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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Cholecalciferol (Vitamin D) Intervention to Prevent Respiratory Infection Study
Scientific title
A double-blind randomised controlled trial to evaluate the efficacy of 20,000 IU/wk cholecalciferol in reducing respiratory tract infection in a cohort of healthy young adults
Secondary ID [1] 279686 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Respiratory Tract Infection 285511 0
Condition category
Condition code
Infection 285701 285701 0 0
Other infectious diseases

Study type
Description of intervention(s) / exposure
Cholecalciferol (20,000 IU oral capsule/week) for 17 weeks.
Intervention code [1] 283976 0
Comparator / control treatment
Placebo (microcellulose capsule)
Control group

Primary outcome [1] 286229 0
Frequency of validated respiratory tract infections during study period. Acute respiratory tract infections defined by respiratory symptoms reported by daily online survey lasting over a day and verified at exam by study nurse.
Timepoint [1] 286229 0
17 weeks
Secondary outcome [1] 295418 0
the proportion of colonisations with respiratory pathogens that go on to symptomatic verified respiratory tract infections. Colonisation detected by nasal swab sampled quantitiative RT-PCR.
Timepoint [1] 295418 0
17 weeks
Secondary outcome [2] 295419 0
Severity (objective and subjective) of respiratory tract infections during the study. Subjective severity of symptoms reported by Likert scale (0-5) for each symptom. Objective severity by number and duration of symptoms.
Timepoint [2] 295419 0
17 weeks
Secondary outcome [3] 295420 0
Mean duration of respiratory tract infections during study. Duration defined as number of days from participant-reported symptom onset to sympton resolution, as reported in daily online questionnaire.
Timepoint [3] 295420 0
17 weeks
Secondary outcome [4] 295421 0
Frequency of non-respiratory tract infections during study. Non-respiratory tract infections defined by non-respiratory symptoms reported by daily online survey lasting over a day and verified at exam by study nurse.
Timepoint [4] 295421 0
17 weeks
Secondary outcome [5] 295422 0
Concentration of serum 25-hydroxyvitamin D by the end of the study
Timepoint [5] 295422 0
17 weeks

Key inclusion criteria
Students undertaking study at the MS1 building of University of Tasmania Medical Sciences Precinct (17 Liverpool St Hobart TAS) for the full duration between May and September 2012
Minimum age
18 Years
Maximum age
45 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
-Persons who have used tobacco within the 6 months preceding study entry
-Persons who have used any vitamin D (cholecalciferol or ergocalciferol) supplements or calcium supplements within the 3 months preceding study entry and/or persons who refuse to not start taking any such supplement during the study
-Persons using any immunomodulatory medication, diuretic medication, antiepileptic medication, or barbiturates.
-Persons who presently have been diagnosed with any chronic infectious disease (e.g. HIV, tuberculosis), chronic immune deficiency or autoimmune condition, or respiratory condition (e.g. asthma, chronic obstructive pulmonary disease).
-Persons who are hypersensitive to vitamin D.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible subjects will be scheduled for an initial session at which their allocation will be dispensed. Neither the participant nor the investigator dispensing treatment allocation or the nurse evaluating participants for the presence of verified acute respiratory tract infections will be aware of the participant's treatment allocation until after the conclusion of the study. Allocation concealment will be by numbering 32 containers and utilising a blocked randomisation computer program to distribute an equivalent number between intervention and placebo blocked on gender. Only the external monitor will know which numbered containers contain intervention and which contain placebo.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised randomisation, blocked on sex.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 2
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 4849 0

Funding & Sponsors
Funding source category [1] 284467 0
Name [1] 284467 0
Royal Hobart Hospital Research Foundation
Address [1] 284467 0
48 Liverpool St
Hobart TAS 7000
Country [1] 284467 0
Primary sponsor type
Menzies Research Institute Tasmania, University of Tasmania
17 Liverpool St
Hobart TAS 7001
Secondary sponsor category [1] 283392 0
Name [1] 283392 0
Royal Hobart Hospital
Address [1] 283392 0
48 Liverpool St
Hobart TAS 7001
Country [1] 283392 0

Ethics approval
Ethics application status
Ethics committee name [1] 286449 0
Tasmanian Health & Medical Human Research Ethics Committee
Ethics committee address [1] 286449 0
Office of Research Services
University of Tasmania
Private Bag 1
Hobart 7001
Ethics committee country [1] 286449 0
Date submitted for ethics approval [1] 286449 0
Approval date [1] 286449 0
Ethics approval number [1] 286449 0

Brief summary
This study will evaluate the efficacy of 20,000 IU/week cholecalciferol supplementation relative to placebo in reducing the frequency of clinically-verified acute respiratory tract infections in a cohort of young adults in Tasmania.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 33601 0
Address 33601 0
Country 33601 0
Phone 33601 0
Fax 33601 0
Email 33601 0
Contact person for public queries
Name 16848 0
Dr Steve Simpson, Jr.
Address 16848 0
Menzies Research Institute Tasmania
Private bag 23
Hobart TAS 7000
Country 16848 0
Phone 16848 0
+61 03 6226 4718
Fax 16848 0
+61 03 6226 7704
Email 16848 0
Contact person for scientific queries
Name 7776 0
Dr Steve Simpson, Jr.
Address 7776 0
Menzies Research Institute Tasmania
Private bag 23
Hobart TAS 7000
Country 7776 0
Phone 7776 0
+61 03 6226 4718
Fax 7776 0
+61 03 6226 7704
Email 7776 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary