Impact of Vitamine D depletion and repletion on rat skeletal muscle

15 months Old Wistar Rat were submitted to 3 differents diets: control, without vitamin D and without vitamin D followed by a supplementation in vitamin D. At sacrifice, skeletal muscle were recovered, quickly frozen in liquid nitrogen. RNA profiling by microarrays was performed. The aim of this study was to examine the effects of vitamin D deficiency on muscle mitochondrial oxidative function in old sarcopenic rats. We hypothesized that suboptimal mitochondrial function contributes to the myopathy in vitamin D-deficient older individuals. 15-month-old Wistar rats were fed a vitamin D-deficient diet (VDD group) or a control diet (1000UI/Kg vit D) for 9 months (n=7-9/group) or a vitamin D-deficient diet followed by supplementation. Our results indicated a link between vitamin D status, muscle mitochondrial oxidative capacities, whole-body energy expenditure and change in body composition in old rats.