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Trial registered on ANZCTR


Registration number
ACTRN12605000017628
Ethics application status
Approved
Date submitted
18/07/2005
Date registered
18/07/2005
Date last updated
18/07/2005
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effect of Vitamin D Supplementation on Blood Pressure and Insulin Sensitivity
Scientific title
A randomised phase III study to evaluate the effects of Vitamin D supplementation on patients with low vitamin D levels to reduce blood pressure levels and improve insulin sensitivity
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Blood Pressure 79 0
Condition category
Condition code
Blood 97 97 0 0
Normal development and function of platelets and erythrocytes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A randomised double-blind clinical trial of 100 ug daily doses of vitamin D3 versus placebo tablets.
Intervention code [1] 26 0
Prevention
Comparator / control treatment
Each participant will receive daily doses of vitamin D3 or placebo for 12 weeks
Control group
Placebo

Outcomes
Primary outcome [1] 123 0
Blood pressure
Timepoint [1] 123 0
Measured at baseline and at 12 weeks.
Secondary outcome [1] 286 0
Insulin sensitivity, as measured by a New Zealand developed index calculated from fasting blood levels of insulin and triglycerides.
Timepoint [1] 286 0

Eligibility
Key inclusion criteria
Aged >40 years (Tongan and Maori) and >65 years (European) 25OHD levels <50 nmol/L.
Minimum age
40 Years
Maximum age
Not stated
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Treated diabetes, treated hypertension, taking of vitamin D supplements (including cod liver oil); serum calcium level above 2.60 mmol/L, regular outdoor activities during the middle of day during the study period, recent high sun exposure (eg. holidays in the Pacific islands); or planned holidays to areas with high sun exposure during the study period.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisationb and packaging of tablets in non-identifiable packets that are used in consecutive order.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation by computer software, no restriction
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 3
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 124 0
New Zealand
State/province [1] 124 0

Funding & Sponsors
Funding source category [1] 133 0
University
Name [1] 133 0
University of Auckland
Address [1] 133 0
Country [1] 133 0
Australia
Primary sponsor type
University
Name
University of Auckland
Address
Country
Australia
Secondary sponsor category [1] 95 0
University
Name [1] 95 0
University of Auckland
Address [1] 95 0
Country [1] 95 0
Australia

Ethics approval
Ethics application status
Approved

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 36336 0
Address 36336 0
Country 36336 0
Phone 36336 0
Fax 36336 0
Email 36336 0
Contact person for public queries
Name 9215 0
Robert Scragg
Address 9215 0
Epidemiology and Biostatistics
School of Population Health
Tamaki Campus
University of Auckland
Private Bag 92019
Auckland 1
Country 9215 0
New Zealand
Phone 9215 0
+64 9 3737599 (Ext. 86336)
Fax 9215 0
Email 9215 0
r.scragg@auckland.ac.nz
Contact person for scientific queries
Name 143 0
Robert Scragg
Address 143 0
Epidemiology and Biostatistics
School of Population Health
University of Auckland
Tamaki Campus
Private Bag 92019
Auckland 1
Country 143 0
New Zealand
Phone 143 0
+64 9 3737599 (Ext. 86336)
Fax 143 0
Email 143 0
r.scragg@auckland.ac.nz

No data has been provided for results reporting
Summary results
Not applicable