The role of calcium in the prevention of cardiovascular disease--a review of observational studies and randomized clinical trials

Evaluating adherence, tolerability and safety of oral calcium citrate in elderly osteopenic subjects: a real-life non-interventional, prospective, multicenter study

BACKGROUND

Osteoporosis is a common concern in the elderly that leads to fragile bones. Calcium supplementation plays a crucial role in improving bone health, reducing fracture risk, and supporting overall skeletal strength in this vulnerable population. However, there is conflicting evidence on the safety of calcium supplements in elderly individuals.

AIM

The aim of this study was to evaluate the adherence, safety and tolerability of calcium citrate supplementation in elderly osteopenic subjects.

METHODS

In this non-interventional, prospective, multicenter study, subjects received daily 500 mg calcium citrate supplementation for up to one year. Adherence was calculated based on compliance and persistence. Safety was assessed through adverse reactions (ARs), deaths, and clinical laboratory evaluations.

RESULTS

A total of 268 Caucasian subjects (91.4% female, mean age 70 ± 4.5 years) participated in the study. Mean adherence to treatment was 76.6 ± 29.5% and half of subjects had an adherence of 91% and ~ 33% of participants achieved complete (100%) adherence. ARs were reported by nine (3.9%) subjects, primarily gastrointestinal disorders, with no serious ARs. The frequency of all adverse events (including ARs) was significantly higher in subjects with adherence of < 80% (41.6%; 32/77) vs. those with adherence ≥ 80% (11%; 16/145, p < 0.0001). Both systolic and diastolic blood pressure decreased from baseline to follow-up visit (change of -2.8 ± 13.9 mmHg, p = 0.0102 and -2.1 ± 10.4 mmHg, p = 0.0116, respectively).

CONCLUSION

This study demonstrated favorable adherence to calcium citrate supplementation in elderly osteopenic subjects. The occurrence of ARs, though generally mild, were associated with lower adherence to calcium supplementation.

The Relationship between Mortality from Cardiovascular Diseases and Total Drinking Water Hardness: Systematic Review with Meta-Analysis

BACKGROUND

Interest in water chemical activity, its content, and its impact on human health has greatly increased throughout the last decade. Some studies suggest that drinking water with high hardness may have preventative effects on cardiovascular diseases. This study aims to investigate the association between drinking water hardness and cardiovascular disease (CVD) mortality.

METHODS

The study selection process was designed to find the association between drinking water hardness and CVDs mortality. The search included both qualitative and quantitative research and was performed in three databases: Web of Science (Clarivate Analytics, Ann Arbor, MI, USA), PubMed (National Institute of Health, Bethesda, MA, USA), and Scopus (Elsevier, RELX Group plc, London, UK). The project was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42020213102.

RESULTS

Seventeen studies out of a total of twenty-five studies qualitatively analyzed indicated a significant relation between total water hardness and protection from CVD mortality. The quantitative analysis concluded that high drinking water hardness has a significantly lowering effect on mortality from CVDs, however, the heterogeneity was high.

CONCLUSIONS

This systematic literature review shows that total water hardness could affect CVD prevention and mortality. Due to the many confounding factors in the studies, more research is needed.

Dietary and nutrient intake among participants of a Brazilian health promotion programme: a cross-sectional study

OBJECTIVE

Developing health promotion activities, aimed at healthy food intake, is essential for improving quality of life and reducing the prevalence of chronic diseases. Thus, the objective of this study is to describe both dietary and nutrient intake, according to length of participation in a health promotion service (Programa Academia da Saúde - PAS).

DESIGN

A cross-sectional study was carried out with a representative sample of PAS units in vulnerable areas of the city. Dietary and nutrient intake were assessed, using the average of two 24-h recalls. Food was categorised according to the NOVA (a systematic grouping of all foods according to the nature, extent and purpose of the industrial processes they undergo) classification. The length of participation in PAS is presented in months and is then examined in tertiles for analysis.

SETTING

Belo Horizonte - Brazil.

PARTICIPANTS

3372 adults (≥20 years).

RESULTS

Users in the third tertile of PAS (24·4-61·6 months) experienced less energy intake, lipids and ultra-processed foods, and more culinary preparations, compared to others. Users in the second (10·1-24·3 months) and third tertiles of PAS had higher carbohydrate intake, Ca and vitamin C v those in the first tertile (0-10 months).

CONCLUSIONS

Results suggest that greater participation in PAS can improve dietary and nutrient intake, showing its potential to promote healthy lifestyles, prevent chronic diseases and offer longitudinal health care.

Dairy product consumption reduces cardiovascular mortality: results after 8 year follow-up of ELSA-Brasil

PURPOSE

To investigate whether the consumption of dairy products and their subgroups is associated with the risk of death from cardiovascular disease (CVD) after 8-year follow-up, and verify if dairy products predict changes in high-sensitivity C-reactive protein (hs-CRP) between two follow-up visits of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

Prospective study with 6671 participants without CVD at baseline. Consumption in grams/day of total dairy, full-fat and low-fat dairy, fermented dairy, and milk was obtained through a food frequency questionnaire and categorized into sex-specific quartiles. Cox regression and linear mixed-effect models were used to estimate associations of dairy products intake with death from CVD and changes in hs-CRP levels, respectively.

RESULTS

After adjustments, individuals in the 3rd and 4th quartiles of total dairy consumption presented, respectively, 62% (HR 0.38; 95% CI 0.15-0.99) and 64% (HR 0.36; 95% CI 0.14-0.94) lower hazards of death from CVD compared to the 1st quartile. Also, participants in the 4th quartile of milk consumption had 66% (HR 0.34; 95% CI 0.14-0.86) lower hazard to die from CVD, but only the 2nd quartile of full-fat dairy consumption indicated a lower hazard to die from CVD (HR 0.30; 95% CI 0.10-0.92). No association was observed between low-fat or fermented dairy products and cardiovascular mortality. Consumption of total dairy and their subgroups did not predict changes in hs-CRP levels after 4-year follow-up.

CONCLUSION

Results suggest beneficial effects of total dairy and milk, but only low-to-moderate full-fat dairy consumption, on the risk of death from CVD. Assuming true effects, public policies should encourage the consumption of dairy products, especially milk.

The Impact of Micronutrients-Calcium, Vitamin D, Selenium, Zinc in Cardiovascular Health: A Mini Review

The role of micronutrients in health and disease has increased the curiosity and interest among researchers. The prime focus of this review is the significance of trace elements- calcium, vitamin D, selenium and zinc with cardiovascular health. WHO identified cardiovascular diseases (CVD) as the leading cause of deaths globally. Identifying the risk factors that could be modified and creating new treatment strategies remains to be the main concern for CVD prevention. The data that showed the relationship between trace elements and various ways in which they may contribute to cardiovascular health and disease from clinical trials and observational studies were collected from databases such as PubMed and Embase. Based on these collected data, it shows that either high or low circulating serum levels can be associated with the development of cardiovascular diseases. Micronutrients through diet contribute to improved cardiac health. However, due to our current lifestyle, there is a huge dependency on dietary supplements. Based on the observational studies, it is evident that supplements cause sudden increase in the circulating levels of the nutrients and result in cardiovascular damage. Thus, it is advisable to restrict the use of supplements, owing to the potent risks it may cause. In order to understand the exact mechanism between micronutrients and cardiac health, more clinical studies are required.

Gut Microbiome, Functional Food, Atherosclerosis, and Vascular Calcifications-Is There a Missing Link?

The gut microbiome is represented by the genome of all microorganisms (symbiotic, potential pathogens, or pathogens) residing in the intestine. These ecological communities are involved in almost all metabolic diseases and cardiovascular diseases are not excluded. Atherosclerosis, with a continuously increasing incidence in recent years, is the leading cause of coronary heart disease and stroke by plaque rupture and intraplaque hemorrhage. Vascular calcification, a process very much alike with osteogenesis, is considered to be a marker of advanced atherosclerosis. New evidence, suggesting the role of dietary intake influence on the diversity of the gut microbiome in the development of vascular calcifications, is highly debated. Gut microbiota can metabolize choline, phosphatidylcholine, and L-carnitine and produce vasculotoxic metabolites, such as trimethylamine-N-oxide (TMAO), a proatherogenic metabolite. This review article aims to discuss the latest research about how probiotics and the correction of diet is impacting the gut microbiota and its metabolites in the atherosclerotic process and vascular calcification. Further studies could create the premises for interventions in the microbiome as future primary tools in the prevention of atherosclerotic plaque and vascular calcifications.

Vitamin D and Vascular Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Vitamin D deficiency has been identified as a potential risk factor for a number of diseases unrelated to the classical skeletal pathophysiology, such as cancer and CVD, but the effects of vitamin D supplementation are less clear. Purpose of this narrative review is to discuss the evidence suggesting an association between vitamin D status and CVD as well as the results of supplementation studies. Vitamin D deficiency has been associated with CVD risk factors such as hypertension, dyslipidemia and diabetes mellitus as well as with cardiovascular events such as myocardial infarction, stroke and heart failure. While vitamin D deficiency might contribute to the development of CVD through its association with risk factors, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells. Moreover, vitamin D has been shown to affect inflammation, cell proliferation and differentiation. While observational studies support an association between low plasma vitamin D levels and increased risk of CVD, Mendelian randomization studies do not support a causal association between the two. At present, high quality randomized trials do not find evidence of significant effects on CVD endpoints and do not support supplementation of vitamin D to decrease CVD events.

Total, dietary, and supplemental calcium intake and risk of all-cause cardiovascular, and cancer mortality: a systematic review and dose-response meta-analysis of prospective cohort studies

Considerable controversy exists regarding the association between calcium intake and mortality risk. Therefore, this study aimed to summarize available findings on the associations of total, dietary and supplemental calcium intake with all-cause, CVD, and cancer mortality. We searched PubMed, Scopus, Embase, and ISI Web of Knowledge until February 2020 to identify eligible publications. Random-effects models were used to calculate pooled effect sizes (ESs) and 95% confidence intervals (CIs) for highest versus lowest categories of calcium intake and to incorporate variation between studies. Linear and non-linear dose-response analyses were done to evaluate the dose-response relations between calcium intake and mortality. 36 publications were included in this systematic review and 35 in the meta-analysis. During the follow-up periods ranging from 4.2 to 28 years, the total number of deaths from all causes was 163,657 (83703 from CVD and 83929 from cancer). Total calcium intake was associated with a lower risk of CVD mortality (Pooled ES for highest v lowest category: 0.91; 95% CI: 0.83-0.99, I²=68.1%, P < 0.001). Dietary calcium intake was associated with a lower risk of all-cause mortality (Pooled ES for highest v lowest category: 0.95; 95% CI: 0.92-0.99, I²=62.1%, P < 0.001). Supplemental calcium intake was not significantly associated with risk of all-cause, CVD and cancer mortality. In the dose-response analysis, there was evidence of nonlinear association between calcium intake and risk of all-cause, CVD, and cancer mortality. In conclusion, a non-linear association between calcium intake with all-cause, CVD, and cancer mortality risk was observed in this meta-analysis. Moderate intake of total (1000-1800), dietary (600-1200), and supplemental calcium (600-1200) was inversely significantly associated with mortality risk but higher calcium intake was not associated with a lower risk of mortality.

Prospective associations between total, animal, and vegetable calcium intake and metabolic syndrome in adults aged 40 years and older

BACKGROUND & AIMS

Calcium (Ca) consumption may contribute to a decreased risk of developing metabolic syndrome (MetS). However, epidemiologic evidence on the association between Ca intake and MetS is limited. This study aimed to evaluate the association between dietary Ca intake (animal-based Ca and vegetable-based Ca separately, as well as total Ca intake) and the incidence risk of MetS and its components in the Korean Multi-Rural Communities Cohort (MRCohort).

METHODS

A total of 5509 participants who did not have MetS were enrolled. Dietary Ca intake was calculated using a food frequency questionnaire composed of 106 items.

RESULTS

After 18,880 person-years of follow-up, 876 participants had developed de novo MetS. A significant inverse association between dietary total Ca intake and MetS were observed (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI) = 0.48-0.81, P for trend = 0.002 for the highest quartile of total Ca intake compared with the lowest quartile). Trends for animal Ca (IRR = 0.77, 95% CI = 0.62-0.97, P for trend = 0.039) and vegetable Ca (IRR = 0.54, 95% CI = 0.40-0.73, P for trend <0.001) were similar. The individual components of overall MetS were also inversely related to total, animal, and vegetable Ca. The tendency for an inverse association was more evident in the group with two of any of the metabolic abnormalities of MetS at baseline than in the group with no more than one MetS component.

CONCLUSIONS

Our findings indicate that a relatively high dietary intake of Ca is associated with lower risk of MetS.

Dietary phosphorus intake and blood pressure in adults: a systematic review of randomized trials and prospective observational studies

BACKGROUND

Elevated blood pressure (BP) is a major cause of preventable disease in the United States and around the world. It has been postulated that phosphorus intake may affect BP, with some studies suggesting a direct and others an inverse association.

OBJECTIVES

We systematically reviewed the literature on the association of dietary phosphorus with BP in adults and performed a qualitative synthesis.

METHODS

We included randomized and nonrandomized behavioral intervention and feeding studies (intervention studies) and prospective observational studies that measured dietary phosphorus intake or urinary phosphorus excretion and BP. We excluded studies of supplements, children, or individuals with major medical conditions. We searched PubMed, Embase, Cochrane Trials, and clinicaltrials.gov on 1 June, 2017 and 22 August, 2018. We assessed studies' risk of bias in their assessment of phosphorus exposure and BP.

RESULTS

We reviewed 4759 publications and included 14 intervention studies (2497 participants), 3 prospective observational cohorts (17,795 participants), and 2 ongoing trials. No included intervention studies were designed specifically to achieve a phosphorus contrast. Two studies found a significant positive association of dietary phosphorus with systolic BP, 4 a significant inverse association, and 8 no significant association. Four studies found a significant inverse association with diastolic BP and 10 no significant associations. Two cohorts found lower risk of incident hypertension comparing the highest with the lowest quintiles of phosphorus intake and 1 found no significant difference: HR: 0.86 (95% CI: 0.75, 0.98); HR: 0.83 (95% CI: 0.68, 1.02); and HR: 0.75 (95% CI: 0.45, 1.27), respectively.

CONCLUSIONS

We found no consistent association between total dietary phosphorus intake and BP in adults in the published literature nor any randomized trials designed to examine this association. This trial was registered at www.crd.york.ac.uk/prospero/ as CRD42017062489.

Common mechanisms and holistic care in atherosclerosis and osteoporosis

Cardiovascular (CV) disease and osteoporosis (OP) have become increasing challenges in the aging population and even more in patients with inflammatory rheumatic diseases, such as rheumatoid arthritis, spondyloarthropathies, and systemic lupus erythematosus. In this review, we discuss how the epidemiology and pathogenesis of CV events and OP are overlapping. Smoking, diabetes mellitus, physical inactivity as conventional risk factors as well as systemic inflammation are among the modifiable risk factors for both CV events and bone loss. In rheumatic patients, systemic “high-grade” inflammation may be the primary driver of accelerated atherogenesis and bone resorption. In the general population, in which some individuals might have low-grade systemic inflammation, a holistic approach to drug treatment and lifestyle modifications may have beneficial effects on the bone as well as the vasculature. In rheumatic patients with accelerated inflammatory atherosclerosis and bone loss, the rapid and effective suppression of inflammation in a treat-to-target regime, aiming at clinical remission, is necessary to effectively control comorbidities.

Associations of Dairy Intake with Arterial Stiffness in Brazilian Adults: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Recent studies have suggested the possible effect of dairy product intake on cardiovascular risk markers, including arterial stiffness. Our aim was to investigate whether dairy food intake is associated with arterial stiffness, which we assessed by carotid-femoral pulse wave velocity (cfPWV) and pulse pressure (PP) in a cross-sectional analysis of baseline data (2008–2010; n = 12,892) of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Dairy consumption was evaluated with a validated food-frequency questionnaire (FFQ) by computing servings per day for total and subgroups of dairy products. Dairy consumption was described in four categories (≤1 serving/day to >4 servings/day). Covariance analysis (ANCOVA) was used to compare cfPWV across increasing intake of dairy food, adjusting for confounding factors, including non-dairy food groups. The intake of total dairy was inversely associated with cfPWV and PP (−0.13 m/s and −1.3 mmHg, from the lowest and to the highest category of dairy intake). Low-fat dairy, fermented dairy and cheese showed an inverse relationship with cfPWV and PP. These findings suggest a beneficial effect of dairy consumption to reduce arterial stiffness. However, further evidence from longitudinal studies or long-term intervention is needed to support reduction of cfPWV and PP mediating the beneficial effects of dairy products on cardiovascular health.

Vitamin D, Calcium, and Cardiovascular Disease: A"D"vantageous or "D"etrimental? An Era of Uncertainty

While the function of vitamin D in regulating calcium homeostasis is well established, there has been growing interest in its role in the prevention of numerous chronic diseases, including cardiovascular disease (CVD). There is mounting epidemiological evidence suggesting that vitamin D deficiency is linked to increased CVD risk. However, the results of previous vitamin D supplementation trials have yielded mixed results in regards to cardiovascular health, and the results of ongoing large-scale randomized controlled trials are not yet available. Further complicating the issue, calcium supplementation, which is often prescribed concurrently with vitamin D, has been associated with increased CVD risk in some (but not all) studies. Thus, it is currently unclear whether vitamin D supplements, particularly for those that are deficient, can help prevent the development of CVD. In addition, there has not been uniform consensus regarding the threshold of 25-hydroxyvitamin D levels that constitutes "sufficiency" across organizational guidelines. This review will provide an update on the most recent evidence regarding the effects of vitamin D and calcium supplements on CVD clinical outcomes, summarize ongoing vitamin D trials, and discuss the current but remarkably disparate recommendations regarding vitamin D deficiency screening and supplementation.

Integrative Medicine for Geriatric and Palliative Care

More than 80% of people in the United States who are older than 65 years have 1 or more chronic medical problems, and 50% have 2 or more. The cost of care for the elderly is at least 3 to 4 times that of younger populations and is rapidly growing, mostly because of a lack of preventive approaches and overly medicalized and fragmented care. This article summarizes the most up-to-date evidence for specific integrative modalities for common geriatric conditions, including falls, frailty, osteoporosis, and end-of-life palliative care.

Risk of Ischemic Stroke Associated With Calcium Supplements With or Without Vitamin D: A Nested Case-Control Study

BACKGROUND

There is controversy surrounding the risk of ischemic stroke associated with the use of calcium supplements either in monotherapy or in combination with vitamin D.

METHODS AND RESULTS

A nested case-control study was performed with patients aged 40 to 89 years old, among whom a total of 2690 patients had a first episode of nonfatal ischemic stroke and for which 19 538 controls were randomly selected from the source population and frequency-matched with cases for age, sex, and calendar year. Logistic regression provided the odds ratios while adjusting for confounding factors. A sensitivity analysis was performed by restricting to patients who were new users of calcium supplements as either monotherapy or with vitamin D. Calcium supplementation with vitamin D was not associated with an increased risk of ischemic stroke (odds ratio 0.85; 95% confidence interval, 0.67-1.08) in the population as a whole or under any of the conditions examined (dose, duration, background cardiovascular risk, sex, or age). Calcium supplement monotherapy was not associated with an increased risk in the population as a whole (odds ratio 1.18; 95% confidence interval, 0.86-1.61), although a significant increased risk at high doses (≥1000 mg/day: odds ratio 2.09; 95% confidence interval, 1.25-3.49; <1000 mg: odds ratio 0.76; 95% confidence interval, 0.45-1.26) compared with nonuse was observed. The sensitivity analysis did not affect the inferences, with similar results observed among new users as to the overall study population.

CONCLUSIONS

This study suggests that calcium supplements given as monotherapy at high doses may increase the risk of ischemic stroke, whereas their combination with vitamin D seems to offset this hazard.

Calcium Intake From Diet and Supplements and the Risk of Coronary Artery Calcification and its Progression Among Older Adults: 10-Year Follow-up of the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Recent randomized data suggest that calcium supplements may be associated with increased risk of cardiovascular disease (CVD) events. Using a longitudinal cohort study, we assessed the association between calcium intake, from both foods and supplements, and atherosclerosis, as measured by coronary artery calcification (CAC).

METHODS AND RESULTS

We studied 5448 adults free of clinically diagnosed CVD (52% female; aged 45-84 years) from the Multi-Ethnic Study of Atherosclerosis. Baseline total calcium intake was assessed from diet (using a food frequency questionnaire) and calcium supplements (by a medication inventory) and categorized into quintiles. Baseline CAC was measured by computed tomography, and CAC measurements were repeated in 2742 participants ≈10 years later. At baseline, mean calcium intakes across quintiles were 313.3, 540.3, 783.0, 1168.9, and 2157.4 mg/day. Women had higher calcium intakes than men. After adjustment for potential confounders, among 1567 participants without baseline CAC, the relative risk (RR) of developing incident CAC over 10 years, by quintile 1 to 5 of calcium intake, were 1 (reference), 0.95 (0.79-1.14), 1.02 (0.85-1.23), 0.86 (0.69-1.05), and 0.73 (0.57-0.93). After accounting for total calcium intake, calcium supplement use was associated with increased risk for incident CAC (RR=1.22 [1.07-1.39]). No relation was found between baseline calcium intake and 10-year changes in log-transformed CAC among those participants with baseline CAC >0.

CONCLUSIONS

High total calcium intake was associated with a decreased risk of incident atherosclerosis over long-term follow-up, particularly if achieved without supplement use. However, calcium supplement use may increase the risk for incident CAC.

The association of calcium supplementation and incident cardiovascular events in the Multi-ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Many US adults use calcium supplements to address inadequate dietary intake and improve bone health. However, recent reports have suggested that use of calcium supplements may elevate cardiovascular disease (CVD) risk. In this study, we examined associations between baseline calcium supplement use and incident myocardial infarction (MI) (n = 208 events) and CVD events (n = 641 events) over 10.3 years in men and women from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort (n = 6236), with dietary calcium intake at baseline also examined as a supplementary objective.

METHODS AND RESULTS

Using Cox proportional hazards models, no compelling associations between calcium intake from supplements or diet and incident CVD events were observed upon multivariate adjustment for potential confounders. An association with lower MI risk was observed comparing those with low levels of calcium supplement use (1-499 mg) to those using no calcium supplements (hazard ratio 0.69, 95% CI 0.48, 0.98, p = 0.039). Relationships were homogeneous by gender, race/ethnicity, or chronic kidney disease. Results were also similar when the analysis was limited to postmenopausal women only.

CONCLUSION

Analysis of incident MI and CVD events in the MESA cohort does not support a substantial association of calcium supplement use with negative cardiovascular outcomes.

Serum Calcium Increase Correlates With Worsening of Lipid Profile: An Observational Study on a Large Cohort From South Italy

Despite the well-documented role of calcium in cell metabolism, its role in the development of cardiovascular disease is still under heavy debate. Several studies suggest that calcium supplementation might be associated with an increased risk of coronary heart disease, whereas others underline a significant effect on lowering high blood pressure and hyperlipidemia. The purpose of this study was to investigate, in a large nonselected cohort from South Italy, if serum calcium levels correlate with lipid values and can therefore be linked to higher individual cardiovascular risk.Eight-thousand-six-hundred-ten outpatients addressed to the Laboratory of Clinical Biochemistry, University of Magna Græcia, Catanzaro, Italy from January 2012 to December 2013 for routine blood tests, were enrolled in the study. Total HDL-, LDL- and non-HDL colesterol, triglycerides, and calcium were determined with standard methods.We observed a significant association between total cholesterol, LDL-cholesterol, HDL-cholesterol, non-HDL cholesterol, triglycerides, and serum calcium in men and postmenopause women. Interestingly, in premenopause women, we only found a direct correlation between serum calcium, total cholesterol, and HDL-cholesterol. Calcium significantly increased while increasing total cholesterol and triglycerides in men and postmenopause women.Our results confirm that progressive increase of serum calcium level correlates with worsening of lipid profile in our study population. Therefore, we suggest that a greater caution should be used in calcium supplement prescription particularly in men and women undergoing menopause, in which an increase of serum lipids is already known to be associated with a higher cardiovascular risk.

Dairy consumption and CVD: a systematic review and meta-analysis

Inverse associations between dairy consumption and CVD have been reported in several epidemiological studies. Our objective was to conduct a meta-analysis of prospective cohort studies of dairy intake and CVD. A comprehensive literature search was conducted to identify studies that reported risk estimates for total dairy intake, individual dairy products, low/full-fat dairy intake, Ca from dairy sources and CVD, CHD and stroke. Random-effects meta-analyses were used to generate summary relative risk estimates (SRRE) for high v. low intake and stratified intake dose-response analyses. Additional dose-response analyses were performed. Heterogeneity was examined in sub-group and sensitivity analyses. In total, thirty-one unique cohort studies were identified and included in the meta-analysis. Several statistically significant SRRE below 1.0 were observed, namely for total dairy intake and stroke (SRRE=0·91; 95% CI 0·83, 0·99), cheese intake and CHD (SRRE=0·82; 95% CI 0·72, 0·93) and stroke (SRRE=0·87; 95% CI 0·77, 0·99), and Ca from dairy sources and stroke (SRRE=0·69; 95% CI 0·60, 0·81). However, there was little evidence for inverse dose-response relationships between the dairy variables and CHD and stroke after adjusting for within-study covariance. The results of this meta-analysis of prospective cohort studies have shown that dairy consumption may be associated with reduced risks of CVD, although additional data are needed to more comprehensively examine potential dose-response patterns.

The association of dairy intake of children and adolescents with different food and nutrient intakes in the Netherlands

Background

Dairy products are nutrient-rich foods that may contribute to adequate nutrient intakes. However, dairy intake might also be associated with other food sources that influence nutrient intakes. Therefore, we studied the association of dairy, milk and cheese intake with intake of foods and nutrients from (non)dairy sources.

Methods

Dietary intake was assessed from 2007 to 2010 through two non-consecutive 24-h dietary recalls in 1007 children (7–13 years) and 706 adolescents (14–18 years). Participants were divided into non-consumers of a particular dairy product and tertiles according to their dairy intake (lowest, medium and highest intake). P for trend was calculated by linear regression over the median intakes of non-consumers and the tertiles for dairy, milk and cheese.

Results

In children, higher dairy consumption was associated with higher intakes of fruits (54.8 g ± 22.3; p < 0.0001), vegetables (25.0 g ± 14.6; p = 0.001) and cereals (18.5 g ± 20.7; p = 0.01) and with lower consumption of non-alcoholic beverages (−281 g ± 101; p = 0.01): soft drinks (−159 g ± 28.2; p < 0.0001) and fruit juices (−40.5 ± 14.8; p = 0.01). Results were comparable for milk consumption. In adolescents, similar results were found for milk and dairy consumption, except for the associations with higher fruits and vegetable intake.

In children and adolescents, higher cheese consumption was associated with higher vegetable and non-alcoholic beverages consumption; and lower meat consumption (−7.8 g ± 4.8; p = 0.05) in children. Higher cheese consumption was also associated with higher intakes of saturated fat (8.5 g ± 0.9), trans-fatty acids (0.48 g ± 0.06), sodium (614 mg ± 59.3) and several vitamins and minerals .

Conclusions

Higher milk and dairy consumption were associated with lower non-alcoholic beverages consumption, and higher cereal, fruit and vegetable consumption in children, which was also reflected in the nutrient intakes. These findings confirm that the consumption of milk and dairy products might be a marker for healthier eating habits.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0524-3) contains supplementary material, which is available to authorized users.

A phase IV, two-armed, randomized, cross-over study comparing compliance with once-a-month administration of vitamin D3 to compliance with daily administration of a fixed-dose combination of vitamin D3 and calcium during two 6-month periods

In a randomized, cross-over study, once monthly administration of vitamin D3 was preferred over a once daily administration of a fixed-dose combination of vitamin D3 and calcium, with a better compliance but without any significant difference in the increase in vitamin D levels.

INTRODUCTION

The aim of the present study was to compare a once-monthly administration of vitamin D3 to a daily administration of a fixed-dose combination of vitamin D3 and calcium during two treatment periods of 6 months.

METHODS

One hundred volunteers aged 50 years old or older were randomized to receive either one drinkable ampoule containing 25,000 IU vitamin D3 (D-Cure®, SMB) once monthly (group VD) or one chewable tablet containing 1000 mg calcium carbonate + 800 IU vitamin D3 (Steovit Forte®, Takeda) once daily (group VDCa) during 6 months. After the first 6 months of treatment, the groups were reversed according to the randomized cross-over design. Treatment compliance (i.e. the primary outcome), preference, acceptability and vitamin D levels and adverse events were all collected.

RESULTS

For the two periods, the patients had a significantly higher compliance in the VD group than in the VDCa group (p < 0.0001). During the study, 50 (56.8 %) patients preferred the VD treatment, 16 (18.2 %) patients preferred the VDCa, and for 22 (25.0 %) patients, neither treatment was preferred. At the end of the first 6 months of treatment, the mean (SD) increase of 25(OH)D was 6.57 ng/mL (8.19) in the VD group and 3.88 ng/mL (10.0) in the VDCa group (p = 0.16 between groups).

CONCLUSION

In this study, a once-monthly administration of vitamin D3 was preferred over a once-daily administration of a fixed-dose combination of vitamin D3 and calcium, with a better compliance but without any significant difference in the increase in vitamin D levels.

Calcium and bone health--goodbye, calcium supplements?

This review assesses (1) the potential role of calcium supplements in the prevention and treatment of osteoporosis and osteoporotic fractures, and (2) the safety of calcium supplements with respect to cardiovascular health as well. With regard to (1), a total calcium intake of < 800 mg/day is associated with increased loss of bone mineral density in peri- and postmenopausal women with an increase in fracture risk. Hereby, the effect of calcium supplements on fracture prevention is dependent primary on baseline calcium intake. The strongest protective effect has been reported in individuals with a calcium intake < 700 mg/day and in high-risk groups. A calcium intake of about 1000-1200 mg/day seems to be sufficient for general fracture prevention. With regard to (2), an analysis of the data based on the Hill criteria does not demonstrate convincing evidence that calcium supplements increase cardiovascular risk. In the long term, total calcium intake of 2500 mg/day (from food and supplements) continues to be classified as safe. This value should not be exceeded for an extended period of time.

Calcium use in the management of osteoporosis: continuing questions and controversies

Calcium is a vital element in the health and maintenance of growing and mature bone. The amount of calcium recommended for ingestion varies by age, and these requirements can be met by dietary sources or calcium supplementation. This article reviews the role of calcium in the body and the benefits and risks to calcium supplementation. The effects of calcium on fracture risk reduction, bone density, and bone turnover markers as well as the conflicting data on cardiovascular events and increased risk of nephrolithiasis associated with supplementation are discussed.

Dietary calcium intake and mortality risk from cardiovascular disease and all causes: a meta-analysis of prospective cohort studies

BACKGROUND

Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy.

METHODS

We identified relevant studies by searching MEDLINE, Embase, and the Cochrane Library databases between 1 September 2013 and 30 December 2013. Reference lists of relevant articles were also reviewed. Observational prospective studies that reported relative risks and 95% confidence intervals for the association of calcium intake with cardiovascular and all-cause mortality were eligible. Study-specific relative risks were pooled using a random-effects model.

RESULTS

In this meta-analysis, 11 prospective studies with 12 independent cohorts, involving 757,304 participants, were eligible. There was evidence of a non-linear association between dietary calcium intake and risk of mortality from cardiovascular disease (P for non-linearity <0.01) and all causes (P for non-linearity <0.01). A dose-response analysis showed a U-shaped relationship between dietary calcium intake and cardiovascular mortality. Intakes that were lower and higher than around 800 mg/day were gradually associated with a higher risk of cardiovascular mortality. For all-cause mortality, we also observed a threshold effect at intakes around 900 mg/day. The risk of all-cause mortality did not decrease further at intakes above 900 mg/day.

CONCLUSIONS

This meta-analysis of prospective cohort studies suggests that dietary calcium intake is associated with cardiovascular mortality in a U-shaped manner and that high dietary calcium intake (>900 mg/day) is not associated with a decreased risk of all-cause mortality.

Calcium supplementation: is protecting against osteoporosis counter to protecting against cardiovascular disease?

Calcium is the dominant mineral in bone and is a shortfall nutrient in the diet. For those consuming inadequate dietary calcium, calcium supplements have been a standard strategy for prevention of osteoporosis. Recently, calcium supplementation has been linked to both increased and decreased cardiovascular disease risk creating considerable uncertainty. Moreover, recent reports have shed uncertainty over the effectiveness of calcium supplements to reduce risk of fracture. The evidence for calcium supplementation effects to both reduce risk of fracture and increase coronary heart disease and mortality are reviewed. Although the importance of good calcium nutrition is well known, determining the advantage of calcium supplementation to either bone or heart health has been hampered by poor subject compliance and study design flaws. At present, the current Recommended Dietary Allowances for calcium still appear to be a good target with potential risks for chronic disease if intakes fall too short or greatly exceed these recommendations.