syndrome (ACS) in children with SCD.

PROCEDURE

A cross-sectional study was conducted in 95 children with SCD who had serum 25-hydroxyvitamin D (25-OHD) measured during comprehensive care examinations. History of acute pain and ACS within two years of obtaining 25-OHD was collected. Associations between 25-OHD levels and acute vaso-occlusive events were analyzed by logistic regression. Odds ratios and 95% confidence intervals were calculated for the risk of pain and ACS associated with vitamin D deficiency (25-OHD <20 ng/ml).

RESULTS

Subjects were 3-20 years old (median 10.6); 48 males, 47 females; 46 African, 49 Hispanic; 72 SS, 20 SC, 1 S/β(0) Thalassemia, and 2 S/β(+) Thalassemia. Median 25-OHD was 16 ng/ml. Fifty-six (59%) were vitamin D-deficient. Thirty-one (33%) and 29 (31%) had at least one episode of pain and ACS, respectively. Serum 25-OHD was significantly associated with pain (P = 0.0121) but not with ACS (P = 0.628). Of those with pain, 73% (23/31) were vitamin D-deficient while 26% (8/31) had 25-OHD ≥20 ng/ml (P = 0.04, OR = 2.7, 95%CI = 1.05-6.94).

CONCLUSIONS

Our findings emphasize the high prevalence of vitamin D deficiency and its potential association with acute pain in SCD. Correcting low vitamin D may offer a simple, low-cost intervention to help reduce acute vaso-occlusive complications.

Effect of different 1, 25-(OH)2D3 doses on high mobility group box1 and toll-like receptors 4 expression in lung tissue of asthmatic mice

We established a mouse model of asthmatic airway remodeling. To investigate the effects of different doses of 1,2 5-(OH)2D3 on airway remodeling, expression of high mobility group box 1 (HMGB1) and Toll-like receptors 4 (TLR4) in asthmatic mice. The female mice (BALB/c) groups consisted of a control group, asthma group and 1,2 5-(OH)2D3 low, middle, high dose group. Each group contained 10 mice. An asthmatic mice model was induced by ovalbumin. The control group and asthma group used physiological saline instead. 1,2 5-(OH)2D3 low, middle and high dose group was given different doses of 1,2 5-(OH)2D3 respectively. Changes in mice airway structure were observed by hematoxylin-eosin (H&E). The expression of HMGB1 and TLR4 in molecular lever were monitored by RT-PCR. We used immunohistochemistry to test HMGB1 and TLR4 protein levels. Obvious changes were noted in the airway of OVA-induced asthma mice compared with the control group by HE. These changes were less pronounced in mice receiving the low and middle doses of 1,2 5-(OH)2D3, but were more pronounced in mice receiving the highest dose of 1,2 5-(OH)2D3. Immunohistochemistry showed that expression of HMGB1 and TLR4 in the asthma group was higher than the control group. And low and middle dose group was decreased compared with asthma group, while higher than the control group; high dose group had an increased expression compared with the asthma group. From RT-PCR we got the same results as immunohistochemistry. In the asthmatic airway remodeling animal model, the appropriate amount of 1,2 5-(OH)2D3 reduced airway remodeling in asthmatic mice, and decreased the expression of HMGB1 and TLR4 in the asthmatic mice. However, over dose might play detrimental effect.

Identification and characterization of a vitamin D₃ decomposition product bactericidal against Helicobacter pylori

This study demonstrated that the vitamin D₃ decomposition product VDP1 exerts an antibacterial action against Helicobacter pylori but not against other bacteria. Treatment with VDP1 induced a collapse of cell membrane structures of H. pylori and ultimately lysed the bacterial cells. A unique dimyristoyl phosphatidylethanolamine in the membrane lipid compositions contributed to the interaction of VDP1 with H. pylori cells. In separate experiments, VDP1 had no influence on the viability of the human cancer cell lines MKN45 and T47D and lacked any vitamin D₃-like hormonal action against the latter. In both ¹H and ¹³C NMR analyses, the spectra patterns of VDP1 corresponded with those of Grundmann's ketone. These results suggest that VDP1 (or Grundmann's ketone-type indene compound) may become a fundamental structure for the development of new antibacterial substances with selective bactericidal action against H. pylori.

Vitamin D as an adjunctive therapy in asthma. Part 2: A review of human studies

Vitamin D deficiency (VDD) is highly prevalent worldwide, with adverse effects on bone health but also potentially other unfavorable consequences. VDD and asthma-incidence/severity share many common risk factors, including winter season, industrialization, poor diet, obesity, dark skin pigmentation, and high latitude. Multiple anatomical areas relevant to asthma contain both the enzyme responsible for producing activated vitamin D and the vitamin D receptor suggesting that activated vitamin D (1,25-dihydroxyvitamin D) may have important local effects at these sites. Emerging evidence suggests that VDD is associated with increased airway hyperresponsiveness, decreased pulmonary function, worse asthma control, and possibly decreased response to standard anti-asthma therapy. However the effect is inconsistent with preliminary evidence from different studies suggesting vitamin D is both beneficial and detrimental to asthma genesis and severity. Current evidence suggests that supplementation with moderate doses of vitamin D may be appropriate for maintenance of bone health in asthmatics, particularly steroid users. However emerging data from an increasing number of randomized, controlled, intervention studies of vitamin D supplementation in pediatric and adult asthma are becoming available and should help determine the importance, if any of vitamin D for asthma pathogenesis. The purpose of this second of a two-part review is to review the current human literature on vitamin D and asthma, discussing the possible consequences of VDD for asthma and the potential for vitamin D repletion as adjunct therapy.

Prevalence of vitamin D deficiency in sickle cell disease: a systematic review

Vitamin D deficiency has emerged as a public health focus in recent years and patients with sickle cell disease (SCD) reportedly have a high prevalence of the condition. Our objectives were to summarize definitions of vitamin D deficiency and insufficiency used in the literature, and to determine the prevalence and magnitude of each in patients with SCD through a systematic review conducted according to PRISMA guidelines. From a PubMed search, 34 potential articles were identified and 15 met eligibility criteria for inclusion. Definitions of deficiency and insufficiency varied greatly across studies making direct comparisons difficult. This review provides evidence to suggest that suboptimal vitamin D levels are highly prevalent among those with SCD, far more so than in comparable non-SCD patients or matched control populations. Defining deficiency as vitamin D < 20 ng/mL, prevalence estimates in SCD populations range from 56.4% to 96.4%. When compared with results from the population-based National Health and Nutrition Examination Survey, however, the general African American population appeared to have a similarly high prevalence of vitamin D deficiency. African American patients with and without SCD were both substantially higher than that of Caucasians. What remains to be determined is whether there are adverse health effects for patients with SCD because of concurrent vitamin D deficiency.

Race differences in the association between multivitamin exposure and wheezing in preterm infants

OBJECTIVE

We aimed to determine whether vitamin D exposure, as estimated by use of multivitamins, is positively or negatively associated with recurrent wheezing in infants born preterm.

STUDY DESIGN

This prospective cohort study enrolled 300 infants, born at 28(0/7) to 34(6/7) weeks gestational age, and conducted follow-up at 3-, 6-, 9- and 12-month adjusted age.

RESULT

Black (55.9%) and non-black (36.6%) infants experienced recurrent wheezing. Adjusted odds ratios (ORs) for the association between multivitamin exposure at 3 months and recurrent wheezing were 2.15 (95% confidence interval (CI): 0.97, 4.75) for black and 0.43 (95% CI: 0.19, 0.96) for non-black infants with an interaction by race (P=0.003). In lag-effect models, ORs were 2.69 (95% CI: 1.41, 5.14) for black and 0.50 (95% CI: 0.27, 0.92) for non-black infants.

CONCLUSION

Differences by race were seen in association between multivitamins and wheezing; population heterogeneity should be considered when evaluating vitamin supplementation.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

Hypovitaminosis D: a novel finding in primary ciliary dyskinesia

Background

A relationship between low levels of serum vitamin D and respiratory infections has been established. No study has examined the frequency and clinical relevance of vitamin D deficiency in patients with primary ciliary dyskinesia (PCD).

Methods

Vitamin D levels were measured in 22 PCD patients (7 females, 10.5 years, range, 2–34 years). In PCD, pulmonary function tests (PFTs), sputum microbiology, self-reported physical activity (PA) level, and quality of life (QoL) by means of the Saint George’s Respiratory Questionnaire (SGRQ), were also assessed.

Results

Seventy-two percent of PCD patients were vitamin-D deficient-to-insufficient and 28% were sufficient. No differences in PFTs parameters were found between vitamin D deficiency-to-insufficiency and sufficiency groups. Patients with vitamin D deficiency-to-insufficiency had significantly higher SGRQ total scores, and thus poorer QoL (p = 0.03). Seventy-nine percent of PCD subjects had limitations in performing vigorous activities, and 53% performed less than 3 hours of PA per week. Vitamin D deficiency-to-insufficiency and sufficiency groups did not show any differences in age at PCD diagnosis or at onset of respiratory symptoms, BMI, atopy, current asthma or bronchiectasis. However, 79% of patients with bronchiectasis had vitamin D deficiency-to-insufficiency. No differences were found in the rate of positive sputum cultures and in the number of antibiotic courses between the two groups.

Conclusions

Hypovitaminosis D is common in PCD patients, and is associated with poorer QoL. We recommend the assessment and treatment of hypovitaminosis D to be included in the routine management of PCD.