A 58 year old Caucasian woman with recurrent pyelonephritis has been on haemodialysis for 20 years. She sustained a low impact fracture of neck of femur but dual energy x-ray absorptiometry (DXA) revealed abnormal bone mineral density (BMD) with clinically significant osteoporosis. Intact parathyroid hormone (PTH) ranged between 80 and 100pg/mL (20 -40ng/L) since parathyroidectomy 8 years ago for secondary hyperparathyroidism. Other laboratory results showed serum calcium 9.9mg/dL (2.47mmol/L), phosphate 5.6mg/dL (1.80mmol/L), total alkaline phosphatase 105U/L, and a low 25-hydroxyvitamin D 10.3ng/mL (25.7nmol/L).
What is the next best step in management