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Trial registered on ANZCTR

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

Titles & IDs
Public title
A randomised control trial of high dose oral vitamin D in type 2 diabetes
Scientific title
A randomised control trial of high dose cholecalciferol in type 2 diabetes to assess C-peptide secretion.
Secondary ID [1] 263098 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diabetes 270851 0
Metabolic function 270852 0
Condition category
Condition code
Metabolic and Endocrine 271028 271028 0 0

Study type
Description of intervention(s) / exposure
Oral Cholecalciferol: 10,000 IU/ day for 2 weeks then 6000 IU/ day for 22 weeks
Intervention code [1] 269445 0
Treatment: Drugs
Comparator / control treatment
Placebo: Tablets were identical in appearance to vitamin D but without vitamin D.
Control group

Primary outcome [1] 279687 0
Glucagon-stimulated change in C-peptide [delta C-peptide (DCP)]. 1mg of glucagon was injected intravenously. Serum C-peptide was measured pre and 6 minutes post the glucagon injection.
Timepoint [1] 279687 0
baseline, 3 months, 6 months
Secondary outcome [1] 294220 0
HOMA-IR, a measure of insulin resistance was calculated from participant's serum insulin and glucose by the formula :plasma insulin x plasma glucose / 22.5.
Timepoint [1] 294220 0
baseline, 3 months, 6 months
Secondary outcome [2] 294221 0
HbA1c, a measure of glycemic control over the last 2-3 months was measured in the serum.
Timepoint [2] 294221 0
baseline, 3 months, 6 months
Secondary outcome [3] 294222 0
Fasting plasma glucose was measured in participants plasma.
Timepoint [3] 294222 0
baseline, 3 months, 6 months
Secondary outcome [4] 294223 0
Post-prandial capillary blood glucose was measured by capillary glucose readings on a home glucometer, measured by participants 2 hours after meals for 48 hours prior to each visit.
Timepoint [4] 294223 0
baseline, 3 months, 6 months

Key inclusion criteria
diabetes diagnosed in the preceding 12 months, age 30- 60, not on insulin treatment, serum vitamin 25-D3 28-85nmol/L glycated hemoglobin (HbA1c) < 8%.
Minimum age
30 Years
Maximum age
60 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
insulin treatment, liver impairment, renal impairment (eGFR <50ml/min), hyperparathyroidism, family or personal history of renal calculi, history of recurrent falls, use of a gait aid, past history of a fragility fracture, personal or family history of osteoporosis and current treatment with oral prednisolone, methotrexate or other immunosuppressive drugs.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
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)

Funding & Sponsors
Funding source category [1] 269926 0
Name [1] 269926 0
Diabetes Australia Research Trust
Address [1] 269926 0
GPO BOX 3156
Country [1] 269926 0
Funding source category [2] 269927 0
Name [2] 269927 0
Munro Foundation
Address [2] 269927 0
c/o 1G Royal Parade Parkville, VIC, 3050
Country [2] 269927 0
Primary sponsor type
Royal Melbourne Hospital
Royal Parade, Parkville, VIC 3050
Secondary sponsor category [1] 268928 0
Name [1] 268928 0
Address [1] 268928 0
Country [1] 268928 0

Ethics approval
Ethics application status

Brief summary
The aim was to investigate the effect of high dose oral cholecalciferol (vitamin D3) on pancreatic beta-cell function and glycemia in adults with type 2 diabetes. The hypothesis was that vitamin D would improve beta-cell function and glycemia.

Beta-cell function was assessed by measuring glucagon stimulated C-peptide. Insulin resistance was measured by calculating a HOMA-IR index from plasma insulin and glucose levels. Glycemia was assessed by measuring fasting plasma glucose, post-prandial capillary glucose and serum glycosylated haemaglobin.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 33195 0
Address 33195 0
Country 33195 0
Phone 33195 0
Fax 33195 0
Email 33195 0
Contact person for public queries
Name 16442 0
Shirley Elkassaby
Address 16442 0
Royal Melbourne Hospital
Department of Endocrinology
Royal Parade, Parkville,
VIC, 3050
Country 16442 0
Phone 16442 0
+61 3 9342-7365
Fax 16442 0
Email 16442 0
Contact person for scientific queries
Name 7370 0
Shirley Elkassaby
Address 7370 0
Royal Melbourne Hospital
Department of Endocrinology
Royal Parade, Parkville, VIC 3050
Country 7370 0
Phone 7370 0
+61 3 9342-7365
Fax 7370 0
Email 7370 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