This study aimed to clarify the relationship between serum 25-hydroxyvitamin D concentration body composition by examining male university rugby players in a cross-sectional manner. The subjects were 36 male rugby players (mean age: 20.2 years) who provided us with data regarding their body composition, blood biochemistry examination, and dietary intake frequency. Examination of their serum concentrations of 25-hydroxyvitamin D 【25 (OH) D】 showed that 58% (21/36 subjects) and 42% (15/36 subjects) had sufficient and insufficient intake of vitamin D, respectively. In comparison of serum 25 (OH) D concentrations between players in individual positions, it was suggested that the concentrations were significantly lower in the forward (FW) players compared with the backs (BK) players (p<0.01). The number of FW players with lipid abnormality was significantly higher than that of BK players (p<0.01). Serum 25 (OH) D concentrations showed negative correlations with weight, Body Mass Index (BMI), total body fat amount, and lean body weight. Multiple linear regression analysis suggested that serum 25 (OH) D concentration would be affected by BMI. The average serum 25 (OH) D concentration among obese class II – IV players was 27.8 ng/mL, which was significantly lower than that of players with a normal weight or obese class I (34.2 ng/mL, p<0.01, 33.1 ng/mL, p<0.01). These findings suggest that vitamin D intake among obese class II – IV players was not sufficient, despite the fact that their intake of vitamin D was 14.1 µg, which was much higher than the adequate intake level. In the future, further studies should clarify how increased intake of vitamin D could improve physical characteristics.

Background and Aims: The gastrointestinal motility effects by carbonated water have not yet been sufficiently investigated. The aim of this study was to determine whether single pre-prandial carbonated water administration might have an effect on the rate of liquid gastric emptying using the 13C-acetic acid breath test. Methods: Eight healthy volunteers (F/M; 3/5) participated in this randomized, 3-way crossover study. The subjects fasted overnight and were randomly assigned to receive 200mL of carbonated water before ingestion of the liquid test meal (200 kcal per 200 mL, containing 100 mg 13C acetate) or 200mL of carbonated water before the test meal or the test meal alone. Under all conditions, breath samples were collected for 150 min following the meal. Liquid gastric emptying was estimated by the values of the following parameters: T1/2, Tlag, the gastric emptying coefficient (GEC) and the regression-estimated constants (β and κ), calculated using the 13CO2 breath excretion curve using the conventional formulae. The parameters between the 3 test conditions were compared statistically. Results: Carbonated water significantly decreased k and beta, but T1/2, Tlag and GEC remained unchanged. Conclusions: The present study revealed that carbonated water has dual effects on liquid emptying: an initial acceleration with a subsequent deceleration in asymptomatic volunteers.