The present study aims to investigate a proper dose of alfacalcidol by using the parathyroid level as a marker due
to the end product of alfacalcidol is calcitriol which has a property of suppression secretion of parathyroid glands. The
research enrolled 259 volunteers which were divided into 2 groups. Each group took the elemental calcium 800 milligram
plus alfacalcidol at the different doses. Group (A) received alfacalcidol 1.0 microgram/day and Group (B) had alfacalcidol
1.5 micrograms/day for 3 months. Group (A) could not suppress the secretion of PTH compared with Group (B) of which the
PTH level was decreased significantly (p = 0.047). Alfacalcidol in both groups can not decrease the bone resorption
monitored by using the bone resorption marker, BetacrossLaps or bCTx.

Keywords: Alfacalcidol, Betacrosslap, bCTx, PTH