Vitamin D Status
Conditions
Keywords
Vitamin D deficiency, Simulated sunlight radiation, Oral vitamin D3
Brief summary
The purpose of this study is to examine the effect of vitamin D supplementation on vitamin D status, immunity and physical performance.
Detailed description
Vitamin D plays a key role in bone mineralisation and has been linked to immune defence maintenance and muscle function. Vitamin D is primarily obtained from endogenous synthesis in response to skin sunlight exposure and follows a seasonal pattern; whereby, vitamin D levels peak at the end of the summer and fall to a trough during winter. If winter vitamin D levels can be increased to match those found in summer using supplementation, it is proposed sufficient vitamin D levels will improve physical performance and reduce susceptibility to illness in military recruits.
Interventions
DIETARY_SUPPLEMENTOral Vitamin D3
DIETARY_SUPPLEMENTPlacebo Oral Vitamin D3
RADIATIONSolar simulated radiation (SSR)
RADIATIONPlacebo SSR
Sponsors
University of East Anglia
University of Manchester
Bangor University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
17 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Passed medical assessment by medical doctor
Exclusion criteria
* Medically deferred by medical doctor * Regular sun bed use * Holiday in a hot sunny climate in \<3 months * Regular vitamin D supplementation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Vitamin D status | Up to 20 months | Circulating 25-hydroxy-vitamin D, 1,25-d OH(OH)D |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Physical performance 1 | Up to 20 months | Vertical Jump height (cm) and peak power output (watts) |
| Physical performance 2 | Up to 20 months | Maximal dynamic lift strength (kg) |
| Physical performance 3 | Up to 20 months | Multi-stage fitness test predicted VO2max (mL/kg/min) |
| Hepatitis B antibody | Up to 20 months | Antibody produced in response to the presence of Hepatitis B antigen (e.g. Hepatitis B vaccine) |
| Mucosal immunity | Up to 20 months | Secretory Immunoglobulin A levels |
Countries
United Kingdom
Contacts
Primary ContactProf Neil Walsh, PhD
Backup ContactDr Julie Greeves, PhD
Outcome results
None listed