Independent Association of Vitamin D With Physical Function in People With Chronic Spinal Cord Injury

Abstract

ObjectiveTo explore the relation between vitamin D and physical function outcomes in people with spinal cord injury (SCI). DesignCross-sectional study. SettingRehabilitation institute. ParticipantsConsecutive patients (N=100; 72 men and 28 women) with chronic SCI admitted to a rehabilitation program. InterventionsNot applicable. Main Outcome MeasuresFunctional independence in activities of daily living (ADL) and leisure time physical activity (LTPA) were assessed as measures of physical function. ResultsVitamin D deficiency (<20ng/mL) was found in 78 patients: they exhibited a significantly higher body mass index, lower functional independence in ADL, and were engaged in a significantly poorer weekly LTPA. At the linear multiple regression analysis, lower 25-hydroxyvitamin D levels showed significant independent associations with poorer functional independence in ADL (β=.59; 95% confidence interval, .36–.82; P<.0001) and with poorer LTPA (β=2.35; 95% confidence interval, 0.77–3.94; P=.004), after adjustment for other predictors of physical function outcomes selected by univariate analyses. ConclusionsIn people with chronic SCI, a low vitamin D level represents an independent predictor of poor physical function.