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Trial registered on ANZCTR

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

Titles & IDs
Public title
The effect of low dose fluoride on bone
Scientific title
A randomized, double-blind, placebo-controlled, dose-finding study of the effects of sodium fluoride on bone turnover, bone density and bone histology in osteopenic post menopausal women.
Secondary ID [1] 262121 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoporosis 1620 0
Condition category
Condition code
Musculoskeletal 1728 1728 0 0

Study type
Description of intervention(s) / exposure
Subjects randomized to placebo or 1 of 3 treatment groups: sodium fluoride 2.5mg daily, per oral, 5mg daily per oral, 10mg daily per oral, for 1 year. No dosage increments Active and placebo tablets are identical in appearance
Intervention code [1] 1592 0
Treatment: Drugs
Comparator / control treatment
Matching placebo, per oral for 1 year
Control group

Primary outcome [1] 2399 0
Change in lumbar spine bone mineral density (BMD
Timepoint [1] 2399 0
At 1 year
Secondary outcome [1] 4170 0
Change in hip BMD
Timepoint [1] 4170 0
At 1 year
Secondary outcome [2] 4171 0
Change in forearm BMD
Timepoint [2] 4171 0
At 1 year
Secondary outcome [3] 4172 0
Change in biochemical markers of bone turnover
Timepoint [3] 4172 0
At 1 year
Secondary outcome [4] 4173 0
Bone histology
Timepoint [4] 4173 0
At 1 year

Key inclusion criteria
Postmenopausal 5 yrs or more (menopause defined as at least 12 months since last period in woman aged > 45 yrs with intact uterus, or serum follicle stimluating hormone (FSH) > 50 IU/l in younger or hysterectomized woman)- Bone density T score less than -1.0 and greater than -2.5 at L1-L4 or Total Hip.- BMD T-score <-2.5 at lumbar spine or total hip, but participant is not a suitable candidate for, or has decided against taking, osteoporosis therapy
Minimum age
45 Years
Maximum age
Not stated
Can healthy volunteers participate?
Key exclusion criteria
Medical Conditions- renal impairment (serum creatinine 120 µmol/L).- congestive heart failure- chronic liver disease.- untreated hypothyroidism or hyperthyroidism.- concurrent major systemic illness, including malignancy.- active major gastrointestinal disease.- metabolic bone diseases, or serum alkaline phosphatase (ALP) > 2x normal limit.- primary hyperparathyroidism. - Vitamin D insufficiency (25 hydroxyvitamin D [OHD] < 50nmol/L)Medications- use of oral glucocorticoid drugs equivalent to an average dose of prednisone 2.5 mg/day in the preceding 12 months- use of aminobisphosphonates within the past 2 years, or etidronate within the past 1 year- use of hormone replacement therapy within the last 12 months- use of other medication known to cause osteoporosis or interfere with bone metabolism.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Staff member enrolling subject unaware of treatment allocation, allocation concealment by central randomization
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Sequence generation by computer-generated random numbers
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
subjects and assessors are blinded
Phase 2
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 outside Australia
Country [1] 482 0
New Zealand
State/province [1] 482 0

Funding & Sponsors
Funding source category [1] 1877 0
Government body
Name [1] 1877 0
Health Research Council of New Zealand
Address [1] 1877 0
PO Box 5541
Wellesley St.,
Country [1] 1877 0
New Zealand
Funding source category [2] 237233 0
Name [2] 237233 0
Auckland Medical research Foundation
Address [2] 237233 0
PO Box 110 139
Auckland 1148
Country [2] 237233 0
New Zealand
Primary sponsor type
Associate Professor Andrew Grey
Department of Medicine
University of Auckland
Private Bag 92019
New Zealand
Secondary sponsor category [1] 1692 0
Name [1] 1692 0
University of Auckland
Address [1] 1692 0
Private Bag 92019
Country [1] 1692 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 3502 0
Auckland-Northern X Regional Ethics Committee
Ethics committee address [1] 3502 0
Ethics committee country [1] 3502 0
New Zealand
Date submitted for ethics approval [1] 3502 0
Approval date [1] 3502 0
Ethics approval number [1] 3502 0

Brief summary
This is a 1 year study designed to investigate the effects of low-dose fluoride therapy on bone. We are testing whether doses of fluoride that are lower than have been studied in previous trials might have positive effects on bone density and metabolism, without affecting bone quality. 180 postmenopausal women with mild bone thinning will be randomly (by chance) allocated to receive placebo (inactive) treatment or one of 3 low doses of fluoride (2.5, 5 or 10 mg/day). Each participant will be seen on 5 occasions during the study, for assessment of bone density and bone-related biochemistry (blood and urine tests). Bone biopsy from the back of the pelvis will be sought from 6-10 participants in each treatment group at the end of the study - this is a voluntary procedure.
Trial website
Trial related presentations / publications
Grey A, Garg S, Dray M, Purvis L, Horne A, Callon K, Gamble G, Bolland M, Reid IR, Cundy T. Low dose fluoride in osteopenic postmenopausal women: a randomized controlled trial. J Clin Endocrinol Metab 2013;98:2301-2307
Public notes

Principal investigator
Name 27526 0
A/Prof Andrew Grey
Address 27526 0
Department of Medicine
university of Auckland
Private Bag 92019
New Zealand
Country 27526 0
New Zealand
Phone 27526 0
Fax 27526 0
Email 27526 0
Contact person for public queries
Name 10781 0
A/Prof Associate Professor Andrew Grey
Address 10781 0
Department of Medicine,
University of Auckland,
Country 10781 0
New Zealand
Phone 10781 0
+64 9 3737599
Fax 10781 0
Email 10781 0
Contact person for scientific queries
Name 1709 0
A/Prof Associate Professor Andrew Grey
Address 1709 0
Department of Medicine,
University of Auckland,
Country 1709 0
New Zealand
Phone 1709 0
+64 9 3737599
Fax 1709 0
Email 1709 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