Vitamin D to Prevent Severe Asthma Exacerbations (Vit-D-Kids Asthma)
Condition: Asthma
MeSH terms: Asthma
Intervention: vitamin D3 4000 IU; Placebo
Intervention description: The vitamin D3 will be in oral gel cap form and contain 4000 International Units (IU) of cholecalciferol per gel cap.; The placebo is a gel cap that is indistinguishable from the vitamin D3 gel cap.
Intervention MeSH terms: Vitamin D; Cholecalciferol
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 192.0
Sex: All
Minimum age: 6 Years
Maximum age: 16 Years
Healthy volunteers: No
Keywords: Vitamin D, severe asthma exacerbations, children

Summary:

      This study will determine whether vitamin D3 prevents severe asthma attacks in children who
      have a serum vitamin D (25(OH)D) level <30 ng/ml and who are being treated with inhaled
      corticosteroids for asthma. Half the participants will receive vitamin D3 at a dose of 4,000
      IU/day, and the other half will receive placebo.
    

Eligibility criteria:

        Inclusion Criteria:

          -  6 to 16 years old

          -  Physician-diagnosed asthma for at least one year

          -  At least one severe asthma exacerbation in the previous year

          -  Use of asthma medications (daily controller medication [ICS or leukotriene inhibitor]
             or inhaled β2-agonist [at least three days per week]) for at least six months in the
             previous year

          -  Vitamin D insufficiency (i.e., serum vitamin D (25(OH)D level <30 ng/ml (75 nmol/L))

          -  FEV1 ≥70 % of predicted

          -  Positive bronchodilator response (i.e., increase in FEV1 ≥8% from baseline after
             inhaled short acting beta agonist or increased airway responsiveness to methacholine
             (PC20 ≤8 mg/ml if not on ICS or PC20 ≤16 mg/ml if on ICS)

          -  Study protocol (i.e., age-appropriate dose of Fluticasone and no other asthma
             controller medications) approved by the child's regular doctor

          -  Parental consent and child's assent to participate in the study.

        Additional inclusion criteria applied after the run-in period, to be eligible for
        randomization:

          -  Adherence with ICS and study medication (≥75% use [at least 21 of 28 days]) during the
             run-in period

          -  Willingness to be randomized and complete study

        Exclusion Criteria:

          -  Serum calcium >10.8 mg/dl

          -  Serum 25(OH) D <14 ng/ml (35 nmol/L)

          -  Chronic respiratory disorder other than asthma

          -  Severe asthma (intubation for asthma at any time OR ≥3 hospitalizations for asthma in
             previous year OR ≥6 severe asthma exacerbations in previous year)

          -  Hepatic/renal disease, rickets, malabsorption, or other diseases that would affect
             vitamin D metabolism

          -  Current smoking, or former smoking if ≥5 pack-years

          -  Immune deficiency, cleft palate or Down's syndrome

          -  Treatment with anticonvulsants or ≥1,000 IU/day of vitamin D2 or D3

          -  Chronic oral corticosteroid therapy

          -  Inability to perform acceptable spirometry

          -  Use of investigational therapies or participation in trials 30 days before or during
             the study

          -  Participant is currently breast feeding an infant

          -  Pregnancy

          -  Weight less than 10 kg

          -  Plans to move out of the study site area in the next year

        Additional exclusion criteria applied after the run-in period:

          -  Any severe asthma exacerbation during the run-in period

          -  Need for asthma medications other than ICS and p.r.n. rescue inhalers during the
             run-in period