Please select the eligibility criteria that correspond to the clinical trial below.
Title: Vitamin D vs. Placebo in the Prevention of Viral-induced Exacerbations in Preschoolers With Asthma: a Pilot RCT
Brief Summary: Viral infections are the main cause of asthma attacks in preschoolers, an age group with the highest rate of emergency visits due to asthma. While high doses of inhaled or oral corticosteroids provide benefits, these have been associated with adverse outcomes. Most asthmatic children have lower blood levels of vitamin D compared to non-asthmatic children. Low vitamin D level has been linked to more frequent and more severe asthma attacks as well as with higher dose requirement of inhaled corticosteroid. Recent studies show that vitamin D supplements can reduce the number of asthma attacks triggered by viral infections in children. Unfortunately, most people forget to take vitamin D every day during the fall and winter season as recommended in Canada. A solution is to give a vitamin D bolus by mouth. This has been shown to safely and effectively increase vitamin D levels in children. The investigators hypothesise that a vitamin D bolus given in clinic will sufficiently increase the blood level of vitamin D to prevent the expected winter decline in vitamin D, compared with placebo in preschool-aged children with asthma. This six-month pilot randomized controlled trial aims to: (1) show that a vitamin D bolus is superior to placebo in raising vitamin D levels; (2) record the number of asthma attacks and viral infections in enrolled participants; and (3) identify problems that may call for protocol changes.


Options:
A: Inclusion Criteria:

* Men and women 18 years of age and older
* Physician-diagnosed asthma for at least previous 12 months
* Asthma confirmed by: (a) β-agonist reversibility of forced expiratory volume in 1 second (FEV1) ≥12 % following 180 mcg (4 puffs) levalbuterol at visit 1 OR (b) methacholine provocative concentration causing a 20% fall in FEV1 (PC20) ≤ 8 mg/ml if not receiving an inhaled corticosteroid or ≤ 16 mg/ml if receiving an inhaled corticosteroid at visit 2. Source documentation for PC20 from an AsthmaNet methacholine challenge completed within 6 months of visit 2 will be accepted.
* Stable asthma controller therapy (inhaled corticosteroid or leukotriene modifier only) dose for past 2 weeks
* FEV1 ≥ 50% of predicted at visit 1
* Vitamin D level of less than 30 ng/ml at visit 0
* Experienced no more than one treatment failure in the VIDA run-in or oral corticosteroid (OCS) response periods on previous enrollments
* For women of childbearing potential: not pregnant, non-lactating, and agree to practice an adequate birth control method for the duration of the study

Exclusion Criteria:

* Taking vitamin D supplements containing \> 1000 IU/day of vitamin D
* Taking \>2500 mg/day calcium supplements
* Chronic oral corticosteroid therapy
* Chronic inhaled corticosteroid therapy \> 1,000 mcg of fluticasone daily or the equivalent
* History of physician-diagnosed nephrolithiasis
* Use of concomitant medications that alter vitamin D metabolism - phenytoin, phenobarbital, cardiac glycosides; or absorption - orlistat, cholestyramine, colestipol; or those that interfere with study endpoints
* Impaired renal function (GFR \< 30 ml/min)
* Asthma exacerbation within past 4 weeks requiring systemic corticosteroids
* Respiratory tract infection within past 4 weeks
* Chronic diseases (other than asthma)
* History of cigarette smoking within the past 1 year or \> 10 pack years total
* Serum calcium greater than 10.2 mg/dl on entry
* Urine calcium/creatinine ratio greater than 0.37 (urinary Ca and Creat in mg)
B: Inclusion Criteria:

* children aged 1-5 years
* physician-diagnosed asthma as per GINA guidelines
* upper respiratory tract infections as the main asthma exacerbation trigger
* ≥4 respiratory infections in the past 12 months
* ≥1 exacerbation requiring rescue oral steroids in the past 6 months or ≥2 in the previous 12 months.

Exclusion Criteria:

* extreme prematurity (\<28 weeks gestation)
* infants \<12 months of age
* breastfed infants with no vitamin D supplementation
* recent (\<1 year) immigrants from countries where rickets and malnutrition prevalent
* other chronic respiratory disease (broncho-pulmonary dysplasia; cystic fibrosis)
* endocrine disorder of calcium/ vitamin D metabolism
* disorder/ disease with associated malabsorption (inflammatory bowel disease)
* kidney/ liver disease
* sickle cell anemia
* medications known to interfere with bone metabolism/ vitamin D levels
* vitamin D supplementation \>1000 IU/ day in past 3 months
* unable to attend medical visit in 3-4 months
* plan to leave the province during the next 6 months.
C: Inclusion Criteria:

1. Healthy children by parental report
2. Have reached their 1st birthday but not past their 6th birthday
3. Present to a TARGet Kids! practice for routine primary healthcare prior to viral season (September through November)
4. Parents provide informed consent to participate.

Exclusion Criteria:

1. Children with gestational age \< 32 weeks
2. Children with chronic illness (except for asthma) on parental report which is known to interfere with vitamin D metabolism and increase the risk of respiratory infection
3. Children with a sibling participating in the study to reduce clustering effects.
D: Inclusion Criteria:

* Primary diagnosis of COPD exacerbation
* Smoking history of at least ten pack years
* GOLD stage II, III and IV as assessed by a post-bronchodilator spirometry
* Informed consent

Exclusion Criteria:

* Tiffeneau index \>70% or FEV1 \>80%
* Hypercalcemia
* Sarcoidosis
* Newly discovered symptomatic osteoporosis (proven by DEXA and RX )
* Active cancer

Answer: B