Browsing by Subject "25-hydroxyvitamin D"

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    Vitamin D Deficiency and Physical Performance in Athletes
    (2013-07) Fitzgerald, John
    The aim of this cross-sectional study was to investigate the relationship between vitamin D status and laboratory measures that are relevant to physical performance in competitive ice hockey players. Data was collected for 53 junior and collegiate ice hockey players residing near Minneapolis, Minnesota (44.9� N) during the offseason (May 16-June 28). Vitamin D status was inversely associated with percent body fat and positively associated with handgrip strength, trended with peak power during the wingate test, but not with vertical jump height after adjusting for measured covariates. Representing a novel finding of this study, 25(OH)D status was inversely related to jump execution time, time to peak power and positively associated with force gradient during the squat jump after adjusting for potential covariates.
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    Vitamin D status and longitudinal lung function decline in the Lung Health Study
    (2014-01) Kunisaki, Ken
    Low vitamin D blood levels are postulated to be a risk factor for worse lung function, largely based on cross-sectional data. We sought to use longitudinal data to test the hypothesis that baseline plasma 25-hydroxyvitamin D [25(OH)D] is lower in subjects with more rapid lung function decline, compared to those with slow lung function decline. We conducted a nested, matched case-control study in the Lung Health Study 3 cohort. Cases and controls were continuous smokers with rapid and slow lung function decline, respectively, over approximately 6 years of follow-up. We compared baseline 25(OH)D levels between cases and controls, matching on date of blood draw and clinical center. Among 196 subjects, despite rapid and slow decliners experiencing strikingly and significantly different rates of decline of forced expiratory volume in one second (-152 vs. -0.3 mL/year; p<0.001), there was no significant difference in baseline 25(OH)D levels (25.0 vs. 25.9 ng/mL; p=0.54). There was a high prevalence of vitamin D insufficiency (35%) and deficiency (31%); only 4% had a normal 25(OH)D level in the winter. Although vitamin D insufficiency and deficiency are common among continuous smokers with established mild to moderate COPD, baseline 25(OH)D levels are not predictive of subsequent lung function decline.