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:

* Diagnosis of sickle cell disease (HbSS, HbSC, HbS Beta-thalassemia)
* Age 3 to 20 years old

Exclusion Criteria:

* Patient (or parent or guardian) unwilling or unable to provide written informed consent (and assent, if applicable)
* Patient unable or unwilling to comply with requirements of the clinical trial
* Participation in other therapeutic clinical trial
* Current diagnosis of rickets
* History of hypercalcemia or diagnosis of any medical condition associated with hypercalcemia, including primary hyperparathyroidism, malignancy, sarcoidosis, tuberculosis, granulomatous disease, familial hypocalciuric hypercalcemia
* Current use of corticosteroids, excluding inhaled steroids
* Current use of anticonvulsants (phenytoin, phenobarbital, carbamazepine)
* Therapy with thiazide diuretics or lithium carbonate
* Known liver or renal disease
* Patients taking medications for pulmonary complications of sickle cell disease not on a stable dose of medications, as defined by a change in medications or doses within the three months prior to study entry
* Patients on chronic red blood cell transfusion therapy
* Absence of baseline record of respiratory events (respiratory infections, asthma exacerbations, episodes of acute chest syndrome) for the preceding year
* Pregnancy
B: Inclusion Criteria:

* age 1-5 years
* physician-diagnosed asthma as per the Global Initiative for Asthma (GINA) guidelines
* URTIs as the main asthma trigger (parental report)
* ≥4 URTIs in the past 12 months (parental report)
* ≥1 asthma exacerbation requiring rescue oral corticosteroids (OCS) in the past 6 months or ≥2 in the past 12 months

Exclusion Criteria:

* intake or intention to use more than 400 IU/day of vitamin D supplement
* extreme prematurity (\<28 weeks gestation)
* infants \<12 months of age
* no vitamin D supplementation when breast-fed
* recent (\<1 year) immigrants from a region at high risk of rickets
* children with vitamin D restrictive diets e.g. vegans
* other chronic respiratory disease (broncho-pulmonary dysplasia; cystic fibrosis)
* condition(s) that alter calcium or vitamin D metabolism/absorption (hypo/hyperparathyroidism, kidney/liver disease, inflammatory bowel disease)
* medications that interfere with vitamin D metabolism (anti-epileptics, diuretics, antacids, anti-fungal drug)
* vitamin D supplementation \>1000 IU/ day in last 3 months
* anticipated difficult follow-up (unable to attend clinic visits; plan to leave the province).
C: Principal Inclusion Criteria:

* Medical record diagnosis of asthma
* Age ≥ 16 years and ≤ 80 years on day of first dose of IMP
* 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 in the study

Principal Exclusion Criteria:

* Diagnosis of COPD
* 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
* Any other condition that, in an investigator's judgement, might compromise patient safety or compliance, interfere with evaluation or preclude completion of the study
* Taking benzothiadiazine derivative, cardiac glycoside, carbamazepine, phenobarbital, phenytoin or primidone
* Taking dietary supplement 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
* Smoking history \>15 pack-years
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