Condition category
Circulatory System
Date applied
25/06/2008
Date assigned
04/09/2008
Last edited
04/10/2013
Prospective/Retrospective
Prospectively 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

Dr Faisel Khan

ORCID ID

Contact details

The Institute of Cardiovascular Research (TICR)
Vascular & Inflammatory Diseases Research Unit
University of Dundee
Ninewells Hospital & Medical School
Dundee
DD1 9SY
United Kingdom
+44 (0)1382 425574
f.khan@dundee.ac.uk

Additional identifiers

EudraCT number

2008-003387-18

ClinicalTrials.gov number

Protocol/serial number

2007cv23; 2008-003387-18; CTA: 21726/0254/001-0001

Study information

Scientific title

The effects of oral vitamin D supplementation on cardiovascular disease risk in UK South Asian women: a randomised, placebo controlled, parallel group, double blinded study

Acronym

Study hypothesis

That oral supplementation of vitamin D will improve cardiovascular function and metabolic and inflammatory parameters in South Asian women.

Please note that as of 06/02/09 this record was updated to include information on the ethics approval and the trial dates. The initial anticipated start date was 01/09/2008, and the initial anticipated end date was 01/03/2009.

Ethics approval

Added 06/02/2009: Tayside Research Ethics Committee NHS gave approval on the 22nd October 2008 (ref: 08/S1402/55)

Study design

Randomised, placebo controlled, parallel group, double blinded study

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Treatment

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

Cardiovascular disease risk

Intervention

Subjects will be given a single dose of 100,000 units of oral vitamin D3 or matching placebo. This dose will be given after baseline assessments. Ingestion will occur in the presence of the research team to ensure 100% adherence to medication.

Intervention type

Supplement

Phase

Not Applicable

Drug names

Vitamin D supplementation

Primary outcome measures

Change in macrovascular endothelial function, which will be assessed by flow mediated dilation (FMD) according to standard guidelines. All measurements will be taken at the start of the study (i.e., before the intervention) and at 4 and 8 weeks post-intervention.

Secondary outcome measures

1. Microvascular endothelial function will be tested using Iontophoresis according to standard guidelines
2. Change in arterial stiffness as measured by pulse wave velocity using the validated SphygmoCor pulse waveform analysis system
3. Change in office blood pressure measured by oscillometric automatic blood pressure device
4. Change in metabolic and inflammatory markers:
4.1. Fasting serum lipid profiles: (COBAS Bio Autoanalyser)
4.2. Fasting glucose, glycosylated haemoglobin (HbA1c) and insulin levels: estimates of insulin resistance will be calculated using the Homeostasis Model (HOMA) (fasting glucose x fasting insulin/22.5)
4.3. Adiponectin and leptin using a commercially available enzyme-linked immunosorbent assay (ELISA) with good sensitivity and reproducibility
4.4. Plasminogen activator inhibitor-1 and tissue plasminogen activator antigen, both measured by ELISA
4.5. C-reactive protein will be measured using a high sensitivity automated turbidimetric assay
4.6. Tumour necrotising factor alpha (TNF-α) and interleukin-6 will be measured by high sensitivity ELISA
4.7. E-selectin - an adhesion molecule expressed only on activated endothelial cells, measured by ELISA
5. Change in serum 25 hydroxyvitamin D and parathyroid hormone (PTH) levels

All measurements will be taken at the start of the study (i.e., before the intervention) and at 4 and 8 weeks post-intervention.

Overall trial start date

12/01/2009

Overall trial end date

11/07/2010

Reason abandoned

Eligibility

Participant inclusion criteria

1. Aged greater than or equal to 18 years
2. Female
3. Serum 25 hydroxyvitamin D less than 75 nmol/L
4. South Asian ethnicity, as defined by the participant

Participant type

Patient

Age group

Adult

Gender

Female

Target number of participants

60

Participant exclusion criteria

1. Symptomatic
2. Cardiovascular disease (including previous stroke, transient ischaemic attack [TIA], angina, myocardial infarction, angioplasty, coronary bypass grafting, symptomatic peripheral vascular disease, chronic heart failure, atrial fibrillation)
3. Already taking vitamin D supplements. Consumption of fish oils will not be a contraindication to enrolment as the vitamin D content is very low relative to the dose used in the study.
4. Estimated glomerular filtration rate less than 40 ml/min (by four-variable Modification of Diet in Renal Disease [MDRD] equation)
5. Liver function tests (alanine aminotransferase [ALT], bilirubin, alkaline phosphatase) greater than 3 x normal. These two criteria will ensure that sufficient renal and hepatic function is available to convert vitamin D to the active 1,25 hydroxy form.
6. Unable to give written informed consent
7. Corrected calcium level of greater than 2.60 or less than 2.15 mmol/L
8. Clinical diagnosis of osteomalacia
9. History of renal calculi, sarcoidosis or metastatic malignancy. Excluding these groups will minimise the risk of side effects from vitamin D supplementation.
10. Pregnant or of child bearing age and not taking reliable contraception

Recruitment start date

12/01/2009

Recruitment end date

11/07/2010

Locations

Countries of recruitment

United Kingdom

Trial participating centre

The Institute of Cardiovascular Research (TICR)
Dundee
DD1 9SY
United Kingdom

Sponsor information

Organisation

University of Dundee (UK)

Sponsor details

c/o Dr James Houston
Research and Innovation Services
11 Perth Road
Dundee
DD1 4HN
United Kingdom
+44 (0)1382 384664
J.Houston@dundee.ac.uk

Sponsor type

University/education

Website

http://www.dundee.ac.uk/

Funders

Funder type

Charity

Funder name

Heart Research UK (UK)

Alternative name(s)

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

2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/24075759

Publication citations

  1. Results

    Witham MD, Adams F, Kabir G, Kennedy G, Belch JJ, Khan F, Effect of short-term vitamin D supplementation on markers of vascular health in South Asian women living in the UK--a randomised controlled trial., Atherosclerosis, 2013, 230, 2, 293-299, doi: 10.1016/j.atherosclerosis.2013.08.005.

Additional files

Editorial Notes