Hip bone loss is attenuated with 1000 IU but not 400 IU daily vitamin D3: A 1‐year double‐blind RCT in postmenopausal women

• Published in: Journal of bone and mineral research 2013-10, Vol.28 (10), p.2202-2213
• Main Authors: Macdonald, Helen M, Wood, Adrian D, Aucott, Lorna S, Black, Alison J, Fraser, William D, Mavroeidi, Alexandra, Reid, David M, Secombes, Karen R, Simpson, William G, Thies, Frank
• Format: Article
• Language: English
• Subjects: Aged; Biomarkers - metabolism; Bone Density - drug effects; BONE LOSS; Bone Resorption - drug therapy; Bone Resorption - physiopathology; BONE TURNOVER MARKERS; Cholecalciferol - administration & dosage; Cholecalciferol - pharmacology; Cholecalciferol - therapeutic use; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Fibroblast Growth Factor-23; Hip - pathology; Hip - physiopathology; Humans; Middle Aged; Parathyroid Hormone - blood; POSTMENOPAUSAL WOMEN; Postmenopause - blood; Postmenopause - drug effects; RANDOMIZED CONTROLLED TRIAL; VITAMIN D; Vitamin D - analogs & derivatives; Vitamin D - blood; Withholding Treatment
• ISSN: 0884-0431; 1523-4681
• DOI: 10.1002/jbmr.1959

ABSTRACT Few year‐long vitamin D supplementation trials exist that match seasonal changes. The aim of this study was to determine whether daily oral vitamin D3 at 400 IU or 1000 IU compared with placebo affects annual bone mineral density (BMD) change in postmenopausal women in a 1‐year double‐blind placebo controlled trial in Scotland. White women aged 60 to 70 years (n = 305) were randomized to one of two doses of vitamin D or placebo. All participants started simultaneously in January/February 2009, attending visits at bimonthly intervals with 265 (87%) women attending the final visit and an additional visit 1 month after treatment cessation. BMD (Lunar iDXA) and 1,25‐dihydroxyvitamin D[1,25(OH)2D], N‐terminal propeptide of type 1 collagen [P1NP], C‐terminal telopeptide of type I collagen [CTX], and fibroblast growth factor‐23 [FGF23] were measured by immunoassay at the start and end of treatment. Circulating PTH, serum Ca, and total 25‐hydroxyvitamin D [25(OH)D] (latter by tandem mass spectrometry) were measured at each visit. Mean BMD loss at the hip was significantly less for the 1000 IU vitamin D group (0.05% ± 1.46%) compared with the 400 IU vitamin D or placebo groups (0.57% ± 1.33% and 0.60% ± 1.67%, respectively) (p