Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N05R0003
Study information
Scientific title
Dietary requirements for vitamin D: an investigation of the relative significance of dietary intake and sunlight on vitamin D status in young and elderly adults
Acronym
Study hypothesis
We hypothesise that additional dietary vitamin D is required to prevent nutritional deficiency during winter in young and elderly adults.
Ethics approval
Ethics approval received from the University of Ulster Research Ethics Committee on the 22nd March 2006 (ref: REC/06/13)
Study design
Double blinded randomised placebo controlled intervention study - multicentre collaboration (University of Ulster and University College Cork)
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Hospitals
Trial type
Treatment
Patient information sheet
Condition
Dietary vitamin D intake and status
Intervention
Oral 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 type
Supplement
Phase
Not Specified
Drug names
Vitamin D supplementation
Primary outcome measure
1. 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 measures
1. 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 trial start date
01/04/2006
Overall trial end date
31/12/2008
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Consenting adult men and women
2. Aged 20 - 85 years
3. In general good health
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
240 from Coleraine and 240 from Cork
Participant exclusion criteria
1. 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)
Recruitment start date
01/04/2006
Recruitment end date
31/12/2008
Locations
Countries of recruitment
Ireland
Trial participating centre
Department of Food and Nutritional Sciences
Cork
N/A
Ireland
Sponsor information
Organisation
Food Standards Agency (UK)
Sponsor details
UK Headquarters
Aviation House
125 Kingsway
London
WC2B 6NH
United Kingdom
Sponsor type
Government
Website
Funders
Funder type
Government
Funder name
Food Standards Agency (UK) (ref: N05R0003)
Alternative name(s)
FSA
Funding Body Type
private sector organisation
Funding Body Subtype
Other non-profit organizations
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
1. 2009 results in http://www.ncbi.nlm.nih.gov/pubmed/19297462
2. 2011 results in http://www.ncbi.nlm.nih.gov/pubmed/21270359
3. 2012 results in http://www.ncbi.nlm.nih.gov/pubmed/22739371
Publication citations
-
Results
Cashman KD, Wallace JM, Horigan G, Hill TR, Barnes MS, Lucey AJ, Bonham MP, Taylor N, Duffy EM, Seamans K, Muldowney S, Fitzgerald AP, Flynn A, Strain JJ, Kiely M, Estimation of the dietary requirement for vitamin D in free-living adults >=64 y of age., Am. J. Clin. Nutr., 2009, 89, 5, 1366-1374, doi: 10.3945/ajcn.2008.27334.
-
Results
Barnes MS, Horigan G, Cashman KD, Hill TR, Forsythe LK, Lucey AJ, McSorley EM, Kiely M, Bonham MP, Magee PJ, Strain JJ, Wallace JM, Maintenance of wintertime vitamin D status with cholecalciferol supplementation is not associated with alterations in serum cytokine concentrations among apparently healthy younger or older adults., J. Nutr., 2011, 141, 3, 476-481, doi: 10.3945/jn.110.131516.
-
Results
Muldowney S, Lucey AJ, Hill TR, Seamans KM, Taylor N, Wallace JM, Horigan G, Barnes MS, Bonham MP, Duffy EM, Strain JJ, Cashman KD, Kiely M, Incremental cholecalciferol supplementation up to 15 μg/d throughout winter at 51-55° N has no effect on biomarkers of cardiovascular risk in healthy young and older adults., J. Nutr., 2012, 142, 8, 1519-1525, doi: 10.3945/jn.111.154005.