The Effects of Vitamin D Supplementation on Aerobic Fitness in Athletes

NCT02278172 | Completed Phase 4

• 1 other identifier: REC14.0087
• Study Type: interventional
• Target: 44
• Locations: 1 country
• Sites: 1

Brief Summary

The primary aim of the study is to identify if vitamin D3 supplementation influences VO2max in athletes. Secondary aims are to determine if vitamin D3 supplementation impacts on measures of muscle function, lung function, body composition, immune function and the self-reported incidence of upper respiratory tract infection. This double-blind, randomised, placebo-controlled trial is of parallel design and will aim to recruit a total of 50 athletes randomised into either a placebo or treatment group for a 12-week intervention.

Conditions

Aerobic Fitness (VO2max)

Keywords

vitamin D; athletes; fitness

Outcome Measures

Primary Outcomes (1)

• Aerobic fitness (VO2max)

  A medical screening questionnaire will be completed prior to the test. Athletes resting blood pressure will be measured twice to rule out resting hypertension. After a standardised warm-up, starting speed will be 8/km/hr at 1% incline, until 17/km/hr, after which incline will increase by 1% every minute until VO2max is met. A metabolic cart (Metalyzer 3B) will measure the athlete's ventilation (oxygen uptake and carbon dioxide output) throughout the test. The test will be terminated when two of the following criterion are met\*: Respiratory exchange ratio reaches/exceeds 1.15 AND VO2 plateau observed OR Heart rate within 10bpm of age-predicted maximum \* Except when volitional exhaustion occurs Athletes will be asked to refrain from strenuous activity for 24 hours prior to VO2max testing in order to control for last bout effects. Post-exercise lactate concentration (age and gender adjusted) will further-verify that VO2max was attained using a Lactate Pro device.

  At baseline and at 12-weeks

Secondary Outcomes (9)

• Hand grip strength

  At baseline and at 12-weeks

• Vertical jump height

  At baseline and at 12-weeks

• Lung function

  At baseline and at 12-weeks

• Nutrient intake

  At baseline only/ at baseline and at 12-weeks

• Self-reported upper respiratory illness

  Once per week up to week 12

Study Arms (2)

Vitamin D3 3000IU (75μg)

ACTIVE COMPARATOR

Treatment solution delivered via oral spray once daily for 12-weeks

Dietary Supplement: Vitamin D

Placebo

PLACEBO COMPARATOR

Placebo solution delivered via oral spray once daily for 12-weeks

Dietary Supplement: Placebo

Interventions

Vitamin D DIETARY_SUPPLEMENT

3000IU (75 μg) vitamin D in a commercially available oral spray solution

Also known as: cholecalciferol, vitamin D3

Vitamin D3 3000IU (75μg)

Placebo DIETARY_SUPPLEMENT

Placebo oral spray solution manufactured to mimic the vitamin D oral spray

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Athletes whose sport does not primarily consist of an anaerobic component
• Apparently healthy
• Over the age of 18

You may not qualify if:

• Resting arterial hypertension
• Individuals who are not an athlete at a University/local sports team
• Athletes who predominantly utilise anaerobic energy systems
• Athletes under the age of 18
• Those that have consumed a supplement containing vitamin D (greater than 400IU/day) or iron supplements for up to 30 days prior to starting the study
• Those with health conditions identified by the screening questionnaire
• Individuals that are on prescribed medication that is known to affect vitamin D metabolism
• Those following a vegan diet
• Those with a physical disability that would prevent successful completion of the exercise test
• Those who have either had a sun holiday in the 4 weeks prior to starting the study
• Those planning a sun holiday during the intervention period

Sponsors & Collaborators

• University of Ulster: lead
• Northern Ireland Executive: collaborator

Study Sites (1)

Human Intervention Studies Unit (HISU), University of Ulster

Coleraine, Londonderry, BT52 1SA, United Kingdom

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

• Pamela J Magee, PhD

  University of Ulster

  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: PRINCIPAL INVESTIGATOR
• PI Title: Dr Pamela Magee

Study Record Dates

• First Submitted: October 27, 2014
• First Posted: October 29, 2014
• Study Start: October 1, 2014
• Primary Completion: April 1, 2015
• Study Completion: April 1, 2015
• Last Updated: May 25, 2016

Record last verified: 2016-05

Locations

GB (1)