Do you recommend checking a serum phosphorus level in patients with recurrent nephrolithiasis?  

For patients with pure calcium phosphate or mixed calcium phosphate/oxalate nephrolithiasis, l routinely check serum phosphorus as part of a panel that also contains serum calcium, PTH, creatinine, and 25-vitamin D, looking for primary hyperparathyroidism, a surgically curable cause of these stones....