Vitamin D supplementation may enhance physical performance of athletes, finds study

Weekly vitamin D supplementation may enhance the physical performance of Athletes, revealed a study published in the International Journal of Preventive Medicine.

Vitamin D is well recognized for its bone and muscle strengthening properties. This sunshine vitamin is known to reduce the risk for conditions such as stress fracture, total body inflammation, infectious illness, and impaired muscle function. Studies in athletes have found that vitamin D status is variable and is dependent on outdoor training time (during peak sunlight), skin color, and geographic location. The U.S. daily adequate intake (AI) for vitamin D of 200 IU is recommended for athletes.

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.

The researchers from the Shahid Beheshti University of Medical Sciences, Tehran conducted a randomized controlled clinical trial which enrolled 70 athletes. 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.

Key observations

• A significant rise in circulating 25(OH)D concentration was observed in the D group, whereas in the P group, there was a statistically significant decrement.


• 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 the P group. Moreover, in the sprint test, only D group had a significant within-group improvement.

"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." concluded the authors.

For reference, click on the link

Alimoradi K, Nikooyeh B, Ravasi AA, Zahedirad M, Shariatzadeh N, Kalayi A, Neyestani TR. Efficacy of Vitamin D supplementation in physical performance of Iranian elite athletes. Int J Prev Med [serial online] 2019 [cited 2019 Aug 8];10:100. Available from: http://www.ijpvmjournal.net/text.asp?2019/10/1/100/259787