Increased internal oxalate production can occur from connective tissue breakdown or high collagen intake.

“when you're breaking down connective tissue if you're an athlete or got injured or surgery you're going to have more breakdown and you have potential with a combination of the inflammatory nature of those activities and the breakdown of connective tissue that amount can go up but if you're eating a lot of collagen which is really popular too right now this is the latest fat is poor collagen in every recipe you can and every smoothie you're upping the the excess of this amino acid that you probably don't need extra of and it can turn into oxalate in the liver to a small degree”