It is important to remember the study only saw a correlation between the dietary supplement and mortality. Glucosamine Sulfate is from what I understand the most common form in the supplements on the shelf. Our bodies produce glucosamine naturally.

> Specifically in humans, glucosamine-6-phosphate is synthesized from fructose 6-phosphate and glutamine by glutamine—fructose-6-phosphate transaminase as the first step of the hexosamine biosynthesis pathway -wikipedia