Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized Phase IV Control Trial of Single High Dose Oral Vitamin D3 (Stoss Therapy) in Pediatric Patients Undergoing HSCT to Prevent Vitamin D Deficiency and Insufficiency During Transplant
Brief Summary: Research has suggested that children with sufficient vitamin D levels undergoing hematopoietic stem cell transplant (HSCT) have improved outcomes, including lower incidences of infection and graft-versus-host disease (GVHD), as well as overall improved survival. However, supplementation in children undergoing HSCT has shown to be a challenge using standard or aggressive supplementation strategies. The primary objective of this study is to determine the safety and efficacy of a single, high dose oral vitamin D (Stoss Therapy) at the start of transplant followed by maintenance supplementation in children undergoing HSCT.


Options:
A: Inclusion Criteria:

* All pediatric patients, ages 1 to 25 years of age, undergoing hematopoietic stem cell transplant at Phoenix Children's hospital
* Patients must sign an informed consent

Exclusion Criteria:

* Prior rejection of hematopoietic stem cell transplant
B: Inclusion Criteria:

* 4-8 years at the start of the intervention
* healthy
* of white, Danish/European origin
* children must be Danish-speaking
* parents must read and speak Danish
* not planning a winter vacation south of a latitude of 51°North (corresponding to Surrey, England)

Exclusion Criteria:

* diseases that may interfere with vitamin D or calcium metabolism
* intake of medication known to affect vitamin D or calcium metabolism
* use of vitamin D containing supplements ≥ 4 days/week the last 8 weeks before intervention start and use of any vitamin D containing supplements the last 4 weeks before intervention start
* concomitant participation in other studies involving dietary supplements or blood sampling
* serum calcium \> 2.7 mmol/L at baseline
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:

* HIV-infected children as defined by ≥ 2 positive HIV DNA PCRs and/or HIV cultures of blood for children less than 18 months of age, or by positive screening and confirmatory serologic testing in those older than 18 months of age
* Stable HIV disease, defined by the absence of change in HIV clinical or immunologic category during the preceding 6 month period, prior to commencing the study
* Age 3 years through 18 years
* Voluntary informed consent

Exclusion Criteria:

* Any antiretroviral medication change in the 6 months prior to the study, or any anticipated antiretroviral medication change during the duration of the study
* Active participation in another treatment trial
* Serum calcium \< 2mmol/L at baseline

Answer: A