The average rates out of BMD loss in earlier article-menopause women is approximately step one% a-year
I provided 59 randomised managed products and you will assessed the consequences out of one another fat reduction calcium supplements provide and you may calcium on the BMD on four skeletal internet sites and also at three time factors. The size of the fresh comment allowed an assessment of your outcomes toward BMD of various types of calcium supplements-diet source or supplements-as well as the outcomes within the extremely important subgroups like those defined because of the amount from calcium, usage of co-administered supplement D, and you may baseline clinical sites web de rencontres musicales gratuits qualities. The outcomes try in keeping with those individuals regarding a young meta-analysis regarding fifteen randomised regulated samples from calcium, and this said an increase in BMD of 1.6-2.0% over two to four years.72
An important maximum would be the fact BMD is a beneficial surrogate getting the fresh new health-related result of crack. I undertook the new feedback, yet not, once the some of the subgroup analyses throughout the dataset away from examples with break once the a keen endpoint have limited stamina,ten and you may a comparison anywhere between randomised controlled samples from slimming down present from calcium and calcium supplements having fracture because the endpoint is difficult while the just two short randomised managed examples out-of dieting sources of calcium supplements reported fracture investigation.10 Various other restriction would be the fact inside the 60% of your own meta-analyses, mathematical heterogeneity within degree is higher (I dos >50%). It seems reasonable variability regarding the outcome of incorporated products, although this was tend to from the exposure off a tiny amount of rural show. Subgroup analyses essentially don’t dramatically clean out otherwise explain the heterogeneity. I used random outcomes meta-analyses you to definitely take heterogeneity into account, in addition to their performance would be translated given that showing the typical result along side number of products.
Effects out-of results
Its lack of people interaction that have baseline losing weight calcium supplements intake or a dose-response loved ones suggests that broadening intake using weight-loss source or using drugs doesn’t right a diet deficiency (whereby deeper consequences could be observed in people with a low consumption and/or highest dosage). An alternative options would be the fact growing calcium intake has actually a deep failing anti-resorptive effect. Calcium beat indicators of bone formation and you will resorption by in the 20%,62 65 73 and broadening milk products consumption also decrease bone turount.74 Inhibition off bone turount could trigger the small observed grows when you look at the BMD.
Increases in BMD of about 1-2% over one to five years are unlikely to translate into clinically meaningful reductions in fractures. So the effect of increasing calcium intake is to prevent about one to two years of normal BMD loss, and if calcium intake is increased for more than one year it will slow down but not stop BMD loss. Epidemiological studies suggest that a decrease in BMD of one standard deviation is associated with an increase in the relative risk of fracture of about 1.5-2.0.75 A one standard deviation change in BMD is about equivalent to a 10% change in BMD. Based on these calculations, a 10% increase in BMD would be associated with a 33-50% reduction in risk of fracture. Therefore, the 1-2% increase in BMD observed with increased calcium intake would be predicted to produce a 5-10% reduction in risk of fracture. These estimates are consistent with findings from randomised controlled trials of other agents. The modest increases in BMD with increased calcium intake are smaller than observed with weak anti-resorptive agents such as etidronate76 and raloxifene.77 Etidronate, however, does not reduce vertebral or non-vertebral fractures, and raloxifene reduces vertebral but not non-vertebral fractures.78 In contrast, potent anti-resorptive agents such as alendronate, zoledronate, and denosumab increase BMD by 6-9% at the spine and 5-6% at the hip over three years.79 80 81 82 These changes are associated with reductions of 44-70% in vertebral fracture, 35-41% in hip fracture, and 15-25% in non-vertebral fractures.78 The magnitude of fracture reduction predicted by the small increases in BMD we observed with increased calcium intake are also consistent with the findings of our systematic review of calcium supplements and fracture.10 We observed small (<15%) inconsistent reductions in total and vertebral fracture overall but no reductions in fractures in the large randomised controlled trials at lowest risk of bias and no reductions in forearm or hip fractures.