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

Relationship between vitamin D receptors gene polymorphism and arteriogenic erectile dysfunction

BACKGROUND

Over the past few decades, a number of studies have linked vitamin-D deficiency with ED (Erectile dysfunction) risk factors. There is a clear correlation between VD (vitamin-D) levels and ED, according to observational and interventional researches that have been reported in the literature. This crucial information encouraged scientists to investigate the impact of VD on erectile function in greater detail. The fact that vitamin D is a component of a healthy penis that begins in early life has just come to light, however there haven't been many research looking at the connection between vitamin D receptor gene polymorphism and erectile dysfunction.

OBJECTIVE

To evaluate the relationship between arteriogenic erectile dysfunction and the vitamin D receptor gene polymorphism.

SUBJECTS AND METHODS

Between October 2022 and October 2023, at Al-Azhar University Hospitals, 40 patients with arteriogenic ED and 40 healthy controls underwent informed consent, a detailed history, a physical examination, a penile duplex ultrasound and the extraction of peripheral blood to determine the type of polymorphism for each of the vitamin D receptors: FokI, BsmI, ApaI and TaqI by polymerase chain reaction (PCR).

RESULTS

There is no statistically significant association between arteriogenic erectile dysfunction and the vitamin D receptors (VDR) gene polymorphisms FokI, BsmI, ApaI and TaqI.

CONCLUSION

Since there is no statistically significant association between the polymorphism of the vitamin D receptor (VDR) gene and arteriogenic erectile dysfunction, it is advised to investigate other VDR gene polymorphisms as well as alternative clinical subtypes of erectile dysfunction.

Asthmatic patients with vitamin D deficiency: Can vitamin D supplementation make a difference

BACKGROUND

Asthma is a major public health concern due to its persistent inflammation of the airways. The intricate and widely variable epidemiology of asthma among nations and populations is a result of the interplay between genetic, environmental, and socioeconomic factors.

OBJECTIVE

This study aims to investigate whether VitD supplementation can reduce the frequency of exacerbations (including the frequency of exacerbations requiring systemic corticosteroids and the frequency of exacerbations necessitating trips to the hospital or emergency room, or both) and improve pulmonary function (clinical indicators such as the FEV1% predicted value).

METHODS

Computers were used to search Pubmed, Medline, ISI Web of Science, Embase, Cachrane Library, CNKI, CBM, VIP, and the Wanfang Database. Asthma/asthma, VitD/VitD, lung function/lung function, retrieval time is from database setup to October 8, 2021, to search all randomized controlled trials (RCTs) on the effect of VitD on human asthma and to retroactively incorporate references to literature were all included in the search criteria. After rigorous screening, quality evaluation, and data extraction of the included literature by two reviewers independently, heterogeneity tests and sensitivity analyses were performed.

RESULTS

The findings show that a total of 12 relevant studies meeting the inclusion criteria were finally included, including 649 cases in the experimental group and 646 cases in the control group. VitD intervention reduced the number of asthma exacerbations, including the rate of exacerbations requiring systemic corticosteroid therapy and the rate of acute exacerbations requiring emergency department or hospital visits or both.

CONCLUSIONS

In the outcome of lung function (FEV1% predicted value), it was shown that VitD supplementation improved lung function; in the outcome of serum 25-hydroxyVitD levels, it was shown that VitD supplementation increased serum 25-hydroxyVitD levels.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Vitamin D and asthma occurrence in children: A systematic review and meta-analysis

PROBLEM

The association between serum 25-Hydroxyvitamin D (25-OHD) level and asthma occurrence in children was controversial.

ELIGIBILITY CRITERIA

The Pubmed, Ovid Medline, Embase, Cochrane Library were systematically searched up to April 13th 2020. All the study measured the serum 25-OHD level in children, or classified the children based on the 25-OHD level into severe vitamin D deficiency, insufficient deficiency and comparing the prevalence of asthma in childhood were included in our study.

SAMPLE

A total of 35 studies were included in our meta-analysis. Among them, 24 studies were included for analyzing the association between 25-OHD level and asthma, and 12 studies evaluated the treatment effect of vitamin D.

RESULTS

The children with asthma (5711 participants) had significant lower 25-OHD level than children without asthma (21,561 participants) (21.7 ng/ml versus 26.5 ng/ml, SMD = -1.36, 95% = -2.40--0.32, P = 0.010). Besides, the children with asthma treated with vitamin D supplement had a significantly lower recurrence rate than the placebo group (18.4% versus 35.9%, RR = 0.35, 95%CI = 0.35-0.79, P = 0.002).

CONCLUSIONS

Children with asthma had a lower 25-OHD level than healthy children. Vitamin D supplement could decrease the asthma recurrence rate in the follow-up years.

IMPLICATIONS

This study implies that lower 25-OHD may cause asthma in childhood.

Obesity-related asthma in children: A role for vitamin D

Excess adipose tissue predisposes to an enhanced inflammatory state and can contribute to the pathogenesis and severity of asthma. Vitamin D has anti-inflammatory properties and low-serum levels are seen in children with asthma and in children with obesity. Here we review the intersection of asthma, obesity, and hypovitaminosis D in children. Supplementation with vitamin D has been proposed as a simple, safe, and inexpensive adjunctive therapy in a number of disease states. However, little research has examined the pharmacokinetics of vitamin D and its therapeutic potential in children who suffer from obesity-related asthma.

Vitamin D Supplementation As a Potential therapeutic Mediator in Asthma: Does Dose Really Matter? a Critical Review of the Literature

Around 400 million people across the globe will suffer from asthma in the next 10 years. Although most asthmatics use asthma medications regularly, they occasionally visit the emergency department for aggressive treatment amidst family anxiousness. Vitamin D (VD) not only regulates the expression of genes associated with calcium homeostasis, but also the genes associated with cancers, autoimmune diseases, and infection. VD has also non-genomic activities e.g. it is a potentially safe and effective novel strategy for decreasing the asthma episodes and controlling exacerbations. Our review assessed the dose, serum level, duration of administration and outcomes of VD in cases of asthmas. Although a body of research evidences the effectiveness of VD supplementation in asthma, other studies showed the insignificant response of VD to asthma either with low dose or low achieved serum VD levels. Nevertheless, recent reviews suggest that manipulating VD status holds promise for primary prevention and treatment of asthma. Future research on the relationship between VD and asthma should consider utilizing adequate doses of VD preparations for sufficient duration (likely to be >12 months) aiming to achieve appropriate level of serum VD (25-hydroxyvitamin D) concentration (likely to be at least >40 ng/mL).

Vitamin D and Male Erectile Function: An Updated Review

Literature support that vitamin-D is important for different systems of the human body including, but not limited to endocrine and immune systems, vasculature and endothelial function of the body. Male erectile function depends on many factors and can be perceived as a health indicator of the body. Epidemiological data have shown that vitamin-D deficiency is also associated with erectile dysfunction. In this review, our aim is to interpret the mechanisms by which vitamin-D might regulate anatomy and physiology of penis. Evidence showed that vitamin-D is needed for an adequate erectile function. Briefly, vitamin-D is crucial for a better healthy body and sexual activity.

Predictive role of IL-17A/IL-10 ratio in persistent asthmatic patients on vitamin D supplement

Asthma is an airway inflammatory disorder. Vitamin (Vit) D is a potent immuno-modulator. It suppresses Interleukin (IL)-17 and induces IL-10. This study aims to investigate the role of IL-17A and IL-10 in predicting asthma control in case of Vit D supplementation. Seventy-nine patients enrolled in this study (42 patients received Vit D supplement and 37 patients did not receive the supplement). The enrolled patients were assessed at the beginning of this study and after 3 months. At the end of the study, there was a significant improvement in pulmonary function parameters in the Vit D supplemented group when compared to both the baseline values and the non-supplemented group. There was a significant decrease in serum IL-17A levels and a significant increase in serum IL-10 levels in comparison with the baseline values (p < 0.0001). The highest correlation of FEV1% improvement percentage was associated with the baseline IL-17A/IL-10 ratio (r = 0.65; p < 0.0001). The IL-17A/IL-10 ratio at a cutoff ≥ 2.66 had a sensitivity of 72.2% and a specificity of 83.3%. The IL-17A/IL-10 ratio had an adjusted odds ratio = 4.66 (p = 0.04). Vit D supplementation reduces the serum IL-17A levels and elevates the serum IL-10 levels in persistent asthmatic patients. So, Vitamin D can be used as an adjunct therapy side by side with the conventional asthma therapy. The IL-17A/IL-10 ratio seems to be a possible predictive biomarker for asthma improvement in patients depending on Vit D supplementation.

Associations between vitamin D and pulmonary function in chronic spinal cord injury

CONTEXT/OBJECTIVE

Individuals with chronic spinal cord injury (SCI) have an increased risk of morbidity and mortality attributable to respiratory diseases. Previous studies in non-SCI populations suggest that vitamin D may be a determinant of respiratory health. Therefore, we sought to assess if lower vitamin D levels were associated with decreased pulmonary function in persons with chronic SCI.

DESIGN

Cross-sectional study.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

312 participants (260 men and 52 women) with chronic SCI recruited from VA Boston and the community participating in an epidemiologic study to assess factors influencing respiratory health.

METHODS

Participants provided a blood sample, completed a respiratory health questionnaire, and underwent spirometry. Linear regression methods were used to assess cross-sectional associations between plasma 25-hydroxyviatmin D and spirometric measures of pulmonary function.

OUTCOME MEASURES

Forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC.

RESULTS

Adjusted and unadjusted for a number of confounders, there was no significant association between plasma vitamin D levels and FEV₁, FVC, or FEV₁/FVC. For example, in fully adjusted models, each 10 ng/ml increase in vitamin D was associated with a 4.4 ml (95%CI -64.4, 73.2, P = 0.90) ml change in FEV_1. Conclusion: There was no significant cross-sectional association between plasma vitamin D and FEV₁, FVC, or FEV₁/FVC in this cohort of individuals with chronic SCI.

Effect of vitamin D deficiency in Korean patients with acute respiratory distress syndrome

BACKGROUND/AIMS

Vitamin D modulates innate and adaptive immune responses, and vitamin D deficiency is associated with increased mortality in hospitalized patients with pneumonia. We evaluated the prevalence of vitamin D deficiency in Korean patients with acute respiratory distress syndrome (ARDS) and its effect on the clinical outcomes of ARDS.

METHODS

We retrospectively analyzed the data of 108 patients who had a measured serum level of 25-hydroxy vitamin D3 (25(OH)D3) at the time of diagnosis with ARDS. The clinical outcomes were evaluated based on 25(OH)D3 levels of 20 ng/mL and stratified by quartiles of 25(OH)D3 levels.

RESULTS

The mean age of patients was 59.4 years old; 77 (71.3%) were male. Vitamin D deficiency was found in 103 patients (95.4%). The mean 25(OH)D3 level was 8.3 ± 7.0 ng/mL. Neither in-hospital mortality (40.0% vs. 68.0%) nor 6-month mortality (40.0% vs. 71.8%) significantly differed between groups. There were no significant differences in 25(OH)D3 level between survivors (8.1 ± 7.6 ng/mL) and non-survivors (8.5 ± 6.8 ng/mL, p = 0.765). There were no trends toward a difference in mortality among quartiles of 25(OH)D3 levels. However, 25(OH)D3 levels were inversely related with length of hospital stay and intensive care unit stay among in-hospital survivors.

CONCLUSION

Vitamin D deficiency was prevalent in Korean patients with ARDS. However, levels of vitamin D were not associated with mortality. A large, prospective study is needed to evaluate the effects of vitamin D deficiency on clinical outcomes of ARDS.

Vitamin D deficiency in childhood: old lessons and current challenges

Hypovitaminosis D in childhood is a re-emerging public health problem in developed countries. New life style habits, current "epidemics" of obesity in children and adolescents worldwide, and other preventable risk factors may play a role in favoring the occurrence of vitamin D deficiency. In addition to skeletal consequences, hypovitaminosis D has been found to be involved in the development of serious health extra-skeletal problems in childhood, including atopy and autoimmunity. The increasing concerns about the global health impact of vitamin D deficiency make further research necessary to fill the gaps of knowledge in this field, and particularly to establish universally accepted "normal" serum 25(OH)D levels in the pediatric population, and to improve strategies for the screening, prevention and treatment of hypovitaminosis D. This review discusses the key points of hypovitaminosis D in childhood in the light of new knowledge, and highlights the limitations of current strategies to control this condition.

The potential of anti-infectives and immunomodulators as therapies for asthma and asthma exacerbations

Asthma is responsible for approximately 25,000 deaths annually in Europe despite available medicines that maintain asthma control and reduce asthma exacerbations. Better treatments are urgently needed for the control of chronic asthma and reduction in asthma exacerbations, the major cause of asthma mortality. Much research spanning >20 years shows a strong association between microorganisms including pathogens in asthma onset, severity and exacerbation, yet with the exception of antibiotics, few treatments are available that specifically target the offending pathogens. Recent insights into the microbiome suggest that modulating commensal organisms within the gut or lung may also be a possible way to treat/prevent asthma. The European Academy of Allergy & Clinical Immunology Task Force on Anti-infectives in Asthma was initiated to investigate the potential of anti-infectives and immunomodulators in asthma. This review provides a concise summary of the current literature and aimed to identify and address key questions that concern the use of anti-infectives and both microbe- and host-based immunomodulators and their feasibility for use in asthma.

Inflammatory activation of human serum albumin- or ovalbumin-modified chitosan particles to macrophages and their immune response in human whole blood

Chitosan particles modified with different albumins cause immune response in human whole blood via platelet activation and phagocytosis.

Asthmatic Patients with Vitamin D Deficiency have Decreased Exacerbations after Vitamin Replacement

Background: Intervention studies with vitamin D in asthma are inconclusive for several reasons, such as inadequate dosing or duration of supplementation or uncontrolled baseline vitamin D status. Our aim was to evaluate the benefit of long term vitamin D add-on in asthmatic patients with actual vitamin D deficiency, that is a serum 25-hydroxy vitamin D (25-OHD ) below 20 ng/mL. Methods: Serum 25-OHD, asthma exacerbations, spirometry and inhaled corticosteroids (CS) dose were evaluated in a cohort of 119 asthmatic patients. Patients with deficiency were evaluated again after one year vitamin supplementation. Results: 25-OHD was low in 111 patients and was negatively related to exacerbations (p < 0.001), inhaled CS dose (p = 0.008) and asthma severity (p = 0.001). Deficiency was found in 90 patients, 55 of whom took the supplement regularly for one year, while 24 discontinued the study and 11 were not adherent. Patients with vitamin D deficiency after 12 months supplementation showed significant decrease of exacerbations (from 2.6 ± 1.2 to 1.6 ± 1.1, p < 0.001), circulating eosinophils (from 395 ± 330 to 272 ± 212 10⁶/L, p < 0.001), and need of oral CS courses (from 35 to 20, p = 0.007) and improvement of airway obstruction. Conclusions: Asthma exacerbations are favored by vitamin D deficiency and decrease after long-term vitamin D replacement. Patients who are vitamin D deficient benefit from vitamin D supplementation.

Associations between serum 25(OH)D concentrations and prevalent asthma among children living in communities with differing levels of urbanization: a cross-sectional study

Background

Prior evidence suggests that vitamin D deficiency may increase the risk of asthma and atopy and impair pulmonary function in children.

Methods

In this cross-sectional analysis nested in a case-control study, we analyzed serum 25(OH)D concentrations in 413 children with asthma and 471 children without asthma living in two geographically adjacent study communities (Pampas and Villa El Salvador). We measured total and antigen-specific IgE levels, pulmonary function, asthma control, and exhaled nitric oxide.

Results

Mean 25(OH)D concentrations were 25.2 ng/mL (SD 10.1) in children with asthma and 26.1 ng/mL (SD 13.7) in children without asthma (p = 0.28). Vitamin D deficiency (25(OH)D < 20 ng/ml) was more common in Pampas than in Villa El Salvador (52.7% vs. 10.5%; p < 0.001). In the overall study population, a 10 ng/ml decrease in serum 25(OH)D concentrations was not significantly associated with odds of asthma (OR 1.09, 95% CI: 0.94 to 1.25). However, vitamin D deficiency was associated with a 1.6-fold increase in odds of asthma in the overall cohort (95% CI: 1.14 to 2.25). After stratifying by site, a 10 ng/mL decrease in serum 25(OH)D concentrations was associated with 18% higher odds of having asthma in Pampas (OR = 1.18, 95% CI 1.02 to 1.38), whereas there was no significant association between 25(OH)D concentrations and asthma in Villa El Salvador (OR = 0.95, 95% CI 0.87 to 1.05). Combined data from these geographically adjacent populations suggests a possible threshold for the relationship between 25(OH)D levels and asthma at approximately 27.5 ng/ml. Serum 25(OH)D concentrations were not clearly associated with asthma control, total serum IgE, atopy, or airway inflammation.

Conclusion

Serum 25(OH)D concentrations were inversely associated with asthma in one study community with a high prevalence of deficiency. Studies are needed to investigate a possible threshold 25(OH)D concentration after which higher vitamin D levels show no further benefit for asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s40733-017-0033-2) contains supplementary material, which is available to authorized users.

Free 25(OH)D concentrations are associated with atopy and lung function in children with asthma

BACKGROUND

Evidence suggests free mono-hydroxyvitamin D (25[OH]D) concentrations are more strongly linked to certain outcomes than total concentrations; however, no studies have examined the relation between free 25(OH)D and respiratory or allergic disease.

OBJECTIVE

To examine associations between total and free 25(OH)D concentrations and asthma outcomes.

METHODS

We quantified total and free 25(OH)D concentrations in 137 Peruvian children with asthma and 152 children without asthma and examined associations with asthma outcomes.

RESULTS

Mean age ± SD was 13 ± 2.5 years, and 50.2% were boys. Mean total and measured free 25(OH)D concentrations were 29 ± 9.5 ng/mL and 5.0 ± 1.3 pg/mL, respectively. Lower free but not total 25(OH)D concentrations were significantly associated with atopy in all children (total, odds ratio [OR] 1.3 per 10-ng/mL decrease, 95% confidence interval [CI] 0.95-1.7, P = .12; vs free, OR 1.3 per 1-pg/mL decrease, 95% CI 1.0-1.6, P = .02) and children with asthma (total, OR 1.1 per 10-ng/mL decrease, 95% CI 0.75-1.7, P = .57; vs free, OR 1.6 per 1-pg/mL decrease, 95% CI 1.0-2.5, P = .04). Free but not total 25(OH)D levels were significantly associated with pre-bronchodilator forced expiratory volume in 1 second (total, 0.11 L, -0.12 to 0.34, P = .34; vs free, 0.20 L, 0.021-0.39, P = .03) and forced vital capacity (total, 0.13 L, -0.12 to 0.37, P = .31; vs free, 0.22 L, 0.026-0.42, P = .03) Z-scores in children with asthma.

CONCLUSION

Atopy, forced expiratory volume in 1 second, and forced vital capacity were more strongly linked to free than to total 25(OH)D concentrations, suggesting the free form might be more relevant in modulating allergic disease risk and pulmonary function in children with asthma.

Vitamin D and Bronchial Asthma: An Overview of Data From the Past 5 Years

PURPOSE

Vitamin D is a potent immunomodulator capable of dampening inflammatory signals in several cell types involved in the asthmatic response. Its deficiency has been associated with increased inflammation, exacerbations, and overall poor outcomes in patients with asthma. Given the increase in the prevalence of asthma over the past few decades, there has been enormous interest in the use of vitamin D supplementation as a potential therapeutic option. Here, we critically reviewed the most recent findings from in vitro studies, animal models, and clinical trials regarding the role of vitamin D in treating bronchial asthma.

METHODS

Using the key terms [Vitamin D, asthma, clinical trials, in vivo and in vitro studies], the [PubMed, Google Scholar] databases were searched for [clinical trials, original research articles, meta-analyses, and reviews], English-language articles published from [2012] to the present. Articles that were [Articles that did not meet these criteria were excluded] excluded from the analysis.

FINDINGS

Several studies have found that low serum levels of vitamin D (< 20 ng/mL) are associated with increased exacerbations, increased airway inflammation, decreased lung function, and poor prognosis in asthmatic patients. Results from in vitro and in vivo studies in animals and humans have suggested that supplementation with vitamin D may ameliorate several hallmark features of asthma. However, the findings obtained from clinical trials are controversial and do not unequivocally support a beneficial role of vitamin D in asthma. Largely, interventional studies in children, pregnant women, and adults have primarily found little to no effect of vitamin D supplementation on improved asthma symptoms, onset, or progression of the disease. This could be related to the severity of the disease process and other confounding factors.

IMPLICATIONS

Despite the conflicting data obtained from clinical trials, vitamin D deficiency may influence the inflammatory response in the airways. Further studies are needed to determine the exact mechanisms by which vitamin D supplementation may induce antiinflammatory effects.

The role of vitamin D supplementation on erectile function

In the last few years growing evidence highlighted vitamin D (VD) deficiency is one of the several dynamics that associates with increased atherosclerotic cardiovascular (ASCV) diseases. ASCV diseases and erectile dysfunction (ED) share common risk factors such as diabetes mellitus, hypertension, smoking, hyperlipidemia, and a sedentary lifestyle. The aim of this review was to summarize current progress in VD research by focusing effect of low VD level on different body systems and erectile function. Here we examine research linking VD deficiency and ED and discuss how VD influences ED and its classic risk factors that also associate to increased ED risk. We also summarize research indicating that VD associates with reduced risk of several nonvascular contributing factors for ED. Available literature demonstrates relatively high rates of low VD serum levels in ED patients. Based on the preclinical and clinical data available in the literature, to date, we infer that VD play a critical role in maintaining erectile function in humans. Nevertheless, this should also be tested through randomized controlled studies on the effect of VD supplementation with larger population.

Effect of alfacalcidol on the pulmonary function of adult asthmatic patients: A randomized trial

BACKGROUND

Despite the use of alfacalcidol in the management of corticosteroid-induced osteoporosis, it has never been considered an adjunct treatment for asthma management. It can target vitamin D deficiency, a possible risk factor for asthma, and, hence, improve pulmonary function of patients with asthma.

OBJECTIVE

To explore the effect of alfacalcidol administration on pulmonary function and study the pattern of vitamin D deficiency in adults with asthma in Egypt.

METHODS

Serum 25-hydroxyvitamin D was measured in 115 adults: 33 healthy subjects and 82 patients with asthma. Then, patients with asthma were randomized to receive standard asthma treatment only (n = 39) or receive it in addition to 1 μg of alfacalcidol daily for 4 months (n = 43). Randomization was stratified by the stage of asthma severity. Spirometry and measurement of 25-hydroxyvitamin were performed at baseline and end of follow-up.

RESULTS

Vitamin D deficiency was more common in patients with asthma (57.3%) than in healthy subjects (21.2%; P < .001). In patients with asthma, alfacalcidol significantly improved forced expiratory volume in the first second and forced vital capacity (P < .001 for the 2 tests). Moreover, more patients in the intervention arm showed improvement in asthma severity stage (P = .04). A nonsignificant difference was observed in improvement of forced expiratory volume in the first second between patients with vitamin D deficiency and those without deficiency in the intervention group (P > .05).

CONCLUSION

Alfacalcidol supplementation improved the pulmonary function and severity stage of adult patients with asthma regardless of deficiency.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02747381.

Verification of Abbott 25-OH-vitamin D assay on the architect system

OBJECTIVES

Analytical and clinical verification of both old and new generations of the Abbott total 25-hydroxyvitamin D (25OHD) assays, and an examination of reference Intervals.

METHODS

Determination of between-run precision, and Deming comparison between patient sample results for 25OHD on the Abbott Architect, DiaSorin Liaison and AB SCIEX API 4000 (LC-MS/MS). Establishment of uncertainty of measurement for 25OHD Architect methods using old and new generations of the reagents, and estimation of reference interval in healthy Irish population.

RESULTS

For between-run precision the manufacturer claims 2.8% coefficients of variation (CVs) of 2.8% and 4.6% for their high and low controls, respectively. Our instrument showed CVs between 4% and 6.2% for all levels of the controls on both generations of the Abbott reagents. The between-run uncertainties were 0.28 and 0.36, with expanded uncertainties 0.87 and 0.98 for the old and the new generations of reagent, respectively. The difference between all methods used for patients' samples was within total allowable error, and the instruments produced clinically equivalent results. The results covered the medical decision points of 30, 40, 50 and 125 nmol/L. The reference interval for total 25OHD in our healthy Irish subjects was lower than recommended levels (24-111 nmol/L).

CONCLUSION

In a clinical laboratory Abbott 25OHD immunoassays are a useful, rapid and accurate method for measuring total 25OHD. The new generation of the assay was confirmed to be reliable, accurate, and a good indicator for 25OHD measurement. More study is needed to establish reference intervals that correctly represent the healthy population in Ireland.

Vitamin D over the first decade and susceptibility to childhood allergy and asthma

BACKGROUND

Vitamin D (25(OH)D) deficiency has been implicated as a possible risk factor for asthma development, but studies at selected time points measuring 25(OH)D levels during childhood have yielded conflicting findings. Prospective studies tracking 25(OH)D levels during the initiation phase of asthma in early childhood have not been reported.

OBJECTIVE

We sought to elucidate relationships between 25(OH)D levels from birth to age 10 years and susceptibility to allergic sensitization, respiratory tract infections, and asthma.

METHODS

Asthma-, allergy-, and respiratory tract infection-associated phenotypes (including pathogen identification) were characterized in a high-risk birth cohort. Plasma 25(OH)D concentrations were quantified at birth and at clinical follow-ups at the ages of 0.5, 1, 2, 3, 4, 5, and 10 years, and relationships with clinical outcomes were examined.

RESULTS

Cross-sectional analyses demonstrated inverse associations between 25(OH)D concentrations and the risk for concurrent sensitization at age 0.5, 2, and 3 years, and mixed-effects regression demonstrated inverse longitudinal associations of 25(OH)D levels with both sensitization and eczema. Multivariate regression modeling suggested that the number of 25(OH)D-deficient follow-ups was positively associated with risk for asthma/wheeze, eczema, and sensitization at 10 years; adjustment for sensitization (particularly by 2 years) in the asthma/wheeze models reduced 25(OH)D associations with these latter outcomes. 25(OH)D levels were also inversely associated with early nasopharyngeal colonization with Streptococcus species and age of first febrile lower respiratory illness, both of which are known asthma risk factors.

CONCLUSION

25(OH)D deficiency in early childhood is associated with increased risk for persistent asthma, potentially through modulating susceptibility to early allergic sensitization, upper respiratory tract colonization with bacterial pathogens, or both. These relationships are only evident if 25(OH)D status is monitored prospectively and longitudinally.

The Current Evidence of Integrative Approaches to Pediatric Asthma

Asthma is a complex, multifactorial, and inflammatory chronic condition, and many children who are diagnosed with asthma integrate complementary therapies into their overall care. Due to the chronic nature of asthma, potentially negative side effects of long-term use of allopathic medications, and desire for natural approaches, patients and their families turn toward complementary therapies. Up to 89% of parents use complementary and alternative medicine (CAM) to treat their child's asthma. This article reviews the current evidence on the most commonly used complementary therapies for pediatric asthma.

Vitamin D3 for uncontrolled childhood asthma: A pilot study

BACKGROUND

Observational and mechanistic data suggest a role for vitamin D in childhood asthma. However, subsequent interventional trials have been inconsistent. We aimed to assess the effect of 15 weeks of vitamin D3 supplementation compared with placebo (PL) in Irish children with asthma.

METHODS

We conducted a double-blind, randomized, PL-controlled trial of vitamin D supplementation (2000 IU/day) in 44 urban, Caucasian children at high latitude. Assessments were completed at baseline and after 15 weeks of supplementation. Outcome measures were lung function, subjective asthma control and biochemical parameters of total vitamin D, allergy, immunity, airway inflammation, and systemic inflammation. Finally, parents/guardians completed a weekly diary during the trial.

RESULTS

There was no significant difference in baseline 25(OH)D levels, but there was a significant increase in median 25(OH)D in the vitamin D3 group (57.5-105 nmol/l) compared with the PL group (52.5-57.5 nmol/l) (p < 0.0001). There was no significant difference between groups regarding subjective asthma control. Compared with PL, there was a significant decrease in school days missed due to asthma (1 vs. 5 days, p = 0.04) and alkaline phosphatase (-3.4 vs. +16; p = 0.037) in the vitamin D3 group, but there were no beneficial effects regarding several other secondary end-points. However, there were non-significant, advantageous changes in the PL group compared with the vitamin D3 group in subjective asthma control and lung function, particularly percentage of predicted forced expiratory volume in 1 s (+2.5 vs. -4; p = 0.06).

CONCLUSION

Vitamin D3 supplementation led to a significant increase in serum 25(OH)D and decreased school days missed (p = 0.04), but no other advantageous changes in asthma parameters compared with PL. The potential adverse effect of vitamin D deficiency on growth and the potential negative effect of high serum 25(OH)D on pulmonary function warrant further investigation.

Serum Vitamin D Is Significantly Inversely Associated with Disease Severity in Caucasian Adults with Obstructive Sleep Apnea Syndrome

STUDY OBJECTIVES

To evaluate vitamin D (25(OH)D) levels in obstructive sleep apnea syndrome (OSAS) and possible relationships to OSAS severity, sleepiness, lung function, nocturnal heart rate (HR), and body composition. We also aimed to compare the 25(OH)D status of a subset of OSAS patients compared to controls matched for important determinants of both OSAS and vitamin D deficiency (VDD).

METHODS

This was a cross-sectional study conducted at an urban, clinical sleep medicine outpatient center. We recruited newly diagnosed, Caucasian adults who had recently undergone nocturnal polysomnography. We compared body mass index (BMI), body composition (bioelectrical impedance analysis), neck circumference, sleepiness (Epworth Sleepiness Scale), lung function, and vitamin D status (serum 25-hydrpoxyvitamin D (25(OH)D) across OSAS severity categories and non-OSAS subjects. Next, using a case-control design, we compared measures of serum 25(OH)D from OSAS cases to non-OSAS controls who were matched for age, gender, skin pigmentation, sleepiness, season, and BMI.

RESULTS

106 adults (77 male; median age = 54.5; median BMI = 34.3 kg/m(2)) resident in Dublin, Ireland (latitude 53°N) were recruited and categorized as non-OSAS or mild/moderate/severe OSAS. 98% of OSAS cases had insufficient 25(OH)D (< 75 nmol/L), including 72% with VDD (< 50 nmol/L). 25(OH)D levels decreased with OSAS severity (P = 0.003). 25(OH)D was inversely correlated with BMI, percent body fat, AHI, and nocturnal HR. Subsequent multivariate regression analysis revealed that 25(OH)D was independently associated with both AHI (P = 0.016) and nocturnal HR (P = 0.0419). Our separate case-control study revealed that 25(OH)D was significantly lower in OSAS cases than matched, non-OSAS subjects (P = 0.001).

CONCLUSIONS

We observed widespread vitamin D deficiency and insufficiency in a Caucasian, OSAS population. There were significant, independent, inverse relationships between 25(OH)D and AHI as well as nocturnal HR, a known cardiovascular risk factor. Further, 25(OH)D was significantly lower in OSAS cases compared to matched, non-OSAS subjects. We provide evidence that 25(OH)D and OSAS are related, but the role, if any, of replenishment has not been investigated.

Can Vitamin D Supplementation in Addition to Asthma Controllers Improve Clinical Outcomes in Patients With Asthma?: A Meta-Analysis

Effects of vitamin D on acute exacerbation, lung function, and fraction of exhaled nitric oxide (FeNO) in patients with asthma are controversial. We aim to further evaluate the roles of vitamin D supplementation in addition to asthma controllers in asthmatics. From 1946 to July 2015, we searched the PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials, and ISI Web of Science using "Vitamin D," "Vit D," or "VitD" and "asthma," and manually reviewed the references listed in the identified articles. Randomized controlled trials which reported rate of asthma exacerbations and adverse events, forced expiratory volume in 1 s (FEV1, % of predicted value), FeNO, asthma control test (ACT), and serum 25-hydroxyvitamin D levels were eligible. We conducted the heterogeneities test and sensitivity analysis of the enrolled studies, and random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference for dichotomous and continuous data, respectively. Cochrane systematic review software Review Manager (RevMan) was used to test the hypothesis by Mann-Whitney U test, which were displayed in Forest plots. Seven trials with a total of 903 patients with asthma were pooled in our final studies. Except for asthma exacerbations (I2 = 81%, χ2 = 10.28, P = 0.006), we did not find statistical heterogeneity in outcome measures. The pooled RR of asthma exacerbation was 0.66 (95% confidence interval: 0.32-1.37), but without significant difference (z = 1.12, P = 0.26), neither was in FEV1 (z = 0.30, P = 0.77), FeNO (z = 0.28, P = 0.78), or ACT (z = 0.92, P = 0.36), although serum 25-hydroxyvitamin D was significantly increased (z = 6.16, P < 0.001). Vitamin D supplementation in addition to asthma controllers cannot decrease asthma exacerbation and FeNO, nor improve lung function and asthma symptoms, although it can be safely applied to increase serum 25-hydroxyvitamin D levels.