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Elemental calcium
About: Elemental calcium is a research topic. Over the lifetime, 333 publications have been published within this topic receiving 21401 citations.
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TL;DR: The effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women are studied.
Abstract: Background. Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known. Methods. We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [±SD] age, 84±6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 μg (800 IU) of vitamin D3, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women. Results. Among the women who completed the 18-month study, the number of hip fra...
2,714 citations
Ohio State University1, Fred Hutchinson Cancer Research Center2, University of Cincinnati3, University of Iowa4, University of California, Davis5, University of Alabama at Birmingham6, University of Arizona7, University of Washington8, Rush University Medical Center9, Wake Forest University10, University of Nevada, Reno11, University of Texas at San Antonio12, Kaiser Permanente13, University of Pittsburgh14, University of California, Los Angeles15, Stony Brook University16, Baylor College of Medicine17, University of North Carolina at Chapel Hill18, Wayne State University19, Howard University20, George Washington University21, University of California, Irvine22, University of Tennessee Health Science Center23, Medical College of Wisconsin24, University of California, San Diego25, Rutgers University26, University of Florida27, National Institutes of Health28, Harvard University29, University of Minnesota30, University of Massachusetts Boston31, University of Miami32, Emory University33, University of Wisconsin-Madison34, Stanford University35, Northwestern University36, University at Buffalo37, Brown University38, Yeshiva University39
TL;DR: Among healthy postmenopausal women, calcium with vitamin D supplementation resulted in a small but significant improvement in hip bone density, did not significantly reduce hip fracture, and increased the risk of kidney stones.
Abstract: Background The efficacy of calcium with vitamin D supplementation for preventing hip and other fractures in healthy postmenopausal women remains equivocal. Methods We recruited 36,282 postmenopausal women, 50 to 79 years of age, who were already enrolled in a Women's Health Initiative (WHI) clinical trial. We randomly assigned participants to receive 1000 mg of elemental calcium as calcium carbonate with 400 IU of vitamin D3 daily or placebo. Fractures were ascertained for an average follow-up period of 7.0 years. Bone density was measured at three WHI centers. Results Hip bone density was 1.06 percent higher in the calcium plus vitamin D group than in the placebo group (P<0.01). Intention-to-treat analysis indicated that participants receiving calcium plus vitamin D supplementation had a hazard ratio of 0.88 for hip fracture (95 percent confidence interval, 0.72 to 1.08), 0.90 for clinical spine fracture (0.74 to 1.10), and 0.96 for total fractures (0.91 to 1.02). The risk of renal calculi increased with...
1,765 citations
University at Buffalo1, Medical College of Wisconsin2, Fred Hutchinson Cancer Research Center3, Pfizer4, Memorial Hospital of Rhode Island5, University of Nevada, Reno6, University of Miami7, University of Minnesota8, University of Massachusetts Medical School9, Emory University10, National Institutes of Health11, University of California, Davis12, Yeshiva University13, University of Wisconsin-Madison14, Stanford University15, Northwestern University16, University of Iowa17, Kaiser Permanente18, University of Arizona19, University of Washington20, Rush University Medical Center21, Wake Forest University22, University of Texas at San Antonio23, University of California, Los Angeles24, University of California, San Diego25, University of Cincinnati26, Baylor College of Medicine27, University of North Carolina at Chapel Hill28, Wayne State University29, Howard University30, George Washington University31, University of California, Irvine32, Ohio State University33, University of Tennessee Health Science Center34, University of Pittsburgh35, Stony Brook University36, Rutgers University37, University of Alabama at Birmingham38, University of Florida39, Harvard University40
TL;DR: Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer among postmenopausal women, and the long latency associated with the development of colorescopy cancer, along with the seven-year duration of the trial, may have contributed to this null finding.
Abstract: Background Higher intake of calcium and vitamin D has been associated with a reduced risk of colorectal cancer in epidemiologic studies and polyp recurrence in polyp-prevention trials. However, randomized-trial evidence that calcium with vitamin D supplementation is beneficial in the primary prevention of colorectal cancer is lacking. Methods We conducted a randomized, double-blind, placebo-controlled trial involving 36,282 postmenopausal women from 40 Women’s Health Initiative centers: 18,176 women received 500 mg of elemental calcium as calcium carbonate with 200 IU of vitamin D3 twice daily (1000 mg of elemental calcium and 400 IU of vitamin D3) and 18,106 received a matching placebo for an average of 7.0 years. The incidence of pathologically confirmed colorectal cancer was the designated secondary outcome. Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case–control study. Results The incidence of invasive colorectal cancer did not differ significantly between women assigned to calcium plus vitamin D supplementation and those assigned to placebo (168 and 154 cases; hazard ratio, 1.08; 95 percent confidence interval, 0.86 to 1.34; P = 0.51), and the tumor characteristics were similar in the two groups. The frequency of colorectal-cancer screening and abdominal symptoms was similar in the two groups. There were no significant treatment interactions with baseline characteristics. Conclusions Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer among postmenopausal women. The long latency associated with the development of colorectal cancer, along with the seven-year duration of the trial, may have contributed to this null finding. Ongoing follow-up will assess the longer-term effect of this intervention. (ClinicalTrials.gov number, NCT00000611.)
970 citations
TL;DR: Calcium supplementation is associated with a significant - though moderate - reduction in the risk of recurrent colorectal adenomas, independent of initial dietary fat and calcium intake.
Abstract: Background and Methods Laboratory, clinical, and epidemiologic evidence suggests that calcium may help prevent colorectal adenomas. We conducted a randomized, double-blind trial of the effect of supplementation with calcium carbonate on the recurrence of colorectal adenomas. We randomly assigned 930 subjects (mean age, 61 years; 72 percent men) with a recent history of colorectal adenomas to receive either calcium carbonate (3 g [1200 mg of elemental calcium] daily) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The primary end point was the proportion of subjects in whom at least one adenoma was detected after the first follow-up endoscopy but up to (and including) the second follow-up examination. Risk ratios for the recurrence of adenomas were adjusted for age, sex, lifetime number of adenomas before the study, clinical center, and length of the surveillance period. Results The subjects in the calcium group had a lower risk of recurrent adenomas. Among the...
834 citations
TL;DR: Women who received calcitriol had a significant reduction in the rate of new vertebral fractures during the second and third years of treatment, as compared with the women who received calcium.
Abstract: Background and Methods. Osteoporosis is a common problem whose management is controversial. To evaluate the efficacy and safety of calcitriol (1,25-dihydroxyvitamin D3) in the treatment of postmenopausal osteoporosis, we conducted a three-year prospective, multicenter, single-blind study in 622 women who had one or more vertebral compression fractures. The women were randomly assigned to receive treatment with calcitriol (0.25 μg twice a day) or supplemental calcium (1 g of elemental calcium daily) for three years. New vertebral fractures were detected by means of lateral roentgenography of the spine each year, and calcium absorption was measured in 392 of the women. Results. The women who received calcitriol had a significant reduction in the rate of new vertebral fractures during the second and third years of treatment, as compared with the women who received calcium (second year, 9.3 vs. 25.0 fractures per 100 patient-years; third year, 9.9 vs. 31.5 fractures per 100 patient-years; P<0.001). This effec...
539 citations