Meta- analysis of a modest number of trials in people with predominantly mild to moderate asthma suggests that vitamin D is likely to reduce both the risk of severe asthma exacerbation and healthcare use .
Children and people with frequent severe asthma exacerbations were under-represented ; additional primary trials are needed to establish whether vitamin D can reduce the risk of severe asthma exacerbation in these groups
BACKGROUND Several clinical trials of vitamin D to prevent  asthma exacerbation  and improve  asthma control  have been conducted in children and adults , but a meta- analysis restricted to double-blind , r and omised , placebo-controlled trials of this intervention is lacking .
OBJECTIVES To evaluate the efficacy of administration of vitamin D and its hydroxylated metabolites in reducing the risk of severe asthma exacerbations ( defined as those requiring treatment with systemic corticosteroids ) and improving asthma symptom control .
The effects of vitamin D supplementation on airway functions in mild to moderate persistent asthma.
BACKGROUND Vitamin D is hypothesized to have some roles in innate and adaptive immunity , inflammation reduction , and remodeling ; therefore , it is supposed to affect the asthma phenotype , severity , and response to inhaled corticosteroid ( ICS ) . OBJECTIVE To explore the synergistic effects of vitamin D supplementation in addition to asthma controllers ( ICS or ICS plus long-acting β-agonist ) on airway functions . METHODS A r and omized clinical trial was conducted in 130 individuals aged 10 to 50 years who lived in Tehran during a 24-week period . Data on age , sex , body mass index , stage of asthma , serum total IgE , history of allergic rhinitis , atopic dermatitis , food allergy , and urticaria were collected .  Spirometric parameters ( forced expiratory volume in 1 second [ FEV1 ] and ratio of FEV1 to forced vital capacity ) and serum vitamin D measurement were obtained before and 8 and 24 weeks after the intervention . Patients were divided in 2 groups r and omly . Both groups received asthma controllers ( budesonide or budesonide plus formoterol ) according to their stage , but the intervention group received vitamin D supplementation ( 100,000-U bolus intramuscularly plus 50,000 U orally weekly ) in addition to asthma controllers . RESULTS FEV1 improved significantly in both groups after 8 weeks , but no significant difference was found between the 2 groups at baseline ( P = .20 ) or after 8 weeks ( P = .99 ) ; however , a significant improvement was seen in the intervention group in the last 16 weeks , and FEV1 was significantly better in the intervention group than the other group after 24 weeks ( P < .001 ) . CONCLUSION Vitamin D supplementation associated with asthma controllers could significantly improve FEV1 in mild to moderate persistent asthma after 24 weeks . TRIAL REGISTRATION i rct .ir Identifier : I RCT 201302079608N1
Meta- analysis of a modest number of trials in people with predominantly mild to moderate asthma suggests that vitamin D is likely to reduce both the risk of severe asthma exacerbation and healthcare use .
Children and people with frequent severe asthma exacerbations were under-represented ; additional primary trials are needed to establish whether vitamin D can reduce the risk of severe asthma exacerbation in these groups
BACKGROUND Several clinical trials of vitamin D to prevent  asthma exacerbation  and improve  asthma control  have been conducted in children and adults , but a meta- analysis restricted to double-blind , r and omised , placebo-controlled trials of this intervention is lacking .
OBJECTIVES To evaluate the efficacy of administration of vitamin D and its hydroxylated metabolites in reducing the risk of severe asthma exacerbations ( defined as those requiring treatment with systemic corticosteroids ) and improving asthma symptom control .