Effects of vitamin D supplementation during exercise training on strength and body composition
Andres E Carrillo1, Michael G Flynn3, Catherine Pinkston2, Melissa M Markofski1, Yan Jiang2, Shawn S Donkin2 and Dorothy Teegarden2
FASEB (Federation of American Societies of Experimental Biology) Journal Vol 24 April 2010 917.20
1 Department of Health and Kinesiology
2 Interdepartmental Nutrition Program, Purdue University, West Lafayette, IN
3 Department of Health and Human Performance, College of Charleston, Charleston, SC
The purpose of this study was to examine the effects of vitamin D supplementation (4,000 IU/day) during an exercise training intervention on body composition, muscular strength, and power. Overweight (BMI: 31.3 ± 3.2 kg/m2) adults (26.1 ± 4.7 years, n=23) were recruited during winter months and randomized into a vitamin D (Vit D, n = 10) or placebo (PL, n = 13) group. Both groups completed 12 wks (3 d/wk) of resistance exercise, and were asked to use the provided sunscreen daily. Vitamin D status (serum 25 hydroxyvitamin D (25OHD)) and body composition (DXA) were assessed at 0 and 12 wks, and muscular strength and power at 0, 4, 8, and 12 wks using Keiser pneumatic resistance equipment. Post 25OHD was increased in VitD (33.4 ± 7.2 ng/mL) compared to baseline (20.8 ± 8.3 ng/mL, p<0.05) and was significantly elevated compared to post PL (23.5 ± 6.0 ng/mL, p<.05). Power was higher, compared to baseline, in Vit D only at week 4 (Fig 1.). Post muscular strength and lean mass were increased in both groups (p<0.05) with no between group differences. Vitamin D supplementation during exercise training induced an early increase in muscular power, but did not alter other indices of muscle function.