Are there any instances when you use vitamin B6 to prevent kidney stones in patients with recurrent calcium oxalate nephrolithiasis who do not have primary hyperoxaluria?  

I occasionally try empirical vitamin B6 in patients with hyperoxaluria that does not respond to usual dietary oxalate restriction plus low fat and higher calcium. I have not done it systematically and have only a handful of cases where it may have helped. Thus, I would not recommend routinely adding...