An investigation of the dietary requirements for vitamin D

ISRCTN	ISRCTN20236112
DOI	https://doi.org/10.1186/ISRCTN20236112
Protocol serial number	N05R0003
Sponsor	Food Standards Agency (UK)
Funder	Food Standards Agency (UK) (ref: 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

Primary study design	Interventional
Study design	Double blinded randomised placebo controlled intervention study - multicentre collaboration (University of Ulster and University College Cork)
Secondary study design	Randomised controlled trial
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
Study objectives	We 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) studied	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
Primary outcome measure(s)	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)
Key secondary outcome measure(s)	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
Completion date	31/12/2008

Eligibility

Participant type(s)	Patient
Age group	Adult
Sex	All
Target sample size at registration	480
Key inclusion criteria	1. Consenting adult men and women 2. Aged 20 - 85 years 3. In general good health
Key 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)
Date of first enrolment	01/04/2006
Date of final enrolment	31/12/2008

Locations

Countries of recruitment

Ireland

Study participating centre

Department of Food and Nutritional Sciences

Cork
N/A
Ireland

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	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