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:

* Patients aged between 6 and 14 years old, of both sexes
* Diagnosis of mild / moderate persistent asthma (GINA step 2/3)
* Allergy mite (Dermatophagoides farinae and pteronyssinus + + + / + + + +)
* Levels of vitamin 25 (OH) D \<30 ng / ml
* Signature of the informed consent of one parent or a legal representative

Exclusion Criteria:

* Cardiovascular disease or systemic
* anatomical abnormalities
* Other respiratory diseases
* Taking probiotics and / or prebiotics in the previous 2 weeks
* Taking vitamin D or systemic corticosteroids within 4 weeks
* Participation in other clinical trials
B: Inclusion Criteria:

* Diagnosis of ABPA as per the International Society for Human and Animal Mycology Working group criteria
* Treatment naïve

Exclusion Criteria:

* Failure to provide informed consent
* Enrollment in another trial of ABPA
* Pregnancy
* Creatinine more than or equal to 1.5 mg/dL
* Immunosuppressive states like chronic liver disease, chronic renal failure, cytotoxic therapy, uncontrolled diabetes mellitus and others
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:

* 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.

Answer: D