Does vitamin D improve markers of vascular health in stroke patients?
| ISRCTN | ISRCTN28737567 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN28737567 |
| Protocol serial number | Res/A107 |
| Sponsor | University of Dundee (UK) |
| Funder | Chest Heart and Stroke Scotland (UK) |
- Submission date
- 21/02/2007
- Registration date
- 01/05/2007
- Last edited
- 26/02/2018
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Small studies have shown that vitamin D, a hormone that the skin usually makes using sunshine, may be able to reduce blood pressure and improve blood vessel health in some people. People who have had a stroke very often have low vitamin D levels, and people with low vitamin D tend to have higher blood pressure. People with high blood pressure have blood vessels that do not work as well as normal, and this leads to a higher risk of heart problems and strokes.
The aim of the study is therefore to test whether giving extra vitamin D to people who have had a stroke in the past helps to reduce blood pressure and improve other measures of blood vessel and heart health.
Who can participate?
Adults aged 18 years and over who have had a stroke
What does the study involve?
The study lasts for 16 weeks. Participants are randomly allocated to one of two groups, and given either a single capsule of vitamin D or a matching placebo (dummy) tablet.
Participants are assessed at the start, and 8 weeks and 16 weeks, with each visit lasting 1.5 hours.
At each visit, participants receive some or all of the following depending on which visit it is:
- Blood pressure measured
- Blood sample taken
- Test the function of the artery in their arm. The artery is scanned with an ultrasound machine before and after inflating a blood pressure cuff on their forearm for 5 minutes. The test is repeated after giving the participant a medication (GTN) spray under their tongue.
- Wear a blood pressure cuff and a heart rate monitor (ECG) for 24 hours including at home
What are the possible benefits and risks of participating?
Although participants are unlikely to benefit directly by taking part in the trial, those who receive the vitamin D might find that blood pressure is lower.
Although this dose of vitamin D has been used before and is known to be safe there is a small possibility of side effects. Participants are closely monitored for side effects caused by high calcium levels: sickness, diarrhoea, thirst or dizziness. To reduce the chance of vitamin D increasing the calcium level in their blood, participants are also asked not to take vitamin D supplements or calcium supplements whilst taking part in this study.
Having blood taken can cause some bruising. The blood pressure cuff causes mild discomfort to some people.
Where is the study run from?
Ninewells Hospital Dundee (UK)
When is the study starting and how long is it expected to run for?
September 2006 to May 2009
Who is funding the study?
Chest Heart and Stroke Scotland (UK)
Who is the main contact?
Dr Miles Witham (Scientific)
m.witham@dundee.ac.uk
Contact information
Scientific
Department of Medicine & Therapeutics
University of Dundee
Ninewells Hospital & Medical School
Dundee
DD1 9SY
United Kingdom
| Phone | +44 (0)1382 632436 |
|---|---|
| m.witham@dundee.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Double blind randomised placebo controlled trial. |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | The effect of vitamin D replacement on markers of vascular health in stroke patients - a randomised controlled trial |
| Study objectives | That a single dose of oral vitamin D can lower blood pressure and improve endothelial function in stroke patients |
| Ethics approval(s) | Tayside Local Research Ethics Committee,14/05/200, ref: 07/S1401/41 |
| Health condition(s) or problem(s) studied | Stroke |
| Intervention | A single oral dose of 100,000 U ergocalciferol (vitamin D) or placebo. |
| Intervention type | Other |
| Primary outcome measure(s) |
Blood pressure (seated office and 24 hour measurements) (added 26/02/2018: measured using a blood pressure cuff) at baseline, 8 and 16 weeks after vitamin D administration. |
| Key secondary outcome measure(s) |
Current secondary outcome measures (as of 26/02/2018): |
| Completion date | 31/05/2009 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Sex | All |
| Target sample size at registration | 68 |
| Key inclusion criteria | 1. Clinical diagnosis of completed stroke (ischaemic or haemorrhagic) 2. Serum 25-hydroxy vitamin D level less than 50 nmol/L |
| Key exclusion criteria | 1. Hyper- or hypocalcaemia 2. Metastatic malignancy 3. Liver function tests over three times limit of normal 4. Estimated glomerular filtration rate (GFR) less than 40 ml/min 5. Previous clinical diagnosis of osteomalacia 6. Taking vitamin D preparations 7. Unable to give written informed consent 8. Unable to swallow tablets orally 9. Atrial fibrilation (to provide a more homogeneous aetiology) |
| Date of first enrolment | 28/01/2008 |
| Date of final enrolment | 31/08/2008 |
Locations
Countries of recruitment
- United Kingdom
- Scotland
Study participating centre
DD1 9SY
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The protocol is available from the authors on request but is not available online. Study data are available for non-commercial, bona-fide academic analyses in collaboration with the authors; decisions on data access will be made between the investigators and the Sponsor (University of Dundee). Participant consent for unrestricted sharing of individual participant data was not obtained Contact for data sharing: Dr Catrina Forde (c.forde@dundee.ac.uk) |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 01/10/2012 | Yes | No | |
| Basic results | 21/02/2018 | 26/02/2018 | No | No | |
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Additional files
- ISRCTN28737567_BasicResults_21Feb18.pdf
- Uploaded 26/02/2018
Editorial Notes
26/02/2018: The following changes were made:
1. Overall trial start date was changed from 01/06/2007 to 30/09/2006
2. Recruitment start date was changed from 01/06/2007 to 28/01/2008
3. Recruitment end date was changed from 30/11/2008 to 31/08/2008
4. Overall trial end date was changed from 30/11/2008 to 31/05/2009
5. Participant inclusion age and gender, participant level data, scientific title and basic results summary were added.
6. Primary and secondary outcome measures were updated.
