Silver Book Fact
A meta-analysis of clinical trials found that calcium supplements reduced the risk of vertebral fractures by around 23%.
Shea B, Wells G, Cranney A, Zytaruk N, et al. Meta-Analysis of Calcium Supplementation for the Prevention of Postmenopausal Osteoporosis. Endocr Rev. 2002; 23(4): 552-9. http://edrv.endojournals.org/cgi/content/full/23/4/552