Effcacy of Vitamin D Supplementation in Physical Performance of Iranian Elite Athletes

International Journal of Preventive Medicine (Int J Prev Med)2008-780210620190707Effcacy of Vitamin D Supplementation in Physical Performance of Iranian Elite Athletes20902090ENDepartment of Nutrition Research, Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Science, TehranDepartment of Nutrition Research, Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, TehranDepartment of Sport Physiology, Faculty of Physical Education and Sport Sciences, University of Tehran, TehranDepartment of Nutrition Research, Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, TehranDepartment of Nutrition Research, Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, TehranDepartment of Nutrition Research, Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, TehranDepartment of Nutrition Research, Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran20190707Background: 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 effcacy 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 signifcant 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 signifcant decrement (-3.1 ± 8.4 ng/mL, P = 0.040). There were no either within‑ or between‑group signifcant differences in Ergo jump, vertical jump, and agility tests. In strength leg press tests, both groups showed a signifcant improvement. However, comparisons of changes revealed that the improvement in D group was signifcantly higher than in P group (P = 0.034). Moreover, in sprint test (one repetition‑Max, 1RM), only D group had a signifcant 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 signifcant improvement of power leg press and sprint tests in D‑supplemented group. Keywords: Athletes, exercise, Vitamin Dhttp://ijpm.mui.ac.ir/index.php/ijpm/article/view/2090http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2090/717717909