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Calcium intake, calcium supplementation and cardiovascular disease and mortality in the British population: EPIC-norfolk prospective cohort study and meta-analysis.
Pana, TA, Dehghani, M, Baradaran, HR, Neal, SR, Wood, AD, Kwok, CS, Loke, YK, Luben, RN, Mamas, MA, Khaw, KT, et al
European journal of epidemiology. 2021;(7):669-683
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Abstract
The role of dietary calcium in cardiovascular disease prevention is unclear. We aimed to determine the association between calcium intake and incident cardiovascular disease and mortality. Data were extracted from the European Prospective Investigation of Cancer, Norfolk (EPIC-Norfolk). Multivariable Cox regressions analysed associations between calcium intake (dietary and supplemental) and cardiovascular disease (myocardial infarction, stroke, heart failure, aortic stenosis, peripheral vascular disease) and mortality (cardiovascular and all-cause). The results of this study were pooled with those from published prospective cohort studies in a meta-analsyis, stratifying by average calcium intake using a 700 mg/day threshold. A total of 17,968 participants aged 40-79 years were followed up for a median of 20.36 years (20.32-20.38). Compared to the first quintile of calcium intake (< 770 mg/day), intakes between 771 and 926 mg/day (second quintile) and 1074-1254 mg/day (fourth quintile) were associated with reduced all-cause mortality (HR 0.91 (0.83-0.99) and 0.85 (0.77-0.93), respectively) and cardiovascular mortality [HR 0.95 (0.87-1.04) and 0.93 (0.83-1.04)]. Compared to the first quintile of calcium intake, second, third, fourth, but not fifth quintiles were associated with fewer incident strokes: respective HR 0.84 (0.72-0.97), 0.83 (0.71-0.97), 0.78 (0.66-0.92) and 0.95 (0.78-1.15). The meta-analysis results suggest that high levels of calcium intake were associated with decreased all-cause mortality, but not cardiovascular mortality, regardless of average calcium intake. Calcium supplementation was associated with cardiovascular and all-cause mortality amongst women, but not men. Moderate dietary calcium intake may protect against cardiovascular and all-cause mortality and incident stroke. Calcium supplementation may reduce mortality in women.
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Additively protective effects of vitamin D and calcium against colorectal adenoma incidence, malignant transformation and progression: A systematic review and meta-analysis.
Huang, D, Lei, S, Wu, Y, Weng, M, Zhou, Y, Xu, J, Xia, D, Xu, E, Lai, M, Zhang, H
Clinical nutrition (Edinburgh, Scotland). 2020;(8):2525-2538
Abstract
BACKGROUND Colorectal cancer (CRC) exhibits a linear progression from normal colonic epithelium, adenoma initiation, carcinoma transformation and even to metastasis. Diet changes might influence carcinogenesis and prognosis. We aimed to determine the effects of vitamin D and calcium on colorectal adenoma incidence, malignancy development and prognosis. METHODS Systematic literature searches (PubMed, Embase, and Cochrane Library databases) and hand searches were performed by September 30, 2019. A random-effects model was adopted to pool relative ratios (RRs) for colorectal tumour incidence or hazard ratios (HRs) for CRC mortality. Stratified analyses were performed by gender, tumour location, calcium intake level and ethnic group. RESULTS Total 854,195 cases from 166 studies were included. The colorectal adenoma incidence was inversely correlated with the circulating 25-hydroxyvitamin D [25(OH)D] level (RR: 0.80, 95% CI: 0.71-0.89), vitamin D intake (RR: 0.87, 95% CI: 0.82-0.92) and calcium intake (RR: 0.86, 95% CI: 0.81-0.91). The CRC incidence was decreased by circulating 25(OH)D (RR: 0.67, 95% CI: 0.59-0.77), vitamin D intake (RR: 0.85, 95% CI: 0.78-0.93) and calcium intake (RR: 0.75, 95% CI: 0.70-0.79). High-level circulating 25(OH)D triggered better overall survival (HR: 0.67, 95% CI: 0.57-0.79) and CRC-specific survival (HR: 0.63, 95% CI: 0.53-0.74). Stratified analyses showed that vitamin D and calcium significantly suppressed colorectal tumour incidence among women. Left-sided CRC risk was reversely related to circulating 25(OH)D (RR: 0.60, 95% CI: 0.41-0.88) and vitamin D intake (RR: 0.73, 95% CI: 0.57-0.93). Circulating 25(OH)D decreased colorectal adenoma (RR: 0.63, 95% CI: 0.48-0.82) and CRC (RR: 0.69, 95% CI: 0.56-0.86) risk in populations with higher calcium intake. European and American populations benefited more from vitamin D intake against colorectal tumour. A significant dose-response relationship was observed between intake of vitamin D or calcium and colorectal tumour incidence. CONCLUSIONS Vitamin D and calcium play additively chemopreventive roles in colorectal adenoma incidence, malignant transformation and progression, especially for women and left-sided CRC patients.
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Calcium supplementation for improving bone density in lactating women: a systematic review and meta-analysis of randomized controlled trials.
Cai, G, Tian, J, Winzenberg, T, Wu, F
The American journal of clinical nutrition. 2020;(1):48-56
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Abstract
BACKGROUND Clinical trials evaluating the effect of calcium supplementation on bone loss in lactating women have been small, with inconsistent results. OBJECTIVES We aimed to determine the effect of calcium supplementation on bone mineral density (BMD) in lactating women. METHODS An electronic search of databases was conducted from inception to January 2020. Two authors screened studies, extracted data, and assessed the risk of bias of eligible studies. Percentage change in BMD was pooled using random-effects models and reported as weighted mean differences (WMDs) with 95% CIs. Risk of bias was assessed using the Cochrane risk of bias tool. RESULTS Five randomized controlled trials including 567 lactating women were included. All had a high risk of bias. Mean baseline calcium intake ranged from 562 to 1333 mg/d. Compared with control groups (placebo/no intervention), calcium supplementation (600/1000 mg/d) had no significant effect on BMD at the lumbar spine (WMD: 0.74%; 95% CI: -0.10%, 1.59%; I2 = 47%; 95% CI: 0%, 81%; n = 527 from 5 trials) or the forearm (WMD: 0.53%; 95% CI: -0.35%, 1.42%; I2 = 55%; 95% CI: 0%, 85%; n = 415 from 4 trials). BMD at other sites was assessed in single trials: calcium supplementation had a small to moderate effect on total-hip BMD (WMD: 3.3%; 95% CI: 1.5%, 5.1%) but no effect on total body or femoral neck BMD. CONCLUSIONS Overall, the meta-analysis indicates that calcium supplementation does not provide clinically important benefits for BMD in lactating women. However, there was adequate dietary intake before supplementation in some studies, and others did not measure baseline calcium intake. Advising lactating women to meet the current recommended calcium intakes (with supplementation if dietary intake is low) is warranted unless new high-certainty evidence to the contrary from robust clinical trials becomes available. More research needs to be done in larger samples of women from diverse ethnic and racial groups.This systematic review was registered at www.crd.york.ac.uk/prospero as CRD42015022092.
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Dietary calcium intake and the risk of metabolic syndrome: evidence from observational studies.
Cheng, L, Hu, D, Jiang, W
Public health nutrition. 2019;(11):2055-2062
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Abstract
OBJECTIVE Epidemiological investigations evaluating the association of dietary Ca intake with metabolic syndrome (MetS) risk have yielded controversial results. Therefore, a meta-analysis was conducted to quantitatively summarize the association between dietary Ca intake and the risk of MetS. DESIGN PubMed, Embase and Web of Science were searched for relevant articles published up to October 2018. The pooled OR and 95 % CI were calculated with a random-effects model. SETTING Meta-analysis.ParticipantsNine cross-sectional studies. RESULTS A total of nine articles with fifteen studies for dietary Ca intake were finally included in the meta-analysis. The combined OR with 95 % CI of MetS for the highest v. lowest category of dietary Ca intake was 0·80 (95 % CI 0·70, 0·91). For dose-response analysis, a non-linear relationship was found between dietary intake of Ca and risk of MetS (P non-linearity<0·001). The threshold for dietary Ca intake was 280 mg/d (OR=0·87; 95 % CI 0·82, 0·93), reducing the risk of MetS by 13 %. CONCLUSIONS The present meta-analysis suggests that dietary Ca intake might reduce the risk of MetS, which needs to be further confirmed by larger prospective cohort studies.
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Dietary Calcium Intake and the Risk of Metabolic Syndrome: A Systematic Review and Meta-Analysis.
Han, D, Fang, X, Su, D, Huang, L, He, M, Zhao, D, Zou, Y, Zhang, R
Scientific reports. 2019;(1):19046
Abstract
Growing evidence has suggested a possible relationship between dietary calcium intake and metabolic syndrome (MetS) risk. However, the findings of these observational studies are inconclusive, and the dose-response association between calcium intake and risk of MetS remains to be determined. Here, we identified relevant studies by searching PubMed and Web of Science databases up to December 2018, and selected observational studies reporting relative risk (RR) with 95% confidence interval (CI) for MetS based on calcium intake and estimated the summary RRs using random-effects models. Eight cross-sectional and two prospective cohort studies totaling 63,017 participants with 14,906 MetS cases were identified. A significantly reduced risk of MetS was associated with the highest levels of dietary calcium intake (RR: 0.89; 95% CI: 0.80-0.99; I2 = 75.3%), with stronger association and less heterogeneity among women (RR: 0.74, 95% CI: 0.66-0.83; I2 = 0.0%) than among men (RR: 1.06, 95% CI: 0.82-1.37; I2 = 72.6%). Our dose-response analysis revealed that for each 300 mg/day increase in calcium intake, the risk of MetS decreased by 7% (RR: 0.93; 95% CI: 0.87-0.99; I2 = 77.7%). In conclusion, our findings suggest that dietary calcium intake may be inversely associated with the risk of MetS. These findings may have important public health implications with respect to preventing the disease. Further studies, in particular longitudinal cohort studies and randomized clinical trials, will be necessary to determine whether calcium supplementation is effective to prevent MetS.
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Dietary calcium intake and hypertension risk: a dose-response meta-analysis of prospective cohort studies.
Jayedi, A, Zargar, MS
European journal of clinical nutrition. 2019;(7):969-978
Abstract
The association of calcium intake with risk of developing hypertension in the general population has not been established yet. We systematically searched PubMed and Scopus databases up to February 2018 to find prospective observational studies investigating the association of calcium intake with risk of developing hypertension. The reported risk estimates were pooled using a random-effects model. Eight prospective cohort studies (248,398 participants and 30,838 cases) were included. Seven studies measured dietary calcium intake, but one study measured total calcium intake (calcium from food and supplements). A significant inverse association was found for the highest versus lowest category of calcium intake (relative risk: 0.89, 95%CI: 0.86, 0.93; I2 = 0%, n = 8), and for each 500 mg/d increment (relative risk: 0.93, 95%CI: 0.90, 0.97; I2 = 64%, n = 7). Summary results were the same with the main analyses when the analyses were restricted only to dietary calcium intake. A nonlinear dose-response meta-analysis exhibited a linear inverse association, with a somewhat steeper trend within the low and moderate intakes. In conclusion, higher dietary calcium intake, independent of adiposity and intake of other blood pressure-related minerals, is slightly associated with a lower risk of developing hypertension.
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Global inequities in dietary calcium intake during pregnancy: a systematic review and meta-analysis.
Cormick, G, Betrán, AP, Romero, IB, Lombardo, CF, Gülmezoglu, AM, Ciapponi, A, Belizán, JM
BJOG : an international journal of obstetrics and gynaecology. 2019;(4):444-456
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BACKGROUND Evidence shows that adequate calcium intake during pregnancy reduces the risk of hypertensive disorders of pregnancy. In most low- and middle-income countries (LMICs) the daily calcium intake is well below recommendations. Mapping calcium intake during pregnancy worldwide and identifying populations with low calcium intake will provide the evidence base for more targeted actions to improve calcium intake. OBJECTIVE To assess dietary calcium intake during pregnancy worldwide. SEARCH STRATEGY MEDLINE and EMBASE (from July 2004 to November 2017). SELECTION CRITERIA Cross-sectional, cohort, and intervention studies reporting calcium intake during pregnancy. DATA COLLECTION AND ANALYSIS Five reviewers working in pairs independently performed screening, extraction, and quality assessment. We reported summary measures of calcium intake and calculated the weighted arithmetic mean for high-income countries (HICs) and LMICs independently, and for geographic regions, among studies reporting country of recruitment, mean intake, and total number of participants. When available, inadequate intakes were reported. MAIN RESULTS From 1880 citations 105 works met the inclusion criteria, providing data for 73 958 women in 37 countries. The mean calcium intake was 948.3 mg/day (95% CI 872.1-1024.4 mg/day) for HICs and 647.6 mg/day (95% CI 568.7-726.5 mg/day) for LMICs. Calcium intakes below 800 mg/day were reported in five (29%) countries from HICs and in 14 (82%) countries from LMICs. CONCLUSION These results are consistent with a lack of improvement in calcium dietary intake during pregnancy and confirm the gap between HICs and LMICs, with alarmingly low intakes recorded for pregnant women in LMICs. From the public health perspective, in the absence of specific local data, calcium supplementation of pregnant women in these countries should be universal. TWEETABLE ABSTRACT Despite dietary recommendations, women in LMICs face pregnancy with diets low in calcium.
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Assessing the efficacy and external validity of interventions promoting calcium or dairy intake in young adults: A systematic review with meta-analysis.
Rouf, AS, Grech, A, Allman-Farinelli, M
Critical reviews in food science and nutrition. 2018;(15):2600-2616
Abstract
Calcium and dairy products have a role in the prevention of chronic diseases and attainment of peak bone mass, during adolescence to young adulthood. However, intakes are often suboptimal and interventions to improve consumption of food sources are needed. This systematic review aimed to investigate the efficacy and external validity of interventions promoting calcium or dairy foods among young adults. Eight databases were searched from inception to identify relevant studies. Inclusion criteria included those aged 18 to 35 years in an intervention promoting calcium or dairy food intake. The mean age of the participants was 19.9 ± 1.4 years. Of the 16 studies that met the selection criteria, five studies were included in the meta-analyses for calcium (pooled effect size 0.35, 95% CI 0.04 to 0.67) and three studies for dairy (pooled effect size 0.31, 95% CI 0.11 to 0.50). The quality of the body of evidence was determined using the GRADE system, and was of overall low quality with high risk of bias. Our review suggests young adults respond favorably to interventions but the effect size is small.
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Protective Effect of Dietary Calcium Intake on Esophageal Cancer Risk: A Meta-Analysis of Observational Studies.
Li, Q, Cui, L, Tian, Y, Cui, H, Li, L, Dou, W, Li, H, Wang, L
Nutrients. 2017;(5)
Abstract
Although several epidemiological studies have investigated the association between dietary calcium intake and the risk of esophageal cancer, the results are inconsistent. This study aimed to make a comprehensive evaluation regarding the association between calcium intake and risk of esophageal cancer through a meta-analysis approach. We searched for all relevant articles from the inception to April 2017, using PUBMED, EMBASE, and Web of Knowledge. The pooled odds ratio (ORs) with the 95% confidence interval (95% CI) for the highest versus the lowest categories of calcium intake was calculated using a Mantel-Haenszel fixed-effect model. In total, 15 articles reporting 17 studies including 3396 esophageal cancer cases and 346,815 controls were selected for the meta-analysis. By comparing the highest vs. the lowest levels of dietary calcium intake, we found that dietary calcium intake was inversely associated with the risk of esophageal cancer (OR = 0.80, 95% CI: 0.71-0.91, I² = 33.6%). The subgroup analysis indicated that the protective function of dietary calcium intake were observed in esophageal squamous cell cancer, but not in esophageal adenocarcinoma in the studies conducted in Asia, but not those in Europe and America. In conclusion, our results suggest that higher dietary calcium intake is associated with a lower risk of esophageal cancer-especially esophageal squamous cell cancer-in Asian populations, though more data from prospective cohort studies are needed.
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The Effects of Dietary Calcium Supplements Alone or With Vitamin D on Cholesterol Metabolism: A Meta-Analysis of Randomized Controlled Trials.
Chen, C, Ge, S, Li, S, Wu, L, Liu, T, Li, C
The Journal of cardiovascular nursing. 2017;(5):496-506
Abstract
BACKGROUND Evidence supports the role of lifestyle interventions as a primary intervention strategy among individuals with dyslipidemia. The role of micronutrients, and calcium in particular, on cholesterol metabolism is not clear and warrants further investigation. OBJECTIVE The aim of this study is to conduct a meta-analysis of controlled clinical trials that have examined the effects of calcium supplements on blood lipids among adults. METHODS MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases were searched up to March 2016 for calcium supplements clinical trials. Other trials were selected from searching bibliography of reviews, meta-analysis, and included trials. Clinical trials with random allocation to calcium supplementation or calcium plus vitamin D supplementation, or control were selected. Data collected included study design, participant characteristics, information of the intervention, and outcomes. Data synthesis was conducted using random effect models. RESULTS A total of 22 trials, representing 4071 participants, met the eligibility criteria. Compared with control group, calcium supplements significantly reduced low-density lipoprotein cholesterol level by -0.12 mmol/L (95% confidence interval, -0.22 to -0.02) and increased high-density lipoprotein cholesterol level by 0.05 mmol/L (95% confidence interval, 0.00 to 0.10). Subgroup analyses revealed that the associations were consistent across study duration and vitamin D cosupplementation status. CONCLUSIONS Calcium supplementation has beneficial effect on blood lipids. Such supplements may be useful as a nonpharmaceutical strategy in cholesterol control.