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

Vitamin D deficiency in children with bronchial asthma in southern Jordan: a cross-sectional study

Objectives

To assess serum 25-hydroxycholecalciferol (25-OH vitamin D) levels in Jordanian children with bronchial asthma, and to examine correlations between 25-OH vitamin D levels and asthma severity and control.

Methods

A cross-sectional study was conducted at the Paediatric Chest Clinic, Al-Karak Governmental Hospital, Southern Jordan, between May 2015 and February 2016. Serum 25-hydroxyvitamin D level was determined in children aged 1–14 years diagnosed with bronchial asthma (6–14 years) or recurrent wheezing episodes (<6 years). Asthma severity was determined based on the Global Initiative for Asthma assessment, the Asthma Control Test, and the Childhood Asthma Control Test. Demographic and clinical characteristics were compared between patients with low and normal 25-OH vitamin D levels, and correlations between asthma severity and 25-OH vitamin D level were assessed.

Results

Out of 98 included children, 25-OH vitamin D levels were deficient and insufficient in 41 (41.8%) and 34 (34.7%) children, respectively. Only 23 (23.5%) had sufficient 25-OH vitamin D levels. A significant correlation was found between severity of asthma symptoms and 25-OH vitamin D deficiency.

Conclusion

25-OH vitamin D deficiency is highly prevalent in Jordanian children with bronchial asthma and correlates significantly with asthma severity.

The role of nutrition in asthma prevention and treatment

Asthma is a chronic respiratory condition characterized by airway inflammation and hyperreactivity. Prevalence has continued to rise in recent decades as Western dietary patterns have become more pervasive. Evidence suggests that diets emphasizing the consumption of plant-based foods might protect against asthma development and improve asthma symptoms through their effects on systemic inflammation, oxidation, and microbial composition. Additionally, increased fruit and vegetable intake, reduced animal product consumption, and weight management might mediate cytokine release, free radical damage, and immune responses involved in the development and course of asthma. The specific aim of this review paper is to examine the current literature on the associations between dietary factors and asthma risk and control in children and adults. Clinical trials examining the mechanism(s) by which dietary factors influence asthma outcomes are necessary to identify the potential use of nutritional therapy in the prevention and management of asthma.

Milk Consumption and Respiratory Function in Asthma Patients: NHANES Analysis 2007-2012

Per the Centers for Disease Control and Prevention, asthma prevalence has steadily risen since the 1980s. Using data from the National Health and Nutrition Examination Survey (NHANES), we investigated associations between milk consumption and pulmonary function (PF). Multivariable analyses were performed, adjusted for a priori potential confounders for lung function, within the eligible total adult population (n = 11,131) and those self-reporting asthma (n = 1,542), included the following variables: milk-consumption, asthma diagnosis, forced vital capacity (FVC), FVC%-predicted (%), forced expiratory volume in one-second (FEV1), FEV1% and FEV1/FVC. Within the total population, FEV1% and FVC% were significantly associated with regular (5+ days weekly) consumption of exclusively 1% milk in the prior 30-days (β:1.81; 95% CI: [0.297, 3.325]; p = 0.020 and β:1.27; [0.16, 3.22]; p = 0.046). Among participants with asthma, varied-regular milk consumption in a lifetime was significantly associated with FVC (β:127.3; 95% CI: [13.1, 241.4]; p = 0.002) and FVC% (β:2.62; 95% CI: [0.44, 4.80]; p = 0.006). No association between milk consumption and FEV1/FVC was found, while milk-type had variable influence and significance. Taken together, we found certain milk consumption tendencies were associated with pulmonary function values among normal and asthmatic populations. These findings propound future investigations into the potential role of dairy consumption in altering lung function and asthma outcomes, with potential impact on the protection and maintenance of pulmonary health.

Can Optimum Solar Radiation Exposure or Supplemented Vitamin D Intake Reduce the Severity of COVID-19 Symptoms?

The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle-income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being.

Clinical correlates of rhinovirus infection in preschool asthma

Background

Investigation of preschool asthma is important since not all children outgrow their illness during this age. Data are scarce on the role of rhinovirus (RV) infections in this patient group.

Objectives

To investigate the role of RV infections in preschool asthma: (i) susceptibility factors, (ii) clinical course, and (iii) medium‐term outcome.

Methods

A total of 130 asthmatic children aged 4‐6 years from the multinational PreDicta cohort were prospectively followed for a 12‐month period. Allergy tests and a standard health questionnaire were carried out at study entry. Respiratory virus presence in nasopharyngeal washes was studied at illness visits and at 3 scheduled visits.

Results

At study entry, mean age of the children was 5.3 years. Of 571 visits, 54% were positive for any virus and 39% for RV. Patient characteristics were only assessed with RV infection due to low number of other viruses. The use of supplementary vitamin D was inversely associated with RV infection (P < .05). RV infection was associated with more severe course of acute illness in terms of more severe nighttime coughing, more sleep disturbances, and more days with runny nose (all P < .05). RV infection was also associated with more severe disease course during the 12‐month follow‐up in terms of more nights with awakenings and more days of exercise‐related symptoms (both P < .05).

Conclusions

Vitamin D supplementation may have an anti‐rhinovirus effect. Both short‐ and medium‐term outcomes suggest RV infection to be an important clinical marker of instable preschool asthma.

Early-onset-early-resolving atopic dermatitis does not increase the risk of development of allergic diseases at 3 Years old

BACKGROUND

Epidemiological findings showed the increased risk of allergic rhinitis (AR) and asthma in the children with preceding atopic dermatitis (AD). In this study, we aimed to observe the development of allergic diseases in infantile AD patients.

METHODS

We followed up the prospective observational cohort enrolling two-to four-month-old exclusively breastfed infants. The presence of physician-diagnosed asthma, AR and AD at age 3 was recorded with the laboratory tests for atopic sensitization.

RESULTS

Fifty infantile AD patients and 48 healthy controls were enrolled. The sex, age and parental atopy history were not significantly different between the two groups. At age 3, 21 (42%) patients had persistent AD in the infantile AD group while only 2 (4.2%) patients had newly diagnosed AD in the control group (p < 0.001). The early-onset-early-resolving AD (subsides before age 2) did not increase the risk of AR and asthma development, and the sensitization to allergens. However, the early-onset-persistent AD (persists after age 2) increased the risk of AR development and sensitization to inhalant allergens (adjusted odds ratio 2.83, 7.07, respectively). The parental atopy status was associated with any allergic disease at age 3 (p = 0.020). The maternal atopy history was the significant factor associated with AD, AR and eosinophilia at age 3 (p = 0.004, 0.014, 0.031, respectively).

CONCLUSION

The early-onset-early-resolving AD was not associated with allergic diseases development at age 3. The parental atopy history and early-onset-persistent AD might be the risk factors for development of allergic diseases at age 3.

Effect of Vitamin D Supplementation on Improvement of Symptoms in Mild-to-Moderate Asthma Patients with Vitamin D Insufficiency and Deficiency

BACKGROUND

In the current study, we assessed the effect of vitamin D supplementation on improvement of symptoms in mild-to-moderate asthma patients with vitamin D insufficiency and deficiency.

MATERIALS AND METHODS

This randomized, controlled clinical trial included 132 mild-to-moderate asthma patients with vitamin D insufficiency (n=66) and those with vitamin D deficiency (n=66). They were assigned randomly to two groups of cases (with two subgroups) and controls (with two subgroups). In the case subgroups, for patients with vitamin D deficiency, a dose of 50,000 U vitamin D supplementation was administered orally on a weekly basis and for six weeks followed by a maintenance dose of 1000 U daily. For patients with vitamin D insufficiency, a dose of 1000 U vitamin D supplementation was prescribed daily. In control group, we administered placebo. The information including asthma symptoms, parameters measured by spirometer (Forced Vital Capacity-FVC, Forced Expiratory Volume in one second-FEV1) and 25-hydroxyvitamin D [25(OH)D] concentration was collected at baseline and three months later and analyzed using SPSS, Version 20.

RESULTS

Improvement of FEV1/FVC ratios were found in both groups but this improvement in both case subgroups of patients with vitamin D insufficiency and deficiency suggested more appropriate results compared to control group (P-value=0.022). Moreover, the correlation between changes in 25(OH)D level and changes in FEV1 was positive and significant in patients receiving vitamin D supplementation within a three-month follow up (r=0.202, P-value=0.042).

CONCLUSION

According to the results, vitamin D supplementation can be associated with the improvement of asthma symptoms and lung function in mild-to-moderate asthma patients with vitamin D insufficiency and deficiency.

Small Airway Disease in Pediatric Asthma: the Who, What, When, Where, Why, and How to Remediate. A Review and Commentary

Asthma affects all portions of the airways. Small airways, however, comprise a substantial component of the conducting lung air flow. In asthma, inflammatory processes can affect the whole respiratory tract, from central to peripheral/small airways. The emphasis in adult and pediatric respiratory disease clinics is to focus on large airway obstruction and reversibility. This information, although valuable, underemphasizes a large portion of the conduction airway of asthmatics. Standard descriptions of asthma management focus on a multiple medication approaches. We particularly focused on the management of asthma in the international guidelines for the Global Initiative for Asthma (GINA). Overall, however, minimal attention is placed on the small airway pool in asthma medical management. We took the opportunity to thoroughly review and present specific data from the adult asthma literature which supported the concept that small airway abnormalities may play a role in the pathogenesis and clinical expression of asthma. Based on the conclusions of the adult asthma literature, we here present a thorough review of the literature as it relates to small airway disease in children with asthma. We used, collectively, individual data sources of data to expand the information available from standard diagnostic techniques, especially spirometry, in the evaluation of small airway disease. As the pharmacological approaches to moderate to severe asthma are advancing rapidly into the realm of biologics, we sought to present potential pharmacological options for small airway dysfunction in pediatrics prior to biological modifier intervention.

Vitamin D: association with eosinophil counts and IgE levels in children with asthma

In this cross-sectional study, we investigated the relationship that levels of vitamin D had with eosinophil counts and IgE levels in 26 children with asthma (6-12 years of age) in the city of Londrina, Brazil. Vitamin D levels were found to correlate significantly, albeit moderately, with age (r = −0.51) and eosinophilia (r = −0.49), although not with IgE levels (r = −0.12). When we stratified the sample into two groups by the median vitamin D level (< or ≥ 24 ng/mL), we found that those in the < 24 ng/mL group were older, had higher eosinophil counts, and had higher IgE levels. To our knowledge, this is the first study to show an association between low levels of vitamin D and more pronounced eosinophilia in children with asthma in Brazil.

Selected Micronutrients: An Option to Boost Immunity against COVID-19 and Prevent Adverse Pregnancy Outcomes in Pregnant Women: A Narrative Review

The coronavirus disease-19 (COVID-19) negatively affects immune system. It is linked with adverse pregnancy outcomes. These complications may be linked with the infections mediated deficiency of micronutrients in pregnant women. COVID-19 cause's malabsorption of micronutrients thereby increases the risk of their deficiency. Both micronutrients deficiencies and poor micronutrients intake can compromise immune function and may increase the risk of pregnancy complications associated with COVID-19 infection. Vita-min A, C, D, E, and selected minerals iron (Fe), selenium (Se), and zinc (Zn) are the micronutrients essential for immuno-competency and play a significant role in the prevention of adverse pregnancy outcomes. Immune function and pregnancy outcomes can be improved by adequate intake of micronutrients in diet or in supplements form. Based on regulatory links between viral infection, micronutrients, immunity, and pregnancy outcomes, this review highlights the role of micronutrients in boosting immunity to reduce or prevent pregnancy complications in COVID-19 infected women.

Back to basics: review on vitamin D and respiratory viral infections including COVID-19

IMPORTANCE

As the scientific community is in a marathon in finding out the cure for COVID-19, in this crisis, it is essential for the physicians not to forget about the basics. Due to the pandemic crisis, in many nursing homes and hospitals, there established new policies on decreasing unnecessary medications to minimize cross-contamination. Sometimes these policies are making providers avoid essential drugs such as Vitamins, including Vitamin D. In this paper, we try to emphasize the importance of Vitamin D in COVID-19 and respiratory viral patients.

RELEVANCE

Vitamin D helps in decreasing the 'pro-inflammatory cytokines' in the lungs and acts in immunomodulatory function, and 'also it will increase the anti-inflammatory, antiviral responses of the respiratory epithelial cells during infection.'

CONCLUSION

Due to the highly contagious nature of COVID-19 and the increased morbidity and mortality with no appropriate therapy and vaccine, one must be cautious and do everything to help COVID-19 patients. In hospitals and other health care settings to decrease cross-contamination, holding other non-essential medications is taking place. Discontinuing Vitamins could increase the mortality and morbidity of those affected, especially in deficient/insufficient individuals. Obtaining serum 25 (OH) D levels in all patients with viral respiratory infections, especially COVID-19, could help in the detection and treatment of Vitamin D deficiency and potentially decrease recovery time and improve outcome. Even though evidence suggests that vitamin D has the anti-inflammatory, antiviral properties, randomized double-blinded controlled trials are needed to verify this further, and to understand Vitamin D and COVID-19 better.

ABBREVIATIONS

Vitamin D receptor-VDR; 25(OH)D- 25 hydroxyvitamin D; 1,25 (OH)D-1,25 dihydroxy Vitamin D; 1α,25-dihydroxy Vitamin D-1,25[OH]2 D or calcitriol; IU- International Units; Interferons stimulated genes- ISG; ARI- acute respiratory infection; RSV- respiratory syncytial virus; RTI- Respiratory tract infections; COPD-Chronic obstructive pulmonary disease; BMI-Basal metabolic index; USA-USA.

Suboptimal Serum 25-Hydroxy-Vitamin D Is Associated with a History of Recent Disease Exacerbation in Pediatric Patients with Bronchial Asthma or Asthma-Suggestive Recurrent Wheezing

Even though vitamin D is widely acknowledged as having a potential immunomodulatory role in asthma, its exact beneficial mechanisms are yet to be clarified. An optimal serum 25-hydroxy-vitamin D (25-OH-VitD) level in pediatric asthma patients might not rely solely on the effect of dose-dependent vitamin D3 intake, but might also be influenced by factors related to insufficient asthma control. We aimed to survey the prevalence of serum 25-OH-VitD deficiency and analyze whether suboptimal levels were associated with asthma severity factors. The current cross-sectional study enrolled 131 pediatric asthma or asthma-suggestive recurrent wheezing patients, for whom serum 25-OH-VitD, IgE, and eosinophil count were assessed. The prevalence of suboptimal serum 25-OH-VitD was 58.8%. A suboptimal vitamin D status was associated with asthma exacerbation in the previous month (p = 0.02). Even under seasonal oral vitamin D3 supplementation, patients with a positive history of asthma attack in the previous four weeks presented significantly lower serum 25-OH-VitD concentrations, compared to their peers with no disease exacerbation. In conclusion, sequential measurements of serum 25-OH-VitD might prove useful for future studies evaluating the dynamic changes in vitamin D3 status in regard to asthma, especially in symptomatic patients.

Effect of Vitamin D3 Supplementation on Severe Asthma Exacerbations in Children With Asthma and Low Vitamin D Levels: The VDKA Randomized Clinical Trial

IMPORTANCE

Severe asthma exacerbations cause significant morbidity and costs. Whether vitamin D3 supplementation reduces severe childhood asthma exacerbations is unclear.

OBJECTIVE

To determine whether vitamin D3 supplementation improves the time to a severe exacerbation in children with asthma and low vitamin D levels.

DESIGN, SETTING, AND PARTICIPANTS

The Vitamin D to Prevent Severe Asthma Exacerbations (VDKA) Study was a randomized, double-blind, placebo-controlled clinical trial of vitamin D3 supplementation to improve the time to severe exacerbations in high-risk children with asthma aged 6 to 16 years taking low-dose inhaled corticosteroids and with serum 25-hydroxyvitamin D levels less than 30 ng/mL. Participants were recruited from 7 US centers. Enrollment started in February 2016, with a goal of 400 participants; the trial was terminated early (March 2019) due to futility, and follow-up ended in September 2019.

INTERVENTIONS

Participants were randomized to vitamin D3, 4000 IU/d (n = 96), or placebo (n = 96) for 48 weeks and maintained with fluticasone propionate, 176 μg/d (6-11 years old), or 220 μg/d (12-16 years old).

MAIN OUTCOMES AND MEASURES

The primary outcome was the time to a severe asthma exacerbation. Secondary outcomes included the time to a viral-induced severe exacerbation, the proportion of participants in whom the dose of inhaled corticosteroid was reduced halfway through the trial, and the cumulative fluticasone dose during the trial.

RESULTS

Among 192 randomized participants (mean age, 9.8 years; 77 girls [40%]), 180 (93.8%) completed the trial. A total of 36 participants (37.5%) in the vitamin D3 group and 33 (34.4%) in the placebo group had 1 or more severe exacerbations. Compared with placebo, vitamin D3 supplementation did not significantly improve the time to a severe exacerbation: the mean time to exacerbation was 240 days in the vitamin D3 group vs 253 days in the placebo group (mean group difference, -13.1 days [95% CI, -42.6 to 16.4]; adjusted hazard ratio, 1.13 [95% CI, 0.69 to 1.85]; P = .63). Vitamin D3 supplementation, compared with placebo, likewise did not significantly improve the time to a viral-induced severe exacerbation, the proportion of participants whose dose of inhaled corticosteroid was reduced, or the cumulative fluticasone dose during the trial. Serious adverse events were similar in both groups (vitamin D3 group, n = 11; placebo group, n = 9).

CONCLUSIONS AND RELEVANCE

Among children with persistent asthma and low vitamin D levels, vitamin D3 supplementation, compared with placebo, did not significantly improve the time to a severe asthma exacerbation. The findings do not support the use of vitamin D3 supplementation to prevent severe asthma exacerbations in this group of patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02687815.

Sufficient vitamin D status positively modified ventilatory function in asthmatic children following a Mediterranean diet enriched with fatty fish intervention study

Asthma in children is the most prevalent allergic disease worldwide that has become a major public health priority. The objective of this study was to examine the relationship between baseline serum vitamin D status, spirometry, and fractional exhaled nitric oxide levels (FeNO) in 64 Greek children with 'mild asthma' aged 5 to 12 years (51.6% male) in a dietary intervention study. We hypothesized that baseline serum vitamin D levels modify the beneficial response of fatty fish intake on pulmonary function in asthmatic children following a Mediterranean diet. The intervention group consumed 2 fatty fish meals/week (≥150 g cooked filleted fish/meal) as part of the Mediterranean diet for six months, and the control group consumed their usual diet. Baseline serum 25(OH)D was determined using enzyme-linked immunoassay and defined as sufficient levels of 25(OH)D ≥25 ng/mL. Only 36% of children were graded as sufficient in 25(OH)D levels on entry into the study with a higher proportion of girls insufficient than boys (61% vs 39% respectively). Participants with sufficient levels of serum 25(OH)D at baseline, consuming the intervention diet increased FEV₁/FVC by 4.89 units (β = 4.89; 95%CI: 1.19-8.61; p = 0.013) and FEF_25-75% by 12.83 units (β = 12.83; 95%CI: 4.27-21.40; p = 0.006) compared to controls. No significant differences in pulmonary function or FeNO were observed for those with insufficient levels of 25(OH) D in the intervention or control groups. In conclusion, sufficient serum vitamin D levels enhanced ventilatory function in response to a dietary intervention in asthmatic children.

Correlation between asthmatic infants with rickets and vitamin D, inflammatory factors and immunoglobulin E

Correlation between asthmatic infants with rickets and vitamin D, inflammatory factors and immunoglobulin was investigated. A total of 60 child patients with asthma who met the inclusion criteria and received treatment from January 2016 to October 2017 were collected. Among them, 17 asthmatic infants with rickets were set as observation group, while 43 child patients with simple asthma were regarded as the control group. Venous blood was drawn from the two groups of subjects after admission. The levels of interleukin-1 (IL-1), IL-6 and IL-17 in serum were determined by ELISA, vitamin D and immunoglobulin E levels in serum were detected using a fully-automatic biochemical analyzer, and wheezing duration during asthma attack was recorded. IL-1, IL-6, IL-17 and immunoglobulin E levels in serum of observation group were significantly higher than those of the control group (P<0.05). The vitamin D level in the observation group was remarkably lower than that in the control group (P<0.05). Wheezing duration in observation group was evidently longer than that in control group (P<0.05). Moreover, IL-1, IL-6, IL-17 and immunoglobulin E levels in serum were positively related to wheezing duration, but the vitamin D level was negatively associated with wheezing duration. Infantile asthma with rickets is closely correlated with vitamin D, inflammatory factors and immunoglobulin E, which are major risk factors in infantile asthma with rickets.

Analysis of 25-hydroxy cholecalciferol, immunoglobulin E, and vitamin D receptor single nucleotide polymorphisms (Apa1, Taq1, and Bsm1), among sample of Egyptian children with bronchial asthma: A case-control study

PURPOSE

The current study aimed to assess the serum levels of vitamin D and immunoglobulin E (IgE) among asthmatic Egyptian children and to find out the possible associations of vitamin D receptor (VDR) polymorphisms with bronchial asthma development.

METHODS

The study included 100 Egyptian children, 50 asthmatic children who were comparable with 50 age, sex, and body mass index-matched, unrelated healthy controls (HCs) clinical assessments of asthmatic children were done using global initiative of asthma. Pulmonary function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC ratio) were performed. Enzyme-linked immunosorbent assays of serum vitamin D3 and total IgE were done. VDR-single nucleotide polymorphisms (SNPs) (ApaI, TaqI, and BsmI) detection has performed using polymerase chain reaction through restriction fragment length polymorphism technique. Data analysis was performed using SPSS version 20.0. The studied SNPs were followed the Hardy Weinberg equation.

RESULTS

The mean serum level of 25(OH) D3 was significantly lower among asthmatic children (13.46 ng/mL ± 10.50 SD) in comparison to HCs (37.53 ng/mL ± 13. 0.40 SD), P < .05. Vitamin D deficiency was detected in 72% of cases with no significant difference in its level regarding asthma control. There was significantly higher IgE level among asthmatic children (99.83 ku/L ± 233.81 SD) versus HCs (7.52 ku/L ± 3.32 SD), P < .05. Asthmatic children were presented more commonly with TaqI t allele (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28-3.96; P < .05) and BsmI b allele (OR, 1.83; 95% CI, 1.05-3.21; P < .05). ApaI a allele was not significantly different among patients versus controls (P > .05). TT + Tt and Bb + bb genotypes were significantly higher among cases versus the controls, P < .05 for all.

CONCLUSIONS

TaqI and BsmI were associated with risk of bronchial asthma development among Egyptian children. High IgE and Low vitamin D status were frequently occurring among asthmatic children.

Evolving concepts in how viruses impact asthma: A Work Group Report of the Microbes in Allergy Committee of the American Academy of Allergy, Asthma & Immunology

Over the past decade, there have been substantial advances in our understanding about how viral infections regulate asthma. Important lessons have been learned from birth cohort studies examining viral infections and subsequent asthma and from understanding the relationships between host genetics and viral infections, the contributions of respiratory viral infections to patterns of immune development, the impact of environmental exposure on the severity of viral infections, and how the viral genome influences host immune responses to viral infections. Further, there has been major progress in our knowledge about how bacteria regulate host immune responses in asthma pathogenesis. In this article, we also examine the dynamics of bacterial colonization of the respiratory tract during viral upper respiratory tract infection, in addition to the relationship of the gut and respiratory microbiomes with respiratory viral infections. Finally, we focus on potential interventions that could decrease virus-induced wheezing and asthma. There are emerging therapeutic options to decrease the severity of wheezing exacerbations caused by respiratory viral infections. Primary prevention is a major goal, and a strategy toward this end is considered.

Vitamin D and Immunity in Infants and Children

The last couple of decades have seen an explosion in our interest and understanding of the role of vitamin D in the regulation of immunity. At the molecular level, the hormonal form of vitamin D signals through the nuclear vitamin D receptor (VDR), a ligand-regulated transcription factor. The VDR and vitamin D metabolic enzymes are expressed throughout the innate and adaptive arms of the immune system. The advent of genome-wide approaches to gene expression profiling have led to the identification of numerous VDR-regulated genes implicated in the regulation of innate and adaptive immunity. The molecular data infer that vitamin D signaling should boost innate immunity against pathogens of bacterial or viral origin. Vitamin D signaling also suppresses inflammatory immune responses that underlie autoimmunity and regulate allergic responses. These findings have been bolstered by clinical studies linking vitamin D deficiency to increased rates of infections, autoimmunity, and allergies. Our goals here are to provide an overview of the molecular basis for immune system regulation and to survey the clinical data from pediatric populations, using randomized placebo-controlled trials and meta-analyses where possible, linking vitamin D deficiency to increased rates of infections, autoimmune conditions, and allergies, and addressing the impact of supplementation on these conditions.

Gestational vitamin D deficiency impairs fetal lung development through suppressing type II pneumocyte differentiation

Gestational vitamin D deficiency is associated with pulmonary diseases. This study aimed to investigate the effect of gestational vitamin D deficiency on fetal lung development in mice. Absolute and relative weights of fetal lungs were reduced in vitamin D deficient (VDD) group. Incrassate mesenchyme, measured by septal wall thickness, accompanied by lessened saccular space, was shown in VDD group. Numerous immature type II pneumocytes, as determined by PAS staining, were observed in VDD group. Moreover, increased Ki67-positive cells, a marker of cell proliferation, was detected in VDD group. The additional experiments showed that Sftpa, Sftpb, Sftpc and Sftpd, four surfactant genes, were downregulated and pro-surfactant protein B was reduced in VDD group. FoxA1, FoxA2 and TTF-1, three transcription factors that regulate surfactant genes, and VEGF, a key regulator for pulmonary maturation, were downregulated in VDD group. These results suggest that gestational vitamin D deficiency impairs fetal lung development partially through suppressing type II pneumocyte differentiation.

Chronic Stress and Glucocorticoid Receptor Resistance in Asthma

PURPOSE

Chronic and persistent exposure to negative stress can lead to adverse consequences on health. Particularly, psychosocial factors were found to increase the risk and outcome of respiratory diseases like asthma. Glucocorticoids (GCs) are the most efficient anti-inflammatory therapy for asthma. However, a significant proportion of patients don't respond adequately to GC administration. GC sensitivity is modulated by genetic and acquired disease-related factors. Additionally, it was proposed that endogenous corticosteroids may limit certain actions of synthetic GCs, contributing to insensitivity. Psychological and physiological stresses activate the hypothalamic-pituitary-adrenal axis, increasing cortisol levels. Here, we review the mechanism involved in altered GC sensitivity in asthmatic patients under stressful situations. Strategies for modulation GC sensitivity and improving GC therapy are discussed.

METHODS

PubMed was searched for publications on psychological chronic stress and asthma, GC resistance in asthma, biological mechanisms for GC resistance, and drugs for steroid-resistant asthma, including highly potent GCs.

FINDINGS

GC resistance in patients with severe disease remains a major clinical problem. In asthma, experimental and clinical evidence suggests that chronic stress induces inflammatory changes, contributing to a worse GC response. GC resistant patients can be treated with other broad-spectrum anti-inflammatory drugs, but these generally have major side effects. Different mechanisms of GC resistance have been described and might be useful for developing new therapeutic strategies against it. Novel drugs, such as highly potent GCs, phosphoinositide 3-kinase-delta inhibitors that reestablish histone deacetylase-2 function, decrease of GC receptor phosphorylation by p38 mitogen-activated protein kinase inhibitors, or phosphatase activators, are currently in clinical development and might be combined with GC therapy in the future. Furthermore, microRNAs (small noncoding RNA molecules) operate as posttranscriptional regulators, providing another level of control of GC receptor levels. Empirical results allow postulating that the detection and study of microRNAs might be a promising approach to better characterize and treat asthmatic patients.

IMPLICATIONS

Many molecular and cellular pathobiological mechanisms are responsible of GC resistance. Therefore detecting specific biomarkers to help identify patients who would benefit from new therapies is crucial. Stress consitutes a negative aspect of current lifestyles that increase asthma morbidity and mortality. Adequate stress management could be an important and positive intervention.

Vitamin D and childhood asthma: causation and contribution to disease activity

PURPOSE OF REVIEW

To review the literature of the past 18 months (April 2017 through September, 2018) relating to vitamin D and childhood asthma.

RECENT FINDINGS

A combined analysis of two clinical trials of maternal vitamin D supplementation trials showed a significant protective effect of vitamin D supplementation trials in the primary prevention of asthma and recurrent wheeze up to age 3 years. Secondary analyses from these trials have also suggested that initial maternal vitamin D status could affect the response to supplementation during pregnancy, with the biggest protective effect in children born to mothers with initial 25hydroxyvitamin D (25OHD) levels of at least 30 ng/ml. A postnatal, 6-month vitamin D supplementation trial in black, premature babies showed a 34% decreased risk of recurrent wheezing at 1 year among the infants who received supplementation. An individual patient data meta-analysis of published clinical trials concluded that vitamin D supplementation decreased the risk of asthma exacerbations in those with 25OHD levels less than 10 ng/ml. Results of observational analyses on primary prevention of asthma and in prevention of exacerbations remain mixed, with the bulk of the evidence suggesting that there is a protective effect of higher vitamin D levels.

SUMMARY

Evidence continues to accumulate that vitamin D supplementation helps to prevent the development of asthma and recurrent wheeze in early life, and may also help in the management of asthma. The level(s) of circulating vitamin D that maximizes these effects remains to be identified.

The association between atopic dermatitis and serum 25-hydroxyvitamin D in children: Influence of sun exposure, diet, and atopy features-A cross-sectional study

BACKGROUND

Previous studies have linked low serum vitamin D (VD) or 25-hydroxyvitamin D (25(OH)D) levels with increased severity of atopic dermatitis (AD) in children.

OBJECTIVE

To investigate the association between serum VD (25(OH)D) levels and AD and AD severity, considering the influence of diet and sun exposure.

METHODS

We performed a prospective cross-sectional study of healthy controls and children diagnosed with AD. Participants were recruited between January 2011 and December 2012, and the following parameters were assessed: age, sex, body mass index (BMI), AD severity, Fitzpatrick skin type, asthma and rhinitis history, dietary VD intake, daily potential sun-induced VD production, sunscreen use, 25(OH)D and IgE serum levels, and results of the ImmunoCAP Phadiatop Infant test.

RESULTS

The study population consisted of 105 healthy controls and 134 AD patients. Serum 25(OH)D levels were significantly lower in moderate and severe AD than in mild AD, although this association was only significant for patients with light Fitzpatrick skin type (mean(SD) 36.7 (11.9) ng/mL; moderate 28.8 [11.5] ng/mL; and severe 27.6 [12.1] ng/mL, P = .045). Logistic regression analysis revealed a positive association between severe AD and both positive ImmunoCAP Phadiatop test and BMI.

CONCLUSION

Our data support an association between VD deficiency and AD severity only in patients with light complexion.

Relationship between serum 25-hydroxyvitamin D and inflammatory cytokines in Nigerian children with asthma

Background: Childhood asthma involves a network of mutually interacting inflammatory mediators and cytokines. The influence of serum vitamin D (an immunomodulatory agent) on these cytokines is poorly understood. This study sets out to determine the relationship between serum T-helper cells type 1 cytokines (Interleukins ILs-1β, 2, 6, 8 and 10), type 2 cytokines (ILs 3, 4,5,9,13), ILs-12, 17 and 25-hydroxyvitamin D (25-OHD) in Nigerian children with asthma.Methods: Children with physician-diagnosed asthma and non-asthmatics aged 2-15 years were consecutively recruited at a tertiary center in Nigeria. Serum 25-OHD and cytokines were assayed using chromatography method and association between these parameters determined.Results: A total of 180 children (90 for each group; mean age 7.5 ± 3.9 years; M:F 1.9:1) were recruited. Fifty-six (76.7%) asthmatics had mild intermittent form and symptoms were sub-optimally controlled in 16 (21.9%). The mean (SD) serum Vitamin D was lower in children with asthma (38.8 ± 17.0 ng/ml vs. 45.5 ± 16.6 ng/ml vs. p = 0.023). Also more proportion of children with asthma had suboptimal serum vitamin D level (26.0% vs. 8.8%; p = 0.022). Deficient vitamin D state was associated with higher serum Th₁ and Th₂ cytokines compared to insufficient state, but the highest cytokine levels were observed in normal vitamin D state. There was significant positive correlation between serum vitamin D and Th₁ cytokines IL-2 and IL-8 as well as Th₂ cytokines (ILs-3, 4, 5 and 9), but negative correlation with IL-13Conclusions: Serum Vitamin D and cytokines were lower in a sample of Nigerian children with asthma than controls. Vitamin D status was not related to asthma severity and control. Serum 25-OHD seems to have a non-linear relationship with Th₁ and Th₂ cytokines in Nigerian asthmatics.

Associations between serum 25-hydroxyvitamin D levels and allergic sensitization in early childhood

BACKGROUND AND OBJECTIVES

Vitamin D status may be related to allergen sensitizations, but the evidence is inconsistent. The objective of this study was to assess whether serum 25-hydroxyvitamin D (25(OH)D) levels were associated with allergic sensitizations in early childhood.

METHODS

Data were collected from 2642 children who visited the Guangdong Women and Children's Hospital from January 2016 to May 2017 for routine health check-ups. Serum 25(OH)D levels were tested by electrochemiluminescence immunoassay. Allergic sensitizations including food and inhalant allergens were tested for specific IgE antibodies at one year (12 months 0 days through 12 months 30 days) and two years (24 months 0 days through 24 months 30 days) of age.

RESULTS

The mean level of serum 25(OH)D was 86.47±27.55nmol/L, with a high prevalence of vitamin D insufficiency (<75nmol/L) in children aged 0-2 years (36.8%). Lower 25(OH)D levels with serum total IgE of more than 200IU/mL (81.54±25.53nmol/L) compared with less than 100IU/mL (87.92±28.05nmol/L). The common sensitization to allergens in children aged one and two years were milk (44.2%), cat epithelium (26.4%), egg (13.1%), dog epithelium (12.7%) and Dermatophagoides farinae (6.7%). After multivariate adjustment, data in 25(OH)D treated as a continuous variable or categories, no consistent associations were found between 25(OH)D levels and allergen-specific IgEs.

CONCLUSIONS

Serum 25(OH)D level showed an inverse relationship with total IgE level in early childhood. However, there is lack of evidence to support associations between low 25(OH)D levels and allergic sensitization to various allergens.

Vitamin D in the prevention of exacerbations of asthma in preschoolers (DIVA): protocol for a multicentre randomised placebo-controlled triple-blind trial

INTRODUCTION

Preschoolers have the highest rate of emergency visits and hospitalisations for asthma exacerbations of all age groups, with most triggered by upper respiratory tract infections (URTIs) and occurring in the fall or winter. Vitamin D insufficiency is highly prevalent in Canadian preschoolers with recurrent asthma exacerbations, particularly in winter. It is associated with more URTIs and, in patients with asthma, more oral corticosteroid (OCS) use. Although evidence suggests that vitamin D supplements significantly decrease URTIs and asthma exacerbations requiring OCS, there is insufficient data in preschoolers. This study aims to determine the impact of vitamin D₃ supplementation on exacerbations requiring OCS, in preschoolers with recurrent URTI-induced asthma exacerbations.

METHODS AND ANALYSIS

This is a phase III, randomised, triple-blind, placebo-controlled, parallel-group multicentre trial of vitamin D₃ supplementation in children aged 1-5 years, with asthma triggered by URTIs and a recent history of frequent URTIs and OCS use. Children (n=865) will be recruited in the fall and early winter and followed for 7 months. They will be randomised to either the (1) intervention: two oral boluses of 100 000 international unit (IU) vitamin D₃ (3.5 months apart) with 400 IU vitamin D₃ daily; or (2) control: identical placebo boluses with daily placebo. The primary outcome is the number of exacerbations requiring OCS per child, documented by medical and pharmacy records. Secondary outcomes include number of laboratory-confirmed viral URTIs, exacerbation duration and severity, parent functional status, healthcare use, treatment deintensification, cost and safety.

ETHICS AND DISSEMINATION

This study has received ethical approval from all sites. Results will be disseminated via international conferences and manuscripts targeting paediatricians and respirologists, and to families of asthmatic children via our Quebec parents-partners outreach programme. If proven effective, findings may markedly influence the management of URTI-induced asthma in high-morbidity preschoolers and could be directly implemented into practice with an update to clinical guidelines.

TRIAL REGISTRATION NUMBER

NCT03365687.

Meta-analysis of vitamin D and lung function in patients with asthma

Background

There is growing literature suggesting a link between vitamin D and asthma lung function, but the results from systematic reviews are conflicting. We conducted this meta-analysis to investigate the relation between serum vitamin D and lung function in asthma patients.

Methods

Major databases, including OVID, MEDLINE, Web of Science and PUBMED, were searched until 10th October 2018. All published observational studies related to vitamin D and asthma were extracted. All meta-analyses were performed using Review Manager 5.3.5.

Results

This quantitative synthesis found that asthma patients with low vitamin D levels had lower forced expiratory volume In 1 s (FEV1) (mean difference (MD) = − 0.1, 95% CI = − 0.11 to − 0.08,p < 0.01;I2 = 49%, p = 0.12) and FEV1% (MD = − 10.02, 95% CI = − 11 to − 9.04, p < 0.01; I2 = 0%, p = 0.82) than those with sufficient vitamin D levels. A positive relation was found between vitamin D and FEV1 (r = 0.12, 95% CI = 0.04 to 0.2, p = 0.003; I2 = 59%,p = 0.01), FEV1% (r = 0.19, 95% CI = 0.13 to 0.26, p < 0.001; I2 = 42%, p = 0.11), forced vital capacity (FVC) (r = 0.17, 95% CI = 0.00 to 0.34, p = 0.05; I2 = 60%, p = 0.04), FEV1/FVC (r = 0.4, 95% CI = 0.3 to 0.51, p < 0.001; I2 = 48%, p = 0.07), and the asthma control test (ACT) (r = 0.33, 95% CI = 0.2 to 0.47, p < 0.001; I2 = 0%, p = 0.7). Subgroup analysis indicated that the positive correlation between vitamin D and lung function remained significant in both children and adults.

Conclusions

Our meta-analysis suggested that serum vitamin D levels may be positively correlated with lung function in asthma patients. Future comprehensive studies are required to confirm these relations and to elucidate potential mechanisms.

1,25-Dihydroxy Vitamin D3 Attenuates the Oxidative Stress-Mediated Inflammation Induced by PM2.5via the p38/NF-κB/NLRP3 Pathway

Vitamin D₃ is reported to be involved in the regulation of inflammatory processes. In this study, biomarkers related to oxidative stress and inflammation were investigated to clarify the protective effects and possible mechanism of 1,25-dihydroxy vitamin D₃ (1,25-(OH)₂D₃) on PM_2.5-induced inflammatory response. In the in vitro study using human bronchial epithelial (HBE) cells, aqueous extracts of PM_2.5 could induce oxidative damage which is characterized by significant increases in production of reactive oxygen species, malonaldehyde concentration, and protein expression of HSPA1A and HO-1. Meanwhile, PM_2.5 caused secretion of inflammatory factors (IL-6, IL-8) in the culture medium as well as phosphorylation of p38, nuclear factor-kappa B (NF-κB) inhibitor alpha (IκBα), and NF-κB p65 proteins. Increases in NLRP3 expression was also observed in HBE cells after PM_2.5 exposure. However, all these biomarkers were remarkably attenuated by a 24-h pretreatment of 1 nM 1,25-(OH)₂D₃. Furthermore, 1,25-(OH)₂D₃ also reduced transcriptional activation of NF-κB induced by PM_2.5 as indicated by a significant decrease in luciferase activity in HBE cells stably transfected with the NF-κB response element (RE)-driven luciferase reporter. Taken together, our findings provided novel experimental evidences supporting that vitamin D₃ could reduce the predominantly oxidative stress-mediated inflammation induced by PM_2.5via the p38/NF-κB/NLRP3 signaling pathway.

Association of vitamin D and diarrhoea in children aged less than five years at Muhimbili national hospital, Dar es Salaam: an unmatched case control study

Background

There has been a growing interest in the non-skeletal roles of vitamin D particularly its immune-modulatory properties which has been shown to influence the susceptibility and severity to infections. There is insufficient data globally on the association between Vitamin D levels and Diarrhoea in children. The objective of the study was to determine the association between vitamin D levels and diarrhoea in children aged less than five years.

Methods

Hospital based unmatched case-control study was carried out at MNH between September 2015 and January 2016. Cases were defined as patients with diarrhoea, Sick controls were patients who did not have diarrhoea but were admitted for other illnesses and Healthy controls were children who had neither diarrhoea nor other co-morbid conditions.

Structured questionnaires were used to capture the demographic data and anthropometric measurements. Blood samples of study participants were tested for serum vitamin D levels and grouped as vitamin D sufficient, insufficient or deficient (VDD). SPSSv.20 was used to carry out the Statistical analysis. Binary logistic regression, Mann-Whitney and Kruskal-Wallis tests were used, a p-value≤ 0.05 was considered to be statistically significant.

Results

A total of 188 children under five were recruited in the study at the ratio of 1 case: 3 controls, of these 47 were Cases, 94 were Sick controls and remaining 47 were Healthy controls. The mean age was 17.01 ± 14.8 months. The mean vitamin D level was 51.18 ± 21.97 nmol/l. Majority of the participants 101 (53.7%) were vitamin D deficient, 64 (34%) were insufficient and 23 (12.2%) had sufficient vitamin D levels. Sick controls were 3.2 times more likely to be VDD compared to cases [95% CI 0.14–0.69; p = 0.0015] and 5.03 times when compared to Healthy controls [95% CI 2.22–11.55; p = 0.000]. Severe acute malnutrition (SAM) was independently associated with diarrhoea (95% CI: 1.26–5.39, p 0.01).

Conclusions

High prevalence of vitamin D deficiency was found in the children under five years studied. Vitamin D levels was not found to be specifically associated with diarrhoea in children under five years of age.

Vitamin D for secondary prevention of acute wheeze attacks in preschool and school-age children

INTRODUCTION

Vitamin D is best known for its role in bone health; however, the discovery of the vitamin D receptor and the expression of the gene encoding the vitamin D 1α-hydroxylase (CYP27B1) enzyme in a wide variety of tissues including immune cells and respiratory epithelium has led to the discovery of potential roles for vitamin D in the prevention of acute wheeze.

METHODS

We review here the literature concerning the relationships between circulating 25-hydroxyvitamin D (25(OH)D) concentration and secondary prevention of acute wheeze attacks in preschool and school-age children.

RESULTS

Epidemiological data suggest that vitamin D insufficiency (25(OH)D <75 nmol/L) is highly prevalent in preschool and school-age children with wheeze. Preschool age children with a history of wheeze attacks and circulating 25(OH)D <75 nmol/L are at increased risk and frequency of future acute wheeze. However, no consistent association between low vitamin D status and risk of acute wheeze is reported in school-age children. Seven randomised controlled trials (RCTs) with relatively small sample sizes (30-430) and variable quality showed inconsistent results regarding the effect of oral vitamin D supplementation during childhood on the risk of asthma attacks, asthma symptom control, inhaled corticosteroid requirements, spirometry and unscheduled healthcare attendances for wheeze. A RCT showed that vitamin D supplementation had no effect on the frequency of unplanned healthcare attendances due to acute wheeze in 22 preschool children.

DISCUSSION

An evidence-based recommendation for the use of vitamin D as a preventive therapy for wheeze attacks cannot be made until results of further trials are available. The assessment of circulating 25(OH)D concentration and the optimisation of vitamin D status to prevent acute respiratory tract infections, and to maintain skeletal and general health in preschool and school-age children with acute wheeze is worthwhile in its own right, but whether this will reduce the risk of acute wheeze attacks is unclear.

The relationship between serum vitamin D level and asthma

OBJECTIVE:

Several studies have established a relationship between low serum vitamin D levels and the onset of asthma in childhood. In this study, we aim to assess the relationship between vitamin D and asthma.

METHODS:

This study included 29 mild and 30 moderate persistent asthma and 38 healthy control group. Evaluation of the three groups was carried out in respect of serum vitamin D levels, Respiratory Function Test (RFT), and Exercise Provocation Test (EPT). The two asthma groups were also examined using the Asthma Control Test (ACT) and Nitric Oxide in Exhaled Breath (FeNO) level.

RESULTS:

The vitamin D levels of the mild and the moderate persistent asthma groups were determined to be lower than the vitamin D levels of the control group (p=0.007). A significant negative correlation was determined in all cases between the vitamin D levels and the broncho-reversibility percentage (p=0.0002). The negative correlation between the vitamin D levels and the broncho-reversibility percentage was more evident in the moderate persistent asthma group (p=0.0001). In the moderate persistent asthma group, a significant positive correlation was determined between the lowness of the maximum forced expiratory volume in EPT and a low vitamin D level (p=0.009). The ACT scores were lower, and the FeNO levels were higher in the moderate asthma group compared to the mild asthma group (p=0.0001).

CONCLUSION:

The findings showed that low serum vitamin D levels were observed more often in children with asthma, and there was a correlation with increased broncho-reversibility in the RFT and increased bronchial hyper-reactivity in the EPT.

The etiologic origins for chronic obstructive pulmonary disease

COPD, characterized by long-term poorly irreversible airway limitation and persistent respiratory symptoms, has resulted in enormous challenges to human health worldwide, with increasing rates of prevalence, death, and disability. Although its origin was thought to be in the interactions of genetic with environmental factors, the effects of environmental factors on the disease during different life stages remain little known. Without clear mechanisms and radical cure for it, early screening and prevention of COPD seem to be important. In this review, we will discuss the etiologic origins for poor lung function and COPD caused by specific adverse effects during corresponding life stages, as well as try to find new insights and potential prevention strategies for this disease.

Obesity and severe asthma

Obesity is an important global health issue for both children and adults. Obesity increases the prevalence and incidence of asthma and also increases the risk for severe asthma. Here we describe the features of severe asthma phenotypes for which obesity is a defining characteristic, including steroid resistance, airway inflammation, and co-morbidities. We also review current concepts regarding the mechanistic basis for the impact of obesity in severe asthma, including possible roles for vitamin D deficiency, systemic inflammation, and the microbiome. Finally, we describe data indicating a role for diet, weight loss, and exercise in the treatment of severe asthma with obesity. Better understanding of the mechanistic basis for the role of obesity in severe asthma could lead to new therapeutic options for this population.

Vitamin D Supplementation in Mechanically Ventilated Patients in the Medical Intensive Care Unit

BACKGROUND

The utility of vitamin D (VITD) supplementation during critical illness and whether it may alter outcomes, including mortality and ventilator-free days, is unclear. We performed a retrospective cohort study in a generalizable population to investigate this question.

METHODS

We included all mechanically ventilated adults admitted to the medical intensive care unit (ICU) service at a tertiary center from 2009 to 2012 who were in the ICU for at least 72 hours. Patients were grouped as having received or not received VITD at any time during the first 7 days of their ICU stay, and we adjusted for the following covariates with multivariable analyses: simplified acute physiology score, age, gender, admission diagnosis, race/ethnicity, admission season, admission day of the week, and VITD supplementation prior to admission.

RESULTS

Among the 610 included patients, 281 received VITD, and 329 did not. There were no differences in outcomes between these groups. However, we did find significantly more ventilator-free days (21.0±2.6 [adjusted mean days±standard error] vs 17.6±2.4, P=0.04) and ICU-free days (18.5±2.5 vs 16.3±2.3, P=0.03) in patients who were taking VITD prior to admission (n=91) vs those who were not (n=519). No patients who were taking VITD before admission died vs 34.5% of those who were not (estimated odds ratio=4.9×10^-7 , 95% CI=3.1×10^-7 to 7.5×10^-7 , P<0.0001).

CONCLUSION

These results suggest that VITD supplementation during critical illness may not provide benefit and that further research investigating potential supplementation in ambulatory patients at high risk of ICU admission (eg, severe underlying chronic disease) is warranted.

Vitamin D Status Modifies the Response to Indoor Particulate Matter in Obese Urban Children with Asthma

BACKGROUND

Indoor fine particulate air pollution (PM_2.5) is linked to asthma morbidity; however, whether vitamin D status influences individual susceptibility to airborne exposures is unclear.

OBJECTIVE

We aimed to determine if vitamin D modifies the effects of indoor PM_2.5 on asthma symptoms in urban children.

METHODS

A total of 120 children aged 5 to 12 years with physician-diagnosed asthma were evaluated at baseline and every 3 months for 9 months. Indoor PM_2.5, serum 25-hydroxy vitamin D (25-OH D) levels, and asthma symptoms were simultaneously assessed at each time point. Adjusting for confounders, generalized estimating equations assessed the 3-way interaction effects of 25-OH D, obesity, and PM on asthma symptoms.

RESULTS

Children were of mean (standard deviation [SD]) age 9.7 (2.2) years, 36% were obese, and 95% self-reported black race. Mean (SD) PM_2.5 indoor exposure was 38.2 (42.9) μg/m³ and 25-OH D was 19.1 (7.5) ng/mL. Three-way interaction models demonstrated significantly greater PM_2.5-associated effects on daytime asthma symptoms only among obese children with low 25-OH D levels (odds ratio [OR]_PM2.5 = 1.26, P = .049 at vitamin D = 15.5 ng/mL, increasingly stronger PM effects at levels <15.5 ng/mL). In homes with increased PM_2.5, higher 25-OH D was associated with decreased symptom odds (eg, OR_{Vitamin D} = 0.87; P = .049 at PM_2.5 = 52.5 μg/m³, increasingly protective effects >52.5 μg/m³) among obese children.

CONCLUSIONS

Among obese urban children with asthma, low individual 25-OH D enhanced adverse respiratory effects associated with indoor PM_2.5. In high PM_2.5 environments, 25-OH D was protective against asthma symptoms. Optimizing vitamin D status in children may help reduce asthma morbidity driven by indoor air pollution.

Complex relationships between vitamin D and allergic sensitization among Puerto Rican 2-year-old children

BACKGROUND

In the United States, Puerto Ricans have a higher prevalence of asthma than other Latino ethnicities. Low vitamin D levels for children living in northern climates could be a factor.

OBJECTIVE

To assess serum 25-hydroxyvitamin D [25(OH)D] distributions (a marker of vitamin D) and associations among vitamin D, allergic sensitization, early wheeze, and home/demographic factors.

METHODS

Puerto Rican infants born in New York City, with a maternal history of atopy, were enrolled in a birth cohort. Blood was collected at age 2 years (n = 154; 82 males and 72 females). Serum 25(OH)D and immunoglobulin E (IgE) (indoor allergen-specific and total) were determined using immunoassays. Home/demographic characteristics and respiratory symptoms were assessed by questionnaire.

RESULTS

The median concentration of 25(OH)D was 22.6 ng/mL; 32% were at risk of deficiency or inadequacy (<12 or 12-19 ng/mL). Serum 25(OH)D levels were lower in the heating (a surrogate for less sun exposure in colder months) compared with nonheating (26.1 vs 22.7 ng/mL, P = .02) season, but were not associated with allergen-specific IgE levels or with level of acculturation (measured by maternal birthplace). However, low 25(OH)D levels (below median) were associated with high total IgE >100 IU/mL (P = .01). Also, 25(OH)D concentrations differed between children who attended daycare and those who did not (21.8 vs 24.5 ng/mL; t test, P = .02). Serum 25(OH)D was not associated with wheeze or asthma by 2 years of age (P = .43).

CONCLUSION

Vitamin D deficiency, possibly linked with allergic pathways, may partially explain the trajectory for disproportionate asthma burden among Puerto Ricans, especially those born and raised in colder climates.

Vitamin D alleviates airway remodeling in asthma by down-regulating the activity of Wnt/β-catenin signaling pathway

Vitamin D exerts a protective role in asthma; however, the molecular mechanisms underlying the vitamin D-attenuated asthma airway remodeling are yet to be elucidated. In this study, Sprague-Dawley (SD) rats were randomly divided into four groups: control, asthma, vitamin D 50 ng/mL, and vitamin D 100 ng/mL. The treatment with 100 ng/mL vitamin D remarkably reduced the thickness of the airway smooth muscle, collagen deposition, and the alpha-smooth muscle actin (α-SMA) mass and airway inflammation. Conversely, the treatment by vitamin D significantly up-regulated the serum levels of 25(OH)₂D₃ that were decreased in asthma. The putative signaling pathway of vitamin D was based on Wnt5a and β-catenin expression assessed by quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) and Western blot, which revealed that the administration of vitamin D significantly decreased the activity of Wnt/β-catenin signaling pathway. These results suggested that administration of vitamin D alleviated the airway remodeling in asthma by down-regulating the activity of Wnt/β-catenin signaling pathway.

Effects of genetic polymorphisms in Vitamin D metabolic pathway on Vitamin D level and asthma control in South Indian patients with bronchial asthma

Objectives:

The study was designed to evaluate the single-nucleotide polymorphisms (SNPs) of genes involved in Vitamin D actions (rs2228570) and metabolic pathways (rs2248137 and rs10766197) and their associations with serum 25-hydroxy Vitamin D (25(OH)D) level and asthma control in South Indian patients with bronchial asthma.

Materials and Methods:

One hundred and two patients of South Indian origin with bronchial asthma either naive to inhaled corticosteroids (ICSs) or not receiving ICS for ≥1 month were included and were treated with ICS (beclomethasone 200 μg twice daily) for 8 weeks. One hundred and one unrelated healthy South Indians were used as controls. Pulmonary function test and fractional exhaled nitric oxide were used to assess asthma control. Serum 25(OH)D levels (chemiluminescence immunoassay) and SNPs in Vitamin D pathway (real-time polymerase chain reaction) were assessed. The associations of SNPs and serum 25(OH)D with asthma control was determined using linear regression. All analyses were performed using SPSS (version 19) and “SNPStats.” P < 0.05 was considered as statistically significant.

Results:

Vitamin D receptor (VDR) polymorphism (rs2228570) was found to be protective against asthma (P = 0.022), while there were no significant associations between the other two SNPs and asthma. Similarly, poor correlation and insignificant associations between the SNPs and serum 25(OH)D levels were observed in both cases and controls. There were also insignificant associations between the SNPs and asthma control.

Conclusion:

VDR polymorphism (rs2228570) was found to be protective against asthma in South Indians, while other genes involved in the metabolic pathway of Vitamin D did not show associations with asthma.

Comorbidity of Vitamin A and Vitamin D Deficiency Exacerbates the Severity of Atopic Dermatitis in Children

<b><i>Background:</i></b> Several studies have suggested that vitamin D (VD) deficiency (VDD) is associated with atopic dermatitis (AD). However, little is known about the relationship between AD and vitamin A (VA). The interaction between VA and VD on AD requires further study. <b><i>Objective:</i></b> We detected serum levels of VA and VD in children with AD to explore how VA deficiency (VAD) and VDD affect AD severity. <b><i>Methods:</i></b> We assessed the SCORing Atopic Dermatitis (SCORAD) index, total immunoglobin E levels and peripheral blood eosinophil counts. VA and VD levels were determined with high-performance liquid chromatography. Correlations among variables were investigated with Pearson’s correlation analysis. <b><i>Results:</i></b> The VD and VA levels were significantly lower in children with AD than in normal children (p &#x3c; 0.001, p = 0.0423). Both VD and VA levels were negatively correlated with SCORAD scores. The SCORAD scores were significantly higher in AD patients with both VDD and VAD (co-deficiency) than in other AD patients. Significant inverse correlations were observed between peripheral blood eosinophil counts and serum VA and VD levels. <b><i>Conclusions:</i></b> VA and VD co-deficiency may exacerbate AD symptoms in children, but the specific mechanism underlying this relationship requires further study. These findings may indicate the need for studies evaluating the use of VD and VA as potential treatments for AD patients.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Vitamin D deficiency promotes prostatic hyperplasia in middle-age mice through exacerbating local inflammation

Vitamin D deficiency is especially prevalent in pregnant women and children. Our recent study demonstrated that vitamin D deficiency in early life disturbed testicular development. This study investigated the effects of vitamin D deficiency in early life on prostatic hyperplasia in middle-aged mice. In control group, dams and their male pups were fed with standard-chow diets. In VDD group, dams were fed with vitamin D deficient (VDD) diets throughout pregnancy and lactation. After weaning, male pups continued to be fed with VDD diets. As expected, prostate weight was elevated and prostatic hyperplasia was observed in VDD-fed mice. The number of prostatic Ki-67-positive epithelial cells, a proliferation marker, was increased in VDD-fed mice. Further analysis found that vitamin D deficiency promoted inflammatory infiltration and stromal fibrosis in prostate of middle-aged mice. Moreover, vitamin D deficiency activated NF-κB and up-regulated Il-6 mRNA in prostate of middle-aged mice. In addition, vitamin D deficiency activated prostatic STAT3, a proliferation pathway in middle-aged mice. Of interest, VDD-induced prostatic inflammation and hyperplasia were partially reversed when VDD diets was replaced with standard diets. These results provide evidence that vitamin D deficiency in early life promotes prostatic hyperplasia in middle-aged mice through exacerbating local inflammation.

Immunomodulation by vitamin D

Vitamin D exerts several immunological functions in addition to its homeostatic functions on calcium and bone metabolism. Current data show that relative vitamin D deficiency (< 75 nmol/l 25-hydroxyvitamin D) as well as acquired seasonal vitamin D deficiency (< 50 nmol/l) are frequent in Germany. As confirmed by our own data, UV exposure plays a major role for maintenance of vitamin D status, e.g., in patients with UV-triggered diseases, vitamin D deficiency is more frequent, even throughout the year. The beneficial impact of vitamin D on immune functions is highlighted by epidemiologic, genetic, and experimental evidence. In the past years, numerous publications have presented associations between vitamin D deficiency, on the one hand, and severity and prevalence of allergic asthma in children and adults, on the other hand.

The Implications of Vitamin D Status During Pregnancy on Mother and her Developing Child

Pregnancy is a time of tremendous growth and physiological changes for mother and her developing fetus with lifelong implications for the child. The concert of actions that must occur so mother does not reject the foreign tissue of the fetus is substantial. There must be exquisite balance between maternal tolerance to these foreign proteins of paternal origin but also immune surveillance and function such that the mother is not immunocompromised. When this process goes awry, the mother may experience such pregnancy complications as preeclampsia and infections. Vitamin D deficiency affects these processes. Controversy continues with regard to the optimal daily intake of vitamin D, when sunlight exposure should be taken into account, and how to define sufficiency during such vulnerable and critical periods of development. The importance of vitamin D supplementation during pregnancy in preventing some of the health risks to the mother and fetus appears linked to achieving 25(OH)D concentrations >40 ng/mL, the beginning point of the plateau where conversion of the vitamin D metabolite 25(OH)D, the pre-hormone, to 1,25(OH)2D, the active hormone, is optimized. Throughout pregnancy, the delivery of adequate vitamin D substrate-through sunlight or supplement-is required to protect both mother and fetus, and when in sufficient supply, favorably impacts the epigenome of the fetus, and in turn, long term health. There is a growing need for future research endeavors to focus not only on critical period(s) from pre-conception through pregnancy, but throughout life to prevent certain epigenetic changes that adversely affect health. There is urgency based on emerging research to correct deficiency and maintain optimal vitamin D status. The impact of vitamin D and its metabolites on genetic signaling during pregnancy in both mother and fetus is an area of great activity and still in its early stages. While vitamin D repletion during pregnancy minimizes the risk of certain adverse outcomes (e.g., preterm birth, asthma, preeclampsia, and gestational diabetes), the mechanisms of how these processes occur are not fully understood. As we intensify our research efforts in these areas. it is only a matter of time that such mechanisms will be defined.

Colorimetric Aptasensor of Vitamin D3: A Novel Approach to Eliminate Residual Adhesion between Aptamers and Gold Nanoparticles

Colorimetric aptasensors based on gold nanoparticles (AuNPs) commonly feature ssDNA probes nonspecifically adsorbed to surface gold particles. A major limitation of this versatile method is the incomplete dissociation of the adsorbed nontarget binding segments of the aptamer sequence upon target binding. This results in weak or nonexistent sensor performance by preventing the particles from aggregating when the optimized salt concentration is added. Rather than removing the nonbinding nucleotides flanking the binding region of the aptamer, proposed herein is an alternative strategy, simply introducing a centrifugation and resuspension step after target recognition that eliminates residual binding between the aptamer and the surface of the particles. The performance of two different vitamin D3 (VTD3) aptamers were tested. The method enhanced the performance of the sensor that used the higher detection limit (1 µM) aptamer by fourfold. The superiority of the proposed method became apparent in a nonworking colorimetric sensor became a highly sensitive sensor with a one nanomolar detection level and excellent discrimination against potential interfering molecules including VTD2 when the centrifugation and resuspension process was implemented. The level of VTD3 in human blood was determined colorimetrically after extraction with n-hexane. The results were in agreement with those obtained by HPLC. The proposed method could be applied to aptamers targeting small molecules with no need to reprocess the SELEX-isolated sequence by knowing the binding region and removing the flanking primers.

25-hydroxyvitamin D and health service utilization for asthma in early childhood

BACKGROUND

Asthma is the most common chronic illness of childhood and a common reason for hospital admission. Studies suggest that low vitamin D levels may be associated with health service utilization (HSU) for childhood asthma. The primary objective was to determine if vitamin D serum levels in early childhood were associated with HSU for asthma including: a) hospital admissions; b) emergency department visits; and c) outpatient sick visits. Secondary objectives were to determine whether vitamin D supplementation in pregnancy or childhood were associated with HSU for asthma.

METHODS

Prospective cohort study of children participating in the TARGet Kids! practice-based research network between 2008 and 2013 in Toronto, Canada. HSU was determined by linking each child's provincial health insurance number to health administrative databases. Multivariable quasi-Poisson and logistic regression were used to evaluate the association between 25-hydroxyvitamin D concentrations, vitamin D supplementation in pregnancy, and childhood and HSU for asthma.

RESULTS

A total of 2926 healthy children aged 0-6 years had 25-hydroxyvitamin D data available and were included in the primary analysis. Mean (IQR) 25-hydroxyvitmain D level was 84 nmol/L (65-98 nmol/L), 218 and 1267 children had 25-hydroxyvitamin D concentrations <50 nmol/L and <75 nmol/L, respectively. In the adjusted models, there were no associations between 25-hydroxyvitamin D concentrations (continuously or dichotomized at 50 and 75 nmol/L), vitamin D supplementation in pregnancy or childhood and HSU for asthma.

CONCLUSIONS

Vitamin D blood values do not appear to be associated with HSU for asthma in this population of healthy urban children.