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

Riverin BD, Maguire JL, Li P - PLoS ONE (2015)

Bottom Line: We qualitatively summarized the main results of efficacy and safety and meta-analyzed data on comparable outcomes across studies.Main planned outcomes measures were ED visits and hospitalizations.One study (moderate-quality, n = 100) reported significantly less ED visits for children treated with vitamin D.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada; Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada.

ABSTRACT

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

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

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

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

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

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

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

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

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

No MeSH data available.


Related in: MedlinePlus

Forest plot of asthma exacerbations.
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pone.0136841.g002: Forest plot of asthma exacerbations.

Mentions: Asthma exacerbations were assessed in five trials, four of which that found that vitamin D supplementation decreased asthma exacerbations, [24,31,34,42] and one that reported no significant effect of the intervention (Table 2). Data was not available for the meta-analysis in two trials. [24,43] The number of children who experienced asthma exacerbation during the intervention was reported as a secondary outcome measure in five trials. [24,31,34,42,43] Of those, one trial defined asthma exacerbation as preceded by symptoms of an acute respiratory infection and requiring β2-agonists and antibiotics (if appropriate), [31] the second as physician-diagnosed asthma attack that included wheezing improved by inhalation of a β stimulant, [34] and three did not specify outcome ascertainment. [24,42,43] The pooled effect estimate for the trials by Majak et al (2011), [31] Urashima et al, [34] and Yadav and Mittal [42] was 0.41, (RR, 95% CI 0.27 to 0.63, P<0.0001) and no statistical heterogeneity was observed (I2 = 0%, P = 0.37) (Fig 2).


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

Riverin BD, Maguire JL, Li P - PLoS ONE (2015)

Forest plot of asthma exacerbations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556456&req=5

pone.0136841.g002: Forest plot of asthma exacerbations.
Mentions: Asthma exacerbations were assessed in five trials, four of which that found that vitamin D supplementation decreased asthma exacerbations, [24,31,34,42] and one that reported no significant effect of the intervention (Table 2). Data was not available for the meta-analysis in two trials. [24,43] The number of children who experienced asthma exacerbation during the intervention was reported as a secondary outcome measure in five trials. [24,31,34,42,43] Of those, one trial defined asthma exacerbation as preceded by symptoms of an acute respiratory infection and requiring β2-agonists and antibiotics (if appropriate), [31] the second as physician-diagnosed asthma attack that included wheezing improved by inhalation of a β stimulant, [34] and three did not specify outcome ascertainment. [24,42,43] The pooled effect estimate for the trials by Majak et al (2011), [31] Urashima et al, [34] and Yadav and Mittal [42] was 0.41, (RR, 95% CI 0.27 to 0.63, P<0.0001) and no statistical heterogeneity was observed (I2 = 0%, P = 0.37) (Fig 2).

Bottom Line: We qualitatively summarized the main results of efficacy and safety and meta-analyzed data on comparable outcomes across studies.Main planned outcomes measures were ED visits and hospitalizations.One study (moderate-quality, n = 100) reported significantly less ED visits for children treated with vitamin D.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada; Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada.

ABSTRACT

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

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

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

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

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

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

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

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

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

No MeSH data available.


Related in: MedlinePlus