Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Ms Beverley Maclaughlin


Contact details

Centre for Health Sciences
Abernethy Building 2
Newark Street
E1 2AT
United Kingdom

Additional identifiers

EudraCT number number


Protocol/serial number


Study information

Scientific title

Randomised, multi-centre, double-blind, placebo-controlled prevention trial of vitamin D supplementation in adult and adolescent patients with asthma


Trial of vitamin D supplementation in asthma

Study hypothesis

Asthma is a common chronic inflammatory condition of the airways. Exacerbations of asthma cause significant morbidity and health care use in the UK. They are commonly precipitated by upper respiratory tract infections (URTI). Vitamin D deficiency is also very common in the UK. A growing body of evidence from laboratory and clinical studies suggests that vitamin D supplementation may prevent exacerbations of asthma by enhancing both anti-inflammatory and antimicrobial immune responses. The study null hypothesis is that vitamin D supplementation will not influence time to upper respiratory tract infection or time to severe asthma exacerbation in adult and adolescent patients with asthma.

Ethics approval

MREC approved (ref: 09/H0703/67)

Study design

Multicentre randomised interventional prevention trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

GP practices

Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Topic: Respiratory; Subtopic: Respiratory (all Subtopics); Disease: Respiratory


1. Dietary Supplement: Cholecalciferol + miglyol oil
2. Dietary Supplement: Miglyol oil

Intervention type



Not Applicable

Drug names

Vitamin D

Primary outcome measure

Time to first upper respiratory tract infection at one year

Secondary outcome measures

1. Asthma Control Test Score, measured at one year
2. Time to first severe asthma exacerbation, measured at one year
3. Proportion of participants experiencing hypercalcaemia, measured at one year
4. Time to unscheduled health service use for upper respiratory tract infection or severe asthma exacerbation, measured at one year

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Medical record diagnosis of asthma, treated at British Thoracic Society (BTS) step 2 or above for at least 28 days before first dose of investigational medical product (IMP)
2. One or more of the following, documented within the last 3 years:
2.1. 12% increase in forced expiratory volume in one second (FEV1) after inhalation of 400 micrograms of salbutamol
2.2. 20% diurnal variability in peak expiratory flow
2.3. Methacholine PC20 (concentration of methacholine causing a 20% fall in FEV1) less than 8 g/L
3. Age 12 years and 80 years on day of first dose of IMP, either sex
4. Contactable by telephone and able to attend face-to-face review at 2, 6 and 12 months post-enrolment
5. If a woman of child-bearing potential, is sexually abstinent or has negative pregnancy test within 7 days of recruitment and agrees to use reliable form of contraception until she has completed the study
6. Able to give written informed consent to participate in the study if aged 16 years; if aged less than 16 years, able to give assent, with a parent or guardian able to give written informed consent for the subject to participate in the study

Participant type


Age group




Target number of participants

Planned sample size: 250

Participant exclusion criteria

1. Diagnosis of COPD as defined by the GOLD guidelines
2. Known sarcoidosis, hyperparathyroidism, nephrolithiasis, active tuberculosis, vitamin D intolerance, liver failure, renal failure, terminal illness, lymphoma or other malignancy not in remission for 3 years
3. Any other condition that, in an investigator's judgement, might compromise patient safety or compliance, interfere with evaluation or preclude completion of the study
4. Taking benzothiadiazine derivative, cardiac glycoside, carbamazepine, phenobarbital, phenytoin or primidone
5. Taking dietary supplement containing vitamin D up to 2 months before first dose of IMP
6. Treatment with any investigational medical product or device up to 4 months before first dose of IMP
7. Breastfeeding, pregnant or planning a pregnancy
8. Baseline corrected serum calcium greater than 2.65 mmol/L
9. Baseline serum creatinine greater than 125 micromol/L
10. Smoking history greater than 15 pack-years
11. Severe asthma exacerbation or URTI up to 28 days before first dose of IMP
12. Inability to use spirometer or peak expiratory flow rate (PEFR) meter
13. Inability to complete diary of symptoms and PEFR

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Centre for Health Sciences
E1 2AT
United Kingdom

Sponsor information


Barts and The London NHS Trust (UK)

Sponsor details

Queen Mary's Innovation Centre
5 Walden Street
E1 2EF
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

National Institute for Health Research

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

National government


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

2015 publication in:

Publication citations

Additional files

Editorial Notes

26/03/2018: Publication reference added. number added. 04/02/2016: No publications found, verifying study status with principal investigator