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Trial registered on ANZCTR


Registration number
ACTRN12617001031358
Ethics application status
Approved
Date submitted
12/07/2017
Date registered
17/07/2017
Date last updated
6/02/2019
Date data sharing statement initially provided
6/02/2019
Date results information initially provided
6/02/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
KiwiC for Vitality Study: Effect of kiwifruit on Vitality, Fatigue and Wellbeing
Scientific title
Kiwifruit and Vitality: a randomised controlled trial on the effect of kiwifruit on vitality, fatigue and wellbeing in participants with low vitamin C status
Secondary ID [1] 292388 0
None
Universal Trial Number (UTN)
U1111-1196-8929
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Vitality 303950 0
Fatigue 303951 0
Wellbeing 303952 0
Condition category
Condition code
Mental Health 303307 303307 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Arm 1, Two SunGold kiwifruit per day for 4 weeks during the intervention period. The intervention period is preceded by a 2 week lead-in and followed by a 2 week washout where no intervention is given.
Arm 2, One oral tablet containing 250 mg vitamin C per day for 4 weeks during the intervention period. The intervention period is preceded by a 2 week lead-in and followed by a 2 week washout where no intervention is given.
Intervention code [1] 298562 0
Treatment: Other
Intervention code [2] 298598 0
Treatment: Drugs
Comparator / control treatment
Arm 3, One oral placebo tablet containing 0 mg vitamin C per day for 4 weeks during the intervention period. The intervention period is preceded by a 2 week lead-in and followed by a 2 week washout where no intervention is given.
Control group
Placebo

Outcomes
Primary outcome [1] 302711 0
Total mood disturbance score assessed using the Profile of Mood States (POMS) questionnaire.
Timepoint [1] 302711 0
Fortnightly for 8 weeks; intermittent nightly smartphone surveys for 8 weeks
Primary outcome [2] 302712 0
Total fatigue score assessed using the Multidimensional Fatigue Symptom Inventory - short form (MFSI-SF).
Timepoint [2] 302712 0
Fortnightly for 8 weeks.
Primary outcome [3] 302713 0
Positive psychological wellbeing assessed using the Warwick-Edinburgh Mental Wellbeing Scale (WEMWS)
Timepoint [3] 302713 0
Fortnightly for 8 weeks.
Secondary outcome [1] 336787 0
Plasma vitamin C.
Timepoint [1] 336787 0
Fortnightly for 8 weeks.
Secondary outcome [2] 336788 0
Fatigue-energy scale of the Short Form Health Survey (SF-36)
Timepoint [2] 336788 0
Intermittent nightly smartphone surveys for 10 weeks.
Secondary outcome [3] 336789 0
Positive psychological wellbeing assessed using the short Flourishing Scale
Timepoint [3] 336789 0
Intermittent nightly smartphone surveys for 8 weeks.

Eligibility
Key inclusion criteria
Plasma vitamin C levels <45 µmol/L
Non-smoker
Minimum age
18 Years
Maximum age
35 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Taking prescription medication (within past three months)
Allergy/intolerance to Kiwifruit
Recent smoker (within previous year)
Taking vitamin C supplements (within past three months)
High fruit/juice & vegetable consumption (greater than or equal to 5 servings/day)
Excessive alcohol consumption ( greater than 21 standard drinks/week)
Diabetes mellitus
Bleeding disorders
Fainting due to fear of needles

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment will be achieved with use of sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Random numbers generation and allocation by sealed opaque envelopes
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Sample size was calculated based on previously attained data using the POMS questionnaire. With a power of 80%, alpha of 0.05 and effect size of 0.8, it was calculated that 25 participants per group were required. Recruitment of 40 participants per group accounts for the observation of potentially smaller effect sizes for some wellbeing measures. An additional 10% (5 participants per group) will be recruited to allow for withdrawal over the duration of the study, therefore requiring 135 participants.
Statistical differences between and within groups for the fortnightly measurements will be determined using ANOVA with post-hoc analysis. Multivariate modelling will also be carried out to take into account time and confounders. Statistical trends over time between and within groups for the smartphone measurements will be analysed using growth curve modelling using the Hierarchical Linear Modelling programme. Statistical significance will be set at P=0.05.

Recruitment
Recruitment status
Completed
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] 9042 0
New Zealand
State/province [1] 9042 0
Dunedin and Christchurch

Funding & Sponsors
Funding source category [1] 296939 0
Commercial sector/Industry
Name [1] 296939 0
Zespri International
Address [1] 296939 0
400 Maunganui Road
Mt Maugnganui 3149
Country [1] 296939 0
New Zealand
Primary sponsor type
University
Name
University of Otago, Christchurch
Address
2 Riccarton Avenue
Christchurch 8140
Country
New Zealand
Secondary sponsor category [1] 295944 0
University
Name [1] 295944 0
University of Otago, Dunedin
Address [1] 295944 0
362 Leith Street
Dunedin 9016
Country [1] 295944 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298145 0
Health and Disability Ethics Commettee
Ethics committee address [1] 298145 0
Ministry of Health
133 Molesworth Street
Thornton
Wellington 6011
Ethics committee country [1] 298145 0
New Zealand
Date submitted for ethics approval [1] 298145 0
30/05/2017
Approval date [1] 298145 0
28/06/2017
Ethics approval number [1] 298145 0
17/NTB/104

Summary
Brief summary
The purpose of the study is to assess the effect of adding SunGold kiwifruit to the diet on changes in vitality, fatigue, and wellbeing. The study aims to determine whether any improvements in these outcomes can be attributed to the high vitamin C content of the fruit. In a previous pilot study, we observed that intake of two kiwifruit/day for six weeks provided a significant 31% increase in vigour and a significant 38% decrease in fatigue in young men with a higher than average total mood disturbance score as assessed by the Profile of Mood States (POMS) questionnaire. Interestingly, intake of half a kiwifruit/day did not have any effect on mood scores, suggesting a dose dependency.
We are now proposing a larger study that includes both men and women, has more extensive measures of vitality, fatigue and wellbeing, and includes a vitamin C and a placebo comparison arm. This randomised controlled trial brings together the expertise of Professor Margreet Vissers, Dr Anitra Carr and Dr Tamlin Conner, New Zealand's leading research experts in vitamin C bioavailability and function (Vissers and Carr) and psychological wellbeing (Conner).
We will recruit participants who have low vitamin C status. Individuals will be randomised to one of three interventions: (1) Two SunGold kiwifruit per day; (2) vitamin C tablet daily (equivalent to the vitamin C content of two kiwifruit); (3) placebo tablet daily. We will monitor vitality/fatigue/wellbeing, using intermittent nightly smartphone surveys and traditional fortnightly assessments. The study will last for 8 weeks (2 week lead-in; 4 week intervention; 2 week washout period). Our hypothesis is that consumption of two SunGold kiwifruit per day will improve vitality, decrease fatigue, and improve wellbeing.
Trial website
http://web.psy.otago.ac.nz/kiwifruit
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 76142 0
Prof Margreet Vissers
Address 76142 0
Center for Free Radical Research
Department of Pathology
University of Otago, Christchurch
2 Riccarton Avenue
Christchurch 8140

Country 76142 0
New Zealand
Phone 76142 0
+64 3 364 1524
Fax 76142 0
+64 3 364 1083
Email 76142 0
margreet.vissers@otago.ac.nz
Contact person for public queries
Name 76143 0
Dr Tamlin Conner
Address 76143 0
Department of Psychology
University of Otago
PO Box 56
Dunedin 9054
Country 76143 0
New Zealand
Phone 76143 0
+64 3 479 7624
Fax 76143 0
Email 76143 0
tconner@psy.otago.ac.nz
Contact person for scientific queries
Name 76144 0
Prof Margreet Vissers
Address 76144 0
Center for Free Radical Research
Department of Pathology
University of Otago, Christchurch
2 Riccarton Avenue
Christchurch 8140
Country 76144 0
New Zealand
Phone 76144 0
+64 3 364 1524
Fax 76144 0
+64 3 364 1083
Email 76144 0
margreet.vissers@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
De-identified results data.
When will data be available (start and end dates)?
Beginning 3 months and ending 5 years following all results publication.
Available to whom?
Researchers, on a case-by-case basis at the discretion of Primary Sponsor.
Available for what types of analyses?
Only to further the aims of the present study and for meta-analyses.
By what mechanism will data be made available?
Access subject to approvals by Principal Investigator, together with requirement to sign data access agreement.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary