Correcting Vitamin D Insufficiency Improves Some, But Not All Aspects of Physical Performance during Winter Training in Taekwondo Athletes.
Int J Sport Nutr Exerc Metab. 2018 May 3:1-25. doi: 10.1123/ijsnem.2017-0412. [Epub ahead of print]
- This is one of a very few trials to find any improvement in just 1 month
- It takes up to 2-6 months to raise the vitamin D levels, then another few months for the body to benefit from the improved levels
- 5,000 IU daily: Vitamin D levels 12 ng ==> 38 ng
- Note – Llow vitamin D levels are typical of indoor sports
- Note - Vitamin D especially increases fast-twitch muscles (used by Taekwondo)
- Note - Might have had a similar improvement with a loading dose of 150,000 IU ( 5,000 IU * 30 days)
- Vitamin D supplementation improves muscle strength in healthy adults – meta-analysis of 6 RCT Aug 2014
- Elite Athletes do well with weekly 35,000 IU of Vitamin D – RCT Feb 2017
- Note 35,000 IU/week is very similar to 5,000 IU/day
- Athletic performance and recovery benefits of Vitamin D (4000-5000 IU and Vitamin K) – Aug 2015
- Vitamin D increased muscle strength by 1% to 19% (varied with dose and duration) – review June 2016
Overview Sports and vitamin D has the following summary
Athletes are helped by vitamin D by:
- Faster reaction time
- Far fewer colds/flus during the winter
- Less sore/tired after a workout
- Fewer micro-cracks and broken bones
- Bones which do break heal much more quickly
- Increased VO2 and exercise endurance Feb 2011
- Indoor athletes especially need vitamin D
- Professional indoor athletes are starting to supplement with vitamin D or use vitamin D beds
- Olympic athletes have used UV/vitamin D since the 1930's
- The biggest gain from the use of vitamin D is by those who exercise less than 2 hours per day.
- Reduced muscle fatigue with 10,000 IU vitamin D daily
- Muscle strength improved when vitamin D added: 3 Meta-analysis
- Sports and Vitamin D category
PDF is available free at Sci-Hub 10.1123/ijsnem.2017-0412.
Jung HC1, Seo MW2, Lee S3, Jung SW2, Song JK2.
1 Department of Kinesiology, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, LA.
2 Department of Taekwondo, College of Physical Education, Global Campus, Kyung Hee University, Gyeonggi-do 17014, South Korea.
3 Department of Counseling, Health, and Kinesiology, College of Education and Human Development, Texas A&M University-San Antonio, San Antonio, TX.
We investigated the effects of vitamin D3 supplementation on physical performance during winter training in vitamin D insufficient taekwondo (TKD) athletes. Thirty-five collegiate male and female TKD athletes, aged 19-22 years with low serum 25(OH)D concentration (28.8±1.10 nmol/L) were randomly assigned to a vitamin D group (N=20) or a placebo group (N=15). Subjects received either a vitamin D3 capsule (5,000 IU/day) or placebo during four weeks of winter training. Blood samples were collected for analyzing serum 25(OH)D concentration. Physical performance tests included Wingate anaerobic test, isokinetic muscle strength and endurance, a counter movement jump (CMJ) test, sit-ups, agility test, and 20 m pacer. Serum 25(OH)D concentrations increased significantly in the vitamin D group (96.0±3.77 nmol/L) after four weeks of supplementation, but no changes were found in the placebo group (F=242.44, p=.000).
There were significant interaction effects for
- anaerobic peak power (F=7.49, p=.010) and
- isokinetic knee extension at 180°/sec (F=6.08, p=.019).
Changes in serum 25(OH)D concentration were positively associated with changes in peak power, and isokinetic knee extension at 180°/sec. However, no significant interaction effects were observed in other performance variables. This study suggests that four weeks of vitamin D supplementation elevates serum 25(OH)D concentration to sufficient levels. Correcting vitamin D insufficiency improves some, but not all aspects of performance. Thus, efficacy of vitamin D supplementation to enhance performance remains unclear.
Vitamin D₃ Supplementation Reduces the Symptoms of Upper Respiratory Tract Infection during Winter Training in Vitamin D-Insufficient Taekwondo Athletes: A Randomized Controlled Trial - Sept 2018
Still not much results since the trial lasted only 1 month and they monitored the respiratory track problems from the first day, even though it would take 2-4 months to restore the levels of vitamin D
Download the PDF from VitaminDWiki
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