Extrait

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 [email protected]

Critère d'inclusion

• Specialty: Dermatology, Primary sub-specialty: Dermatology; UKCRC code/ Disease: Musculoskeletal/ Disorders of bone density and structure

Liens

• isrctn