Sunlight exposure and vitamin D in the ageing population

ISRCTN ISRCTN14201277
DOI https://doi.org/10.1186/ISRCTN14201277
Secondary identifying numbers 30640
Submission date
07/11/2016
Registration date
16/11/2016
Last edited
14/01/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Skin and Connective Tissue Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Vitamin D is essential for healthy bones and muscles, particularly in older people where low levels contribute to weak bones and falls. Sunlight exposure of the skin is the major source of vitamin D. Older adults may have reduced capacity of the skin to make vitamin D, but it is unknown how this, or their sun-exposure behaviour, influences their vitamin D levels. This study will examine vitamin D production in 65-84 year-olds following exposure to low amounts of simulated sunlight that mimic national policy on UK summer exposures. In addition, it will compare naturally-gained sunlight exposure levels and vitamin D. The aim of this study is to find out whether exposure to simulated (artificial) summer sunlight while casually dressed can produce a sufficient rise in vitamin D levels in older adults compared to natural sunlight exposure.

Who can participate?
Healthy white Caucasian older adults.

What does the study involve?
In the first part of the study, participants are randomly allocated to one of two groups, with six times more participants being allocated to the first group. Those in the first group are exposed to artificial sunlight containing UV radiation (UVR) three times per week for six weeks. Those in the second group are exposed to sham light (artificial sunlight with the UVR filtered out) three times a week for six weeks. In both groups, the UVR exposure is performed in a horizontal irradiation cabinet (like a tanning bed) and takes approximately 6 minutes. Participants are followed up during the 6 week course of UVR exposures, providing a blood sample at the beginning of each week, as well as being asked to keep a record of their diet for the first and sixth week of the study to assess dietary vitamin D intake.
In the second part of the study, for one week in September and January participants are asked to wear a special badge to measure their sunlight exposure. In the same week, participants use a simple diary to record their time spent outdoors, clothing and sunscreen use, and complete a diet log to estimate dietary vitamin D intake. The following week, participants attend the Photobiology Unit to provide a blood sample to test for vitamin D levels.

What are the possible benefits and risks of participating?
There are no direct benefits or risks involved with participating.

Where is the study run from?
Salford Royal Hospital (UK)

When is the study starting and how long is it expected to run for?
March 2015 to December 2017

Who is funding the study?
Dunhill Medical Trust (UK)

Who is the main contact?
Dr Mark Farrar
mark.farrar@manchester.ac.uk

Contact information

Dr Mark Farrar
Scientific

Photobiology Unit
Dermatology Centre
Salford Royal Hospital
Stott Lane
Salford
M6 8HD
United Kingdom

ORCiD logoORCID ID 0000-0001-8602-7279
Phone +44 161 2060214
Email mark.farrar@manchester.ac.uk

Study information

Study designRandomised; Both; Design type: Prevention, Education or Self-Management, Complex Intervention, Cohort study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Not specified
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleSunlight exposure and vitamin D status in the UK's ageing population
Study objectivesThe aim of this study is to determine if exposure to simulated summer sunlight while casually dressed can produce a sufficient rise in vitamin D levels to avoid deficiency in older adults (65 years and over) in comparison to vitamin D acquired through natural sunlight exposure.
Ethics approval(s)1. University of Manchester Research Ethics Committee 1, 05/05/2016, ref: UREC16143
2. North West (Haydock) Research Ethics Committee, 05/07/2016, ref: 16/NW/0467
Health condition(s) or problem(s) studiedSpecialty: Dermatology, Primary sub-specialty: Dermatology; UKCRC code/ Disease: Musculoskeletal/ Disorders of bone density and structure
InterventionInterventional study:
Participants are randomised to one of two groups (active or control) with a 6:1 allocation using a computer-generated randomisation sequence.

Active group: Participants receive exposure 1.3 standard erythemal doses of solar-simulated ultraviolet radiation (UVR) three times per week for six weeks.

Control group: Participants receive sham exposure of irradiation cabinet fitted with filters to block UVR three times per week for six weeks.

In both groups, each UVR exposure is performed in a horizontal irradiation cabinet and takes approximately 6 minutes. Participants wear clothing that reveals the arms and lower legs during the exposure.

Participants are followed up during the 6 week course of UVR exposures, providing a blood sample at the beginning of each week. Participants also complete a diet log during the first and last week of the course to estimate dietary vitamin D intake.

Observational study:
For one week in each of September and January, participants will wear a dosimeter badge to measure their sunlight exposure. In the same week, subjects will use a simple diary to record their time spent outdoors, clothing and sunscreen use, and complete a diet log to estimate dietary vitamin D intake. The following week, subjects will attend the Photobiology Unit to provide a blood sample. The observation period is one week with follow-up one week later.
Intervention typeOther
Primary outcome measureSerum 25-hydroxyvitamin D concentration measured by liquid chromatography/tandem mass-spectrometry at baseline, 1, 2, 3, 4, 5 and 6 weeks (intervention study) and in September and January (observation study).
Secondary outcome measures1. Serum parathyroid hormone measured at baseline and week 6 (intervention) and in September and January (observation)
2. Bone turnover markers measured at baseline and week 6 (intervention) and in September and January (observation)
3. Dietary vitamin D intake assessed thorough diet logs at baseline and week 6 (intervention) and in September and January (observation)
4. Sun exposure measured by dosimeter badges and diaries in September and January (observation only)
Overall study start date01/03/2015
Completion date31/05/2019

Eligibility

Participant type(s)Patient
Age groupSenior
SexBoth
Target number of participantsPlanned Sample Size: 125; UK Sample Size: 125
Key inclusion criteria1. Healthy, ambulant, male and female adults aged 65-84 years
2. White Caucasian
3. Willing and capable of participating to the extent and degree required by the protocol
Key exclusion criteria1. Taking medication influencing vitamin D, or that is bone-active or photoactive 
2. History of sunbathing/sunbed use within 3 months
3. History of skin cancer or photosensitivity
4. Taking any vitamin D, fish oil or calcium supplements (intervention study only)
Date of first enrolment01/06/2016
Date of final enrolment01/09/2017

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Salford Royal Hospital
Photobiology Unit
Stott Lane
Salford
M6 8HD
United Kingdom

Sponsor information

University of Manchester
Hospital/treatment centre

FBMH Research Office
3.53 Simon Building
Oxford Road
Manchester
M13 9PL
England
United Kingdom

ROR logo "ROR" https://ror.org/027m9bs27

Funders

Funder type

Charity

Dunhill Medical Trust

No information available

Results and Publications

Intention to publish date31/12/2021
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planOutcomes will be communicated to the research community through publication in high-impact open access general and specialist journals within one year of the study end-date. Findings will be communicated to wider audiences via relevant charities and societies promoting research and public education, including the Dunhill Medical Trust (funder). Communication of findings to UK government bodies formulating health policy and guidance relating to vitamin D acquisition will be expedited through the investigatory team’s several active roles on relevant public health and medical committees.
IPD sharing planThe datasets generated during and/or analysed during the current study are/will be available upon request from the Principal Investigator Prof Lesley Rhodes (Lesley.e.rhodes@manchester.ac.uk)

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
HRA research summary 28/06/2023 No No

Editorial Notes

14/01/2021: The intention to publish date was changed from 31/05/2020 to 31/12/2021.
22/10/2019: The following changes were made to the trial record:
1. The overall end date was changed from 01/12/2017 to 31/05/2019.
2. The intention to publish date was changed from 01/12/2018 to 31/05/2020.