Effect of Glucosamine on Joint Structure and Quality of Life (JOG)

The goal of this study is 1) to develop a biomarker of of cartilage synthesis by determining if there is a relationship between changes in the status of knee cartilage and the amount of a biomarker called CTX-II in urine. 2) We will also characterize people who have experienced cartilage loss and/or reduced functional ability using performance tests and a questionnaire. 3) The administration of glucosamine in a beverage for six months will be used to promote the alteration in cartilage status and improve function in people with mild to moderate joint pain. A secondary goal will be to assess the effect of glucosamine on the skin in a small subset of women.