title: Effect of alendronate and vitamin D₃ on fractional calcium absorption in a double-blind, randomized, placebo-controlled trial in postmenopausal osteoporotic women.
abstract: Menopause and increasing age are associated with a decrease in calcium absorption that can contribute to the pathogenesis of osteoporosis. We hypothesized that alendronate plus vitamin D(3) (ALN + D) would increase fractional calcium absorption (FCA). In this randomized, double-blind, placebo-controlled multicenter clinical trial, 56 postmenopausal women with 25-hydroxyvitamin D [25(OH)D] concentrations of 25 ng/mL or less and low bone mineral density (BMD) received 5 weekly doses of placebo or alendronate 70 mg plus vitamin D(3) 2800 IU (ALN + D). Calcium intake was stabilized to approximately 1200 mg/d prior to randomization. FCA was determined using a dual-tracer stable-calcium isotope method. FCA and 25(OH)D were similar between treatment groups at baseline (0.31 ± 0.12 ng/mL and 19.8 ± 4.7 ng/mL, respectively). After 1 month of treatment, subjects randomized to ALN + D experienced a significant least squares (LS) mean [95% confidence interval (CI)] increase in FCA [0.070 (0.042, 0.098)], whereas FCA did not change significantly in the placebo group [-0.016 (-0.044, 0.012)]. After ALN + D treatment, patients had higher 25(OH)D levels (LS mean difference 7.3 ng/mL, p < .001). The rise in serum 1,25-dihydroxyvitamin D(3) (p < .02) and parathyroid hormone (p < .001) were greater in the ALN + D group than in placebo-treated patients. ALN + D was associated with an increase in FCA of 0.07. To our knowledge, there is no other trial showing such a marked rise in calcium absorption owing to treatment with a bisphosphonate or owing to a small rise in 25(OH)D. This unique response of ALN + D is important for the treatment of osteoporosis, but the exact mechanism requires further study.
authors: Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ 08901, USA. shapses@AESOP.Rutgers.edu
authors: Sue A
authors: SA
authors: Shapses
authors: David L
authors: DL
authors: Kendler
authors: Richard
authors: R
authors: Robson
authors: Karen E
authors: KE
authors: Hansen
authors: Robert M
authors: RM
authors: Sherrell
authors: M Paul
authors: MP
authors: Field
authors: Eric
authors: E
authors: Woolf
authors: Yulia
authors: Y
authors: Berd
authors: Ann Marie
authors: AM
authors: Mantz
authors: Arthur C
authors: AC
authors: Santora
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000009:adverse effects / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002118:Calcium / Q000378:metabolism* / Q000652:urine; D002762:Cholecalciferol / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000652:urine; D010919:Placebos
chemical_list: D050071:Bone Density Conservation Agents; D010919:Placebos; D002762:Cholecalciferol; D002118:Calcium; D019386:Alendronate