Relationship between blood Vitamin C and longitudinal change in physical performance among Japanese community dwelling elderly women

点击翻译按钮获取中文摘要

Recent studies have suggested that there is a beneficial relationship between antioxidant vitamin C intake and physical performance. A cross sectional study we conducted in 2006 on community dwelling elderly women found that the concentration of blood vitamin C was related to physical performance. The present study aimed to investigate the relationship between vitamin C concentration in the blood and changes in physical performance in elderly women.In order to provide a longitudinal analysis with high quality evidence, a follow-up survey was conducted in 2009 and the results were compared to the 2006 survey results from the aforementioned study, which served as a baseline.Analysis of the relationship between the blood vitamin C concentration at baseline and changes in handgrip strength during the follow-up period showed a negative correlation (adjusted for baseline age and grip strength: r=-0.1, p=0.02). However, this correlation was not observed when the subjects who took vitamin C supplements were excluded. Analysis of the relationship between changes in blood vitamin C concentration and changes in grip strength over the three-year period showed a positive correlation(r=0.11, P=0.016). A similar result was obtained even after the subjects who were taking vitamin C supplements were excluded (r=0.10, P=0.043).