A 50 year old male CKD- raised creatinine for more than 4 years came to me a month ago Serum Cr. 5 mg/dl, serum calcium > 13 mg/dl, USG - nephrocalcinosis & contracted kidney with altered CMD, 24 hr urine calcium -WNL, serum PTH - low (12 pg/ml) Serum phosphate - WNL, H/O wt loss, clinical exam - no positive findings 1,25 D 3 - sent.

What could be done further?