Micronutrients and the Risk of Allergic Diseases in School Children.

Microelements and vitamins are believed to have immunomodulatory effects. The aim of the study was to establish the role of antioxidants (vitamins A, E, D) and microelements such as copper (Cu), selenium (Se), and zinc (Zn) levels in allergic diseases in schoolchildren. The study uses a cohort of 80 children (40 with and 40 without allergy/asthma diagnosis) aged 9 to 12 years recruited for the Polish Mother and Child Cohort Study. At nine to twelve years old, the children were tested for microelement and vitamin content and health status (including skin-prick test and spirometry, urine cotinine level). Demographic data were collected from mothers by an allergist. The risk of asthma occurrence was found to be significantly related to the levels of Cu and Zn. The level of Cu was also particularly closely associated with allergic rhinitis and was indicated as a significant predictor of food allergy. The levels of Cu and Zn, and poor nutritional status in general, can influence the immune system and may be considered risk factors for developing asthma, allergic rhinitis and food allergy.

The role of antioxidants and 25-hydroxyvitamin D during pregnancy in the development of allergic diseases in early school-age children - Polish Mother and Child Cohort Study.

Purpose: Based on the available data, alterations of the antioxidant defense as well as the vitamin status in mothers may affect the prenatal process of lung and immune system development as a pathophysiological background of increased prevalence of allergic diseases. The primary aim of the current study was to assess the associations among cord blood concentrations of zinc (Zn); copper (Cu); selenium (Se); ß-carotene; and vitamin A, E, and D, and the occurrence of atopic dermatitis, food allergy, allergic rhinitis, and asthma in early school-age children. Methods: We evaluated 211 children, 7-9 years old, from the Polish Mother and Child Cohort Study. the women were interviewed during pregnancy to collect demographic and socioeconomic data, and the medical and reproductive history. At delivery, umbilical cord blood plasma was sampled. Seven to nine years after the birth, the child's exposure and health status (including skin-prick test and spirometry for allergy assessment and urine sample for cotinine level) were examined. In the analyses, a multivariable model was applied. Results: Statistically significant relationships were found among Zn; Cu; Se; and vitamin A, E, and D concentrations in cord blood; and the prevalence of food allergy, allergic rhinitis, atopic dermatitis, and asthma in children ages 7-9 years after adjustment for several confounders. Conclusion: We showed an imbalance in the antioxidant defense system in cord blood, which may lead to the occurrence of allergic diseases later in life. The maternal diet may have substantial potential to modify immune tolerance and, consequently, the development of allergic disease in the offspring.Clinical trial NCT01861548, www.clinicaltrials.gov.

Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis.

BACKGROUND: Randomised controlled trials (RCTs) exploring the potential of vitamin D to prevent acute respiratory infections have yielded mixed results. Individual participant data (IPD) meta-analysis has the potential to identify factors that may explain this heterogeneity. OBJECTIVES: To assess the overall effect of vitamin D supplementation on the risk of acute respiratory infections (ARIs) and to identify factors modifying this effect. DATA SOURCES: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, ClinicalTrials.gov and the International Standard Randomised Controlled Trials Number (ISRCTN) registry. STUDY SELECTION: Randomised, double-blind, placebo-controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration having incidence of acute respiratory infection as a prespecified efficacy outcome were selected. STUDY APPRAISAL: Study quality was assessed using the Cochrane Collaboration Risk of Bias tool to assess sequence generation, allocation concealment, blinding of participants, personnel and outcome assessors, completeness of outcome data, evidence of selective outcome reporting and other potential threats to validity. RESULTS: We identified 25 eligible RCTs (a total of 11,321 participants, aged from 0 to 95 years). IPD were obtained for 10,933 out of 11,321 (96.6%) participants. Vitamin D supplementation reduced the risk of ARI among all participants [adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.81 to 0.96; heterogeneity p < 0.001]. Subgroup analysis revealed that protective effects were seen in individuals receiving daily or weekly vitamin D without additional bolus doses (aOR 0.81, 95% CI 0.72 to 0.91), but not in those receiving one or more bolus doses (aOR 0.97, 95% CI 0.86 to 1.10; p = 0.05). Among those receiving daily or weekly vitamin D, protective effects of vitamin D were stronger in individuals with a baseline 25-hydroxyvitamin D [25(OH)D] concentration of < 25 nmol/l (aOR 0.30, 95% CI 0.17 to 0.53) than in those with a baseline 25(OH)D concentration of ≥ 25 nmol/l (aOR 0.75, 95% CI 0.60 to 0.95; p = 0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (aOR 0.98, 95% CI 0.80 to 1.20; p = 0.83). The body of evidence contributing to these analyses was assessed as being of high quality. LIMITATIONS: Our study had limited power to detect the effects of vitamin D supplementation on the risk of upper versus lower respiratory infection, analysed separately. CONCLUSIONS: Vitamin D supplementation was safe, and it protected against ARIs overall. Very deficient individuals and those not receiving bolus doses experienced the benefit. Incorporation of additional IPD from ongoing trials in the field has the potential to increase statistical power for analyses of secondary outcomes. STUDY REGISTRATION: This study is registered as PROSPERO CRD42014013953. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Clinical and immunological effects of vitamin D supplementation during the pollen season in children with allergic rhinitis.

INTRODUCTION: Vitamin D deficiency has been proposed as a potential contributing factor in patients with allergic diseases. We compared the clinical and immunological effects of vitamin D supplementation to placebo during the pollen season in children with allergic rhinitis. MATERIAL AND METHODS: Thirty-eight children aged 5-12, sensitive to grass pollen, participated in a prospective, randomized, double-blind, placebo-controlled trial. Children received either vitamin D 1000 IU daily supplementation or placebo. We studied symptoms/medication score, lung function, exhaled nitric oxide concentration (FENO), methacholine bronchial provocation test and serum level of 25(OH)D, as well as; CD4+CD25+Foxp3+ cells, TLR4, IL-1, IL-6, TNF and the IL-10 and transforming growth factor ß1 (TGF-ß1) levels in cell culture supernatants. RESULTS: Vitamin D therapy was effective in reduction of the symptoms/medication score (p = 0.0371). In vitamin D group an increase in the CD4+CD25+Foxp3+ cells (7.06 vs. 10.5%; p = 0.0013) and serum 25(OH)D concentration (49.6 vs. 96.6 ng/ml; p = 0.0001) and in control group an increase in FENO (15.6 vs. 21 ppb; p = 0.0331) and serum 25(OH)D level were observed (82.9 vs. 100.3 ng/ml; p = 0.0003).We revealed a higher increase from baseline in the percentage of CD4+CD25+Foxp3+ cells in the vitamin D group compared to the control group (p = 0.0058). A significant correlation between CD4+CD25+Foxp3+ cell induction and FENO reduction in the vitamin D group was observed (p = 0.0217). CONCLUSIONS: Vitamin D 1000 IU as a supplementary treatment of grass pollen allergy in children with allergic rhinitis during the pollen season significantly reduced the symptoms/medication score. The study revealed an immunological effect of vitamin D.

Comparison of the effect of 5-grass pollen sublingual immunotherapy tablets and drops in children with rhinoconjunctivitis.

BACKGROUND: One of the most important aspects of sublingual immunotherapy (SLIT) is the regimen of administration. AIM: To find any differences in symptom-medication scores between the two groups of SLIT tablets and drops, given pre-coseasonally (starting 8 weeks before the pollen season) in children with rhinoconjunctivitis allergy to grass pollen. The secondary outcome were the differences in lung function and induction of T-regulatory forkhead box P3 (FOXP3) positive cells. METHODS: This was a retrospective, secondary analysis of pooled data obtained from our two prospective randomized placebo controlled trials that involved children who underwent SLIT. Forty-one children, ages 6-18 years, with allergic rhinitis (AR), sensitive to grass pollen, participated in the study. RESULTS: Treatment with both tablets and drops significantly reduced all symptoms (nasal, asthma, and ocular) within the groups; there was no significant difference between both groups. When compared with the tablet therapy, there was a trend for drops therapy to be more effective in the reduction of combined symptom-medication score, but the difference was not statistically significant (p = 0.1036); there was no significant difference in asthma and nasal scores. We showed a significant decrease in the fractional exhaled nitric oxide level comparable in both immunotherapy groups. There were no differences between the groups in the induction of CD4+ CD25+ FOXP3+-positive cells in peripheral blood. CONCLUSIONS: Both protocols showed similar decreases in symptom-medication scores; however, when compared with tablet therapy, there was a trend for drops therapy to be more effective in the reduction of combined symptom-medication score.

Vitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data.

BACKGROUND: A previous aggregate data meta-analysis of randomised controlled trials showed that vitamin D supplementation reduces the rate of asthma exacerbations requiring treatment with systemic corticosteroids. Whether this effect is restricted to patients with low baseline vitamin D status is unknown. METHODS: For this systematic review and one-step and two-step meta-analysis of individual participant data, we searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science for double-blind, placebo-controlled, randomised controlled trials of vitamin D3 or vitamin D2 supplementation in people with asthma that reported incidence of asthma exacerbation, published between database inception and Oct 26, 2016. We analysed individual participant data requested from the principal investigator for each eligible trial, adjusting for age and sex, and clustering by study. The primary outcome was the incidence of asthma exacerbation requiring treatment with systemic corticosteroids. Mixed-effects regression models were used to obtain the pooled intervention effect with a 95% CI. Subgroup analyses were done to determine whether effects of vitamin D on risk of asthma exacerbation varied according to baseline 25-hydroxyvitamin D (25[OH]D) concentration, age, ethnic or racial origin, body-mass index, vitamin D dosing regimen, use of inhaled corticosteroids, or end-study 25(OH)D levels; post-hoc subgroup analyses were done according to sex and study duration. This study was registered with PROSPERO, number CRD42014013953. FINDINGS: Our search identified 483 unique studies, eight of which were eligible randomised controlled trials (total 1078 participants). We sought individual participant data for each and obtained it for seven studies (955 participants). Vitamin D supplementation reduced the rate of asthma exacerbation requiring treatment with systemic corticosteroids among all participants (adjusted incidence rate ratio [aIRR] 0·74, 95% CI 0·56-0·97; p=0·03; 955 participants in seven studies; high-quality evidence). There were no significant differences between vitamin D and placebo in the proportion of participants with at least one exacerbation or time to first exacerbation. Subgroup analyses of the rate of asthma exacerbations treated with systemic corticosteroids revealed that protective effects were seen in participants with baseline 25(OH)D of less than 25 nmol/L (aIRR 0·33, 0·11-0·98; p=0·046; 92 participants in three studies; moderate-quality evidence) but not in participants with higher baseline 25(OH)D levels (aIRR 0·77, 0·58-1·03; p=0·08; 764 participants in six studies; moderate-quality evidence; pinteraction=0·25). p values for interaction for all other subgroup analyses were also higher than 0·05; therefore, we did not show that the effects of this intervention are stronger in any one subgroup than in another. Six studies were assessed as being at low risk of bias, and one was assessed as being at unclear risk of bias. The two-step meta-analysis did not reveal evidence of heterogeneity of effect (I2=0·0, p=0·56). INTERPRETATION: Vitamin D supplementation reduced the rate of asthma exacerbations requiring treatment with systemic corticosteroids overall. We did not find definitive evidence that effects of this intervention differed across subgroups of patients. FUNDING: Health Technology Assessment Program, National Institute for Health Research (reference number 13/03/25).

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data.

Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect.Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials.Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015.Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome.Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality.Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.Systematic review registration PROSPERO CRD42014013953.

Effect of Lactobacillus rhamnosus GG and vitamin D supplementation on the immunologic effectiveness of grass-specific sublingual immunotherapy in children with allergy.

BACKGROUND: An important issue in sublingual immunotherapy (SLIT) is how to improve efficacy. OBJECTIVE: To compare the clinical and immunologic efficacy of SLIT given alone and, to enhance clinical efficacy, given with probiotic or vitamin D supplementation. METHODS: One hundred children, ages 5-12 years, sensitive to grass pollen, with allergic rhinitis participated in a 5-month prospective, randomized, double-blind, placebo-controlled trial. Children received 5-grass SLIT 300 IR tablets with either vitamin D 1000 IU daily supplementation, probiotic, or placebo. The control group included children with allergy who did not qualify for immunotherapy. Primary end points included a symptom-medication score, lung function, and exhaled nitric oxide concentration. The secondary end point was the immunologic efficacy measured by the following: CD4(+)CD25(+)Foxp3(+) (forkhead box P3) cells, Toll-like receptor (TLR) 4, interleukin (IL) 1, IL-6, tumor necrosis factor, IL-10, and transforming growth factor ß-1 levels in cell culture supernatants. RESULTS: Reduction in the symptom-medication score and improvement in lung function as well as a significant increase in the percentage of CD4(+)CD25(+)Foxp3(+) in children who received SLIT in all the groups were observed compared with control group. In the SLIT-probiotic group, between-group analysis showed significantly higher CD4(+)CD25(+)Foxp3(+) induction compared with the SLIT group and higher reduction in the percentage of TLR-positive cell group compared with the SLIT-vitamin D group (Fig. 1). An increase in CD4(+)CD25(+)Foxp3(+) induction, reduction in TLR-positive cells recruitment and an increase in transforming growth factor ß-1 production were independently associated with a better clinical effect of SLIT in children. CONCLUSIONS: We demonstrated the clinical and immunologic effect of probiotic and vitamin D supplementation on SLIT. Probiotic supplementation showed better clinical and immunologic response in children with allergic rhinitis.

The clinical effect of vitamin D supplementation combined with grass-specific sublingual immunotherapy in children with allergic rhinitis.

BACKGROUND: An important issue in sublingual immunotherapy (SLIT) is how to improve efficacy. OBJECTIVE: To compare the clinical efficacy of SLIT with vitamin D supplementation with placebo in children with allergic rhinitis. Secondary end points included lung function, exhaled nitric oxide concentration, methacholine bronchial provocation test, and serum level of calcifediol (25[OH]D). METHODS: Fifty children, ages 5-12 years, sensitive to grass pollen, with allergic rhinitis (eight patients had concomitant asthma) participated in a 5-month prospective, randomized, double-blind, placebo-controlled trial. Children received a 5-grass pollen sublingual 300 IR tablet with either vitamin D 1000 IU daily supplementation or placebo. RESULTS: When compared with the placebo group, SLIT plus vitamin D group therapy was more effective in the reduction of nasal symptoms (p = 0.04), asthma symptoms (p = 0.001), and the combined symptom-medication score (p = 0.001); there was no significant difference between the groups in medication and ocular scores. We observed a significant improvement of forced expiratory volume in 1 second (vitamin D group, p = 0.014; placebo group, p = 0.015) and the proportion of a person's vital capacity expired in the first second of forced expiration levels (vitamin D group, p = 0.004; placebo group, p < 0.001), within both groups, between visits. Fractional exhaled nitric oxide and provocative dose producing a 20% fall in forced expiratory volume in 1 second results did not statistically significantly differentiate the study participants in terms of receiving SLIT along with vitamin D or placebo. We showed a significant increase in calcifediol in the SLIT plus vitamin D group as well as in SLIT plus placebo group. CONCLUSIONS: Vitamin D supplementation combined with grass-specific SLIT was more effective in the reduction of nasal and asthma symptoms. Vitamin D supplementation combined with SLIT provides an effective and well-tolerated new immunotherapy modality for treating children with allergic rhinitis. A 5-grass pollen sublingual 300 IR tablet was effective in both studied groups and also in children with comorbid mild asthma.

Inhaled corticosteroids may have a beneficial effect on bone metabolism in newly diagnosed asthmatic children.

BACKGROUND: The adverse effect of inhaled corticosteroids (ICS) treatment on bone metabolism in children with asthma is still controversial, and a possible beneficial effect of vitamin D added to ICS on bone turnover is uncertain. OBJECTIVE: We conducted a randomized, double-blind, parallel-group, 6-month trial to assess the effects of a medium and high dose of ICS and a high-dose ICS with vitamin D on bone metabolism in children with newly diagnosed atopic asthma. METHODS: 96 children were equally randomized to 4 groups receiving the following doses of inhaled budesonide [µg/day]: 400 (ICS 400 group), 800 (ICS 800 group), 800 with oral vitamin D (ICS 800 with vit D group), and montelukast as a control (control group). Markers of bone production (osteocalcin, alkaline phosphatase) and bone degradation (amino-terminal cross-linked telopeptide of type I collagen--NTx, carboxy-terminal telopeptides of type I collage), and also concentration of 25-hydroxycholecalciferol (25OH D) and calcium-phosphorus balance (calcium, phosphorus, parathormon-PTH) in serum and/or urine were assessed twice: before and after 6 months of treatment. RESULTS: We obtained a significant decrease in phosphorus and PTH serum levels in ICS 400 and ICS 800 with vit D groups compared to control group, and a significant decrease of NTx urine level in ICS 800 with vit D group. CONCLUSIONS: Medium doses of inhaled corticosteroids exert an advantageous effect on bone metabolism in newly diagnosed asthmatic children. Vitamin D together with a high dose of inhaled corticosteroids has a beneficial effect on both calcium-phosphorus balance and collagen turnover.