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DO IT Trial: Vitamin D Outcomes and Interventions In Toddlers (DO IT)

This study has been completed.
Mount Sinai Hospital, Canada
St. Michael's Hospital, Toronto
Information provided by (Responsible Party):
Jonathon Maguire, The Hospital for Sick Children Identifier:
First received: August 16, 2011
Last updated: November 16, 2015
Last verified: November 2015

Vitamin D can be made in the skin by exposure to sunlight and can be found in certain foods. Vitamin D levels are alarmingly low in many North American children. Several health issues have been linked with low vitamin D. These include colds caused by viruses and asthma attacks. However, no study has determined whether vitamin D supplementation can reduce the risk of these conditions in young children where they are most common and most severe.

The goals of this study are to determine whether wintertime high dose vitamin D supplementation of preschoolers can prevent colds and asthma attacks. The investigators also aim to work out how much money would be saved by the health care system and society if preschoolers were routinely supplemented with Vitamin D during the winter. The investigators believe that preschoolers receiving 'high dose' vitamin D supplementation during the wintertime will be less likely to have colds, asthma attacks, and low vitamin D levels and will be less likely to use the medical system and keep their parents away from work.

Condition Intervention Phase
Respiratory Tract Infections
Drug: Vitamin D - Cholecalciferol 400 IU
Drug: Vitamin D3 - Cholecalciferol 2000 IU
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: DO IT Trial: Vitamin D Outcomes and Interventions In Toddlers

Resource links provided by NLM:

Further study details as provided by The Hospital for Sick Children:

Primary Outcome Measures:
  • Number of Laboratory confirmed upper respiratory tract infections [ Time Frame: Up to 8 months ]
    Parents of enrolled children will be asked to obtain a nasal swab from their child and complete a symptom checklist with each URTI. Reverse transcriptase polymerase chain reaction will be performed on each sample. Samples will be tested for 18 common respiratory viruses using the ID-TagTM RVP assay using the Luminex xMAPTM system.

Secondary Outcome Measures:
  • Number of parent reported upper respiratory tract infections [ Time Frame: Up to 8 months ]
    Parental reported URTI symptoms will be defined as two or more of fever, cough, runny nose, sore throat, headache, vomiting, feels unwell, muscle aches, ear ache or infection, poor appetite, not sleeping well, cranky/fussy, low energy or crying more than usual from a validated parent completed symptom checklist.

  • Number of Asthma exacerbations [ Time Frame: Up to 8 months ]
    Asthma exacerbation will be defined as a wheezing episode in children with asthma as obtained from parent completed symptom checklist based on the International Study of Asthma and Allergies in Childhood (ISAAC).

  • Serum vitamin D level [ Time Frame: 5-8months ]
    Blood for serum levels will be drawn by trained pediatric phlebotomists from for determination of 25-hydroxyvitamin D. Total 25-hydroxyvitamin D will be measured from serum samples using a competitive two-step chemiluminescence assay.

  • Direct and indirect economic costs associated with upper respiratory tract infections [ Time Frame: 16 months ]
    Cost-consequence and cost-effectiveness analyses will be conducted using data from this clinical trial. A societal perspective will be employed as both direct health service utilization costs as well as indirect costs to families from URTI will be calculated for the 400 IU per day versus 2000 IU per day groups.

Enrollment: 703
Study Start Date: September 2011
Study Completion Date: October 2015
Primary Completion Date: May 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 2000 IU per day vitamin D Drug: Vitamin D3 - Cholecalciferol 2000 IU
One drop per day (liquid), 2000 IU, 4 to 9 months depending on date of enrollment and date of follow-up
Other Name: Ddrops 2000 IU
Active Comparator: 400 IU per day vitamin D Drug: Vitamin D - Cholecalciferol 400 IU
One drop per day (liquid), 400 IU, 4 to 9 months depending on date of enrollment and date of follow-up
Other Names:
  • Baby Ddrops
  • Health Canada NPN #80001869


Ages Eligible for Study:   1 Year to 5 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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.
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Please refer to this study by its identifier: NCT01419262

Canada, Ontario
St. Michael's Hospital
Toronto, Ontario, Canada, M5B 1W8
Hospital for Sick Children
Toronto, Ontario, Canada, M5G 1X8
Sponsors and Collaborators
The Hospital for Sick Children
Mount Sinai Hospital, Canada
St. Michael's Hospital, Toronto
Principal Investigator: Jonathon L Maguire, MD, MSc St. Michael's Hospital, Toronto, Ontario, Canada
  More Information

Responsible Party: Jonathon Maguire, Physician/ Principal Investigator, The Hospital for Sick Children Identifier: NCT01419262     History of Changes
Other Study ID Numbers: 1000025147
Study First Received: August 16, 2011
Last Updated: November 16, 2015

Keywords provided by The Hospital for Sick Children:
Vitamin D
Randomized Controlled Trial
Child, Preschool
Dietary Supplements
Respiratory Tract Infections

Additional relevant MeSH terms:
Respiratory Tract Infections
Respiratory Tract Diseases
Deficiency Diseases
Nutrition Disorders
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on April 28, 2017