An investigation of the dietary requirements for vitamin D

ISRCTN ISRCTN20236112
DOI https://doi.org/10.1186/ISRCTN20236112
Secondary identifying numbers N05R0003
Submission date
20/12/2007
Registration date
21/02/2008
Last edited
17/10/2012
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Kevin Cashman
Scientific

Department of Food and Nutritional Sciences
University College Cork
Cork
N/A
Ireland

Study information

Study designDouble blinded randomised placebo controlled intervention study - multicentre collaboration (University of Ulster and University College Cork)
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Scientific titleDietary requirements for vitamin D: an investigation of the relative significance of dietary intake and sunlight on vitamin D status in young and elderly adults
Study objectivesWe hypothesise that additional dietary vitamin D is required to prevent nutritional deficiency during winter in young and elderly adults.
Ethics approval(s)Ethics approval received from the University of Ulster Research Ethics Committee on the 22nd March 2006 (ref: REC/06/13)
Health condition(s) or problem(s) studiedDietary vitamin D intake and status
InterventionOral daily supplementation with vitamin D3 of the following doses:
1. Placebo (no treatment)
2. 5 mcg
3. 10 mcg
4. 15 mcg

Supplementation is provided for six months from October to March. There is no additional follow-up. However there is a run-in phase during the preceding summer when participants are asked to keep a diary of sun exposure and activities outdoors. This is assessed in July and August.
Intervention typeSupplement
Primary outcome measure1. Serum 25 hydroxyvitamin D concentrations
2. Serum parathyroid hormone concentrations
3. Serum calcium concentrations
4. Dietary calcium and vitamin D intakes (from four-day food diary and food frequency questionnaire)
Secondary outcome measures1. Bone mineral density (from dual energy x-ray absorptiometry [DXA] scan of spine, hip and whole body)
2. Body composition measurements
3. Immune markers
4. Bone turnover markers
Overall study start date01/04/2006
Completion date31/12/2008

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants240 from Coleraine and 240 from Cork
Key inclusion criteria1. Consenting adult men and women
2. Aged 20 - 85 years
3. In general good health
Key exclusion criteria1. Severe medical illness
2. Hypercalcaemia
3. Known intestinal malabsorption syndrome
4. Excessive alcohol use
5. Those who took medications known to interfere with vitamin D metabolism
6. Pregnancy or planning to become pregnant during the six months of the intervention
7. Those taking high dose vitamin D-containing supplements for three months before initiation of study
8. Those who over the six-month course of intervention are planning a winter vacation to a location at which either the altitude or the latitude would be predicted to result in significant cutaneous vitamin D synthesis from solar radiation (e.g., a mountain ski resort or a winter sun coastal resort)
Date of first enrolment01/04/2006
Date of final enrolment31/12/2008

Locations

Countries of recruitment

  • Ireland

Study participating centre

Department of Food and Nutritional Sciences
Cork
N/A
Ireland

Sponsor information

Food Standards Agency (UK)
Government

UK Headquarters
Aviation House
125 Kingsway
London
WC2B 6NH
United Kingdom

Website http://www.food.gov.uk
ROR logo "ROR" https://ror.org/05p20a626

Funders

Funder type

Government

Food Standards Agency (UK) (ref: N05R0003)
Private sector organisation / Other non-profit organizations
Alternative name(s)
The Food Standards Agency, FSA
Location
United Kingdom

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article results 01/05/2009 Yes No
Results article results 01/03/2011 Yes No
Results article results 01/08/2012 Yes No