Condition category
Digestive System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Irritable bowel syndrome (IBS) is a common condition that affects the digestive system. IBS is usually experienced for a life-time and symptoms include bloating, constipation, diarrhoea, and stomach cramps. These symptoms can affect a person for days, weeks or even months at a time. This can be a difficult condition to live with and can have a large impact on a person's everyday life. The cause of IBS is unknown, although it is thought to be associated with a family history of IBS, stress and certain foods. IBS cannot be cured but can often be managed with medication and dietary changes. Research has shown that people with IBS also have low levels of vitamin D. The aim of this study is to assess whether increasing vitamin D levels in people with IBS helps to improve their symptoms.

Who can participate?
Men and women aged between 18-60 years with a diagnosis of IBS

What does the study involve?
Each person will be put into one of two groups to receive either a vitamin D or placebo (dummy) supplement mouth spray to be taken each day for 12 weeks. All participants will be asked to fill in a total of seven Symptom Severity Questionnaires (SSS-IBS), two Quality of Life Questionnaires (QoL), and one Food Frequency Questionnaire (FFQ). All participants will have blood samples taken at the first and last appointment. This will be done with a finger prick blood test kit. All participants will take a mouth spray, only half of the volunteers will get the active (real) vitamin D supplement.

What are the possible benefits and risks of participating?
The supplement that participants will be taking are well under the advised limit, however, there is a very unlikely risk of vitamin D levels going too high. Side effects of excessive vitamin D levels include raised calcium blood levels, nausea and constipation. Participants will be monitored closely for any problems they may experience during the study. There will also be small risks involved with taking blood samples, such as pain around the site of
insertion, as with any blood test. These risks will be clearly explained to the participants. The finger prick only occurs twice; at the start and end of the 12 weeks. Volunteers on the active (real) supplement may benefit from their participation in the research as they may see an improvement in their symptoms and all volunteers will receive a £50.00 voucher as a thank you for their participation.

Where is the study run from?
This study will be run from the Medical School at the University of Sheffield.

When is the study starting and how long is it expected to run for?
Recruitment will occur three times over the next 2 years. The first two rounds will occur in the winter periods (Jan-Apr) in 2018 and 2019 in the local area with the goal of reaching 160 volunteers. A further recruitment will take place in 2019 to recruit volunteers from outside the local area and will use postal and online methods to complete the research. The anticipated start date of the trial is September 2018 and will run until September 2020.

Who is funding the study?
This research has been part funded by the University of Sheffield and by an industry partner BetterYou.

Who is the main contact?
The main person to contact regarding this study is Dr Bernard Corfe, Senior Lecturer in Oncology Principal Investigator in Molecular Gastroenterology, Fellow of Insigneo,

Trial website

Contact information



Primary contact

Dr Bernard Corfe


Contact details

The University of Sheffield
The Medical School
Beech Hill Road
S10 2RX
United Kingdom
S10 2RX
United Kingdom



Additional contact

Mrs Claire Williams


Contact details

The Medical School
Beech Hill Road
S10 2RX
United Kingdom
S10 2RX
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

To assess whether an increase of vitamin D in subjects with irritable bowel syndrome improves symptoms (D-IBS)



Study hypothesis

The hypothesis is that a 3000 IU vitamin D supplement will reduce symptom severity and improve quality of life compared with placebo in participants with IBS, based on self-reported outcomes.

Ethics approval

University of Sheffield,19/12/2017, Registration number: 160216727, Reference Number: 016753

Study design

Double-blind placebo-controlled two-arm parallel-design study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

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


Irritable bowel syndrome


Patients administered 3000 IU (75 microg) vitamin D sublingual spray or placebo sublingual spray once daily for 12 weeks

Intervention type



Drug names

Primary outcome measure

Reduction in Total Symptom Severity for IBS, measured by visual analogue scale (VAS) at baseline and exit, and a cumulative measure taken fortnightly across the intervention period (weeks 0, 2, 4, 6, 8, 10, 12).

Secondary outcome measures

1. Serum vitamin D concentrations will be assessed at baseline and exit: bloodspots will be taken and analysed by liquid chromatography-mass spectrometry .
2. Quality of life is assessed at baseline and exit using The Irritable Bowel Syndrome - Quality of Life questionnaire (IBS-QOL)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Clinical diagnosis of IBS using the ROME criteria and reaching severity score of 150 on SSS scale at time of recruitment. As some participants may have active IBS but historic diagnosis, no one version of ROME is specified as long as a clinical diagnosis was made at the time.

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Pregnant or lactating
2. Regular use of nutritional supplements
3. BMI >30 kg/m2
4. BMI <18 kg/m2
5. Any history of gastrointestinal disorders (Crohn’s disease, ulcerative colitis, diverticulitis)
6. Diabetes mellitus

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

The University of Sheffield
The Medical School Beech Hill Road Sheffield S10 2RX United Kingdom
S10 2RX
United Kingdom

Sponsor information


The University of Sheffield

Sponsor details

The Medical School
Beech Hill Road
Oncology and Metabolism
S10 2RX
United Kingdom

Sponsor type




Funder type

Not defined

Funder name


Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

The University of Sheffield

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal

IPD sharing statement
As there are no repositories for trial data, we will share an annotated, anonymised spreadsheet on request following publication of any papers.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes