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Athletes helped by weekly 50,000 IU Vitamin D – RCT Aug 2019

Efficacy of Vitamin D supplementation in physical performance of Iranian elite athletes

Karamollah Alimoradi1, Bahareh Nikooyeh2, Ali Asghar Ravasi3, Maliheh Zahedirad2, Nastaran Shariatzadeh2, Ali Kalayi2, Tirang Reza Neyestani2


This study would have found much more benefit it any of the following:

  1. Study lasted ~ 8 weeks (note: periodic dosing often not plateau until 6 months)
  2. Add cofactors which increase the response to the vitamin D (e.g. Magnesium, Omega-3)
  3. Add activators for the Vitamin D Receptor (exampls:e high intensity exercise, Resveratrol)

Note: For some health problems weekly dosing is BETTER than daily (Vitamin D Receptor)

Overview Sports and vitamin D has the following summary

Athletes are helped by vitamin D by:

  1. Faster reaction time
  2. Far fewer colds/flus during the winter
  3. Less sore/tired after a workout
  4. Fewer micro-cracks and broken bones
  5. Bones which do break heal much more quickly
  6. Increased VO2 and exercise endurance Feb 2011
  7. Indoor athletes especially need vitamin D
  8. Professional indoor athletes are starting to supplement with vitamin D or use vitamin D beds
  9. Olympic athletes have used UV/vitamin D since the 1930's
  10. The biggest gain from the use of vitamin D is by those who exercise less than 2 hours per day.
  11. Reduced muscle fatigue with 10,000 IU vitamin D daily
  12. Muscle strength improved when vitamin D added: 3 Meta-analysis
  13. Reduced Concussions
    See also: Sports and Vitamin D category 212 items

Sports category starts with

212 items in Sports category

Sports benefits from up to 50 ng (click on chart for details)
Sports benefit up to 50 ng @ /is.gd/Vitdsports
see also Concussions

 Download the PDF from VitaminDWiki
Vitamin D Levels got to 42 ng in 8 weeks, but suspect levels were only high enough to be of some benefit for 3 weeks


Background: There has been no report of the vitamin D status of the professional athletes from Iran to date. This study was performed to evaluate the efficacy of weekly vitamin D supplementation on athletic performance in Iranian athletes expedited to Asian competition in Taipei, China, 2015.

Methods: This study was a randomized controlled clinical trial. Seventy subjects were enrolled in the study. The athletes were randomly divided into two groups: vitamin D supplement (D; received 50,000 IU of vitamin D supplement weekly) and control (P, received a placebo weekly). Duration of the study was 8 weeks. Anthropometric, dietary, athletic performance, and biochemical evaluations were performed for all subjects in the beginning and in the end of the intervention period.

Results: A significant rise in circulating 25(OH)D concentration was observed in D group (17.3 ± 16.9 ng/mL, P < 0.001), whereas in P group, there was a statistically significant decrement (−3.1 ± 8.4 ng/mL, P = 0.040). There were no either within- or between-group significant differences in Ergo jump, vertical jump, and agility tests. In strength leg press tests, both groups showed a significant improvement. However, comparisons of changes revealed that the improvement in D group was significantly higher than in P group (P = 0.034). Moreover, in sprint test (one repetition-Max, 1RM), only D group had a significant within-group improvement (P = 0.030).

Conclusions: Weekly supplementation with 50,000 IU vitamin D resulted in nearly 17 ng/mL increment in circulating calcidiol. This increase was associated with significant improvement of power leg press and sprint tests in D-supplemented group.

D2 not good - clipped from PDF
"a research group found that 6 weeks vitamin D 2 (ergocalciferol) supplementation in National Association for Stock Car Auto Racing pit crew athletes not
only decreased serum concentrations of 25(OH) D3 by 21% but resulted in augmented muscular damage biomarkers, as well.[47]"

Created by admin. Last Modification: Monday August 26, 2019 16:19:57 GMT-0000 by admin. (Version 10)

Attached files

ID Name Comment Uploaded Size Downloads
12461 Increase.jpg admin 10 Aug, 2019 20:58 16.62 Kb 30
12460 Leg press.jpg admin 10 Aug, 2019 18:13 51.90 Kb 33
12459 Iran Athletes weekly .pdf admin 10 Aug, 2019 18:12 642.97 Kb 12
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