Correcting calcium nutritional deficiency prevents spine fractures in elderly women

Calcium supplementation for people with overweight or obesity

BACKGROUND

Obesity is a major health problem worldwide as it can lead to high blood pressure, heart disease, stroke, diabetes, and insulin resistance. The prevalence of overweight and obesity is increasing worldwide across different age groups. There is evidence of an inverse relationship between calcium intake and body weight. The clinical relevance of a small reduction in body weight has been questioned. However, at a population level, a small effect could mitigate the observed global trends.

OBJECTIVES

To assess the effects of calcium supplementation on weight loss in individuals living with overweight or obesity.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS (Latin American and Caribbean Health Science Information database), and two clinical trials registries. The date of the last search of all databases (except Embase) was 10 May 2023. No language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials evaluating the effect of calcium in participants with overweight or obesity of any age or gender. We excluded studies in participants with absorption problems. We included studies of any dose with a minimum duration of two months. We included the following comparisons: calcium supplementation versus placebo, calcium-fortified food or beverage versus placebo, or calcium-fortified food or beverage versus non-calcium-fortified food or beverage. We excluded studies that evaluated the effect of calcium and vitamin D or mixed minerals compared to placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were body weight, health-related quality of life, and adverse events. Our secondary outcomes were anthropometric measures other than body weight, all-cause mortality, and morbidity.

MAIN RESULTS

We found 18 studies that evaluated the effect of calcium compared to placebo or control, with a total of 1873 randomised participants (950 participants in the calcium supplementation groups and 923 in the control groups). All included studies gave oral calcium supplementation as the intervention. We did not find any studies evaluating calcium-fortified foods. We excluded 38 studies, identified four ongoing studies, and listed one study as 'awaiting classification'. Sixteen studies compared calcium supplementation to placebo; two studies compared different doses of calcium supplementation. Doses ranged from very low (0.162 g of calcium/day) to high (1.5 g of calcium/day). Most studies were performed in the USA and Iran, lasted less than six months, and included only women. Low-certainty evidence suggests that calcium supplementation compared to placebo or control may result in little to no difference in body weight (mean difference (MD) -0.15 kg, 95% confidence interval (CI) -0.55 to 0.24; P = 0.45, I2 = 46%; 17 studies, 1317 participants; low-certainty evidence). We downgraded the certainty of the evidence by two levels for risk of bias and heterogeneity. None of the included studies reported health-related quality of life, all-cause mortality, or morbidity/complications as outcomes. Only five studies assessed or reported adverse events. Low-certainty evidence suggests a low frequency of adverse events, with no clear difference between intervention and control groups. Moderate-certainty evidence shows that calcium supplementation compared to placebo or control probably results in a small reduction in body mass index (BMI) (MD -0.18 kg/m2,95% CI -0.22 to -0.13; P < 0.001, I2 = 0%; 9 studies, 731 participants) and waist circumference (MD -0.51 cm, 95% CI -0.72 to -0.29; P < 0.001, I2 = 0%; 6 studies, 273 participants). Low-certainty evidence suggests that calcium supplementation compared to placebo or control may result in a small reduction in body fat mass (MD -0.34 kg, 95% CI -0.73 to 0.05; P < 0.001, I2 = 97%; 12 studies, 812 participants).

AUTHORS' CONCLUSIONS

Calcium supplementation for eight weeks to 24 months may result in little to no difference in body weight in people with overweight or obesity. The current evidence is of low certainty, due to concerns regarding risk of bias and statistical heterogeneity. We found that the degree of heterogeneity might be partly explained by calcium dosage, the presence or absence of a co-intervention, and whether an intention-to-treat analysis was pursued. While our analyses suggest that calcium supplementation may result in a small reduction in BMI, waist circumference, and fat mass, this evidence is of low to moderate certainty. Future studies could investigate the effect of calcium supplementation on lean body mass to explore if there is a change in body composition.

Refracture following vertebral fragility fracture when bone fragility is not recognized: summarizing findings from comparator arms of randomized clinical trials

PURPOSE

Since vertebral fragility fractures (VFFs) might increase the risk of subsequent fractures, we evaluated the incidence rate and the refracture risk of subsequent vertebral and non-vertebral fragility fractures (nVFFs) in untreated patients with a previous VFF.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library up to February 2022 for randomized clinical trials (RCTs) that analyzed the occurrence of subsequent fractures in untreated patients with prior VFFs. Two authors independently extracted data and appraised the risk of bias in the selected studies. Primary outcomes were subsequent VFFs, while secondary outcomes were further nVFFs. The outcome of refracture within ≥ 2 years after the index fracture was measured as (i) rate, expressed per 100 person-years (PYs), and (ii) risk, expressed in percentage.

RESULTS

Forty RCTs met our inclusion criteria, ranging from medium to high quality. Among untreated patients with prior VFFs, the rate of subsequent VFFs and nVFFs was 12 [95% confidence interval (CI) 9-16] and 6 (95% CI 5-8%) per 100 PYs, respectively. The higher the number of previous VFFs, the higher the incidence. Moreover, the risk of VFFs and nVFFs increased within 2 (16.6% and 8%) and 4 years (35.1% and 17.4%) based on the index VFF.

CONCLUSION

The highest risk of subsequent VFFs or nVFFs was already detected within 2 years following the initial VFF. Thus, prompt interventions should be designed to improve the detection and treatment of VFFs, aiming to reduce the risk of future FFs and properly implement secondary preventive measures.

The Influences of Macronutrients on Bone Mineral Density, Bone Turnover Markers, and Fracture Risk in Elderly People: A Review of Human Studies

Osteoporosis is a health condition that involves weak bone mass and a deteriorated microstructure, which consequently lead to an increased risk of bone fractures with age. In elderly people, a fracture attributable to osteoporosis elevates mortality. The objective of this review was to examine the effects of macronutrients on bone mineral density (BMD), bone turnover markers (BTMs), and bone fracture in elderly people based on human studies. A systematic search was conducted in the PubMed®/MEDLINE® database. We included human studies published up to April 2023 that investigated the association between macronutrient intake and bone health outcomes. A total of 11 meta-analyses and 127 individual human studies were included after screening the records. Carbohydrate consumption seemed to have neutral effects on bone fracture in limited studies, but human studies on carbohydrates' effects on BMD or/and BTMs are needed. The human studies analyzed herein did not clearly show whether the intake of animal, vegetable, soy, or milk basic proteins has beneficial effects on bone health due to inconsistent results. Moreover, several individual human studies indicated an association between eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and osteocalcin. Further studies are required to draw a clear association between macronutrients and bone health in elderly people.

Association between a Calcium-to-Magnesium Ratio and Osteoporosis among Puerto Rican Adults

BACKGROUND

The ratio of calcium-to-magnesium intake (Ca:Mg) may be important for bone due to their competitive absorption. The Ca:Mg ratio has been related to health outcomes, but few studies have related it to bone.

OBJECTIVES

The purpose of this analysis was to examine associations between the Ca:Mg intake with bone mineral density (BMD) and osteoporosis among Puerto Rican adults.

METHODS

Adults, aged 47-79 y, from the Boston Puerto Rican Osteoporosis Study, with complete BMD and dietary data (n = 955) were included. BMD was assessed with dual-energy X-ray absorptiometry and diet by a food frequency questionnaire. Calcium and magnesium intakes from food were energy adjusted, and the Ca:Mg was calculated. Adjusted linear and logistic regression models were utilized for testing associations between Ca:Mg and bone outcomes.

RESULTS

Calcium intake was greater in the highest compared with lowest tertile, whereas magnesium intake was similar across tertiles. Mean BMD at hip sites was higher in the middle, compared with the lowest, tertile. Higher odds of osteoporosis were observed for the highest and lowest tertiles, compared with the middle tertile, after adjustment (T3 compared with T2 OR: 2.79; 95% CI: 1.47, 5.3; T1 compared with T2 OR: 2.01; 95% CI: 1.03, 3.92). Repeated analyses without supplement users (n = 432) led to stronger differences and ORs, but lost significance for some comparisons.

CONCLUSIONS

Dietary calcium and magnesium are important for bone, perhaps not independently. The Ca:Mg intake ratio appeared most protective within a range of 2.2-3.2, suggesting that a balance of these nutrients may be considered in recommendations for osteoporosis..

Association between dietary selenium intake and the prevalence of osteoporosis: a cross-sectional study

Objective

To examine the correlation between dietary selenium (Se) intake and the prevalence of osteoporosis (OP) in the general middle-aged and older population in China.

Methods

Data for analyses were collected from a population based cross-sectional study performed at the Xiangya Hospital Health Management Centre. Dietary Se intake was evaluated using a validated semi-quantitative food frequency questionnaire. OP was diagnosed on the basis of bone mineral density scans using a compact radiographic absorptiometry system. The correlation between dietary Se intake and the prevalence of OP was primarily examined by multivariable logistic regression.

Results

This cross-sectional study included a total of 6267 subjects (mean age: 52.2 ± 7.4 years; 42% women), and the prevalence of OP among the included subjects was 9.6% (2.3% in men and 19.7% in women). Compared with the lowest quartile, the energy intake, age, gender and body mass index (BMI)-adjusted odds ratios of OP were 0.72 (95% confidence interval [CI] 0.55–0.94), 0.72 (95% CI 0.51–1.01) and 0.47 (95% CI 0.31–0.73) for the second, third and fourth quartiles of dietary Se intake, respectively (P for trend = 0.001). The results remained consistent in male and female subjects. Adjustment for additional potential confounders (i.e., smoking status, drinking status, physical activity level, nutritional supplements, diabetes, hypertension, fibre intake, and calcium intake) did not cause substantial changes to the results.

Conclusions

In the middle-aged and older humans, participants with lower levels of dietary Se intake have a higher prevalence of OP in a dose-response manner.

Comparison of fracture risk using different supplemental doses of vitamin D, calcium or their combination: a network meta-analysis of randomised controlled trials

OBJECTIVE

Inconsistent findings in regard to association between different concentrations of vitamin D, calcium or their combination and the risk of fracture have been reported during the past decade in community-dwelling older people. This study was designed to compare the fracture risk using different concentrations of vitamin D, calcium or their combination.

DESIGN

A systematic review and network meta-analysis.

DATA SOURCES

Randomised controlled trials in PubMed, Cochrane library and Embase databases were systematically searched from the inception dates to 31 December 2017.

OUTCOMES

Total fracture was defined as the primary outcome. Secondary outcomes were hip fracture and vertebral fracture. Due to the consistency of the original studies, a consistency model was adopted.

RESULTS

A total of 25 randomised controlled trials involving 43 510 participants fulfilled the inclusion criteria. There was no evidence that the risk of total fracture was reduced using different concentrations of vitamin D, calcium or their combination compared with placebo or no treatment. No significant associations were found between calcium, vitamin D, or combined calcium and vitamin D supplements and the incidence of hip or vertebral fractures.

CONCLUSIONS

The use of supplements that included calcium, vitamin D or both was not found to be better than placebo or no treatment in terms of risk of fractures among community-dwelling older adults. It means the routine use of these supplements in community-dwelling older people should be treated more carefully.

PROSPERO REGISTRATION NUMBER

CRD42017079624.

Molecular-Based Treatment Strategies for Osteoporosis: A Literature Review

Osteoporosis is an unavoidable public health problem in an aging or aged society. Anti-resorptive agents (calcitonin, estrogen, and selective estrogen-receptor modulators, bisphosphonates, anti-receptor activator of nuclear factor κB ligand antibody along with calcium and vitamin D supplementations) and anabolic agents (parathyroid hormone and related peptide analogs, sclerostin inhibitors) have major roles in current treatment regimens and are used alone or in combination based on the pathological condition. Recent advancements in the molecular understanding of bone metabolism and in bioengineering will open the door to future treatment paradigms for osteoporosis, including antibody agents, stem cells, and gene therapies. This review provides an overview of the molecular mechanisms, clinical evidence, and potential adverse effects of drugs that are currently used or under development for the treatment of osteoporosis to aid clinicians in deciding how to select the best treatment option.

Dairy foods and bone health throughout the lifespan: a critical appraisal of the evidence

The consumption of high-Ca, high-protein dairy foods (i.e. milk, cheese, yogurt) is advocated for bone health across the lifespan to reduce the risk of low-trauma fractures. However, to date, the anti-fracture efficacy of dairy food consumption has not been demonstrated in randomised controlled trials but inferred from cross-sectional and prospective studies. The anti-fracture efficacy of dairy food consumption is plausible, but testing this requires a robust study design to ensure outcomes are suitably answering this important public health question. The evidence of skeletal benefits of dairy food consumption is equivocal, not because it may not be efficacious but because the study design and execution are often inadequate. The key issues are compliance with dietary intervention, dropouts, sample sizes and most importantly lack of deficiency before intervention. Without careful appraisal of the design and execution of available studies, precarious interpretations of outcomes may be made from these poorly designed or executed studies, without consideration of how study design may be improved. Dairy food interventions in children are further hampered by heterogeneity in growth: in particular sex and maturity-related differences in the magnitude, timing, location and surface-specific site of bone accrual. Outcomes of studies combining children of different sexes and maturity status may be masked or exaggerated by these differences in growth, so inaccurate conclusions are drawn from results. Until these critical issues in study design are considered in future dairy food interventions, the anti-fracture efficacy of dairy food consumption may remain unknown and continue to be based on conjecture.

Under-Recognition of Fractures as Osteoporosis Indicators

After the first fracture, the risk of subsequent fractures increases significantly. Medical treatment can reduce the risk of a second fracture by about 50%, but many older adults do not receive osteoporosis medication following their first fracture. This observational study aimed to understand primary care management patterns of older adults after osteoporotic fractures at the Miami Veterans Affairs (VA) Healthcare System. A retrospective review of 219 fracture cases selected by International Classification of Disease (ICD-9) codes between October 2015 and September 2016 identified 114 individuals age ≥50 years who had a non-traumatic fracture code entered in their medical record for the first time. Among them, 72 (63%) did not undergo a bone mineral density (BMD) test or receive treatment in the 12 months following their fracture. Of the 40 individuals who had a BMD test post-fracture, 17 (100%) received or were considered for anti-osteoporosis treatment if their T-score indicated osteoporosis (T-score ≤−2.5), but only 8/23 (35%) if the T-score was >−2.5. Physicians are more likely to prescribe osteoporosis therapy based on a BMD T-score diagnosis of osteoporosis, rather than a clinical diagnosis of osteoporosis based on a low-trauma fracture. A change in practice patterns is necessary to decrease the incidence of fractures.

Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis

IMPORTANCE

The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal. Previous studies have reached mixed conclusions regarding the association between calcium, vitamin D, or combined calcium and vitamin D supplements and fracture incidence in older adults.

OBJECTIVE

To investigate whether calcium, vitamin D, or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults.

DATA SOURCES

The PubMed, Cochrane library, and EMBASE databases were systematically searched from the inception dates to December 24, 2016, using the keywords calcium, vitamin D, and fracture to identify systematic reviews or meta-analyses. The primary randomized clinical trials included in systematic reviews or meta-analyses were identified, and an additional search for recently published randomized trials was performed from July 16, 2012, to July 16, 2017.

STUDY SELECTION

Randomized clinical trials comparing calcium, vitamin D, or combined calcium and vitamin D supplements with a placebo or no treatment for fracture incidence in community-dwelling adults older than 50 years.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers performed the data extraction and assessed study quality. A meta-analysis was performed to calculate risk ratios (RRs), absolute risk differences (ARDs), and 95% CIs using random-effects models.

MAIN OUTCOMES AND MEASURES

Hip fracture was defined as the primary outcome. Secondary outcomes were nonvertebral fracture, vertebral fracture, and total fracture.

RESULTS

A total of 33 randomized trials involving 51 145 participants fulfilled the inclusion criteria. There was no significant association of calcium or vitamin D with risk of hip fracture compared with placebo or no treatment (calcium: RR, 1.53 [95% CI, 0.97 to 2.42]; ARD, 0.01 [95% CI, 0.00 to 0.01]; vitamin D: RR, 1.21 [95% CI, 0.99 to 1.47]; ARD, 0.00 [95% CI, -0.00 to 0.01]. There was no significant association of combined calcium and vitamin D with hip fracture compared with placebo or no treatment (RR, 1.09 [95% CI, 0.85 to 1.39]; ARD, 0.00 [95% CI, -0.00 to 0.00]). No significant associations were found between calcium, vitamin D, or combined calcium and vitamin D supplements and the incidence of nonvertebral, vertebral, or total fractures. Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose, sex, fracture history, dietary calcium intake, and baseline serum 25-hydroxyvitamin D concentration.

CONCLUSIONS AND RELEVANCE

In this meta-analysis of randomized clinical trials, the use of supplements that included calcium, vitamin D, or both compared with placebo or no treatment was not associated with a lower risk of fractures among community-dwelling older adults. These findings do not support the routine use of these supplements in community-dwelling older people.

Aging human body: changes in bone, muscle and body fat with consequent changes in nutrient intake

Aging affects almost all physiological processes, but changes in body composition and body phenotype are most observable. In this review, we focus on these changes, including loss of bone and muscle and increase in body fat or redistribution of the latter, possibly leading to osteosarcopenic obesity syndrome. We also address low-grade chronic inflammation, prevalent in aging adults and a cause of many disorders including those associated with body composition. Changes in dietary intake and nutritional requirements of older individuals, that all may lead to some disturbances on tissue and organ levels, are discussed as well. Finally, we discuss the hormonal changes in the aging body, considering each of the tissues, bone, muscle and fat as separate endocrine organs, but yet in the continuous interface and communication with each other. Although there are still many unanswered questions in this field, this review will enable the readers to better understand the aging human body and measures needing to be implemented toward reducing impaired health and disability in older individuals.

Associations of dietary calcium intake with metabolic syndrome and bone mineral density among the Korean population: KNHANES 2008-2011

Excessive amount of calcium intake increased risk for metabolic syndrome in men. However, modest amount decreased the risk of metabolic syndrome and osteoporosis in postmenopausal women. Modest amount of calcium also increased bone mineral density (BMD) in both men and postmenopausal women.

INTRODUCTION

The present study aimed to evaluate the associations of dietary calcium intake with metabolic syndrome and bone mineral density (BMD) in Korean men and women, especially postmenopausal women.

METHODS

The study was performed using data from the Korean National Health and Nutrition Examination Survey (2008-2011) and included 14,705 participants (5953 men, 4258 premenopausal women, and 4494 postmenopausal women). Clinical and other objective characteristics, presence of metabolic syndrome, and the BMD of the femur neck and lumbar spine were evaluated according to dietary calcium intake.

RESULTS

There was a higher tendency for metabolic syndrome in men with a dietary calcium intake of >1200 mg/day than with ≤400 mg of calcium intake; >400 and ≤800 mg of calcium intake was helpful for postmenopausal women to decrease risk for metabolic syndrome. Overall, the group with calcium intake >400 and ≤800 mg daily had significantly increased BMD in both femoral neck and lumbar spine from both men and postmenopausal women. From both femoral neck and lumbar spine, the prevalence of osteoporosis in postmenopausal women significantly decreased in the group whose calcium intake was >400 and ≤800 mg daily.

CONCLUSION

Excessive dietary calcium may increase the prevalence of metabolic syndrome in men. For postmenopausal women, calcium intake does not increase the risk of metabolic syndrome, but modest amount decreases the risk. It may increase the BMD in men and postmenopausal women, and also reduce the prevalence of both osteoporosis and metabolic syndrome in postmenopausal women.

Perioperative Medical Management of Spine Surgery Patients With Osteoporosis

Management of spine surgery patients with osteoporosis is challenging because of the difficulty of instrumenting and the potential complications, including nonunion and adjacent level fractures. Treatment of this patient population should involve a multidisciplinary approach including the spine surgeon, primary care physician, endocrinologist, and physical therapist. Indication for preoperative treatment before spinal fusion surgery is unclear. All patients should receive calcium and vitamin D. Hormone replacement therapy, including estrogen or selective estrogen receptor modulators, should be considered for elderly female patients with decreased bone mass. Bisphosphonates or intermittent parathyroid hormone are reserved for those with significant bone loss in the spine. Pretreatment with antiresorption medications affect bone remodeling, which is a vital part of graft incorporation and fusion. Although there have been numerous animal studies, there is limited clinical evidence. Accordingly, surgery should be delayed, if possible, to treat the osteoporosis before the intervention. Treatment may include bisphosphonates, as well as newer agents, such as recombinant parathyroid hormone. Further clinical data are needed to understand the relative advantages/disadvantage of antiresorptive vs anabolic agents, as well as the impact of administration of these medications before vs after fusion surgery. Future clinical studies will enable better understanding of the impact of current therapies on biomechanics and fusion outcomes in this unique and increasingly prevalent patient population.

The treatment of severe postmenopausal osteoporosis : a review of current and emerging therapeutic options

Several chemical entities have shown their ability to reduce axial and/or appendicular fractures in patients with osteoporosis. Since patients who have experienced a previous fracture are at high risk for subsequent vertebral or hip fracture, it is of prime importance to treat such patients with medications that have unequivocally demonstrated their ability to reduce fracture rates in patients with prevalent fractures. Results obtained with calcium and vitamin D, in this particular population, are not fully satisfactory and these medications are probably better used in conjunction with other therapeutic regimens. Bisphosphonates have shown their ability to reduce vertebral (alendronate, risedronate, ibandronate) and non-vertebral (alendronate, risedronate) fractures in patients with established osteoporosis. Raloxifene has also shown similar properties, notwithstanding its effect on non-vertebral fractures, which has only been derived from a post hoc analysis limited to patients with prevalent severe vertebral fractures at baseline. This compound also has interesting non-skeletal benefits, including effects on the breast and heart. Teriparatide, a bone-forming agent, promptly reduces the rate of vertebral and all non-vertebral fractures, without significant adverse effects. Strontium ranelate, the first agent shown to concomitantly decrease bone resorption and stimulate bone formation, has also shown its ability to reduce rates of vertebral and non-vertebral fractures in patients with established osteoporosis. It significantly reduces hip fractures in elderly individuals at high risk for such events. Its safety profile is also excellent.

Effects of Zoledronate on Mortality and Morbidity after Surgical Treatment of Hip Fractures

We aimed to evaluate the effects of intertrochanteric femoral fractures on mortality, morbidity, and cost of zoledronate treatment in elderly patients treated by osteosynthesis. Based on Evans classification, 114 patients with unstable intertrochanteric femoral fractures were treated with osteosynthesis. After the surgical treatment of intertrochanteric fractures, the treatment group (M/F, 24/32; mean age, 76.7 ± SD years) received zoledronate infusion, and the control group (M/F, 20/38; mean age, 80.2 ± SD years) received placebo. Postoperative control visits were performed at 6-week, 3-month, 6-month, and 12-month time points. Functional level of patients was evaluated by the modified Harris hip score and Merle d'Aubigné hip score. By 12 months, the mean HHS in treatment and control groups was 81.93 and 72.9, respectively. For time of death of the patients, mortality was found to be 57.1% (16/28) on the first 3 months and 92.9% (26/28) on the first six months. The mortality rate in the treatment and control groups was 14.3% (8/56) and 34.5% (20/58), respectively. The use of zoledronic acid after surgical treatment of intertrochanteric femoral fractures in osteoporotic elderly patients is a safe treatment modality which helps to reduce mortality, improves functional outcomes, and has less side effects with single dose use per year.

The Role of Calcium in Ameliorating the Oxidative Stress of Fluoride in Rats

The present study was carried out to investigate the effects of fluoride toxicity on some biochemical, hormonal, and histological parameters of female rats and the protective role of calcium against such effects. Adult female albino rats were divided into five groups; control group received distilled water for 60 days, calcium group received calcium carbonate with dose of 50 mg/kg three times per week for 60 days, fluoride group received sodium fluoride with dose of 20 mg/kg three times per week for 60 days, calcium + fluoride group received calcium carbonate (50 mg/kg) then after 2 h received sodium fluoride (20 mg/kg) three times per week for 60 days, and fluoride + calcium group received sodium fluoride (20 mg/kg) three times per week for 30 days then received calcium carbonate (50 mg/kg) three times per week for another 30 days. The results showed that the levels of thiobarbituric acid reactive substances, urea, creatinine, alkaline phosphatase, triiodothyronine, thyroxine, parathormone, phosphorous, magnesium, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma glutamyl transferase were significantly increased in rats treated with fluoride while serum estradiol, calcium, and organ glutathione were significantly decreased. The histological examination of the femur bone revealed that fluoride treatment induced thinning of bone trabeculae with wilding of marrow space, demineralization, and loss of trabeculae interconnections. Also, the histological examination of hepatic and renal tissues of fluoride-treated rats showed some damages in these tissues while administration of calcium carbonate for 30 or 60 days during fluoride treatment minimized such damages. It could be concluded that administration of calcium to female rats can ameliorate the hazardous effects of fluoride observed in the biochemical, hormonal, and histological parameters.

Calcium intake and bone mineral density: systematic review and meta-analysis

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.

Calcium intake and risk of fracture: systematic review

OBJECTIVE

To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures.

DESIGN

Systematic review of randomised controlled trials and observational studies of calcium intake with fracture as an endpoint. Results from trials were pooled with random effects meta-analyses.

DATA SOURCES

Ovid Medline, Embase, PubMed, and references from relevant systematic reviews. Initial searches undertaken in July 2013 and updated in September 2014.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials or cohort studies of dietary calcium, milk or dairy intake, or calcium supplements (with or without vitamin D) with fracture as an outcome and participants aged >50.

RESULTS

There were only two eligible randomised controlled trials of dietary sources of calcium (n=262), but 50 reports from 44 cohort studies of relations between dietary calcium (n=37), milk (n=14), or dairy intake (n=8) and fracture outcomes. For dietary calcium, most studies reported no association between calcium intake and fracture (14/22 for total, 17/21 for hip, 7/8 for vertebral, and 5/7 for forearm fracture). For milk (25/28) and dairy intake (11/13), most studies also reported no associations. In 26 randomised controlled trials, calcium supplements reduced the risk of total fracture (20 studies, n=58,573; relative risk 0.89, 95% confidence interval 0.81 to 0.96) and vertebral fracture (12 studies, n=48,967. 0.86, 0.74 to 1.00) but not hip (13 studies, n=56,648; 0.95, 0.76 to 1.18) or forearm fracture (eight studies, n=51,775; 0.96, 0.85 to 1.09). Funnel plot inspection and Egger's regression suggested bias toward calcium supplements in the published data. In randomised controlled trials at lowest risk of bias (four studies, n=44,505), there was no effect on risk of fracture at any site. Results were similar for trials of calcium monotherapy and co-administered calcium and vitamin D. Only one trial in frail elderly women in residential care with low dietary calcium intake and vitamin D concentrations showed significant reductions in risk of fracture.

CONCLUSIONS

Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures. Evidence that calcium supplements prevent fractures is weak and inconsistent.

Calcium Supplements and Cardiovascular Disease: A Review

Dietary or supplemental calcium intake has long been encouraged for optimal bone health. However, more recently, the safety of calcium supplementation has been questioned because of a possible association between supplemental calcium and cardiovascular risk. Whereas calcium may have a beneficial or neutral effect on cardiovascular risk factors such as blood pressure, cholesterol, weight, and diabetes, available evidence does not provide a definitive answer for an association with cardiovascular disease (CVD). To date, no calcium trials have studied cardiovascular disease as a primary end point, and larger trials with longer follow-up are needed. In this review, we present results from observational studies and randomized controlled trials (RCTs) that have evaluated calcium intake (dietary or supplemental) in relation to cardiovascular risk factors and cardiovascular disease as a secondary outcome. Results from RCTs are mixed regarding CVD risk in those using supplemental calcium with or without vitamin D, and more large-scale randomized trials designed specifically with CVD as the primary end point are needed. Evidence suggests that it is reasonable to encourage adequate dietary calcium intake, especially for postmenopausal women who are at greatest risk for osteoporotic fracture.

Building healthy bones throughout life: an evidence-informed strategy to prevent osteoporosis in Australia

Osteoporosis imposes a tremendous burden on Australia: 1.2 million Australians have osteoporosis and 6.3 million have osteopenia. In the 2007–08 financial year, 82 000 Australians suffered fragility fractures, of which > 17 000 were hip fractures. In the 2000–01 financial year, direct costs were estimated at $1.9 billion per year and an additional $5.6 billion on indirect costs. Osteoporosis was designated a National Health Priority Area in 2002; however, implementation of national plans has not yet matched the rhetoric in terms of urgency. Building healthy bones throughout life, the Osteoporosis Australia strategy to prevent osteoporosis throughout the life cycle, presents an evidence-informed set of recommendations for consumers, health care professionals and policymakers. The strategy was adopted by consensus at the Osteoporosis Australia Summit in Sydney, 20 October 2011. Primary objectives throughout the life cycle are: to maximise peak bone mass during childhood and adolescence to prevent premature bone loss and improve or maintain muscle mass, strength and functional capacity in healthy adults to prevent and treat osteoporosis in order to minimise the risk of suffering fragility fractures, and reduce falls risk, in older people. The recommendations focus on three affordable and important interventions — to ensure people have adequate calcium intake, vitamin D levels and appropriate physical activity throughout their lives. Recommendations relevant to all stages of life include: daily dietary calcium intakes should be consistent with Australian and New Zealand guidelines serum levels of vitamin D in the general population should be above 50nmol/L in winter or early spring for optimal bone health regular weight-bearing physical activity, muscle strengthening exercises and challenging balance/mobility activities should be conducted in a safe environment.

Calcium supplementation increases blood creatinine concentration in a randomized controlled trial

Background

Calcium supplements are widely used among older adults for osteoporosis prevention and treatment. However, their effect on creatinine levels and kidney function has not been well studied.

Methods

We investigated the effect of calcium supplementation on blood creatinine concentration in a randomized controlled trial of colorectal adenoma chemoprevention conducted between 2004–2013 at 11 clinical centers in the United States. Healthy participants (N = 1,675) aged 45–75 with a history of colorectal adenoma were assigned to daily supplementation with calcium (1200 mg, as carbonate), vitamin D₃ (1000 IU), both, or placebo for three or five years. Changes in blood creatinine and total calcium concentration were measured after one year of treatment and multiple linear regression was used to estimate effects on creatinine concentrations.

Results

After one year of treatment, blood creatinine was 0.013±0.006 mg/dL higher on average among participants randomized to calcium compared to placebo after adjustment for other determinants of creatinine (P = 0.03). However, the effect of calcium treatment appeared to be larger among participants who consumed the most alcohol (2–6 drinks/day) or whose estimated glomerular filtration rate (eGFR) was less than 60 ml/min/1.73 m² at baseline. The effect of calcium treatment on creatinine was only partially mediated by a concomitant increase in blood total calcium concentration and was independent of randomized vitamin D treatment. There did not appear to be further increases in creatinine after the first year of calcium treatment.

Conclusions

Among healthy adults participating in a randomized clinical trial, daily supplementation with 1200 mg of elemental calcium caused a small increase in blood creatinine. If confirmed, this finding may have implications for clinical and public health recommendations for calcium supplementation.

Trial Registration

ClinicalTrials.gov NCT00153816

Calcium revisited: part II calcium supplements and their effects

Calcium supplements were tested in pregnancy and lactation, in childhood and adolescence, in pre- and postmenopausal women and in elderly persons with various effects on bone density and fracture incidence. They must be properly chosen and adequately used. In this case, the reported minor negative side-effects do not restrict their use. All these aspects are reviewed here.

Association between the awareness of osteoporosis and the quality of care for bone health among Korean women with osteoporosis

Background

The prevalence of osteoporosis is increasing and is a socio-economic burden worldwide. Although screening tests for osteoporosis in Korea are easily accessible, this condition remains undertreated. Evaluating post-diagnostic behavior changes may be helpful for improving the quality of care for bone health in osteoporotic patients.

Methods

After reviewing the Fourth Korean National Health and Nutrition Examination Survey 2008–2009, 1,114 women with osteoporosis aged >50 years were included in this cross-sectional study. Factors related to bone health were categorized into the following groups: (1) behavioral health (smoking, alcohol consumption, and physical activity); (2) measured factors (lean body mass [kg], appendicular skeletal muscle mass [kg], and serum vitamin D level [nmol/L]); and (3) nutritional factors (calcium intake, vitamin/mineral supplementation, and healthy supplementary food). Logistic regression analysis and analysis of covariance was conducted after adjusting for age, education, income, residential area, height, weight, and self-perceived health using a weighted method.

Results

Doctors diagnosed 39.5% of patients with osteoporosis, and these patients were compared with the control group. The awareness group, who had been diagnosed with osteoporosis by a doctor, had a lower proportion of smokers and higher serum vitamin D level than the control group, who had never been diagnosed with osteoporosis. No other associations were found for quality of bone health care variables. The awareness group had higher odds ratios of vitamin/mineral replacement and healthy supplementary food but no other differences were observed, indicating the patients’ beliefs in bone health care do not follow the recommended clinical guidelines (e.g. higher physical activity, lower alcohol consumption).

Conclusion

To improve the quality of care for bone health in osteoporotic patients, an initial step should be the development of post-diagnostic procedures such as patient counseling and education through a multi-team care approach.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-334) contains supplementary material, which is available to authorized users.

Patients' response toward an automated orthopedic osteoporosis intervention program

Osteoporosis is overshadowed in an era of chronic illnesses, and a care gap exists between physicians and patients. The aim of this study was to determine the effectiveness of implementing an automated system for identifying and sending a letter to patients at high risk for osteoporosis. Patients 50 years of age and older were tagged with an International Classification of Diseases, Ninth Revision, diagnostic code upon initial visit to the emergency department (ED), identifying potential fragility fractures. Automatically generated letters were sent via our osteoporosis database system to each patient 3 months after the initial visit to the ED. The letter indicated that he or she was at risk for osteoporosis and suggested that the patient schedule a follow-up appointment with a physician. Patients were subsequently telephoned 3 months after receiving the letter and asked about their current plan for follow-up. The control group did not receive a letter after departure from the ED. In the control group, 84 (85.71%) individuals of the total 98 did not have any follow-up but the remaining 14 (14.29%) sought a follow-up. In the intervention group, 62 (60.19%) individuals of 103 did schedule a follow-up, while the remaining 41 (39.81%) did not seek a follow-up. Thus, the patient follow-up response rate after fracture treatment improved with intervention (P < .0001). Current literature has demonstrated the low rate of follow-up care addressing osteoporosis in patients experiencing fragility fractures (1%-25% without intervention). Research has shown the effectiveness of various types of intervention programs for improving the continuum of care for these high-risk patients. Nonautomated intervention programs can have a multitude of human-related system failures in identifying these patients. Our study successfully implements an automated system that is able to be applied to most hospitals with minimal cost and resources.

The efficacy of calcium supplementation alone in elderly Thai women over a 2-year period: a randomized controlled trial

Supplementation with elemental calcium 500 mg/day alone for 2 years is able to decrease bone turnover and is effective in retarding bone loss at lumbar spine and slowing bone loss at femoral neck in elderly Thai women who had low dietary calcium intake.

INTRODUCTION

Most elderly Thais have a total dietary calcium intake of less than the recommended amount. The aim of the study was to investigate the effect of calcium supplementation on bone mineral density and biochemical indices of bone remodeling in Thai postmenopausal women.

METHODS

Four hundred and four healthy postmenopausal women 60 years old or older without osteoporosis were recruited and conducted in a randomized, double-blinded, placebo-controlled trial. They were randomly given elementary calcium 500 mg/day or placebo for 2 years. Dietary calcium intake was calculated from the nutrient compositional analysis of the 3-day food records. Serum 25 hydroxyvitamin D was measured by radioimmunoassay and bone turnover markers were determined by electrochemiluminescence immunoassay.

RESULTS

The age of the subjects was 65.8 ± 4.4 years. All baseline characteristics of the subjects in the calcium-supplemented group and the placebo group were not statistically different. At the end of the study, significant decreases in serum C-terminal telopeptide of type I collagen and serum total procollagen type I amino terminal propeptide in the calcium-supplemented group were observed, while there was no change in the placebo group. In addition, plasma parathyroid hormone decreased, although not significantly, only in the calcium-supplemented group. Percent changes from baseline of lumbar spine (L2-L4) bone mineral density increased 2.76% in the calcium-supplemented group and 0.87% in the placebo group, whereas the percent changes from baseline of femoral neck decreased 0.21% in the calcium-supplemented group and 0.90% in the placebo group.

CONCLUSIONS

Calcium supplementation is necessary for the decrease of bone turnover and prevention of bone loss in Thai elderly women.

The effect of different amounts of calcium intake on bone metabolism and arterial calcification in ovariectomized rats

Low calcium (Ca) intake is the one of risk factors for both bone loss and medial elastocalcinosis in an estrogen deficiency state. To examine the effect of different amounts of Ca intake on the relationship between bone mass alteration and medial elastocalcinosis, 6-wk-old female SD rats were randomized into ovariectomized (OVX) control or OVX treated with vitamin D(3) plus nicotine injection (VDN) groups. The OVX treated with VDN group was then divided into 5 groups depending on the different Ca content in their diet, 0.01%, 0.1%, 0.6%, 1.2%, and 2.4% Ca intakes. After 8 wk of experimentation, the low Ca intake groups of 0.01% and 0.1% showed a low bone mineral density (BMD) and bone properties significantly different from those of the other groups, whereas the high Ca intake groups of 1.2% and 2.4% showed no difference compared with the OVX control. Only in the 0.01% Ca intake group, a significantly higher Ca content in the thoracic artery was found compared with that of the OVX control. Arterial tissues of the 0.01% Ca intake group showed an increase of bone-specific alkaline phosphatase (BAP) activity, a marker of bone mineralization, associated with arterial Ca content. However, the high Ca intake did not affect arterial Ca content nor arterial BAP activity. These results suggested that a low Ca intake during periods of rapid bone loss caused by estrogen deficiency might be one possible cause for the complication of both bone loss and medial elastocalcinosis.

Calcium supplements and cancer risk: a meta-analysis of randomised controlled trials

Some evidence suggests that Ca and vitamin D supplements affect cancer risk; however, it is uncertain whether the effects are due to Ca, vitamin D or the combination. We investigated the effect of Ca supplements without co-administered vitamin D on cancer risk. Medline, Embase and the Cochrane Central Register of Controlled Trials, reference lists of meta-analyses and two clinical trial registries were searched for randomised, placebo-controlled trials of Ca supplements ( ≥ 500 mg/d), with ≥ 100 participants and duration >1 year. The lead authors of eligible trials supplied data on cancer outcomes. Trial-level data were analysed using random-effects meta-analyses and patient-level data using Cox proportional hazards models. A total of sixteen trials were eligible, six had no data available, ten provided trial-level data (n 10 496, mean duration 3·9 years), and of these, four provided patient-level data (n 7221, median duration 3·5 years). In the meta-analysis of trial-level data, allocation to Ca did not alter the risk of total cancer (relative risk 0·95, 95 % CI 0·76, 1·18, P= 0·63), colorectal cancer (relative risk 1·38, 95 % CI 0·89, 2·15, P= 0·15), breast cancer (relative risk 1·01, 95 % CI 0·64, 1·59, P= 0·97) or cancer-related mortality (relative risk 0·96, 95 % CI 0·74, 1·24, P= 0·75), but reduced the risk of prostate cancer (relative risk 0·54, 95 % CI 0·30, 0·96, P= 0·03), although there were few events. The meta-analysis of patient-level data showed similar results, with no effect of Ca on the risk of total cancer (hazard ratio 1·07, 95 % CI 0·89, 1·28, P= 0·50). Ca supplements without co-administered vitamin D did not alter total cancer risk over 4 years, although the meta-analysis lacked power to detect very small effects, or those with a longer latency.

Calcium nutrition and extracellular calcium sensing: relevance for the pathogenesis of osteoporosis, cancer and cardiovascular diseases

Through a systematic search in Pubmed for literature, on links between calcium malnutrition and risk of chronic diseases, we found the highest degree of evidence for osteoporosis, colorectal and breast cancer, as well as for hypertension, as the only major cardiovascular risk factor. Low calcium intake apparently has some impact also on cardiovascular events and disease outcome. Calcium malnutrition can causally be related to low activity of the extracellular calcium-sensing receptor (CaSR). This member of the family of 7-TM G-protein coupled receptors allows extracellular Ca2+ to function as a "first messenger" for various intracellular signaling cascades. Evidence demonstrates that Ca2+/CaSR signaling in functional linkage with vitamin D receptor (VDR)-activated pathways (i) promotes osteoblast differentiation and formation of mineralized bone; (ii) targets downstream effectors of the canonical and non-canonical Wnt pathway to inhibit proliferation and induce differentiation of colorectal cancer cells; (iii) evokes Ca2+ influx into breast cancer cells, thereby activating pro-apoptotic intracellular signaling. Furthermore, Ca2+/CaSR signaling opens Ca2+-sensitive K+ conductance channels in vascular endothelial cells, and also participates in IP(3)-dependent regulation of cytoplasmic Ca2+, the key intermediate of cardiomyocyte functions. Consequently, impairment of Ca2+/CaSR signaling may contribute to inadequate bone formation, tumor progression, hypertension, vascular calcification and, probably, cardiovascular disease.

Calcium metabolism and correcting calcium deficiencies

Calcium is the most abundant cation in the human body, of which approximately 99% occurs in bone, contributing to its rigidity and strength. Bone also functions as a reservoir of Ca for its role in multiple physiologic and biochemical processes. This article aims to provide a thorough understanding of the absorptive mechanisms and factors affecting these processes to enable one to better appreciate an individual's Ca needs, and to provide a rationale for correcting Ca deficiencies. An overview of Ca requirements and suggested dosing regimens is presented, with discussion of various Ca preparations and potential toxicities of Ca treatment.

[Are calcium and vitamin D supplements for everyone?: Cons]

Calcium and vitamin D supplements are one of the most widely used treatments in the field of bone metabolism and, especially due to its frequency, in the case of the osteoporosis. Sometimes the use of these treatments can be easily justified because there is plenty of evidence or because prescription is mandatory. But other times, not only because of the possibility of adverse events, the indication of these therapies is more controversial. Furthermore, and particularly in the context of osteoporosis, it may be suggested that prescribing calcium and vitamin D supplements to the general population may reduce the impact of disease.

Vitamin D supplementation versus combined calcium and vitamin D in older female patients - an observational study

BACKGROUND

In most developed countries overt vitamin D deficiency, characterized by rickets or osteomalacia, is now uncommon. However, subclinical vitamin D insufficiency is extremely common and may contribute to the development of skeletal and non-skeletal problems. Standard practice involves supplementation with a combination of vitamin D and calcium although the benefit of adding calcium to vitamin D supplements has not been fully established and may reduce adherence due to its bulky and chalky consistency.

PURPOSE OF STUDY

To compare the effects of vitamin D alone versus vitamin D/calcium supplements on vitamin D levels, bone profile and parathyroid hormone level.

POPULATION

Older (> 65 years) female patients living in the community and long term care institutions.

INTERVENTIONS

Either 800 iu of vitamin D3 or a composite supplement of 800 iu vitamin D3 and 1000 mg calcium were given to patients in an open-labelled observational study. Serum 25-hydroxy-vitamin D, parathyroid hormone, calcium, phosphate and alkaline phosphatase levels were assessed at baseline and after 3 months of treatment.

RESULTS

Serum 25-hydroxy-vitamin D levels rose from baseline levels of 25 ± 16 to 79 ± 16 in those treated with vitamin D alone and from 35 ± 24 nmol/L to 70 ± 24 nmol/L in those treated with vitamin D and calcium. Serum PTH levels fell by similar amounts in both groups. In both community dwellers and institutionalised patients, those treated with vitamin D alone were at least as likely to achieve normalisation of serum vitamin D levels as those on combined calcium/vitamin D treatment.

CONCLUSION

Vitamin D alone appears as effective as combined calcium/vitamin D treatment in restoring serum vitamin D levels in older community dwelling and institutionalised patients. A prospective randomised trial would help confirm these findings.

Calcium supplementation in postmenopausal women to reduce the risk of osteoporotic fractures

PURPOSE

The most recent large-scale studies evaluating the effects of calcium supplementation for prevention of osteoporosis-related fractures in postmenopausal women are reviewed.

SUMMARY

Osteoporosis is a very common disease associated with significant morbidity and mortality. For many years, use of a calcium supplement (preferably in combination with vitamin D to optimize calcium absorption) has been recommended for postmenopausal women to decrease fracture risk. However, five large-scale, randomized, controlled trials have called into question the benefits of calcium in reducing fracture risk, and four of the studies indicated that calcium users may be at increased risk for renal stones and gastrointestinal problems. However, all five studies had one or more important limitations, including possible selection bias and study participants' relatively high baseline calcium intake and generally low adherence to treatment regimens. Moreover, in some of the studies, vitamin D was not included in the treatment protocol or was not used at levels sufficient to optimize calcium absorption. In three of the five trials, subgroup analysis of the most treatment-adherent participants indicated significant reductions in osteoporotic fracture risk with calcium supplement use.

CONCLUSION

Results of recent clinical trials indicate that calcium supplementation does not significantly reduce fracture risk in postmenopausal women. However, evidence from the same studies suggests that beneficial effects on fracture risk may be seen in women who are adherent to therapy. Postmenopausal women should continue calcium supplementation to reduce osteoporosis risk.

An Asian viewpoint on the use of vitamin D and calcium in osteoporosis treatment: physician and patient attitudes and beliefs

BACKGROUND

Osteoporosis treatment guidelines recommend calcium and vitamin D supplementation for both prevention as well as treatment, however, compliance with these guidelines is often unsatisfactory. This study investigated the opinion of Asian physicians and Asian patients regarding vitamin D and calcium and patients' use of both.

METHODS

Physicians selected from Malaysia, Taiwan, Philippines, Korea and Singapore were asked to grade the significance of vitamin D and calcium in the treatment of osteoporosis and their patients' use of these supplements. In addition, physicians recruited seven eligible osteoporotic women to answer a questionnaire to determine their use of vitamin D and calcium, and their attitudes and beliefs regarding these supplements.

RESULTS

In total, 237 physicians and 1463 osteoporosis patients completed the questionnaire. The results revealed that 22% of physicians in Malaysia, 12% in Taiwan, 72% in the Philippines, 50% in Korea and 24% in Singapore rated the importance of vitamin D supplementation as being extremely important. For calcium, 27% of physicians in Malaysia, 30% in Taiwan, 80% in the Philippines, 50% in Korea and 38% in Singapore rated the importance as being extremely important. Forty-three percent of patients in Malaysia, 38% in Taiwan, 73% in the Philippines, 35% in Korea and 39% in Singapore rated the importance of vitamin D as being extremely important. For calcium, 69% of patients in Malaysia, 58% in Taiwan, 90% in the Philippines, 70% in Korea and 55% in Singapore rated the importance as being extremely important. In addition, results of the patient questionnaire revealed that only a very small number regularly took both supplements. In addition, the results indicated that, with the exception of patients from the Philippines, the majority of patients had no or infrequent discussion with their physician about vitamin D and calcium.

CONCLUSIONS

There is generally suboptimal appreciation by both physicians and patients of the importance of vitamin D and calcium for maintenance of bone health as reflected in the low number of patients who reported regularly taking these supplements. Recognition of this problem should translate to appropriate action to improve education for both physicians and patients, with a goal to increase use of these supplements among Asian patients with osteoporosis.

Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis

OBJECTIVE

To investigate whether calcium supplements increase the risk of cardiovascular events.

DESIGN

Patient level and trial level meta-analyses.

DATA SOURCES

Medline, Embase, and Cochrane Central Register of Controlled Trials (1966-March 2010), reference lists of meta-analyses of calcium supplements, and two clinical trial registries. Initial searches were carried out in November 2007, with electronic database searches repeated in March 2010.

STUDY SELECTION

Eligible studies were randomised, placebo controlled trials of calcium supplements (>or=500 mg/day), with 100 or more participants of mean age more than 40 years and study duration more than one year. The lead authors of eligible trials supplied data. Cardiovascular outcomes were obtained from self reports, hospital admissions, and death certificates.

RESULTS

15 trials were eligible for inclusion, five with patient level data (8151 participants, median follow-up 3.6 years, interquartile range 2.7-4.3 years) and 11 with trial level data (11 921 participants, mean duration 4.0 years). In the five studies contributing patient level data, 143 people allocated to calcium had a myocardial infarction compared with 111 allocated to placebo (hazard ratio 1.31, 95% confidence interval 1.02 to 1.67, P=0.035). Non-significant increases occurred in the incidence of stroke (1.20, 0.96 to 1.50, P=0.11), the composite end point of myocardial infarction, stroke, or sudden death (1.18, 1.00 to 1.39, P=0.057), and death (1.09, 0.96 to 1.23, P=0.18). The meta-analysis of trial level data showed similar results: 296 people had a myocardial infarction (166 allocated to calcium, 130 to placebo), with an increased incidence of myocardial infarction in those allocated to calcium (pooled relative risk 1.27, 95% confidence interval 1.01 to 1.59, P=0.038).

CONCLUSIONS

Calcium supplements (without coadministered vitamin D) are associated with an increased risk of myocardial infarction. As calcium supplements are widely used these modest increases in risk of cardiovascular disease might translate into a large burden of disease in the population. A reassessment of the role of calcium supplements in the management of osteoporosis is warranted.

Prevention of hip fractures in long-term care: relevance of community-derived data

Osteoporosis and falling are two major contributing factors to fractures in older persons; the relevant contribution of these may vary according to age, setting, and frailty. The purpose of this review was to examine the existing evidence on osteoporosis treatments to determine whether participants in clinical trials include or resemble the older and frailer adult population living in long-term care (LTC). The trials (N=50) used to support major Canadian guidelines for osteoporosis treatment were reviewed because these are used to recommend treatment for all older adults, and several more-recent studies were added. Trials conducted specifically with participants living in LTC were also reviewed (N=6). The majority of studies (96.0%) on osteoporosis treatments were conducted with community-dwelling participants, with many excluding participants resembling the LTC population. Mean ages ranged from 52 to 84, although for the majority of studies, the mean age was younger than 70. Similarly, 80.0% of studies conducted in LTC included only residents who were ambulatory, mobile, able to transfer independently, or not permanently bedridden. Mean ages in these studies ranged from 83 to 85. These findings suggest that frail older adults, particularly the oldest and frailest adults in LTC, are neglected in clinical trials of osteoporosis fracture prevention. There is little evidence to support the application of community-based guidelines to the LTC population, and studies directly involving this population are needed. The role of age, frailty, and the mechanics of falls in hip fracture are discussed.

Patient preference and acceptability of calcium plus vitamin D3 supplementation: a randomised, open, cross-over trial

Preference for a drug formulation is important in adherence to long-term medication for chronic illnesses such as osteoporosis. We investigated the preference for and acceptability of chewable tablet containing calcium and vitamin D (Calci Chew D₃, Nycomed) compared to that of a sachet containing calcium and vitamin D₃ (Cad, Will-Pharma). This open, randomised, cross-over trial was set up to compare the preference and acceptability of two calcium plus vitamin D₃ formulations (both with 500 mg calcium and 400/440 IU vitamin D3), given twice a day in patients with osteoporosis. Preference and acceptability were assessed by means of questionnaires. Preference was determined by asking the question, which treatment the patient preferred, and acceptability was measured by scoring five variables, using rating scales. Of the 102 patients indicating a preference for a trial medication, 67% preferred the chewable tablet, 19% the sachet with calcium and vitamin D_3, and 15% stated no preference. The significant preference for Calci Chew D₃ (p < 0.0001) was associated with higher scores for all five acceptability variables. The two formulations were tolerated equally well. A significant greater number of patients considered the chewable tablet as preferable and acceptable to the sachet, containing calcium and vitamin D₃. Trial registration: Current Controlled Trials ISRCTN18822358.

The effect of calcium supplementation on bone loss in 32 controlled trials in postmenopausal women

SUMMARY

In 32 controlled trials of calcium supplementation (700-2000 mg) in 3,169 postmenopausal women, mean bone loss in the controls was -1.07% p.a. and in the treated subjects -0.27% p.a. (P for difference <0.001). The effect was similar at all measured sites and at all doses of 700 mg or more but became weaker after 4 years.

INTRODUCTION

We have reviewed 32 trials of calcium supplementation in 3,169 postmenopausal women.

METHODS

We found 24 publications reporting 32 controlled trials lasting at least 1 year, which provided annual percentage changes in bone mass or density at one or more sites in the calcium-treated and control subjects.

RESULTS

The median calcium supplement was 1,000 mg, median duration of the trials 2 years and total number of sites measured 79. The average of the mean rates of change in bone mass or density was -1.07% p.a. (P < 0.001) in the controls and -0.27% p.a. (ns) in the treated subjects (P for difference < 0.001). The effect of calcium was much the same at all measured sites (forearm/hand, proximal femur, spine, and total body and others). Supplements of less than 700 mg were not effective, but there was no significant beneficial effect of higher doses. There was significantly faster bone loss at total calcium intakes below 1,150 mg than on intakes over 1,350 mg. The effect of calcium appeared to be lost after 4 years of treatment.

CONCLUSION

Calcium supplementation of about 1,000 mg daily has a significant preventive effect on bone loss in postmenopausal women for at least 4 years.

[Austrian guidance for the pharmacological treatment of osteoporosis in postmenopausal women--update 2009]

Osteoporosis is a systemic skeletal disease characterized by diminished bone mass and deterioration of bone microarchitecture, leading to increased fragility and subsequent increased fracture risk. Therapeutic measures therefore aim at reducing individual fracture risk. In Austria, the following drugs, all of which have been proven to reduce fracture risk, are currently registered for the treatment of postmenopausal osteoporosis: alendronate, risedronate, etidronate, ibandronate, raloxifene, teriparatide (1-34 PTH), 1-84 PTH, strontium ranelate and salmon calcitonin. Fluorides are still available, but their role in daily practice has become negligible. Currently, there is no evidence that a combination of two or more of these drugs could improve anti-fracture potency. However, treatment with PTH should be followed by the treatment with an anticatabolic drug such as bisphosphonates. Calcium and vitamin D constitute an important adjunct to any osteoporosis treatment.

Prevention of vertebral fractures in osteoporosis: mixed treatment comparison of bisphosphonate therapies

OBJECTIVE

The objective was to compare the efficacy of bisphosphonates regarding the prevention of vertebral fractures in postmenopausal women with osteoporosis.

METHODS

Seven randomized placebo controlled trials investigating the effects of zoledronic acid (one study), alendronate (three studies), ibandronate (one study), and risedronate (two studies) in terms of fractures with a follow-up of 3 years were identified with a systematic literature search. The endpoint of interest was vertebral fractures. Results of all trials were analyzed simultaneously with a Bayesian mixed treatment comparison (MTC). With MTC the relative treatment effect of one intervention to another can be obtained in the absence of head-to-head evidence. MTC can be considered a valid method when included studies are comparable regarding effect modifying baseline patient and study characteristics.

RESULTS

There is a 98% probability that zoledronic acid shows the greatest reduction in vertebral fractures of all four bisphophonates compared. Zoledronic acid showed an OR of 0.28 (95% Credible Interval 0.22; 0.35) relative to placebo, an OR of 0.57 (0.36; 0.92) relative to ibandronate, an OR of 0.54 (0.39; 0.75) relative to alendronate, and an OR of 0.49 (0.34; 0.69) relative to risedronate. Alendronate, ibandronate, and risedronate showed comparable vertebral fracture reductions. Indirect comparisons using a conservative random effects model supported these findings.

CONCLUSION

An indirect comparison of findings from placebo controlled randomized studies indicates that zoledronic acid provides a greater vertebral fracture risk reduction in postmenopausal women with osteoporosis than ibandronate, alendronate, or risedronate.

Acute suppression of bone turnover with calcium infusion in persons with spinal cord injury

BACKGROUND

Some people with chronic spinal cord injury (SCI) have low vitamin D levels and secondary hyperparathyroidism.

OBJECTIVE

To determine whether, and to what extent, an acute calcium infusion decreased levels of N-telopeptide (NTx), a marker of osteoclastic activity, in individuals with chronic SCI.

STUDY DESIGN

Case series.

SUBJECTS

Eight men with chronic SCI. A relatively low serum 25 hydroxyvitamin D concentration (25[OH]D < or =20 ng/mL) and/or a high parathyroid hormone (PTH) (>55 pg/mL) was a prerequisite for study inclusion.

METHODS

Calcium gluconate bolus 0.025 mmol elemental calcium/kg over 20 minutes followed by a constant infusion of 0.025 mmol/kg per hour for 6 hours was infused; blood samples were collected every 2 hours for measurement of serum total calcium, creatinine, NTx, and PTH.

RESULTS

All results are expressed as means (+/- SDs). Baseline serum 25-hydroxyvitamin D level was 14.5 +/- 3.5 ng/mL (range: 10.2-19.6 ng/mL); PTH, 70 +/- 25 pg/mL (range: 37-100 pg/mL); and NTx, 21 +/- 7 nM bone collagen equivalents (BCE) (range: 14-34 nM). At 2, 4, and 6 hours after the calcium infusion, serum calcium rose from 9.3 +/- 0.2 to 10.8 +/- 0.9, 10.5 +/- 0.8, and 10.6 +/- 0.6 mg/d; PTH was suppressed from 70 +/- 25 pg/mL to 18 +/- 12, 16 +/- 9, and 15 +/- 9 pg/mL, respectively; NTx fell from 21 +/- 8 nM BCE to 17 +/- 5, 12 +/- 4, and 12 +/- 3 nM BCE, respectively.

CONCLUSIONS

Serum NTx is a marker for bone collagen catabolism, and its reduction suggests that bone turnover was decreased. A relative deficiency of vitamin D associated with chronically elevated levels of PTH would be expected to increase bone turnover and to worsen the bone loss associated with immobilization.

Calcium and bone health: position statement for the Australian and New Zealand Bone and Mineral Society, Osteoporosis Australia and the Endocrine Society of Australia

This position statement was prepared by the Working Group of the Australian and New Zealand Bone and Mineral Society and Osteoporosis Australia. The final statement was endorsed by the Endocrine Society of Australia. Currently, the balance of evidence remains in favour of fracture prevention from combined calcium and vitamin D supplementation in elderly men and women. Adequate vitamin D status is essential for active calcium absorption in the gut and for bone development and remodelling. In adults with a baseline calcium intake of 500-900 mg/day, increasing or supplementing this intake by a further 500-1000 mg/day has a beneficial effect on bone mineral density. Calcium intake significantly above the recommended level is unlikely to achieve additional benefit for bone health.

Association of total calcium and dietary protein intakes with fracture risk in postmenopausal women: the 1999-2002 National Health and Nutrition Examination Survey (NHANES)

OBJECTIVE

We examined the associations of total calcium intake (TCI) and dietary protein intake (DPI) with risk of fracture.

METHODS

A total of 2006 postmenopausal women >or=50 y of age who were measured in the 1999-2002 National Health and Nutrition Examination Survey were included in the study. Weighted mean TCI and DPI and percentage of distributions of selected characteristics were estimated by TCI category and fracture status. Multivariate logistic regression models were used to assess the effect of TCI and DPI on risk of fracture.

RESULTS

Thirteen percent of participants reported a fracture history, of whom 17.8% consumed a total of >or=1200 mg of calcium per day and 23.8% consumed <400 mg/d. TCI was not associated with fracture risk when controlling for all selected covariates. In women who consumed <46 g/d of dietary protein, those with a TCI >or=1200 mg/d had a significantly higher risk of fracture than those with the lowest TCI (adjusted odds ratio 5.98, 95% confidence interval 1.15-31.13), whereas in women who consumed >70 g/d of dietary protein, those with a TCI >or=1200 mg/d had an insignificant lower risk of fracture (adjusted odds ratio 0.69, 95% confidence interval 0.20-2.39).

CONCLUSION

TCI is not associated with risk of fracture among postmenopausal women. Adequate TCI in the presence of inadequate DPI may not be protective against fractures. Optimal proportion of TCI and DPI warrants further investigation among older women.