A Prospective Trial on the Effects of Vitamin D Supplementation in Collegiate Swimmers and Divers

Phase 3

Completed

• Conditions: Healthy
• Interventions: Dietary Supplement: Vitamin D; Dietary Supplement: Placebo

• Registration Number: NCT01488227
• Lead Sponsor: University of Kentucky

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Study Start: 2011-08
• Study First Submitted: 2011-11-29
• Study First Submitted QC: 2011-12-06
• Study First Posted: 2011-12-08
• Primary Completion: 2012-03
• Study Completion: 2012-03
• Status Verified: 2013-02
• Last Update Submitted: 2013-02-22
• Last Update Posted: 2013-02-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 45

Inclusion Criteria

• University of Kentucky Swimmers and Divers, at least 18 years old.
• No recent history of Vitamin D supplementation beyond 400IU

Exclusion Criteria

• hormone replacement therapy,
• high dose Vitamin D supplementation,
• history of renal disease or kidney stones,
• organ transplantation,
• sarcoidosis,
• parathyroid disease,
• history of high blood calcium levels.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Vitamin D	Vitamin D	Vitamin D
Oil pill	Placebo	Contains vegetable and soybean oil supplied by Nature Made by Pharmavite LLC located in Northridge, CA and is United States Pharmacopeia (USP) certified.

Primary Outcome Measures

Name	Time	Method
25(OH)D)	3 measurement periods over 6 months	Baseline, Midpoint, and Endpoint measures include a blood draw for 25(OH)D status.

Secondary Outcome Measures

Name	Time	Method
Inflammatory Cytokines	Baseline and Enpoint	Baselineand Endpoint measures include a blood draw inflammatory cytokines (TNF alpha, IL1-B, IL6)
Bone Turnover Markers	Baseline, Midpoint, Endpoint	Baseline, Midpoint, and Endpoint measures include a blood draw for bone turnover markers (BSAP, NTx).
DXA Body Composition	Baseline and Endpoint	Baseline and Endpoint measures include Body Composition measures (DXA) for fat, muscle and bone composition
Vitamin D Lifestyle Survey	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	6 months	We will track injury and illness type and incidence over the course of the 6 month intervention

Trial Locations

Locations (1)

University of Kentucky; 🇺🇸 Lexington, Kentucky, United States