Combination of Alfacalcidol with Calcium Can Improve Quadriceps Muscle Strength in Elderly Ambulatory Thai Women Who Have Hypovitaminosis D: A Randomized Controlled Trial
Thawee Songpatanasilp MD, MSc*, La-or Chailurkit PhD**, Akekachai Nichachotsalid BSc**, Manoj Chantarasorn MD*
Affiliation : * Department of Orthopedics, Phramongkutklao Army Hospital and College of Medicine, Bangkok, Thailand ** Division of Endocrinology and Metabolism, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Objective : The purpose of this study was to evaluate the efficacy of alfacalcidol and calcium on the improve-
ment of muscle strength in ambulatory elderly Thai women in age group of 65 or more who have hypovitami-
nosis D.
Material and Method: Seventy-two postmenopausal women age 65 years or more were enrolled to this study.
Blood was collected from all participants for measured of 25(OH)D3, intact PTH and vitamin D receptor
(VDR) genotypes. After blood collection, the quadriceps muscle strength was measured using the isokinetic
dynamometer device. There were 42 subjects who satisfy the eligible criteria and agreed to participate in the
experimental randomized controlled study. These subjects were randomized into two groups, one received
calcium 1500 g/day combined with alfacalcidol 0.5 mg/day. Another group received calcium 1500 g/day with
placebo.
Results : After 12 weeks of intervention, 40 subjects had the second muscle strength measurement (2 dropped
out). By ANCOVA analysis, there were significant improvement of muscle strength in the group that received
alfacalcidol compared to placebo in both 30o/sec (20.28 vs.16.29, p = 0.025) and 60o/sec (20.32 vs. 15.05, p
= 0.002) angular velocities.
Conclusion : Daily doses of 0.5 mg alfacalcidol with calcium effectively improved muscle strength in elderly
Thai women who had low level of 25(OH)D3 compared to calcium alone.
Keywords : Vitamin D metabolite, Hypovitaminosis D, Alfacalcidol, Muscle strength, Falls
