Asia Pac J Clin Nutr. 2017 Jan;26(1):85-88. doi: 10.6133/apjcn.102015.12.
Kara M1, Ekiz T2, Kara Ö3, Tiftik T4, Malas FÜ4, Özbudak Demir S4, Özgirgin N4.
Forty-ish adults in Turkey, mostly women: divided into 2 groups Vitamin D - based on cutpoint of 14 ng
Note: Turkey, like much of the Middle East, has low vitamin D levels
|Torque||9 ng |
| 21 ng |
|Knee flexion |
(180 degrees/sec )
|Knee extension |
(180 degrees/sec )
See also VitaminDWiki
- Vitamin D supplementation improves muscle strength in healthy adults – meta-analysis of 6 RCT Aug 2014
- Elderly lower limb muscle strength improved with Vitamin D supplementation - Meta-analysis Oct 2013
- Vitamin D increased muscle strength by 1% to 19% (varied with dose and duration) – review June 2016
- Fastest US High School sprinters are both at the school taking lots of vitamin D (Matthews) May 2016
- Book on Sports and vitamin D - Aug 2011 Dr. Cannell
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
BACKGROUND AND OBJECTIVES:
The objective of this study was to explore the association between 25- hydroxyvitamin D (25(OH)D) and muscle strength/architecture.
METHODS AND STUDY DESIGN:
Thirty patients (27 women, 3 men) were allocated into Group I (n=15, mean age; 44.4±9.4 years) and Group II (n=15, mean age; 39.0±9.9 years) according to the median of 25(OH)D (<13.7 ng/mL vs >13.7 ng/mL, respectively). Peak torque/body weight of the knee flexor/extensor muscles at 60°/sec and 180°/sec and those of ankle flexor/ extensor muscles at 30°/sec and 90°/sec were evaluated by using a Biodex System 3 Pro Multijoint System isokinetic dynamometer. A 7-12 MHz linear array probe was used to evaluate thickness (MT), pennation angle (PA) and fascicle length (FL) of medial gastrocnemius and vastus lateralis muscles.
Mean of 25(OH)D was 9.4±2.5 ng/mL and 20.7±8.3 ng/mL in Groups I and II, respectively. Although all isokinetic strength parameters were lower in Group I, significant differences were found in knee flexion at 180°/sec (p=0.007), knee extension at 30°/sec (p=0.038) and 180°/sec (p=0.001), and ankle extension at 30°/sec (p=0.002) and 90°/sec (p=0.007). On the other hand, no significant difference was found between the groups regarding MT, PA and FL values (all p>0.05).
In light of our results, we can argue that 25(OH)D is associated with muscle strength but not with muscle architecture. Further studies concerning the long-term follow-up effects of 25(OH)D treatment on muscle strength are awaited.