Xiaomin Sun1,2, Kumpei Tanisawa3, Yuping Zhang4, Tomoko Ito3, Satomi Oshima3, Mitsuru Higuchi3, Zhen-Bo Cao5. 1. School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China. 2. Global Health Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China. 3. Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan. 4. Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan. 5. School of Kinesiology, Shanghai University of Sport, Shanghai, China, caozb_edu@yahoo.co.jp.
Abstract
INTRODUCTION: This study aimed to clarify whether 1 year of vitamin D3 supplementation has a direct effect on body composition and physical fitness in healthy adults. METHODS: Ninety-five participants randomly received either 420 IU vitamin D3 per day (n = 48) or placebo (n = 47) in a double-blind manner for 1 year. Lean body mass and percentage body fat were determined. Physical fitness including hand grip strength, leg extension power and cardiorespiratory fitness (CRF) were assessed. Serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) concentrations were assessed using ELISA kits. RESULTS:Serum 25(OH)D and (1,25[OH]2D) concentrations significantly increased by approximately 11.2 ± 9.2 ng/mL (pinteraction <0.001)and 7.0 ± 7.8 pg/mL (pinteraction <0.001) after 1 year of vitamin D3 supplementation respectively. Lean body mass significantly increased from 43.8 ± 9.6 to 44.3 ± 9.8 kg in vitamin D group, while no change was observed in placebo group (from 42.6 ± 8.9 to 42.4± 8.9 kg) after 1 year intervention. Furthermore, no treatment effects on other indicators of body composition and physical fitness were observed. CONCLUSIONS: One year of vitamin D supplementation effectively improves lean body mass, but not muscle strength and CRF in healthy adults.
RCT Entities:
INTRODUCTION: This study aimed to clarify whether 1 year of vitamin D3 supplementation has a direct effect on body composition and physical fitness in healthy adults. METHODS: Ninety-five participants randomly received either 420 IU vitamin D3 per day (n = 48) or placebo (n = 47) in a double-blind manner for 1 year. Lean body mass and percentage body fat were determined. Physical fitness including hand grip strength, leg extension power and cardiorespiratory fitness (CRF) were assessed. Serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) concentrations were assessed using ELISA kits. RESULTS: Serum 25(OH)D and (1,25[OH]2D) concentrations significantly increased by approximately 11.2 ± 9.2 ng/mL (pinteraction <0.001)and 7.0 ± 7.8 pg/mL (pinteraction <0.001) after 1 year of vitamin D3 supplementation respectively. Lean body mass significantly increased from 43.8 ± 9.6 to 44.3 ± 9.8 kg in vitamin D group, while no change was observed in placebo group (from 42.6 ± 8.9 to 42.4± 8.9 kg) after 1 year intervention. Furthermore, no treatment effects on other indicators of body composition and physical fitness were observed. CONCLUSIONS: One year of vitamin D supplementation effectively improves lean body mass, but not muscle strength and CRF in healthy adults.