Objective: Previous studies have suggested that alpha-D3 therapy can cause deterioration in renal function. We have, therefore, examined the long-term effect of 1 alpha-hydroxyvitamin D3 (alpha-D3) administration upon renal function in hypoparathyroid patients.
Design: This is a prospective long-term follow-up study of alpha-D3 administration on hypoparathyroid patients at a mean daily dose of 1 microgram (range 0.5-2.5 micrograms) during a total of 2040 patient-months.
Patients: Seventeen unselected patients (14 females and 3 males), two with primary and 15 with post-surgical hypoparathyroidism.
Results: The significant effect of alpha-D3 on serum and urinary calcium was achieved during the first week of treatment and remained stable at the same range during the close follow-up of 2040 patient-months. No significant change was observed in the serum creatinine during the whole follow-up period. During follow-up, five women developed hypercalciuria and one patient developed hypercalcaemia that disappeared when the dose of the drug was reduced or discontinued.
Conclusions: From our study we concluded that alpha-D3 is a safe and effective drug in the long-term therapy of hypoparathyroid patients.