The Effects of Vitamin D Supplementation on VO2max in Athletes: a Randomised, Double-blind, Placebo-controlled Trial
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 1
- 主要终点
- Aerobic fitness (VO2max)
研究概览
简要总结
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Athletes whose sport does not primarily consist of an anaerobic component
- •Apparently healthy
- •Over the age of 18
排除标准
- •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
研究组 & 干预措施
Placebo
Placebo solution delivered via oral spray once daily for 12-weeks
干预措施: Placebo (Dietary Supplement)
Vitamin D3 3000IU (75μg)
Treatment solution delivered via oral spray once daily for 12-weeks
干预措施: Vitamin D (Dietary Supplement)
结局指标
主要结局
Aerobic fitness (VO2max)
时间窗: At baseline and at 12-weeks
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.
次要结局
- 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)
- Physical activity levels(At baseline and at 12-weeks)
- Body composition(At baseline and at 12-weeks)
- Vitamin D status(At baseline and at 12-weeks)
- Immune function(At baseline and at 12-weeks)
研究者
Dr Pamela Magee
Dr Pamela Magee
University of Ulster