Up to now, the effectiveness of an oral daily alfacalcidol on SHPT has been confirmed at the dose of 0.25-0.5 μg /day (average 0.364μg /day), 0.5 μg /day, and 1.0 μg /day. The effective dose of OCT has also been verified, and furthermore, it has also been reported that intravenous vitamin D was more effective than oral vitamin D for suppressing PTH secretion. Accordingly, at present intravenous vitamin D therapy is the standard treatment for SHPT, and there are established protocols with regard to dosage and administration. However, no protocols have been established for maintenance therapy using intravenous or oral vitamin D preparations after the control of iPTH target range has been achieved.