Carson EL, et al. - In the present study, researchers examined seasonal changes in vitamin D status and any associated changes in fat-free mass (FFM), muscle strength and quality of life (QoL) in COPD patients. The present data indicated that muscle strength and QoL were positively anticipated by 25(OH)D concentration, independent of age, sex and smoking status. This investigation highlighted the need for health policies to include a recommendation for year-round vitamin D supplementation in housebound COPD patients, and wintertime supplementation in nonhousebound patients, to maintain optimal 25(OH)D concentrations to protect musculoskeletal health. In patients with COPD, an optimal vitamin D status might have potential benefits for QoL.