The lower exremity isokinetic muscle strength and quality of life evaluation in the condition of vitamin D efficiency

Vitamin D deficiency has almost become an epidemic currently. Vitamin D has vital functions in many other systems as well as musculoskeletal system. Osteomalacic muscle weakness originates with damaged muscle metabolism and this weakness responds to Vitamin D treatment.The aim of the study was to explore whether the lower extremity muscle strength and endurance is affected and to inspect the effects of Vitamin D deficiency on the quality of life.32 controls with Vitamin D levels ?12 ng/mL and 32 patients <12 ng/mL were included to the study. All paticipants were evaluated with WHOQOL-BREF questionnare for quality of life. Muscle strength, endurance and functional capacity were assessed by isokinetic examination for knee muscle strength and fatique index, and 6 minute walking test.The group with Vitamin D levels <12 ng/mL had significantly lower walking distance. Muscle strength measured by isokinetic tests was slightly lower than the control group. The same group had slightly higher fatique index and lower WHOQOL-BREF scores in the social and psychological domains.. The differences of walking distance and WHOQOL-BREF between two gropus were statistically significant. Inadequate sensitivity of isokinetic tests, adaptation problems and young age of subjects might have obscured a more pronounced muscle weakness.The results of this study has shown that functional capacity and quality of life is affected by Vitamin D deficiency.