A Prospective Trial on the Effects of Vitamin D Supplementation in Collegiate Swimmers and Divers
Objective 1: Determine if Vitamin D supplementation can improve body composition, reduce injuries and illnesses, and improve performance in collegiate swimmers and divers.
Objective 2: Examine how baseline Vitamin D levels predict outcome variables over the course of the intervention period.
|Healthy||Dietary Supplement: Vitamin D Dietary Supplement: Placebo||Phase 3|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
|Official Title:||A Prospective Trial on the Effects of Vitamin D Supplementation on 25(OH)D, Body Composition and Injury in Collegiate Swimmers and Divers|
- 25(OH)D) [ Time Frame: 3 measurement periods over 6 months ]Baseline, Midpoint, and Endpoint measures include a blood draw for 25(OH)D status.
- Inflammatory Cytokines [ Time Frame: Baseline and Enpoint ]Baselineand Endpoint measures include a blood draw inflammatory cytokines (TNF alpha, IL1-B, IL6)
- Bone Turnover Markers [ Time Frame: Baseline, Midpoint, Endpoint ]Baseline, Midpoint, and Endpoint measures include a blood draw for bone turnover markers (BSAP, NTx).
- DXA Body Composition [ Time Frame: Baseline and Endpoint ]Baseline and Endpoint measures include Body Composition measures (DXA) for fat, muscle and bone composition
- Vitamin D Lifestyle Survey [ Time Frame: Baseline, Midpoint, Endpoint ]Baseline, Midpoint, and Endpoint measures include a behavioral survey for estimating 25(OH)D status (solar exposure, food and other supplemental intake)
- injury and illness incidence [ Time Frame: 6 months ]We will track injury and illness type and incidence over the course of the 6 month intervention
|Study Start Date:||August 2011|
|Study Completion Date:||March 2012|
|Primary Completion Date:||March 2012 (Final data collection date for primary outcome measure)|
Experimental: Vitamin D
Dietary Supplement: Vitamin D
4000 IU of Vitamin D daily for 6 months
Other Name: Vitamin D by Nature Made by Pharmavite LLC
Placebo Comparator: Oil pill
Contains vegetable and soybean oil supplied by Nature Made by Pharmavite LLC located in Northridge, CA and is United States Pharmacopeia (USP) certified.
Dietary Supplement: Placebo
Acts as a control for the Vitamin D intervention
Other Name: Placebo by Nature Made by Pharmavite LLC
The investigators plan to recruit from approximately 45 male and female University of Kentucky Swimmers and Divers, at least 18 years of age in August 2011. Approximately equal numbers of men and women will be recruited. The entire athletic team(s) will be recruited. With a conservative dropout rate of 30%, the investigators final sample size should be approximately 22 participants (per group).Following baseline measures, participants will be randomized to one of two groups (Vitamin D 4000 IU or Placebo control) and monitored over the course of their athletic season. Measurements will be repeated at Midpoint (3 months) and Endpoint (6 months).
Participants will have no recent history of Vitamin D supplementation beyond what is normally found in a multivitamin (400 IUs).
Following the informed consent process a medical history and Vitamin D questionnaire (screenings), and urine pregnancy test (for female athletes) will be administered prior to more invasive baseline testing procedures (blood draw and DXA). A blood draw will then be conducted at baseline, midpoint and endpoint. Collected blood for the purposes of this study will assess Vitamin D status (25(OH)D), parathyroid hormone, ionized calcium, bone turnover markers, and inflammatory cytokines. A Vitamin D lifestyle questionnaire will be administered at all 3 time points and incidence of illness and injury will be documented over 6 months following randomization. DXA measures will only occur at Baseline and Endpoint.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01488227
|United States, Kentucky|
|University of Kentucky|
|Lexington, Kentucky, United States, 40506|
|Study Director:||Maja Redzic, B.S.||University of Kentucky|
|Study Director:||Regina M Lewis, B.S.||University of Kentucky|
|Principal Investigator:||David T Thomas, PhD||University of Kentucky|