title: Impact of Calcium and Two Doses of Vitamin D on Bone Metabolism in the Elderly: A Randomized Controlled Trial.
abstract: The optimal dose of vitamin D to optimize bone metabolism in the elderly is unclear. We tested the hypothesis that vitamin D, at a dose higher than recommended by the Institute of Medicine (IOM), has a beneficial effect on bone remodeling and mass. In this double-blind trial we randomized 257 overweight elderly subjects to receive 1000 mg of elemental calcium citrate/day, and the daily equivalent of 3750 IU/day or 600 IU/day of vitamin D3 for 1 year. The subjects' mean age was 71 ± 4 years, body mass index 30 ± 4 kg/m2, 55% were women, and 222 completed the 12-month follow-up. Mean serum 25 hydroxyvitamin D (25OHD) was 20 ng/mL, and rose to 26 ng/mL in the low-dose arm, and 36 ng/mL in the high-dose arm, at 1 year (p < 0.05). Plasma parathyroid hormone, osteocalcin, and C-terminal telopeptide (Cross Laps) levels decreased significantly by 20% to 22% in both arms, but there were no differences between the two groups for any variable, at 6 or 12 months, with the exception of serum calcitriol, which was higher in the high-dose group at 12 months. Bone mineral density (BMD) increased significantly at the total hip and lumbar spine, but not the femoral neck, in both study arms, whereas subtotal body BMD increased in the high-dose group only, at 1 year. However, there were no significant differences in percent change BMD between the two study arms at any skeletal site. Subjects with serum 25OHD <20 ng/mL and PTH level >76 pg/mL showed a trend for higher BMD increments at all skeletal sites, in the high-dose group, that reached significance at the hip. Adverse events were comparable in the two study arms. This controlled trial shows little additional benefit in vitamin D supplementation at a dose exceeding the IOM recommendation of 600 IU/day on BMD and bone markers, in overweight elderly individuals. © 2017 American Society for Bone and Mineral Research.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Maya
authors.initials: M
authors.lastname: Rahme
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Sima Lynn
authors.initials: SL
authors.lastname: Sharara
authors.affiliation: Department of Rheumatology, Hotel Dieu de France, Beirut, Lebanon.
authors.forename: Rafic
authors.initials: R
authors.lastname: Baddoura
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Habib
authors.affiliation: Department of Endocrinology, Hotel Dieu de France, Beirut, Lebanon.
authors.forename: Georges
authors.initials: G
authors.lastname: Halaby
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Asma
authors.initials: A
authors.lastname: Arabi
authors.affiliation: Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Ravinder J
authors.initials: RJ
authors.lastname: Singh
authors.affiliation: Department of Endocrinology and Metabolism, University Hospital of Odense, Odense, Denmark.
authors.forename: Moustapha
authors.initials: M
authors.lastname: Kassem
authors.affiliation: Department of Healthcare Policy and Research, Weill Cornell Medicine, NY, USA.|Weill Cornell Medicine, Doha, Qatar.
authors.forename: Ziyad
authors.initials: Z
authors.lastname: Mahfoud
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Maha
authors.initials: M
authors.lastname: Hoteit
authors.affiliation: Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Rose T
authors.initials: RT
authors.lastname: Daher
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Darina
authors.initials: D
authors.lastname: Bassil
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Karim
authors.initials: K
authors.lastname: El Ferkh
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Ghada
authors.initials: G
authors.lastname: El-Hajj Fuleihan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000008:administration & dosage / Q000493:pharmacokinetics; D002762:Cholecalciferol / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D010384:Pelvic Bones / Q000378:metabolism*; D013997:Time Factors
chemical_list: D010281:Parathyroid Hormone; D002762:Cholecalciferol; D002118:Calcium
keywords: Elderly; IOM; bone markers; bone mineral density (BMD); high-dose vitamin D