REVIEW URRENT C OPINION
Vitamin D and skeletal muscle function in athletes Pamela R. von Hurst and Kathryn L. Beck
Purpose of review To highlight recently published data about the vitamin D status of athletes, and effect of vitamin D supplementation on muscle strength and performance in the athletic population. The vitamin D receptor exists in skeletal muscle, and muscle weakness has been reported in individuals who are severely deficient [25(OH)D 75 nmol/l
Summer
28.7% – 50–75 nmol/l 43.9% – 25–50 nmol/l 11.7% – 75 nmol/l
End of Summer
52.5% – 50–75 nmol/l
No significant association between 25(OH)D and grip strength.
13.8% – 100 nmol/l) [20]. These results are in agreement with unpublished work undertaken in our New Zealand laboratory. In a 6-month randomized double blind placebo-controlled trial, we investigated the effect of 50 000 IU of vitamin D3 per month on muscle strength and power in female adolescent athletes (dancers, gymnasts, swimmers). Median (25th, 75th percentile) serum 25(OH)D
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542
Population
10 male professional soccer players (five intervention, five placebo), 18 5 years
25 club level athletes (including football and rugby), placebo – 21 1 years, 20000 IU – 22 2 years, 40000 IU – 21 1 years
Author
Close et al. [13]
www.co-clinicalnutrition.com
Close et al. [20]
Vitamin D – 29 25 nmol/l, Placebo – 53 29 nmol/l 70% – 100 nmol/l
Vitamin D – 103 25 nmol/l, placebo – 74 24 nmol/l
End
Baseline
25 (OH)D status at baseline and end
United Kingdom
Location, latitude and season
Table 2. Intervention studies investigating the effect of vitamin D on muscle strength in athletes
Vitamin D supplementation had no significant effect on 1-RM bench press, 1-RM leg press, 20 m sprint and vertical jump.
Significant improvement for 10 m sprint and vertical jump, and a trend for improved 1-RM bench press 1-RM back squat in the intervention group compared with placebo. No significant improvement for 30 m sprint time or Illinois agility run test.
Results
Micronutrients
Volume 17 Number 6 November 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
24 elite male and female classical ballet dancers, 20–35 years (17 intervention, seven control)
54 female athletes (dancers, gymnasts, swimmers), 13–18 years (26 intervention, 28 placebo)
28 NASCAR pit crew athletes, placebo (n ¼ 13) – 27.3 0.9 years, intervention (n ¼ 15) – 27.1 1.5 years
Wyon et al. [22]
Mitchell [23]
Nieman et al. [4]
N/A 100% – 75 nmol/l during previous winter
52.38 N Winter
57.7% – >75 nmol/l, 30.8% – 50–75 nmol/l, 11.5% -
Vitamin D and skeletal muscle function in athletes Pamela R. von Hurst and Kathryn L. Beck
Purpose of review To highlight recently published data about the vitamin D status of athletes, and effect of vitamin D supplementation on muscle strength and performance in the athletic population. The vitamin D receptor exists in skeletal muscle, and muscle weakness has been reported in individuals who are severely deficient [25(OH)D 75 nmol/l
Summer
28.7% – 50–75 nmol/l 43.9% – 25–50 nmol/l 11.7% – 75 nmol/l
End of Summer
52.5% – 50–75 nmol/l
No significant association between 25(OH)D and grip strength.
13.8% – 100 nmol/l) [20]. These results are in agreement with unpublished work undertaken in our New Zealand laboratory. In a 6-month randomized double blind placebo-controlled trial, we investigated the effect of 50 000 IU of vitamin D3 per month on muscle strength and power in female adolescent athletes (dancers, gymnasts, swimmers). Median (25th, 75th percentile) serum 25(OH)D
1363-1950 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
www.co-clinicalnutrition.com
541
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
542
Population
10 male professional soccer players (five intervention, five placebo), 18 5 years
25 club level athletes (including football and rugby), placebo – 21 1 years, 20000 IU – 22 2 years, 40000 IU – 21 1 years
Author
Close et al. [13]
www.co-clinicalnutrition.com
Close et al. [20]
Vitamin D – 29 25 nmol/l, Placebo – 53 29 nmol/l 70% – 100 nmol/l
Vitamin D – 103 25 nmol/l, placebo – 74 24 nmol/l
End
Baseline
25 (OH)D status at baseline and end
United Kingdom
Location, latitude and season
Table 2. Intervention studies investigating the effect of vitamin D on muscle strength in athletes
Vitamin D supplementation had no significant effect on 1-RM bench press, 1-RM leg press, 20 m sprint and vertical jump.
Significant improvement for 10 m sprint and vertical jump, and a trend for improved 1-RM bench press 1-RM back squat in the intervention group compared with placebo. No significant improvement for 30 m sprint time or Illinois agility run test.
Results
Micronutrients
Volume 17 Number 6 November 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
24 elite male and female classical ballet dancers, 20–35 years (17 intervention, seven control)
54 female athletes (dancers, gymnasts, swimmers), 13–18 years (26 intervention, 28 placebo)
28 NASCAR pit crew athletes, placebo (n ¼ 13) – 27.3 0.9 years, intervention (n ¼ 15) – 27.1 1.5 years
Wyon et al. [22]
Mitchell [23]
Nieman et al. [4]
N/A 100% – 75 nmol/l during previous winter
52.38 N Winter
57.7% – >75 nmol/l, 30.8% – 50–75 nmol/l, 11.5% -
