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

A Prospective Trial on the Effects of Vitamin D Supplementation on 25(OH)D, Body Composition and Injury 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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Dietary supplement: Vitamin D; Dietary supplement: Placebo

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 Type: Interventional
• Enrollment (Actual): 45
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • Kentucky
    • Lexington, Kentucky, United States, 40506
      • University of Kentucky

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vitamin D	Dietary supplement: Vitamin D; 4000 IU of Vitamin D daily for 6 months; Other Names: 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 Names: Placebo by Nature Made by Pharmavite LLC

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inflammatory Cytokines	Baselineand Endpoint measures include a blood draw inflammatory cytokines (TNF alpha, IL1-B, IL6)	Baseline and Enpoint
Bone Turnover Markers	Baseline, Midpoint, and Endpoint measures include a blood draw for bone turnover markers (BSAP, NTx).	Baseline, Midpoint, Endpoint
DXA Body Composition	Baseline and Endpoint measures include Body Composition measures (DXA) for fat, muscle and bone composition	Baseline and Endpoint
Vitamin D Lifestyle Survey	Baseline, Midpoint, and Endpoint measures include a behavioral survey for estimating 25(OH)D status (solar exposure, food and other supplemental intake)	Baseline, Midpoint, Endpoint
injury and illness incidence	We will track injury and illness type and incidence over the course of the 6 month intervention	6 months

Collaborators and Investigators

• Sponsor: University of Kentucky
• Investigators: 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

Study record dates

Study Major Dates

• Study Start: August 1, 2011
• Primary Completion (Actual): March 1, 2012
• Study Completion (Actual): March 1, 2012

Study Registration Dates

• First Submitted: November 29, 2011
• First Submitted That Met QC Criteria: December 6, 2011
• First Posted (Estimate): December 8, 2011

Study Record Updates

• Last Update Posted (Estimate): February 25, 2013
• Last Update Submitted That Met QC Criteria: February 22, 2013
• Last Verified: February 1, 2013

More Information

Terms related to this study

• Keywords: Vitamin D; injury; body composition; athletes; inflammatory markers; Vitamin D status in athletes; 25(OH)D; illness
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Micronutrients; Bone Density Conservation Agents; Calcium-Regulating Hormones and Agents; Vitamin D; Cholecalciferol; Vitamins; Ergocalciferols
• Other Study ID Numbers: UL1RR033173 (U.S. NIH Grant/Contract)