Abstracted by Marcia J. Egles, MD, June 24, 2008 from \u201cEffect of calcium supplementation on fracture risk: a double-blind randomized controlled trial\u201d by Heike A Bischoff-Ferrari, Judy R Rees,\u00a0 Maria V Grau,\u00a0 Elizabeth Barry, Jiang Gui and John A Baron in The American Journal of Clinical Nutrition, Vol. 87, No. 6, 1945-1951, June 2008.\n<\/p>\n
\nThe medical literature contains conflicting findings and opinions about calcium supplements, with or without vitamin D, for bone health and osteoporosis prevention (1). A clinical trial begun in 1988 at six US locations, from Minnesota to southern California, found a clear benefit in reducing fracture risk among generally healthy Americans receiving 1,200 mg of supplemental calcium daily for four years. This was a follow-up to the Calcium Polyp Prevention Study (2).\n<\/p>\n
REFERENCE<\/strong><\/p>\n 1\u00a0 Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, et al. Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials. Am J Clin Nutr 2007;86:1579\u201380<\/p>\n 2\u00a0 Baron JA, Beach M, Mandel JS, et al. Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group. N Engl J Med 1999;340(2):101\u20137<\/p>\n","protected":false},"excerpt":{"rendered":" Abstracted by Marcia J. Egles, MD, June 24, 2008 from \u201cEffect of calcium supplementation on fracture risk: a double-blind randomized<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[727],"tags":[],"class_list":["post-16758","post","type-post","status-publish","format-standard","hentry","category-727"],"acf":[],"yoast_head":"\n
\nThe study
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\nCalcium Polyp Prevention included 1,118 men and women aged 27\u201379 (mean age 61) who had recently had a benign polyp* detected and removed during colonoscopy. They were randomly assigned to placebo tablets or 3 grams of calcium preparation (1,200 mg elemental calcium) daily for four years, without vitamin D or other calcium-containing supplements. Mean dietary calcium intake was 865 mg\/day in the placebo group and 889 mg\/day in the calcium group. Average blood vitamin D levels were slightly low, though nearly normal, in both groups. More than 83% reported taking at least 80% of the tablets over four years.
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\nThe original study reported a
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\nmodest reduction in bowel polyps at repeat colonoscopy in the calcium group compared with placebo. Participants were told the results but not their group allocation. Only 2% used calcium supplements before the trial, whereas 26% reported taking them for at least half of the follow-up years.
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\nThe new study
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\nexamined fractures in both groups during the four-year calcium treatment and through the end of follow-up in 2003. It recruited 930 participants, 72% men, for extended follow-up. Fractures were reported by telephone interviews, classified and confirmed through medical-record review by two independent physicians. Fractures were classified as minimal-trauma or significant-trauma. Minimal trauma meant a fracture following a fall from standing height or while sitting, standing or walking. Significant trauma included sports injuries, accidents or falls down stairs.
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\nDuring the four years of treatment
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\n, there were no minimal-trauma fractures in the calcium group versus nine in the placebo group. After calcium treatment ended, minimal-trauma fracture rates were statistically similar in both groups. Significant-trauma fracture rates were similar between groups during treatment and follow-up.
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\nThis is an important clinical trial
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\nshowing a modest reduction in fractures among generally healthy adults receiving 1,200 mg supplemental calcium daily. Including their usual dietary intake, total calcium intake among treated Americans was about 2,100 mg\/day. The source reports that the US National Institutes of Health and other experts generally recommend 1,200 mg calcium daily for adults and regard a total of 2,000\u20132,500 mg\/day from food and supplements as safe.<\/p>\n