Vitamin D Deficiency Clinical Trial
Official title:
The Interrelationship Between Vitamin D, Bone, Illness, Injury and Its Impact on Exercise Performance
Athletes and active individuals have been identified as an at-risk group for a low vitamin D
status, specifically those residing in countries of higher latitude (such as the United
Kingdom). This especially applies to those who train indoors for their sport, this is because
Vitamin D is primarily produced following skin exposure to ultraviolet B (UVB) exposure.
Vitamin D is essential for the maintenance of optimal bone and musculoskeletal health. It has
also been suggested to play a role in the prevention of illness incidence, such as in upper
respiratory tract infections (URTI). More recent research has indicated that an improved
Vitamin D status may also play a role in enhancing exercise performance. Therefore, having a
poor vitamin D status could negatively impact athletic training and competition. The purpose
of this study is to evaluate the prevalence of vitamin D deficiency in university athletes
and inactive controls in spring and autumn.
During this study the subjects will be asked to visit the labs on two occasions, at the
beginning of the study for baseline measurements, and again on two occasions at the end of
the study. Participants will have the following outcomes assessed: Sport performance
(vertical jump height, muscular strength and aerobic fitness), peripheral Quantitative
Computed Tomography (pQCT) scan of the bone mineral composition of the tibia, total body
composition via Dual Energy X-ray Absorptiometry (DEXA),total and hip/femoral head bone
mineral density and content to assess fracture risk via DEXA. Serum 25(OH)D levels (≈15ml of
whole blood will be collected for these measurements. Dietary intake using self-reported food
diaries. In addition illness and injury incidence will be recorded daily throughout the study
in a booklet provided to the participants.Throughout the trial, the participants will be
contacted via telephone/ email on a monthly basis to discuss any issues and maintain good
communication.
During this study the subjects will be asked to visit the labs on 4 different occasions.
There will be two occasions, at the beginning of the study for baseline measurements, and
again on two occasions at the end of the study.
Data collection will take place across two testing sessions (separated by ~24 - 72 hrs) in
the Autumn and Spring period.
Session 1
- Peripheral Quantitative Computed Tomography (pQCT) scan of the bone mineral composition
of the tibia.
- Total and percentage lean and fat mass and total bone mineral density via Dual Energy
X-ray Absorptiometry (DEXA).
- Sport performance: Vertical jump height and maximal oxygen uptake (VO2 max) test.
Session 2
- Fasting serum 25(OH)D levels, lipid profile, glucose, insulin, serum calcium, albumin,
parathyroid hormone, C- terminal telopeptide (CTX), full blood count, kidney, thyroid
and liver function (≈15ml of whole blood will be collected for these measurements).
- Collection of self-reported food diaries to assess dietary intake
- Sport performance: muscular strength
Aerobic fitness will be tested using a VO2 max exercise protocol using a stationary cycle
ergometer, the participants will be expected to perform this to maximal effort or exhaustion.
The test will consist of progressive increments in cycling workload (power output, W) until
volitional fatigue. The test will take about 8 - 12 minutes to complete and is dependent upon
the fitness of the participants. This will take place in the Sport & Exercise Science
laboratories based in the Clinical Investigation Unit (22AX00). All subjects will be
supervised during exercise at all times and will implement an adequate warm-up and cool-down
to minimize the risk of injury. Staff will be on hand throughout the testing trained
adequately in basic life support (including defibrillation).
Muscular strength assessments will be performed at the Surrey Human Performance Institute.
Muscular strength of the knee extensor and handgrip muscles will be determined using an
Isokinetic Dynamometer and a handgrip dynamometer respectively. For each assessment three
maximal effort isometric contractions will be performed and peak torque (nM) and strength
(kg) will be recorded. Muscular power will be assessed through performance of a
countermovement jump (CMJ).
Body composition (absolute and relative amount of lean and fat mass), whole body bone mineral
density and hip and femur bone mineral density will be measured with the use of DEXA (located
in the Sport & Exercise Science laboratories based in the Clinical Investigation Unit). Two
scans will be performed: one for the assessment of whole body bone mineral density and body
composition, and the other scan is performed to specifically assess fracture risk by scanning
the hip and femoral head. Effective exposure doses for these scans are ~8uSv and ~4uSv
respectively. The total effective dose is depending on the size ('thickness' & height) of the
volunteer and is approximately equivalent to the cosmic radiation exposure received in 45min
of a transatlantic flight, or the radiation dose received on eating 80g of Brazil nuts
(Health Protection Agency).
Bone mineral content of the tibia will be assessed using pQCT and this will be correlated to
bone mineral density data obtained from DEXA. One scan will be performed and effective
exposure doses will be between 1.5-1.8uSv which is comparable to 10 min on a transatlantic
flight or one handful of Brazil nuts. The estimated total exposure dose for a single subject
during the entire study is ~28uSv which is the same level of exposure as an average UK
citizen is exposed to over the course of 4 days via background radiation.
Results of the body composition, bone mineral density, jump height, muscular strength,
aerobic fitness (maximal oxygen uptake: VO2max) and dietary intake from the self-reported
food diaries will be made available to the subjects upon request. The results from the blood
analysis will be reported to the subject if there are any health concerns raised. If the
results are within healthy ranges the participants will not be contacted unless specifically
requested for this information. The investigators will not be contacting their GPs if there
are any concerns raised in the study however it will be stressed that participants should
contact a GP to discuss the results found.
Upon commencing the study, the participants will be required to track their incidence of
illness and training habits during the 20-week experimental period between baseline and
conclusion measurements. Throughout this period the incidence of illness and days trained
during the months must be recorded in a check-list booklet, which will be provided. An email
reminder will be sent to prompt all participants to complete these booklets on a daily basis
during the experimental period, this should only take 1-2 minutes every evening. Throughout
the duration of the trial, the participants will be contacted via telephone/ email on a
monthly basis to discuss any issues and maintain good communication.
;
Status | Clinical Trial | Phase | |
---|---|---|---|
Active, not recruiting |
NCT04244474 -
Effect of Vitamin D Supplementation on Improvement of Pneumonic Children
|
Phase 1/Phase 2 | |
Recruiting |
NCT05459298 -
ViDES Trial (Vitamin D Extra Supplementation)
|
N/A | |
Suspended |
NCT03652987 -
Endocrine and Menstrual Disturbances in Women With Polycystic Ovary Syndrome (PCOS)
|
||
Completed |
NCT04476511 -
The Efficacy and the Safety of Vitamin D3 30,000 IU for Loading Dose Schedules
|
Phase 3 | |
Completed |
NCT03920150 -
Vitamin D 24'000 IU for Oral Intermittent Supplementation
|
Phase 3 | |
Completed |
NCT03264625 -
The Effects of Oral Vitamin D Supplementation on the Prevention of Peritoneal Dialysis-related Peritonitis
|
Phase 2 | |
Completed |
NCT04183257 -
Effect of Escalating Oral Vitamin D Replacement on HOMA-IR in Vitamin D Deficient Type 2 Diabetics
|
Phase 4 | |
Recruiting |
NCT05084248 -
Vitamin D Deficiency in Adults Following a Major Burn Injury
|
Phase 4 | |
Completed |
NCT05506696 -
Vitamin D Supplementation Study
|
N/A | |
Completed |
NCT00092066 -
A Study to Evaluate the Safety, Tolerability, and Efficacy of an Investigational Drug and Dietary Supplement in Men and Postmenopausal Women With Osteoporosis (0217A-227)
|
Phase 3 | |
Completed |
NCT03234218 -
Vitamin D Levels in Liver Transplantation Recipients Prospective Observational Study
|
||
Completed |
NCT02714361 -
A Study to Investigate the Effect of Vitamin D3 Supplementation on Iron Status in Iron Deficient Women
|
N/A | |
Completed |
NCT03203382 -
Corneal Nerve Structure in Sjogren's
|
||
Completed |
NCT02906319 -
Vitamin D and HbA1c Levels in Diabetic Patients With CKD
|
N/A | |
Completed |
NCT02118129 -
Vitamin D Among Young Adults: an Intervention Study Using a Mobile 'App'.
|
N/A | |
Completed |
NCT02275650 -
The Role of Narrowband Ultraviolet B Exposure in the Maintenance of Vitamin D Levels During Winter
|
N/A | |
Not yet recruiting |
NCT01419821 -
Vitamin D and Its Affect on Growth Rates and Bone Mineral Density Until Age 5
|
N/A | |
Completed |
NCT02187146 -
The Effects of Serum Vitamin D and IVF Outcome
|
N/A | |
Completed |
NCT01688102 -
The Effect of Oral Vitamin D Versus Narrow-Band UV-B Exposure on the Lipid Profile
|
N/A | |
Completed |
NCT01741181 -
Vitamin D Supplementation in Patients With Diabetes Mellitus Type 2
|
Phase 4 |