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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Evaluating if the improved vitamin D status through sun exposure, food or supplements could benefit Type 2 Diabetes patients according to blood test biomarkers (HbA1c)
Scientific title
The Role of Vitamin D in Controlling and Reducing Diabetes Mellitus Risks via changes in HbA1c and blood glucose
Secondary ID [1] 300290 0
Nil known
Universal Trial Number (UTN)
Trial acronym
D4D or D4T2DM
Linked study record

Health condition
Health condition(s) or problem(s) studied:
type 2 diabetes 315875 0
vitamin D deficiency 315876 0
Condition category
Condition code
Metabolic and Endocrine 314156 314156 0 0
Diet and Nutrition 314293 314293 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
Arm1. Vitamin D supplement group – MUST take Ostelin Vitamin D3 oral supplements 500IU per day for 9 months duration.

Arm2. Dietary intake group – MUST follow the dietary plan (dietary plan including a list of vitamin D rich food using “µg vitamin D /gram food” as reference , a 3 day Vitamin D meal plan and 3 suggested cooking recipes) prescribed by Accredited Practising Dietitian (with min 5 years experiences) to obtain 10-15µg vitamin D per pay; participants are responsible for preparing the food for themselves and do not have to follow the recipes but are required to tick the vitamin D rich food list in order to reach 10-15µg vitamin D per pay and keep the record for duration of 9 months.

Arm3. Sun exposure group – MUST expose about 15% of body surface (hands, face and arms) under the sun anytime from 10am to 4pm for 3-4 min/d from December to January, or 8 min/d from July to August or 10– 11 min/d from February to June or September to November in order to obtain approximately 12.5 µg/d of vitamin D; duration for 9 months.

Control group - no interventions nor changes are required or provided to this group in current trial

We will have a monthly check (10-30min phone call or personal visit, on 2nd, 4th,5th,6th,7th, 8th month) and a face to face interview (1 hour, on base line, 3rd and 9th month, conducted in Earlwood Medical Centre) conducted by Requested Nurse (RN) or health practitioners who received GCP training to follow up the participants and collect the data.

Following sessions will delivered in both monthly phone call and face to face interview and undifferentiated to all 3 intervention groups and the control group: Information delivery session, anthropometry assessment (height, weight and BMI), data collection (dietary data via 3 day food recall using either smart phone application ‘east diet diary’ or paper base, and/or 24 hour food recall and/or food frequency questionnaire, sun exposure data via questionnaire adapted from 45 and up Questionnaire, and supplement pill count), adherence session (reminder text, phone call checking and offering plan for next stage), problem and safety session, adverse event assessment and/or blood test ( a blood test of blood glucose, HbA1c and vitamin D will be conducted only on baseline, 3rd and 9th month during face to face interview by RN).
Intervention code [1] 316562 0
Treatment: Other
Intervention code [2] 316563 0
Intervention code [3] 316564 0
Comparator / control treatment
Control group is a no-treatment group hence will never receive interventions nor changes in current trial.
Control group

Primary outcome [1] 322542 0
Blood Glucose level through blood test
Timepoint [1] 322542 0
Baseline (before intervention), 3rd month(primary endpoint) and 9 months post commencement of the intervention.
Primary outcome [2] 322684 0
HbA1c through blood test
Timepoint [2] 322684 0
Baseline (before intervention), 3rd month(primary endpoint) and 9 months post commencement of the intervention.
Primary outcome [3] 322783 0
serum 25(OH)D through blood test
Timepoint [3] 322783 0
Baseline (before intervention), 3rd month(primary endpoint) and 9 months post commencement of the intervention.
Secondary outcome [1] 379734 0
Timepoint [1] 379734 0

Key inclusion criteria
1) Aged greater than or equal to 18 years old; 2) Diagnosed with Type 2 Diabetes in the preceding 12 months, and not on diabetic medication or insulin treatment; 3) Serum 25OHD is between 28 nmol/l and 85 nmol/l and not on vitamin D supplements or any relevant medications; 4) Do not have thyroid diseases, liver impairment, renal failure, cancer, osteoporosis, dementia, mental diseases or taking relevant medications; 5) Not pregnant or breastfeeding women.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1) Unable to give written informed consent or follow the instructions in current trial; 2) are already on vitamin D supplementation or relevant diabetes control medications; 3) have liver impairment, renal failure (eGFR <50 ml/min), cancer, osteoporosis, dementia, mental disease, and thyroid diseases including hyperparathyroidism, hypercalcaemia, or taking any relevant medications; 4) are < 18 years old or are pregnant or breastfeeding women. 5) are vegen and can not ingest any animal product.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All participants who give consent for participation, and who fulfil the inclusion criteria, will be randomised. An independent investigator will send the randomisation instruction & sealed opaque envelopes contain printed randomisation numbers to the study therapist who is not involved in recruitment or outcome assessment. For every randomisation number, the corresponding code for the intervention group will be found inside the envelope. Only the study therapist will open the envelope and will find the treatment to be conducted for this participant. The therapist then gives the information about treatment that allocated to the patient. The randomisation list will be stored in the two centres for the whole time period of study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomly assigned to one of four different groups with an equal ratio referring to the permuted block randomisation. The software randomisation package MINUM will be used for sequence generation. The block sizes will not be disclosed, to ensure concealment.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
By setting the significance level a=0.05, the power 1-ß = 0.8 based on Campbell & Machin (1993) formula: m=(Za + Z2ß)2{p1(1-p1)+p2(1-p2)}/d2, (Za + Z2ß)2 = 7.849, d=p2-p1=0.7-0.35= 0.35; therefore m=28. Therefore the sample size for each group in the current study was calculated to be at least 28, with at least 112 in total. With the consideration of a dropout rate 10%-20%, it is planned to recruit 123-134 participants in total hence 31-34 participants for each group.

Data are expressed as means ± SDs. Initially, the Kolmogorov–Smirnov goodness-of-fit test will be used to assess the normal distribution of the values. Secondly, two-factor repeated-measures analysis of variance (ANOVA) with a Bonferroni correction will be used in the current trial with time stages and interventions as factors. Tukey’s post-hoc comparison will be applied to identify the differences between four intervention groups at 3 months and 9 months in the case of significant interaction finding in ANOVA. Thirdly, correlations between variables will be evaluated by using either a Pearson (r) (for data with normal distribution) or a Spearman (rs) (for data with no normal distribution) correlation. A p-value <0.05 is considered to be statistically significant. All statistical analyses will be computed using the Statistical Package for Social Science version 17 (SPSS, Chicago, IL, USA). Missing values are to be treated according to the last observation carried forward (LOCF) method and will be assessed via sensitivity analysis.

Recruitment status
Not yet recruiting
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 hospital [1] 15711 0
Earlwood Medical Centre - Earlwood
Recruitment hospital [2] 15712 0
Bangor Medical Centre - Bangor
Recruitment postcode(s) [1] 29036 0
2206 - Earlwood
Recruitment postcode(s) [2] 29037 0
2234 - Bangor

Funding & Sponsors
Funding source category [1] 304710 0
Other Collaborative groups
Name [1] 304710 0
Earlwood Medical Centre
Address [1] 304710 0
356 Homer street, Earlwood NSW 2206
Country [1] 304710 0
Funding source category [2] 304816 0
Other Collaborative groups
Name [2] 304816 0
Bangor Medical Centre
Address [2] 304816 0
121, Shop 6, Bangor Shopping Centre, Yala Rd, Bangor NSW 2234
Country [2] 304816 0
Funding source category [3] 304817 0
Name [3] 304817 0
Australian Traditional Medicine Society
Address [3] 304817 0
Suite 12, 27 Bank St Meadowbank, NSW, 2114
Country [3] 304817 0
Primary sponsor type
University of Technology, Sydney
15 Broadway, Ultimo NSW 2007
Secondary sponsor category [1] 305027 0
Name [1] 305027 0
Address [1] 305027 0
Country [1] 305027 0

Ethics approval
Ethics application status
Ethics committee name [1] 305137 0
UTS (University of Technology, Sydney) Human Research Ethics Committee
Ethics committee address [1] 305137 0
15 Broadway, Ultimo NSW 2007
Ethics committee country [1] 305137 0
Date submitted for ethics approval [1] 305137 0
Approval date [1] 305137 0
Ethics approval number [1] 305137 0

Brief summary
The D4D/D4T2DM trial is designed as a multi-centre, single-blind, randomized, parallel group, superiority study to determine the role of Vitamin D from the oral supplement, sun exposure and dietary invention in controlling and reducing DM risks.

The current study hypothesised that adequate vitamin D level will help with correcting blood sugar level and HbA1c. Eligible participants will be randomised in equal proportion into one of 4 groups: vitamin D supplement, dietary intervention, sun exposure and control group for duration of 9 months.

This study will help to understand and explain the possible association between vitamin D and Diabetes Mellitus, help to reduce the cost of clinical care; the cost of medicine; reduce the compliance of DM and reduce the incidence of hospitalization.
Trial website
Trial related presentations / publications

Public notes
Yu, X.F., Zaslawaki, C. and Lim, C.E.D., 2018. Vitamin D on glycaemia control in type 2
diabetes patients: A systematic review of randomised clinical trials. Journal of the
Australian Traditional-Medicine Society, 24(2).

Principal investigator
Name 99370 0
A/Prof Chris Zaslawski
Address 99370 0
School of Life Sciences, Program Director, School of Medical and Molecular Biosciences, University of Technology, 15 Broadway, Ultimo, NSW 2007
Country 99370 0
Phone 99370 0
+61 2 9541 7856
Fax 99370 0
Email 99370 0
Contact person for public queries
Name 99371 0
A/Prof Chris Zaslawski
Address 99371 0
School of Life Sciences, Program Director, School of Medical and Molecular Biosciences, University of Technology, 15 Broadway, Ultimo, NSW 2007
Country 99371 0
Phone 99371 0
+61 2 9541 7856
Fax 99371 0
Email 99371 0
Contact person for scientific queries
Name 99372 0
A/Prof Chris Zaslawski
Address 99372 0
School of Life Sciences, Program Director, School of Medical and Molecular Biosciences, University of Technology, 15 Broadway, Ultimo, NSW 2007
Country 99372 0
Phone 99372 0
+61 2 9541 7856
Fax 99372 0
Email 99372 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
What data in particular will be shared?
individual participant data underlying published results only
When will data be available (start and end dates)?
Immediately following publication, no end date
Available to whom?
only researchers who provide a methodologically sound proposal,
and case-by-case basis at the discretion of Primary Sponsor
Available for what types of analyses?
only to achieve the aims in the approved proposal
How or where can data be obtained?
Access subject to approvals by Principal Investigator A/Prof Chris Zaslawski, please contact as following:
School of Life Sciences, Program Director, School of Medical and Molecular Biosciences, University of Technology, Sydney
02 9514 7856
What supporting documents are/will be available?
Study protocol
Informed consent form
How or where can supporting documents be obtained?
Type [1] 6457 0
Study protocol
Citation [1] 6457 0
Link [1] 6457 0
Email [1] 6457 0
Other [1] 6457 0
Type [2] 6458 0
Informed consent form
Citation [2] 6458 0
Link [2] 6458 0
Email [2] 6458 0
Other [2] 6458 0
Summary results
No Results