- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03318029
Vitamin D Supplementation and Sunlight Exposure in Brazilian Women Living in Opposite Latitudes (The D-SOL Study) (D-SOL)
A Systems Biology Approach to the Interaction Between Vitamin D Supplementation and Sunlight Exposure in Brazilian Women Living in Opposite Latitudes (The D-SOL Study).
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
During this study the subjects were asked to visit the Clinical Investigation Unit, FHMS, University of Surrey in the UK or the Research Clinic, Faculty of Nutrition, Federal University of Goiás in Brazil, on two occasions, at the beginning of the study for baseline measurements and at the conclusion of the study. The investigators examined four to eight fasted subjects per study morning. Trial visits lasted approximately 45-60 minutes each and took place in the morning (7am-11am). Participants were offered refreshments at the end of their appointment.
If participants wished to be screened for participation in the study, they would receive the Participant Information Sheet and then be checked against the study inclusion and exclusion criteria using a 'Screening Questionnaire' , administered by a member of the D-SOL Research Team by phone or self-reported by email.
Baseline visit:
If eligible, participants were invited for the baseline visit. At this visit, they were first given time to discuss the Participant Information Sheet and any questions they may have regarding the study. Informed consent was discussed and participants were asked to sign the consent form, and offered a copy to keep for themselves.
Baseline procedures:
- Health and Lifestyle questionnaire administered by a member of the D-SOL Research Team.
- Anthropometrics and blood pressure measured, and fasted blood sample taken (serum 25OHD levels, 1,25-dihydroxy vitamin D, serum calcium, albumin, parathyroid hormone, C-terminal telopeptide (CTX) ≈25ml) with an additional ≈10 ml for genetic profiling and ≈15 for storage for future measurements of nutritional markers.
- pQCT scan of the non-dominant forearm (UK trial) or dual energy x-ray absorptiometry (DEXA) scan (Brazil trial).
- Bioelectrical impedance analysis (BIA) for body composition.
- Provision of randomly assigned daily supplement (30 days' supply), food diaries and sunlight dosimeters and sunlight exposure diary to be returned at 12 week visit. Follow-up appointment details arranged.
Final visit
- Final adverse event/compliance interview completed with investigator.
- Daily outdoor exposure diary, food diary and sunlight dosimeter received from participant and checked for consistency at visit.
- Anthropometrics and blood pressure measured, and blood sample taken (serum 25OHD levels, 1,25-dihydroxy vitamin D, serum calcium, albumin, parathyroid hormone, C-terminal telopeptide (CTX) ≈25ml) with an additional ≈10 ml for genetic profiling and ≈15 for storage for future measurements of nutritional markers.
- Bioelectrical impedance analysis (BIA) for body composition.
DNA profiling procedure - After 12 weeks: Selection of participant samples encompassing the best and worst supplementation-responders in each group, subject to previous consent form singed by participant. Vitamin D related genes will be genotyped in DNA isolated from the study blood samples, DNA will be extracted and vitamin D polymorphisms will be determined by University of Surrey's genetic labs.
A trained phlebotomist took the blood samples required as part of the trial protocol. Medical cover was available at all times.
Throughout the duration of the trial, the participants were contacted via telephone on a fortnightly basis to discuss any issues with any adverse event and compliance and to maintain good communication with the participants. In the case of a serious adverse event (SAE) this would be recorded and reported it to both the Sponsor (University of Surrey) and the Surrey Ethics Committee.
The final interview was completed at the final study visit. Participants have also been asked to return any supplements that were missed to confirm compliance.
For University of Surrey participants: A peripheral quantitative computed tomography (pQCT) scan was performed on the participant's non-dominant forearm at the baseline visit, to measure volumetric bone mineral density at the 4% and 66% radial site. This will allow for separate measurements of trabecular volumetric bone mineral density (vBMD) and trabecular area (4% site) and cortical vBMD and cortical area (66% site), as well as strength strain index, a measure of bone strength. pQCT also measures bone geometry alongside bone density. Therefore the muscle cross sectional area can be determined, which is a measure of muscle force, to which bone strength is adapted to. One scan was performed at baseline only and effective exposure doses were between ~1.5-1.8uSv.
For Federal University of Goiás participants: Body composition (absolute and relative amount of lean and fat mass), whole body mineral density and lower spine and femur bone mineral density was measured with the use of DEXA (located at the Nutrition Clinic based at the Federal University of Goiás), at baseline only. Two scans were performed at baseline for each participant: one to assess the whole body mineral density and body composition, and the other to specifically assess fracture risk by scanning the spine and femoral head. Effective exposure doses for theses scans are ~8uSv and ~4uSv respectively.
Results of the body composition, vitamin D status and dietary intake from the self-reported food diaries will be made available to the subjects upon request. The results from the blood analysis will be reported to the subject if there are any health concerns raised. If the results are within healthy ranges the participants will not be contacted unless they specifically request for this information. The investigators will not be contacting their general practitioner (GP) if there are any concerns raised in the study however the investigators will stress that they should contact their GP themselves to discuss the results.
The trial was conducted in compliance with the principles of the Declaration of Helsinki (2008), the principles of Good Clinical Practice and in accordance with The Medicines for Human Use (Clinical Trials) Regulations 2004 and Amended Regulations 2006.
Detailed protocol and supporting documents were submitted for review by the University of Surrey Ethics Committee and the Federal University of Goiás, Brazil. The study received favourable ethical opinion from both Committees prior to commencing the study. Annual progress reports and a final report will be submitted to the ethics committees as defined in their respective regulations.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
Goiás
-
Goiânia, Goiás, Brazil, 74605-080
- Federal University of Goiás
-
-
-
-
Surrey
-
Guildford, Surrey, United Kingdom, GU2 7XH
- University of Surrey
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
Brazilian nationality Living in the UK or in Brazil for more than 2 months
Exclusion Criteria:
- Currently receiving treatment for medical conditions that are likely to affect vitamin D metabolism ( osteoporosis therapy, anti-estrogens treatment, antiepileptic drugs, breast-cancer treatment)
- Hypercalcaemia (>2.5mmol/L) - assessed and excluded at baseline
- Regular use of sun-beds
- Having a holiday trip for more than 4 weeks, one month prior to commencing the study or plans for a holiday trip out of the country of residence within the study period.
- Use of vitamin supplements containing vitamin D (if the prospective participants agrees to stop Vitamin D supplementation to join the study, a wash-out period of 8 weeks prior to commencing the trial would be acceptable).
- Pregnant or planning a pregnancy during the study period.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Placebo Comparator: Placebo UK trial
Placebo and living in the UK
|
rice flour with no vitamin D
|
Active Comparator: Vitamin D UK trial
Vitamin D supplementation and living in the UK
|
Vitamin D supplementation of 600 IU daily for 12 weeks
|
Placebo Comparator: Placebo Brazil Trial
Placebo and living in the Brazil
|
rice flour with no vitamin D
|
Active Comparator: Vitamin D Brazil Trial
Vitamin D supplementation and living in Brazil
|
Vitamin D supplementation of 600 IU daily for 12 weeks
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Change from baseline vitamin D status at 12 weeks of vitamin D supplementation
Time Frame: baseline and 12 weeks
|
These will be assessed by measuring serum 25(OH)D (in nmol/L) levels in participants at baseline and 12 weeks
|
baseline and 12 weeks
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Analyze the difference regarding time and intensity of sun exposure between Brazilian women living in Brazil and Brazilian women living in the UK.
Time Frame: baseline
|
These will be assessed by participants use of individual sunlight dosimeters and self-reported sun exposure diary
|
baseline
|
Prevalence of inadequate dietary Vitamin D intake in these women
Time Frame: baseline
|
These will be assessed by self-reported food diaries
|
baseline
|
Baseline prevalence of insufficient/deficient levels of vitamin D in these women.
Time Frame: baseline
|
These will be assessed by measuring serum 25(OH)D (in nmol/L) levels in participants at baseline
|
baseline
|
Change in the number of participants with insufficient/deficient levels of vitamin D after intervention
Time Frame: baseline and after 12 weeks intervention
|
These will be assessed by measuring serum 25(OH)D (in nmol/L) levels in participants during winter (baseline and final visit)
|
baseline and after 12 weeks intervention
|
Influence of latitude on vitamin D optimal levels.
Time Frame: baseline
|
These will be assessed by comparing measurements of serum 25(OH)D (in nmol/L) levels in participants at baseline between women living in the UK (latitude 51 North) and those living in Brazil (latitude 16 South)
|
baseline
|
Influence of skin pigmentation on vitamin D optimal levels.
Time Frame: baseline
|
These will be assessed by comparing baseline measurements of serum 25(OH)D (in nmol/L) levels and self-reported skin type
|
baseline
|
Vitamin D status influence on bone health
Time Frame: baseline
|
Elucidation of the association between Vitamin D status and markers of calcium of calcium metabolism
|
baseline
|
Vitamin D supplementation response dependence on initial vitamin D levels.
Time Frame: baseline and after 12 weeks intervention
|
Assessed by comparing baseline and after intervention measurements of serum 25(OH)D (in nmol/L) levels.
|
baseline and after 12 weeks intervention
|
Genetic and enzymatic mechanisms underlying the response to vitamin D supplementation
Time Frame: baseline and after 12 weeks intervention
|
These will be assessed by genotyping for polymorphisms related to vitamin D metabolism
|
baseline and after 12 weeks intervention
|
Collaborators and Investigators
Sponsor
Collaborators
Investigators
- Study Chair: Kath Hart, Ph.D, Lecturer, Department of Nutritional Sciences, University of Surrey
- Study Chair: Patricia Borges Botelho, Ph.D, Lecturer, Post-graduate Department of Nutrition, Federal University of Goiás
- Study Chair: Laura Tripkovic, Ph.D, Teaching Fellow, Department of Nutritional Sciences, University of Surrey
Publications and helpful links
General Publications
- Lips P. Vitamin D deficiency and secondary hyperparathyroidism in the elderly: consequences for bone loss and fractures and therapeutic implications. Endocr Rev. 2001 Aug;22(4):477-501. doi: 10.1210/edrv.22.4.0437.
- Adams JS, Hewison M. Update in vitamin D. J Clin Endocrinol Metab. 2010 Feb;95(2):471-8. doi: 10.1210/jc.2009-1773.
- Bandeira F, Griz L, Freese E, Lima DC, The AC, Diniz ET, Marques TF, Lucena CS. Vitamin D deficiency and its relationship with bone mineral density among postmenopausal women living in the tropics. Arq Bras Endocrinol Metabol. 2010 Mar;54(2):227-32. doi: 10.1590/s0004-27302010000200020.
- Wang TJ, Zhang F, Richards JB, Kestenbaum B, van Meurs JB, Berry D, Kiel DP, Streeten EA, Ohlsson C, Koller DL, Peltonen L, Cooper JD, O'Reilly PF, Houston DK, Glazer NL, Vandenput L, Peacock M, Shi J, Rivadeneira F, McCarthy MI, Anneli P, de Boer IH, Mangino M, Kato B, Smyth DJ, Booth SL, Jacques PF, Burke GL, Goodarzi M, Cheung CL, Wolf M, Rice K, Goltzman D, Hidiroglou N, Ladouceur M, Wareham NJ, Hocking LJ, Hart D, Arden NK, Cooper C, Malik S, Fraser WD, Hartikainen AL, Zhai G, Macdonald HM, Forouhi NG, Loos RJ, Reid DM, Hakim A, Dennison E, Liu Y, Power C, Stevens HE, Jaana L, Vasan RS, Soranzo N, Bojunga J, Psaty BM, Lorentzon M, Foroud T, Harris TB, Hofman A, Jansson JO, Cauley JA, Uitterlinden AG, Gibson Q, Jarvelin MR, Karasik D, Siscovick DS, Econs MJ, Kritchevsky SB, Florez JC, Todd JA, Dupuis J, Hypponen E, Spector TD. Common genetic determinants of vitamin D insufficiency: a genome-wide association study. Lancet. 2010 Jul 17;376(9736):180-8. doi: 10.1016/S0140-6736(10)60588-0. Epub 2010 Jun 10.
- Mendes MM, Hart KH, Williams EL, Mendis J, Lanham-New SA, Botelho PB. Vitamin D Supplementation and Sunlight Exposure on Serum Vitamin D Concentrations in 2 Parallel, Double-Blind, Randomized, Placebo-Controlled Trials. J Nutr. 2021 Oct 1;151(10):3137-3150. doi: 10.1093/jn/nxab209.
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- D-SOL
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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