The Effect of Vitamin D Supplementation on Muscle Power in Elite Cyclist

NCT01518725 | Completed Phase 4 DMC

• 1 other identifier: ED11189
• Study Type: interventional
• Target: 103
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to evaluate the change in vitamin D status with the change in muscular strength and muscular power in highly trained athletes over a 9-month study period. The investigators hypothesize that the greatest muscular strength and power gains will be demonstrated in the athletes who achieve and maintain a 25(OH)-D \> 50 ng/mL (but \< 100 ng/mL) over the 6 month study duration. This hypothesis will be tested by carrying out the following specific aims: Aim 1. to determine the extent to which increasing serum 25(OH)D to \> 50 ng/mL is associated with improved muscular power by assessing specific performance measures (e.g. Vertical Jump Test and Wingate test) relative to lean body mass; and Aim 2. to examine the correlation between vitamin D status and muscular power over time.

Conditions

Muscle Power

Keywords

Muscle Power; Vitamin D; Vitamins; Cholecalciferol

Outcome Measures

Primary Outcomes (2)

• Change in Vitamin D status from baseline to 3 months and 6 months

  Non fasting blood samples will be used for the evaluation of vitamin D metabolites. Venous blood (\~5 cc) will be collected from the non-dominant arm by a trained phlebotomist, centrifuged at 2,000 rpm and serum stored at -80° C. Two vitamin D metabolites, 25 (OH) D and 1,25 (OH)2 D and serum PTH will be assessed.

  Up to 6 months

• Change in Power Output from baseline to 3 months and 6 months

  Power will be assessed using a Vertical Jump Test and a Wingate Power Test.

  Up to 6 months

Secondary Outcomes (3)

• Sun Exposure Questionnaire

  Up to 6 months

• Skin Tone Measurement

  Up to 6 months

• Food Frequency Questionnaire

  Up to 6 months

Study Arms (2)

Vitamin D Supplementation

EXPERIMENTAL

The vitamin D supplementation will consist of 100 mcg of vitamin D/d, to be taken throughout the day. Participants will achieve 100 mcg by taking 2 x 25 mcg capsules per day. One will be taken at each time point (i.e., morning and evening) throughout the day.

Dietary Supplement: Vitamin D

Gel-like Substance

PLACEBO COMPARATOR

Participants in the placebo group will receive a capsule containing the inactive ingredients that include cellulose and silica to create a gel-like substance

Dietary Supplement: Placebo

Interventions

Vitamin D DIETARY_SUPPLEMENT

The vitamin D supplementation will consist of a capsule of 100 mcg of vitamin D/d, to be taken throughout the day. Participants will achieve 100 mcg by taking 2 x 25 mcg capsules per day. One will be taken at each time point (i.e., morning and evening) throughout the day. They will take the vitamin D supplement for the 6 month intervention period

Also known as: Cholecalciferol

Vitamin D Supplementation

Placebo DIETARY_SUPPLEMENT

Participants in the placebo group will receive a capsule containing the inactive ingredients that include cellulose and silica to create a gel-like substance

Gel-like Substance

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Elite Cyclist (level 1,2 or 3)

You may not qualify if:

• Currently prescribed vitamin D without physician approval to participate in study
• Participants who respond "yes' to PAR-Q and do not get physician approval to participate in study

Sponsors & Collaborators

• Oklahoma State University: lead
• Mid America Athletic Training Association: collaborator

Study Sites (1)

Oklahoma State University

Stillwater, Oklahoma, 74078, United States

Location

MeSH Terms

Interventions

Vitamin D; Cholecalciferol

Intervention Hierarchy (Ancestors)

Secosteroids; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Cholestenes; Cholestanes; Sterols; Membrane Lipids; Lipids

Study Officials

• Rachel A Hildebrand, M.Ed

  Oklahoma State University

  PRINCIPAL INVESTIGATOR

• Brenda Smith, PhD

  Oklahoma State University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 18, 2012
• First Posted: January 26, 2012
• Study Start: January 1, 2012
• Primary Completion: August 1, 2013
• Study Completion: August 1, 2013
• Last Updated: April 29, 2015

Record last verified: 2015-04

Locations

US (1)