Clinical trial NCT02278172: The Effects of Vitamin D Supplementation on Aerobic Fitness in Athletes
Official title: The Effects of Vitamin D Supplementation on VO2max in Athletes: a Randomised, Double-blind, Placebo-controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Aerobic Fitness (VO2max)
Keywords: vitamin D
athletes
fitness
Lead sponsor: University of Ulster
Sponsor class: OTHER
Collaborators: name: Northern Ireland Executive
First posted: 2014-10-29
Enrollment: 44
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Aerobic fitness (VO2max)
timeFrame: At baseline and at 12-weeks
Secondary outcomes:
measure: Hand grip strength
timeFrame: At baseline and at 12-weeks
measure: Vertical jump height
timeFrame: At baseline and at 12-weeks
measure: Lung function
timeFrame: At baseline and at 12-weeks
measure: Nutrient intake
timeFrame: At baseline only/ at baseline and at 12-weeks
measure: Self-reported upper respiratory illness
timeFrame: Once per week up to week 12
measure: Physical activity levels
timeFrame: At baseline and at 12-weeks
measure: Body composition
timeFrame: At baseline and at 12-weeks
measure: Vitamin D status
timeFrame: At baseline and at 12-weeks
measure: Immune function
timeFrame: At baseline and at 12-weeks
Other outcomes:
Locations:
city: Coleraine
country: United Kingdom
facility: Human Intervention Studies Unit (HISU), University of Ulster
state: Londonderry
Study officials:
affiliation: University of Ulster
name: Pamela J Magee, PhD
role: PRINCIPAL_INVESTIGATOR
References: