D-Light Intervention (D-Light)

January 14, 2016 updated by: University of Ulster

D-Light Intervention: A Randomised Controlled Human Intervention Study to Assess the Impact of Vitamin D From Milk and Supplements on Functional Health Outcomes and Future Vitamin D Synthesis From UV Exposure

Vitamin D insufficiency has become a global concern, with low vitamin D status associated with bone disorders, cardiovascular disease and certain cancers. The United Kingdom (UK) and Ireland are at particular risk of vitamin D deficiency owing to the northerly latitude, increased use of sunscreen, decreased sun exposure and a high level of cloud cover. A recent survey in the UK showed that more than 50% of UK adults have insufficient vitamin D status, with lower levels noted in the winter months. Variations in vitamin D status have been known to vary between summer and winter, owing to our northern latitude (52-55°N) the Ultraviolet (UV)-B intensity in Northern Ireland is inadequate to promote the dermal synthesis of vitamin D during the winter months, causing us to rely on dietary sources. The aim of this intervention is to investigate the main effects of vitamin D3-fortified milk and supplemental vitamin D3 on vitamin D status and functional health outcomes during the winter, and how this intervention will affect subsequent dermal synthesis of vitamin D from UV exposure. Participants will be recruited from the local community. Blood samples will be collected from each participant at two timepoints (September/October and March/April). Pre- and post-intervention blood pressure, grip strength, height, weight, waist and hip circumferences will be measured, in addition participants will undergo a dual energy x-ray absorptiometry (DXA) scan to assess body composition and bone mineral density. Information on general health, lifestyle, physical activity, dietary intake and typical behaviours in the sun will be collected. Following the dietary intervention, a subset of participants will be invited to participate in a follow-up study, examining UV exposure during the summer months, when they will wear a personal wrist dosimeter for 1 month, complete a sun dairy and provide 2 additional blood samples.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
52

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • Coleraine, United Kingdom, BT52 1SA
        • Human Intervention Studies Unit

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 20-40 years old
  • Apparently healthy
  • Living on the island of Ireland

Exclusion Criteria:

  • Below 20 years and aged 40 years or above
  • Not living on the island of Ireland
  • Pregnant or lactating women and those planning to become pregnant
  • Individuals who have been taking a vitamin D or calcium containing supplement in the previous three months
  • Those with food intolerances or allergies that would affect their ability to consume study milk
  • Individuals following a diet which excludes milk (e.g. vegans)
  • Those with a diagnosed chronic medical condition or on prescribed medication known to effect vitamin D metabolism
  • Those who are planning a sun holiday during the winter months (Oct-Mar)
  • Adults with learning, or any other difficulties that would prevent them from completing the study protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Treatment 1
500ml fortified milk (10µg vitamin D3) +1 supplement capsule (10µg vitamin D3) daily for 24 weeks
Dietary supplement: Fortified milk (10µg vitamin D3)
Dietary supplement: 10µg vitamin D3 supplement
Experimental: Treatment 2
500ml fortified milk (10µg vitamin D3) +1 supplement capsule (placebo) daily for 24 weeks
Dietary supplement: Fortified milk (10µg vitamin D3)
Dietary supplement: Placebo supplement
Experimental: Treatment 3
500ml unfortified milk (placebo) +1 supplement capsule (10µg vitamin D3) daily for 24 weeks
Dietary supplement: 10µg vitamin D3 supplement
Dietary supplement: Unfortified milk (placebo)
Placebo Comparator: Treatment 4
500ml unfortified milk (placebo) +1 supplement capsule (placebo) daily for 24 weeks
Dietary supplement: Placebo supplement
Dietary supplement: Unfortified milk (placebo)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in vitamin D status (25-hydroxyvitamin D serum concentration)
Time Frame: Baseline + post-intervention (24weeks)
Blood analysis
Baseline + post-intervention (24weeks)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in body composition
Time Frame: Baseline + post-intervention (24weeks)
Assessed by dual energy X-ray absorptiometry (DXA)
Baseline + post-intervention (24weeks)
Change in muscle strength
Time Frame: Baseline + post-intervention (24weeks)
Assessed by grip strength
Baseline + post-intervention (24weeks)
Change in inflammation status
Time Frame: Baseline + post-intervention (24weeks)
Blood analysis
Baseline + post-intervention (24weeks)
Change in lipid profile
Time Frame: Baseline + post-intervention (24weeks)
Blood analysis
Baseline + post-intervention (24weeks)
Change in glucose levels
Time Frame: Baseline + post-intervention (24weeks)
Blood analysis
Baseline + post-intervention (24weeks)
Change in insulin concentrations
Time Frame: Baseline + post-intervention (24weeks)
Blood analysis
Baseline + post-intervention (24weeks)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
UV exposure (follow-up)
Time Frame: 8 weeks post-intervention (32-40 weeks)
Assessed by UV wrist monitors
8 weeks post-intervention (32-40 weeks)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Ulster

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Dairy Council for Northern Ireland
Agri-food & Biosciences Institute
Center for Nutrition and Health, RIVM (The Netherlands)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2015

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 1, 2015

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 11, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 10, 2015

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 13, 2015

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 15, 2016

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 14, 2016

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 13/NI/0091

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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