Context: Parathyroidectomy is the only effective therapy for osteitis fibrosa cystica in hyperparathyroidism.

Objective: To describe the changes of skeletal and non-skeletal manifestations in a patient with hyperparathyroidism and renal failure after oral vitamin D therapy.

Design: A descriptive case report.

Setting: The patient was followed-up in a referral center.

Patient: A 55 yr-old male patient with moderate renal failure was referred for expansile lytic lesions affecting several ribs and the spinous process of T12. His creatinine was 1.8 mg/dl, calcium 8.9 mg/dl, PTH 666 pg/ml and 1,25 dyhydroxy-vitamin D (1,25 (OH)₂ D) 27 pg/ml. BMD Z-scores by dual energy x-ray absorptiometry were -4.1 at the spine, -1.7 at the hip and -4.3 at the forearm.

Main outcome measures: The main outcome measures were the skeletal manifestations of hyperparathyroidism.

Results: At 10 months of therapy, calcium level was 10 mg/d, PTH level declined to 71 pg/ml and BMD increased by 12% at the spine and 18% at the hip. Computerized tomography (CT) cuts revealed marked regression in the lytic lesions. At two years, BMD increased by an additional 6% at the spine and there were no further changes in the lytic lesions by CT. The VDR genotype using three restriction enzymes Bsm1, Taq1 and Apa1 was Bb, tt and AA. Conclusions: we showed regression of severe skeletal abnormalities of hyperparathyroidism documented by serial CT images in response to oral vitamin D therapy. It is possible that the VDR genotype of the patient have modulated this response.