(Abstract:)
Objective: The aim of the present study was to explore whether combined calcium and vitamin D supplementation is beneficial for osteoporosis in postmenopausal women.
Methods: We searched the PubMed, Cochrane library, Web of science and Embase databases and reference lists of eligible articles up to Feb, 2020. Randomized controlled trials (RCTs) evaluating the effect of combined calcium and vitamin D on osteoporosis in postmenopausal women were included in the present study.
Results: Combined calcium and vitamin D significantly increased total bone mineral density (BMD) (standard mean differences (SMD) = 0.537; 95% confidence interval (CI): 0.227 to 0.847), lumbar spine BMD (SMD = 0.233; 95% CI: 0.073 to 0.392; P < 0.001), arms BMD (SMD = 0.464; 95% CI: 0.186 to 0.741) and femoral neck BMD (SMD = 0.187; 95% CI: 0.010 to 0.364). It also significantly reduced the incidence of hip fracture (RR = 0.864; 95% CI: 0.763 to 0.979). Subgroup analysis showed that combined calcium and vitamin D significantly increased femoral neck BMD only when the dose of the vitamin D intake was no more than 400 IU d-1 (SMD = 0.335; 95% CI: 0.113 to 0.558), but not for a dose more than 400 IU d-1 (SMD = -0.098; 95% CI: -0.109 to 0.305), and calcium had no effect on the femoral neck BMD. Subgroup analysis also showed only dairy products fortified with calcium and vitamin D had a significant influence on total BMD (SMD = 0.784; 95% CI: 0.322 to 1.247) and lumbar spine BMD (SMD = 0.320; 95% CI: 0.146 to 0.494), but not for combined calcium and vitamin D supplement.
Conclusion: Dairy products fortified with calcium and vitamin D have a favorable effect on bone mineral density. Combined calcium and vitamin D supplementation could prevent osteoporosis hip fracture in postmenopausal women.
(Abstract:)
The aim was to meta-analyze randomized controlled trials of calcium plus vitamin D supplementation and fracture prevention. Meta-analysis showed a significant 15 % reduced risk of total fractures (summary relative risk estimate [SRRE], 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87).
Introduction: Calcium plus vitamin D supplementation has been widely recommended to prevent osteoporosis and subsequent fractures; however, considerable controversy exists regarding the association of such supplementation and fracture risk. The aim was to conduct a meta-analysis of randomized controlled trials [RCTs] of calcium plus vitamin D supplementation and fracture prevention in adults.
Methods: A PubMed literature search was conducted for the period from July 1, 2011 through July 31, 2015. RCTs reporting the effect of calcium plus vitamin D supplementation on fracture incidence were selected from English-language studies. Qualitative and quantitative information was extracted; random-effects meta-analyses were conducted to generate summary relative risk estimates (SRREs) for total and hip fractures. Statistical heterogeneity was assessed using Cochran’s Q test and the I (2) statistic, and potential for publication bias was assessed.
Results: Of the citations retrieved, eight studies including 30,970 participants met criteria for inclusion in the primary analysis, reporting 195 hip fractures and 2231 total fractures. Meta-analysis of all studies showed that calcium plus vitamin D supplementation produced a statistically significant 15 % reduced risk of total fractures (SRRE, 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87). Numerous sensitivity and subgroup analyses produced similar summary associations. A limitation is that this study utilized data from subgroup analysis of the Women’s Health Initiative.
Conclusions: This meta-analysis of RCTs supports the use of calcium plus vitamin D supplements as an intervention for fracture risk reduction in both community-dwelling and institutionalized middle-aged to older adults.
(Abstract:)
Objective: To determine whether increasing calcium intake from dietary sources affects bone mineral density (BMD) and, if so, whether the effects are similar to those of calcium supplements.
Design: Random effects meta-analysis of randomised controlled trials.
Data sources: Ovid Medline, Embase, Pubmed, and references from relevant systematic reviews. Initial searches were undertaken in July 2013 and updated in September 2014.
Eligibility criteria for selecting studies: Randomised controlled trials of dietary sources of calcium or calcium supplements (with or without vitamin D) in participants aged over 50 with BMD at the lumbar spine, total hip, femoral neck, total body, or forearm as an outcome.
Results: We identified 59 eligible randomised controlled trials: 15 studied dietary sources of calcium (n=1533) and 51 studied calcium supplements (n=12,257). Increasing calcium intake from dietary sources increased BMD by 0.6-1.0% at the total hip and total body at one year and by 0.7-1.8% at these sites and the lumbar spine and femoral neck at two years. There was no effect on BMD in the forearm. Calcium supplements increased BMD by 0.7-1.8% at all five skeletal sites at one, two, and over two and a half years, but the size of the increase in BMD at later time points was similar to the increase at one year. Increases in BMD were similar in trials of dietary sources of calcium and calcium supplements (except at the forearm), in trials of calcium monotherapy versus co-administered calcium and vitamin D, in trials with calcium doses of ≥ 1000 versus <1000 mg/day and ≤ 500 versus >500 mg/day, and in trials where the baseline dietary calcium intake was <800 versus ≥ 800 mg/day.
Conclusions: Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD, which are unlikely to lead to a clinically significant reduction in risk of fracture.