Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12620001140943
Ethics application status
Approved
Date submitted
16/07/2020
Date registered
2/11/2020
Date last updated
2/11/2020
Date data sharing statement initially provided
2/11/2020
Type of registration
Retrospectively registered

Titles & IDs
Public title
Vitamin D status of Australian women
Scientific title
Determinants of vitamin D status (as measured by 25(OH)D and dietary intake) in women: the role of environmental factors, ethnicity and diet
Secondary ID [1] 301795 0
none
Universal Trial Number (UTN)
U1111-1255-4091
Trial acronym
VDAW
Linked study record

Health condition
Health condition(s) or problem(s) studied:
vitamin D deficiency 318270 0
metabolic 318566 0
Condition category
Condition code
Diet and Nutrition 316287 316287 0 0
Other diet and nutrition disorders
Metabolic and Endocrine 316580 316580 0 0
Other endocrine disorders
Musculoskeletal 316581 316581 0 0
Other muscular and skeletal disorders
Public Health 316582 316582 0 0
Epidemiology

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
This is an observational study which will require one visit to the IHMRI clinical trials area/building 41, at the University of Wollongong. The visit will take place in winter 2020 and winter 2021 (June-August). The duration of the visit will last approximately 2 hours, and the total duration of involvement in the study will last 4 days, to include the time wearing the dosimeter and filling in the 4 day food diary. Of these 4 days, one day will be a weekend day.

Recruited participants will come to IHMRI clinical trials area/building 41 fasted. The following measurements will be taken:

1. Consent taking
Consent will be taken by the trained investigators at the beginning of the session. The participants will be given ample time to read and understand each point within the consent form and be giving time to ask any questions before initialling and signing off. Participants will be made aware that they do not have to take part, and that there will be no adverse consequences if they do not participate.

2. Anthropometric measurements
The following anthropometrical measurements will be taken from each participant: Weight, height, waist to hip ratio, waist circumference, waist to height ratio and body composition.

Weight and body composition will be measured to the nearest 0.1kg. This will be achieved using a Tanita Body Composition Analyser BC-418. Standing height will be measured using a wall stadiometer, to the nearest 0.1cm. Waist and hip circumference will be measured using a non-extendable standard measure tape, at the narrowest point of the torso for waist measurement (if this cannot be estimated, the level of the belly button will be used as a reference point), and the widest part of the hips for the hip measurement, to the nearest 0.1cm.

Waist to hip ratio will be calculated by dividing the waist measurement by the hip measurement (waist ÷ hip) and the waist to height ratio will be calculated by dividing the waist measurement by the height measurement (waist ÷ height)

3. Dual energy X-ray absorptiometry (DEXA) scan
Two DEXA scans will be taken. One scan to assess whole body bone mineral density and body composition, and the other to specifically assess fracture risk by scanning the femoral the hip and femoral head. Effective exposure doses for these scans are approximately 9 uSv and 8 uSv respectively. Total research protocol dose is approximately 18 uSv, this is equivalent to approximately 3 days of natural background radiation.

Prior to the DEXA scan, participants will take a pre-scan questionnaire, which includes declaring they are not pregnant. Participants will be given the option to take a pregnancy test before the DEXA scans.

4. Blood sample
An 8 hour-fasted blood sample will be taken by a trained phlebotomist.

The following collection tubes will be used:
• 2 x 10ml BD Vacutainer® SSTTM (red top) tube: serum 25OHD, calcium and albumin, P1NP, CTX, lipid profile, micronutrient status
• 6ml BD Vacutainer® EDTA (purple) tube: PTH plasma, blood glucose level

Blood sampling will occur once, with approximately 30ml of blood taken.

Serum 25(OH)D for the analyses of vitamin D status will be sent to the University of Sao Paulo, Brazil for analysis. The remaining analytes will be analysed in laboratories in Australia.

Calcium and P1NP and CTX (bone markers) are directly related to vitamin D status due to the role of vitamin D in calcium homeostasis, and this bone health. We are including these measures in order to assess the effect of vitamin D status on musculoskeletal health. Because vitamin D is a fat-soluble vitamin and is stored in adipocytes, it is necessary to have an indication of participants’ lipid status. Regarding micronutrient status, we will investigate those micronutrients known to impact on vitamin D status, namely the minerals serum calcium and phosphorus.

Blood samples will be stored at -80°C at the University of Wollongong.

5. International Physical Activity Questionnaire (IPAQ) short form
A physical activity questionnaire will be undertaken to obtain data on physical activity in everyday lives.

6. Sun exposure questionnaire
The sun exposure questionnaire measures how often participants spend in the sun across different seasons, what body parts were exposed and if they have been on a recent summer holiday. This questionnaire was designed specifically for this study.

7. Lifestyle questionnaire
The lifestyle questionnaire measures a range of factors including skin type, medical history, education, behaviours and attitudes towards sun exposure and knowledge and consumption of vitamin D. This questionnaire was designed specifically for this study.

8. Sit-to-stand test
The 30 second Sit to Stand Test is used to measure leg strength and endurance. A chair without arms will be placed against a wall to prevent slipping. The participant will sit in the chair with their back straight, feet shoulder width apart on floor, with their arms crossed at their wrists and held against the chest. If the participant uses their arms to stand up they are scored 0. The participant will complete as many full stands as possible within 30 seconds.

9. Grip strength test
The purpose of this test is to measure the maximum isometric strength of the hand and forearm muscles. Placing their arm at a right angle with the elbow at the side of the body, the participant will use their non-dominant hand to hold the hand grip dynamometer. The participant will squeeze the dynamometer with maximum effort for 5 seconds. An average of three tests will be taken, to the nearest 0.1kg.

10. Instruction on how to complete a 4-day food diary
4-day food diaries will be kept to measure dietary intake, in particular, intake of vitamin D. These will be used at home for four days, one of which days will be a weekend day. The participants are asked to record the time, what they eat, method of cooking and the amount eaten. They will be instructed to send these back to the investigators using the freepost envelopes provided. The researchers may phone or email the participants if any further information of their diet is required. Data will be analysed using Foodworks® nutritional analysis software. This diary was designed specifically for this study.

11. Instructions on how to wear a dosimeter to measure UVB exposure
Participants will be asked to wear a dosimeter polysulphone film badge to measure UVB exposure. The dosimeters are clipped to the outer clothing with a pin, worn on the upper chest/shoulder region. Individuals are asked to wear the badge on from sunrise to sunset, for 4 days, one of which will be a weekend day. They are instructed to store the dosimeter in the supplied envelope (of thick and dark material to prevent further UVB exposure during storage) until returning.

Data will be read pre and post use at the University of Southern Queensland. A x Spectophotometer (CV <1%) will be used at 330nm to detect a change in absorbency.

Results of individual badge doses are reported in standard erythema dose (SED) units (1 SED = 100 J/m2).
Intervention code [1] 318096 0
Early Detection / Screening
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 324456 0
Vitamin D status as assessed by serum 25(OH)D, measured by Liquid Chromatography with tandem mass spectrometry (LC-MS-MS)
Timepoint [1] 324456 0
One measurement on the day of visit (Approximately 2 hour session)
Primary outcome [2] 324457 0
Vitamin D status as measured by dietary intake, measured by a 4-day food diary, analysed using Foodworks
Timepoint [2] 324457 0
One measurement analysed after the 4 day food diary is completed (one of which days is a weekend day)
Primary outcome [3] 324458 0
Composite: Musculoskeletal health (bone mineral composition, bone density and body composition ((body fat percentage)), measured using dual energy x-ray absorptiometry
Timepoint [3] 324458 0
One measurement on the day of the 2 hour visit session
Secondary outcome [1] 384714 0
Weight measured by tanita body composition analyser
Timepoint [1] 384714 0
One measurement on the day of the 2 hour visit session
Secondary outcome [2] 384715 0
Sun exposure, as measured by a dosimeter polysulphone film badge
Timepoint [2] 384715 0
One measurement measured after 4 days of daily dosimeter wearing
Secondary outcome [3] 384716 0
Lifestyle factors, as measured by a non-validated lifestyle questionnaire that was developed specifically for this study
Timepoint [3] 384716 0
one measurement of the day of the study visit
Secondary outcome [4] 384717 0
Physical activity levels, as measured by the International Physical Activity Questionnaire (IPAQ) short form
Timepoint [4] 384717 0
One measurement on the day of the study visit
Secondary outcome [5] 385482 0
Maximum isometric strength of the hand and forearm muscles measured by grip strength dynamometer
Timepoint [5] 385482 0
One measurement on the day of the study visit
Secondary outcome [6] 385484 0
Muscular endurance measured by 30 second sit-to-stand test
Timepoint [6] 385484 0
One measurement on the day of the study visit
Secondary outcome [7] 385488 0
Height measured by a stadiometer
Timepoint [7] 385488 0
One measurement on the day of the study visit
Secondary outcome [8] 385489 0
Hip circumference measured using a measuring tape
Timepoint [8] 385489 0
One measurement on the day of the study visit
Secondary outcome [9] 385490 0
Waist circumference measured using a measuring tape
Timepoint [9] 385490 0
One measurement on the day of the study visit
Secondary outcome [10] 385491 0
Body mass index (BMI) measured by tanita body composition analyser
Timepoint [10] 385491 0
One measurement on the day of the study visit
Secondary outcome [11] 385492 0
Percentage body fat measured by tanita body composition analyser
Timepoint [11] 385492 0
One measurement on the day of the study visit
Secondary outcome [12] 385493 0
Fat mass measured by tanita body composition analyser
Timepoint [12] 385493 0
One measurement on the day of the study visit
Secondary outcome [13] 385494 0
Fat free mass measured by tanita body composition analyser
Timepoint [13] 385494 0
One measurement on the day of the study visit
Secondary outcome [14] 385495 0
Percentage total body water measured by tanita body composition analyser
Timepoint [14] 385495 0
One measurement on the day of the study visit
Secondary outcome [15] 385496 0
Basal metabolic rate measured by tanita body composition analyser
Timepoint [15] 385496 0
One measurement on the day of the study visit
Secondary outcome [16] 388241 0
Sun exposure behaviour
Timepoint [16] 388241 0
As measured by a study specific sun exposure questionnaire

Eligibility
Key inclusion criteria
• Women
• Australian
- Self-reported ethnicity
• Living in Australia for >2 months
• Aged 18-35 or >55 years
• No significant health issues
• Pre-menopausal (regular menstrual periods) or Post-menopausal (menstrual periods stopped for longer than 12 consecutive months)
Minimum age
18 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
• Women in perimenopause or menopause
• Pregnant or planning pregnancy during study period
• Hypercalcaemia (>2.5mmol/L) – assessed and excluded at baseline
• Currently receiving treatment for medical conditions that are likely to affect vitamin D metabolism (osteoporosis, hormone replacement therapy, anti-estrogens treatment, antiepileptic drugs and breast cancer treatment)
• Regular use of sun beds
• Having a sun holiday one month prior to participation in study
• Women who take vitamin D or calcium supplements (or multivitamin supplements that contain these vitamins)
• Living in Australia for less than 2 months

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Note: The equal signs in this field mean equal to.

s = (z-score)2 * p * (1-p)/(margin of error)2
where z=1.96, considering a confidence level of 95%
margin of error = 0.05, considering a margin error of 5%
p = 0.5
s = (1.96)2 * 0.5 * (1-0.5)/(0.05)2
s = 3.8416 * 0.25/0.0025
s = 384.16
Sample size calculation:
Population = 70, 000 considering female population of Wollongong according to the 2016 Australian census [112]
s = (infinite population)/1 + [(infinite population-1)/population]
s = 384.16/1+[(384.16-1)/70,000]
s = 384
s = (z-score)2 * p * (1-p)/(margin of error)2
where z=1.96, considering a confidence level of 95%
margin of error = 0.05, considering a margin error of 5%
p = 0.5
s = (1.96)2 * 0.5 * (1-0.5)/(0.05)2
s = 3.8416 * 0.25/0.0025
s = 384.16
Sample size calculation:
Population = 70, 000 considering female population of Wollongong according to the 2016 Australian census [112]
s = (infinite population)/1 + [(infinite population-1)/population]
s = 384.16/1+[(384.16-1)/70,000]
s = 384


Statistical Analysis
Statistical analysis will be undertaken with support from the University of Wollongong statistical department. All statistical analysis will be carried out using SPSS statistical software (version 25; SPSS Inc., Chicago, IL). Data will be checked for normality using appropriate testing. Appropriate parametric/non-parametric analysis will be applied.


Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
1/09/2020
Date of last participant enrolment
Anticipated
24/08/2021
Actual
Date of last data collection
Anticipated
31/08/2021
Actual
Sample size
Target
100
Accrual to date
42
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 30774 0
2500 - Wollongong
Recruitment postcode(s) [2] 30775 0
2522 - University Of Wollongong

Funding & Sponsors
Funding source category [1] 306228 0
University
Name [1] 306228 0
University of Wollongong
Country [1] 306228 0
Australia
Primary sponsor type
University
Name
University of Wollongong
Address
Faculty of Science, Medicine and Health
University of Wollongong
Northfields Avenue
Wollongong
NSW 2522
Country
Australia
Secondary sponsor category [1] 306707 0
None
Name [1] 306707 0
Address [1] 306707 0
Country [1] 306707 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 306439 0
University of Wollongong and Illawarra Shoalhaven Local Health District Health and Medical Human Research Ethics Committee
Ethics committee address [1] 306439 0
Human Research Ethics Committee
University of Wollongong
Northfields Ave Wollongong
NSW 2522
Ethics committee country [1] 306439 0
Australia
Date submitted for ethics approval [1] 306439 0
03/04/2020
Approval date [1] 306439 0
14/07/2020
Ethics approval number [1] 306439 0
2020/162

Summary
Brief summary
Vitamin D deficiency remains a global public health issue, with clinical rates growing. Vitamin D deficiency is well known to be linked to musculoskeletal conditions, however there is also strong epidemiological evidence linking deficiency with diabetes, cardiovascular disease, osteoporosis, osteoarthritis and some cancers. The condition has a significant financial impact on not only individuals, but also the economy, therefore is of public health importance.

As majority of vitamin D is synthesised through cutaneous exposure to the sun, it is unlikely that vitamin D deficiency is perceived to be an issue for much of the Australian population. However, vitamin D deficiency is prevalent in Australia, due to the many individual and environmental factors that impact on vitamin D status, such as skin colour, dressing habits, latitude and season. The Australian Health Survey 2011-12 identified that 23% of the population were vitamin D deficient (defined as <50nmol/L), which equivalates to approximately 4 million people (ABS 2014).

Our study will look at the vitamin D status of women living in Australia in winter 2020/2021. This study will take place in Wollongong, on the South East Coast of Australia, Latitude 34.42° S, 150.89° E. We will determine which factors such as dietary intake, sun exposure and muscular strength contribute to vitamin D status. The findings of this study will not only fill this gap in the knowledge, but may also contribute to the literature which informs public health policy on vitamin D.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 103878 0
A/Prof Karen Charlton
Address 103878 0
Building 42
Faculty of Science, Medicine and Health
University of Wollongong
Northfields Avenue
Wollongong
NSW 2522
Country 103878 0
Australia
Phone 103878 0
+61 2 4221 4754
Fax 103878 0
Email 103878 0
karenc@uow.edu.au
Contact person for public queries
Name 103879 0
Miss Rebecca Vearing
Address 103879 0
Building 42
Faculty of Science, Medicine and Health
University of Wollongong
Northfields Avenue
Wollongong
NSW 2522
Country 103879 0
Australia
Phone 103879 0
+61 428906663
Fax 103879 0
Email 103879 0
rv876@uowmail.edu.au
Contact person for scientific queries
Name 103880 0
Miss Rebecca Vearing
Address 103880 0
Building 42
Faculty of Science, Medicine and Health
University of Wollongong
Northfields Avenue
Wollongong
NSW 2522
Country 103880 0
Australia
Phone 103880 0
+61 428906663
Fax 103880 0
Email 103880 0
rv876@uowmail.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.