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D-Light Intervention (D-Light)

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ClinicalTrials.gov Identifier: NCT02495584
Recruitment Status : Completed
First Posted : July 13, 2015
Last Update Posted : January 15, 2016
Sponsor:
Collaborators:
Dairy Council for Northern Ireland
Agri-food & Biosciences Institute
Center for Nutrition and Health, RIVM (The Netherlands)
Information provided by (Responsible Party):
University of Ulster

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
25-hydroxyvitamin D Concentration (Vitamin D Status) Dietary Supplement: Fortified milk (10µg vitamin D3) Dietary Supplement: Unfortified milk (placebo) Dietary Supplement: 10µg vitamin D3 supplement Dietary Supplement: Placebo supplement Not Applicable

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 52 participants
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Prevention
Official Title: 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
Study Start Date : September 2014
Actual Primary Completion Date : October 2015
Actual Study Completion Date : October 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D
Drug Information available for: Vitamin D

Arm Intervention/treatment
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: Unfortified milk (placebo)
Dietary Supplement: 10µg vitamin D3 supplement
Placebo Comparator: Treatment 4
500ml unfortified milk (placebo) +1 supplement capsule (placebo) daily for 24 weeks
Dietary Supplement: Unfortified milk (placebo)
Dietary Supplement: Placebo supplement



Primary Outcome Measures :
  1. Change in vitamin D status (25-hydroxyvitamin D serum concentration) [ Time Frame: Baseline + post-intervention (24weeks) ]
    Blood analysis


Secondary Outcome Measures :
  1. Change in body composition [ Time Frame: Baseline + post-intervention (24weeks) ]
    Assessed by dual energy X-ray absorptiometry (DXA)

  2. Change in muscle strength [ Time Frame: Baseline + post-intervention (24weeks) ]
    Assessed by grip strength

  3. Change in inflammation status [ Time Frame: Baseline + post-intervention (24weeks) ]
    Blood analysis

  4. Change in lipid profile [ Time Frame: Baseline + post-intervention (24weeks) ]
    Blood analysis

  5. Change in glucose levels [ Time Frame: Baseline + post-intervention (24weeks) ]
    Blood analysis

  6. Change in insulin concentrations [ Time Frame: Baseline + post-intervention (24weeks) ]
    Blood analysis


Other Outcome Measures:
  1. UV exposure (follow-up) [ Time Frame: 8 weeks post-intervention (32-40 weeks) ]
    Assessed by UV wrist monitors



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   20 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02495584


Locations
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United Kingdom
Human Intervention Studies Unit
Coleraine, United Kingdom, BT52 1SA
Sponsors and Collaborators
University of Ulster
Dairy Council for Northern Ireland
Agri-food & Biosciences Institute
Center for Nutrition and Health, RIVM (The Netherlands)
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Responsible Party: University of Ulster
ClinicalTrials.gov Identifier: NCT02495584    
Other Study ID Numbers: 13/NI/0091
First Posted: July 13, 2015    Key Record Dates
Last Update Posted: January 15, 2016
Last Verified: January 2016
Keywords provided by University of Ulster:
Vitamin D
Fortified milk
Supplementation
UV exposure
Winter
Healthy adults
Body Composition
Muscle function
Blood pressure
Additional relevant MeSH terms:
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Vitamin D
Ergocalciferols
Cholecalciferol
Vitamins
Micronutrients
Nutrients
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents
Calcium-Regulating Hormones and Agents