Narong BunyaratavejMahidol University2018-05-032018-05-032011-10-01Journal of the Medical Association of Thailand. Vol.94, No.10 SUPPL. (2011)012522082-s2.0-84858033850https://repository.li.mahidol.ac.th/handle/20.500.14594/12271The 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.Mahidol UniversityMedicineArticleSCOPUS