Please select the eligibility criteria that correspond to the clinical trial below.
Title: Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness in Asthma
Brief Summary: The purpose of the study is to find out if taking vitamin D in addition to an asthma controller medication helps to prevent worsening of asthma symptoms and asthma attacks.


Options:
A: 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.
B: 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
C: Principal Inclusion Criteria:

* Medical record diagnosis of COPD, emphysema or bronchitis
* Post-bronchodilator FEV1 / FVC \< 70% or post-bronchodilator FEV1 / slow VC \< 70%
* Post-bronchodilator FEV1 \< 80% predicted
* Age ≥ 40 years on day of first dose of IMP
* Smoking history ≥ 15 pack-years
* If a woman of child-bearing potential, is sexually abstinent or has negative pregnancy test within 7 days of recruitment and agrees to use reliable form of contraception until she has completed the study
* Able to give written informed consent to participate

Exclusion Criteria:

* Current diagnosis of asthma
* Known clinically significant bronchiectasis
* Known sarcoidosis, hyperparathyroidism, nephrolithiasis, active tuberculosis, vitamin D intolerance, liver failure, renal failure, terminal illness, lymphoma or other malignancy not in remission for ≥ 3 years
* Taking benzothiadiazine derivative, cardiac glycoside, carbamazepine, phenobarbital, phenytoin or primidone
* Taking dietary supplement or topical preparation containing vitamin D up to 2 months before first dose of IMP
* Treatment with any investigational medical product or device up to 4 months before first dose of IMP
* Breastfeeding, pregnant or planning a pregnancy
* Baseline corrected serum calcium \> 2.65 mmol/L
* Baseline serum creatinine \> 125 micromol/L
D: 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)

Answer: D