Condition category
Nutritional, Metabolic, Endocrine
Date applied
20/12/2007
Date assigned
21/02/2008
Last edited
17/10/2012
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Prof Kevin Cashman

ORCID ID

Contact details

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

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 measures

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

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

http://www.food.gov.uk

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

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

Results - basic reporting

Publication summary

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

  1. 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.

  2. 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.

  3. 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.

Additional files

Editorial Notes