Association of dietary calcium intake at dinner versus breakfast with cardiovascular disease in U.S. adults: the national health and nutrition examination survey, 2003-2018.

BACKGROUND: Currently, it is still largely unknown whether the proportion of calcium intake at breakfast and dinner is associated with cardiovascular disease (CVD) in the general population. OBJECTIVES: The aim of this study was to evaluate the association of dietary calcium intake at dinner versus breakfast with CVD in a nationally representative sample of US adults. METHODS: The study population consisted of 36,164 US adults (including 4,040 CVD cases) from the NHANES 2003 to 2018. According to the ratio of dietary calcium intake at dinner and breakfast (Δ = dinner/breakfast), 36,164 participants were divided into five groups. After adjustment for a series of confounder factors, logistic regression analyses were performed to examine the association between Δ and CVD. Dietary substitution models were used to explore the changes in CVD risk when a 5% dietary calcium intake at dinner was substituted with dietary calcium intake at breakfast. RESULTS: Compared with participants in the lowest quintile, participants in the highest quintile were more likely to have CVD, with an adjusted OR of CVD of 1.16 (95% CI, 1.03 to 1.31). When the total calcium intake remained constant, replacing a 5% dietary calcium intake at dinner with dietary calcium intake at breakfast was associated with a 6% lower risk of CVD. CONCLUSIONS: Compared to the lowest quintile of Δ, participants in the highest quintile of Δ were likely to experience CVD in the general population. It is necessary to scientifically allocate dietary calcium intake at breakfast and dinner.

The protective association of dairy intake and the adverse impact of iron on gestational diabetes risk.

Background: Gestational diabetes (GDM) is a pregnancy-related glucose intolerance with significant implications for maternal and fetal health. Calcium is essential for insulin secretion and metabolism, while iron intake may also impact GDM. This case-control study was conducted to investigate the relationship between calcium and iron intake with the risk of GDM. Methods: GDM was defined as Fasting Blood Sugar>92mg/dL or 75g Oral-Glucose-Tolerance-Test 120-minutes>153mg/dL. A 168-Item food-frequency-questionnaire was used to collect dietary calcium and iron intake from 24-40 weeks of gestation. The impact of total iron, red, processed/unprocessed meat consumption, calcium, and dairy intake on GDM were investigated. Results: A total of 229 GDM and 205 non-GDM women (18-45 years) participated. GDM group had higher pre-pregnancy weight, weight gain, and pre-pregnancy BMI. Across all models, GDM risk significantly increased in the third and fourth quartiles of iron intake. The fourth quartile had an Odds Ratio (OR) of 2.68 (CI 95%, 4.89-1.56; P<0.001) compared to the reference. Heme-iron consumption in the fourth quartiles increased GDM risk. In the second calcium intake model, ORs for the second, third, and fourth quartiles were 0.51 (CI 95%, 0.91-0.25), 0.43 (CI 95%, 0.77-0.24), and 0.35 (CI 95%, 0.63-0.19), respectively (P<0.001 all), reducing GDM risk by 50-65% compared to the first quartile. Dairy consumption in all quartiles of the first and second models was associated with lower GDM risk. Conclusions: Consumption of heme-iron through red and processed meat associated with an increased chance of developing GDM. Dairy intake reduces the chances of developing GDM in pregnant women.

A perspective on the benefits of consumption of parboiled rice over brown rice for glycaemic control.

PURPOSE: Rice is a staple food for over 3.5 billion people worldwide. The nutritional content of rice varies with different post-harvest processing techniques. Major varieties include brown rice (BR), white rice (WR) and parboiled rice (PBR). While consumption of BR is advocated due to its higher nutritional content compared to other varieties, some studies have indicated lower post-prandial blood glucose (PPBG) levels when PBR is consumed. This apparent benefit of PBR consumption is not well publicised and no commentaries on underlying mechanisms are available in literature. METHODS: In this review, we looked into differential nutrient content of PBR, as compared to BR and WR, and tried to understand how their consumption could be associated with glycaemic control. Various roles played by these nutrients in mechanisms of insulin secretion, insulin resistance, nutrient absorption and T2DM-associated inflammation were reviewed from literature-based evidence. RESULTS: We report differential nutritional factors in PBR, with respect to BR (and WR), such as higher calcium and selenium content, lower phytic acids, and enriched vitamin B6 which might aid PBR's ability to provide better glycaemic control than BR. CONCLUSION: Our interpretation of reviewed literature leads us to suggest the possible benefits of PBR consumption in glycaemic control and its inclusion as the preferred rice variant in diets of T2DM patients and at-risk individuals.

Dual nuclear magnetic resonance for probing intrinsic bone structure and a potential gut-bone axis in ovariectomized rats.

Currently, the existence of a gut-bone axis receives massive attention, and while sound premises and indirect proofs exist for the gut-bone axis concept, few studies have provided actual data linking the gut and bone physically. This study aimed to exploit the versatile nature of nuclear magnetic resonance (NMR) to link NMR relaxometry data on bone mineralization with NMR spectroscopic profiling of gut metabolites. For this purpose, sample material was obtained from a 6-week intervention study with ovariectomized (OVX) rats (n = 49) fed with seven different diets varying in calcium content (0.2-6.0 mg/kg) and prebiotic fiber content (0-5.0% w/w). This design ensured a span in (i) calcium available for bone mineralization and (ii) metabolic activity in the gut. After termination of the intervention, longitudinal (T1 ), transverse (T2 ) relaxation, and mechanical bone strength were measured on the excised femur bones. A PLS model with high predictability (Q2 = 0.86, R2 = 0.997) was demonstrated between T2 decay curves and femur mechanical strength. Correlations were established between bone T2 populations and gut short-chain fatty acids. In conclusion, the present dual NMR approach showed strong correlation between T2 relaxation and mechanical strength of the bone, and when metabolic activity in the gut was modulated by inulin, the potential existence of a gut-bone axis was demonstrated.

Bone resorption and dietary calcium in pregnancy-a window to future maternal bone health.

BACKGROUND: Pregnancy is characterized by increased bone turnover and reversible loss of bone mineral density (BMD) to meet fetal calcium demands. The long-term effect of bone turnover and maternal diet in pregnancy on maternal bone is not well established. OBJECTIVE: We aimed to determine if an association exists between [1] bone resorption, [2] dietary calcium, and [3] serum 25-hydroxyvitamin D in pregnancy with maternal BMD 5-year postpartum. DESIGN: This is a prospective, longitudinal study of 107 women recruited to the ROLO low glycemic index dietary intervention trial in pregnancy and followed-up at 13, 28, and 34 weeks' gestation and 5 years' postpartum. At 13 and 28 weeks' gestation, a biomarker of bone resorption, urine cross-linked N-telopeptide of type I collagen (uNTX), was measured. At the 5-year follow-up BMD was measured using dual-energy X-ray absorptiometry. Anthropometry, dietary intakes, and serum 25-hydroxyvitamin D were measured in pregnancy and at 5 years. Multiple linear regression, controlling for confounders, was used for analysis. RESULTS: Mean BMD at 5 years was 1.208 g/cm2. In pregnancy, 24-34% reported dietary calcium intakes <800 mg/day. Vitamin D deficiency (< 30 nmol/L) was observed in 38-41% of women in pregnancy and in 29% of women at the 5-year follow-up. At 13 and 28 weeks' gestation, uNTX levels greater than the median were associated with 0.060 and 0.050 g/cm2 lower BMD 5 years later, respectively. Dietary calcium <800 mg/day in trimester 3 was associated with 0.072 g/cm2 lower BMD 5 years later. Vitamin D deficiency at 5 years, but not in pregnancy, was associated with lower BMD. CONCLUSION: Higher bone resorption and low dietary calcium in pregnancy were associated with lower BMD 5 years later. These findings could enable the identification of women at risk of declining of BMD in later life, but further research is needed. Adequate dietary calcium should be advised in the antenatal setting to promote lifelong maternal bone health.

Acute Oral Calcium Suppresses Food Intake Through Enhanced Peptide-YY Secretion Mediated by the Calcium-Sensing Receptor in Rats.

BACKGROUND: Dietary calcium has been proposed to reduce appetite in human studies. Postprandial satiety is mainly controlled by gut hormones. However, the effect of calcium on appetite and the role of gut hormones remain unclear. OBJECTIVES: We examined whether oral administration of calcium reduces food intake in rats and investigated the underlying mechanism. METHODS: Male Sprague Dawley rats (8-12 wk old) were used after an overnight fastifffng. In a series of 2 trials with 1-wk interval between challenges, food intake was measured 0.5-24 h after oral gavage of a vehicle (saline containing 1.5% carboxymethyl cellulose) as the control treatment, or the vehicle containing various calcium compounds [calcium chloride (CaCl2), calcium carbonate, calcium lactate, in a random order] at 150 mg calcium/kg dose. A conditional taste aversion test was conducted. In separate experiments, plasma calcium and gut hormone concentrations were measured 15 or 30 min after oral administration of the calcium compounds. In anesthetized rats, portal peptide-YY (PYY) concentrations were measured after intraluminal administration of a liquid meal with or without additional calcium. RESULTS: Oral CaCl2 reduced food intake acutely (30 min, ∼20%, P < 0.05) compared with control rats, without taste aversion. Plasma PYY concentration was higher (100%, P < 0.05) in CaCl2-preloaded rats than in control rats, 15 min after administration. In anesthetized rats, luminal meal + CaCl2 induced a 4-fold higher increase in plasma PYY than the control treatment did. Oral administration of a calcium-sensing receptor (CaSR) agonist suppressed food intake (∼30%, P < 0.05), but CaCl2 and CaSR agonist did not suppress food intake under treatment with a PYY receptor antagonist. Furthermore, the CaSR antagonist attenuated the effect of CaCl2 on food intake. CONCLUSIONS: CaCl2 suppresses food intake partly by increasing CaSR-mediated PYY secretion in rats. Our findings could at least partially explain the satiating effect of calcium.

Dietary calcium and vitamin K are associated with osteoporotic fracture risk in middle-aged and elderly Japanese women, but not men: the Murakami Cohort Study.

Although dietary Ca, vitamin D and vitamin K are nutritional factors associated with osteoporosis, little is known about their effects on incident osteoporotic fractures in East Asian populations. This study aimed to determine whether intakes of these nutrients predict incident osteoporotic fractures. We adopted a cohort study design with a 5-year follow-up. Subjects were 12 794 community-dwelling individuals (6301 men and 6493 women) aged 40-74 years. Dietary intakes of Ca, vitamin D and vitamin K were assessed with a validated FFQ. Covariates were demographic and lifestyle factors. All incident cases of major osteoporotic limb fractures, including those of the distal forearm, neck of humerus, neck or trochanter of femur and lumbar or thoracic spine were collected. Hazard ratios (HR) for energy-adjusted Ca, vitamin D and vitamin K were calculated with the residual method. Mean age was 58·8 (sd 9·3) years. Lower energy-adjusted intakes of Ca and vitamin K in women were associated with higher adjusted HR of total fractures (Pfor trend = 0·005 and 0·08, respectively). When vertebral fracture was the outcome, Pfor trend values for Ca and vitamin K were 0·03 and 0·006, respectively, and HR of the lowest and highest (reference) intake groups were 2·03 (95 % CI 1·08, 3·82) and 2·26 (95 % CI 1·19, 4·26), respectively. In men, there were null associations between incident fractures and each of the three nutrient intakes. Lower intakes of dietary Ca and vitamin K were independent lifestyle-related risk factors for osteoporotic fracture in women but not men. These associations were robust for vertebral fractures, but not for limb fractures.

Calcium intake, calcium supplementation and cardiovascular disease and mortality in the British population: EPIC-norfolk prospective cohort study and meta-analysis.

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.

Association of dietary calcium intake, total and ionized serum calcium levels with preeclampsia in Ethiopia.

BACKGROUND: Preeclampsia is a well-known cause of maternal mortality and morbidity in Ethiopia. The exact pathophysiology has not been fully understood. Calcium and magnesium deficiencies have been given emphasis to play roles in the pathophysiology. Although evidence is abundant, they are equivocal. The study aimed to see the association of dietary calcium intake, serum total calcium level and ionized calcium level with preeclampsia. It also evaluated the association between dietary calcium intake and serum calcium levels. MATERIALS AND METHODS: An unmatched case-control study was conducted in Gandhi Memorial, Tikur Anbessa, and Zewditu Memorial Hospitals, all in Addis Ababa, between October to December, 2019. Cases were 42 women with preeclampsia and controls were 42 normotensive women. The medical and obstetric history was gathered using a structured questionnaire and the dietary calcium intake information using a 24-h dietary recall. The serum levels of total serum calcium and ionized (free) calcium were measured using an inductively coupled mass spectrophotometer. Bivariate and multivariate logistic regression and Pearson correlation test were utilized during data analysis. RESULTS: In comparison with controls, women with preeclampsia had lower mean (± 1SD) levels of ionized calcium level (1.1 mmol/l ± 0.11), total serum calcium level (1.99 mmol/l ± 0.35) and lower median (IQR) dietary calcium intake (704 mg/24 h,458-1183). The odds of having preeclampsia was almost eight times greater in those participants with low serum ionized calcium level (OR 7.5, 95% CI 2.388-23.608) and three times higher in those with low total serum calcium level (OR 3.0, 95% CI 1.024-9.370). Low dietary calcium intake also showed statistically significant association with preeclampsia (OR 3.4, 95% CI 1.092 -10.723). Serum ionized calcium level and total serum calcium level showed positive correlation of moderate strength (p = 0.004, r = 0.307), but no correlation was found between dietary calcium intake with both forms of serum calcium levels. CONCLUSION: This study showed significant association between low dietary calcium intake and low serum calcium levels with preeclampsia, hence this can be used as a supportive local evidence for the current context-specific recommendation of calcium supplementation in societies with low-dietary calcium consumption in an attempt to prevent preeclampsia, therefore implementation study should be considered in Ethiopia to look for the feasibility of routine supplementation.

Dietary calcium intake in a cohort of individuals evaluated for low bone mineral density: a multicenter Italian study.

BACKGROUND: A low calcium intake is a well-known factor that influences the bone mineral density (BMD) maintenance. In the presence of inadequate calcium intake, secondary hyperparathyroidism develops, leading to an increased bone turnover and fracture risk. AIMS: To assess the dietary calcium intake in relation with osteoporosis and fragility fracture in a cohort of Italian individuals evaluated for low BMD. METHODS: A 7-day food-frequency questionnaire was administered to 1793 individuals, who were consecutively referred at the Centers of the Italian Society for Osteoporosis, Mineral Metabolism and Skeletal Diseases (SIOMMMS) for low BMD. RESULTS: In 30.3% and 20.9% of subjects, the calcium intake was inadequate (< 700 mg/day) and adequate (> 1200 mg/day), respectively. As compared with patients with adequate calcium intake, those with inadequate calcium intake were younger (65.5 ± 10.8 vs 63.9 ± 11.5 years, p = 0.03) and they more frequently reported adverse reactions to food (3.2% vs 7.2% p = 0.01) and previous major fragility fractures (20.8% vs 27.0%, p = 0.03). Patients with calcium intake < 700 mg/day showed a higher prevalence of diabetes mellitus, idiopathic hypercalciuria and food allergy/intolerance (8.1%, 5.1%, 7.2%, respectively) than patients with calcium intake > 700 mg/day (5.3%, 3.0%, 4.1%, respectively, p < 0.04 for all comparisons), also after adjusting for age, gender and body mass index. In 30.3% of fractured subjects, the calcium intake was < 700 mg/day. DISCUSSION: In Italy, a low calcium intake is highly prevalent in individuals at risk for low BMD. Importantly, an inadequate calcium intake is highly prevalent even in patients with history of fragility fractures. CONCLUSIONS: Only about a fifth of patients being assessed for low BMD in an Italian SIOMMMS referral Centre have an adequate calcium intake.

Association between Dietary Calcium Intake and Bone Mineral Density in Older Adults.

Calcium is a requisite nutrient in maintaining bone health. High calcium intake has been recommended for osteoporosis prevention. However, the relationship of dietary calcium intake with bone mineral density (BMD) in the elderly remained controversial. We aimd to evaluate the association between them in older adults. Using data from the Nutrition and Health Examination Survey (NHANES, 2001-2006), we conducted multivariate logistic regression analyses to explore the association of dietary calcium intake with lumbar BMD in older adults. Subgroup analyses were also performed. We included 2904 older adults aged ≥ 60 (43.63% men) for analysis. Higher dietary calcium intake was associated with greater lumbar BMD after adjusting for other covariates. In the subgroup analysis stratified by sex, this positive association existed in women, but not in men. In conclusion, for older adults aged ≥ 60, higher dietary calcium intake is associated with a higher lumbar BMD in women, but not in men.

The Evidence and Controversy Between Dietary Calcium Intake and Calcium Supplementation and the Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Cohort Studies and Randomized Controlled Trials.

Objective: Our objective was to synthesize both trial and observational studies and undertake a meta-analysis to explore the associations between calcium from dietary and supplemental intakes and cardiovascular disease (CVD) risks.Methods: Data sources were from PubMed, Cochrane Central, Scopus, and Web of Science, published from the inception dates up to March 2019. Randomized controlled trials (RCTs) and prospective cohort studies with data on dietary or supplemental intake of calcium, with or without vitamin D, and cardiovascular outcomes, were included.Results: Of the 1,212 identified studies, 26 prospective cohort studies and 16 RCTs were included. Results of cohort studies reveled that dietary calcium intakes (DCIs) ranging from 200 to 1500 mg/d did not affect the risk of CVD, coronary heart disease (CHD), and stroke (relative risk (RR) RR for CVD = 0.96, 95% CI, 0.87-1.05; RR for CHD = 0.98, 95% CI, 0.88-1.08; RR for stroke = 0.94, 95% CI, 0.85-1.04). Pooled RR of RCTs showed that the risk of CHD due to calcium supplements (CSs) increased 8% (RR = 1.08, 95% CI, 1.02-1.22; I2 = 0.0%) and increased 20% allocated to CSs alone (RR = 1.20, 95% CI, 1.08-1.33; I2 = 0.0%). CSs increased the risk of myocardial infarction (MI) by 14% (RR = 1.14, 95% CI, 1.05-1.25; I2 = 0.0%), and CSs alone increased the MI risk 21% (RR = 1.21, 95% CI, 1.08-1.35; I2 = 0.0%).Conclusions: We concluded that calcium intake from dietary sources do not adequately increase the risk of CVD including CHD and stroke, while calcium supplements might raise CHD risk, especially MI.

Calcium intake and colon cancer risk subtypes by tumor molecular characteristics.

BACKGROUND: A preventive potential of high calcium intake against colorectal cancer has been indicated for distal colon cancer, which is inversely associated with high-level CpG island methylator phenotype (CIMP), high-level microsatellite instability (MSI), and BRAF and PIK3CA mutations. In addition, BRAF mutation is strongly inversely correlated with KRAS mutation. We hypothesized that the association between calcium intake and colon cancer risk might vary by these molecular features. METHODS: We prospectively followed 88,506 women from the Nurses' Health Study and 47,733 men from the Health Professionals Follow-up Study for up to 30 years. Duplication-method Cox proportional cause-specific hazards regression was used to estimate multivariable hazard ratios (HRs), and 95% confidence intervals (95% CIs) for the associations between calcium intake and the risk of colon cancer subtypes. By Bonferroni correction, the α-level was adjusted to 0.01. RESULTS: Based on 853 colon cancer cases, the inverse association between dietary calcium intake and colon cancer risk differed by CIMP status (pheterogeneity = 0.01). Per each 300 mg/day increase in intake, multivariable HRs were 0.84 (95% CI 0.76-0.94) for CIMP-negative/low and 1.12 (95% CI 0.93-1.34) for CIMP-high. Similar differential associations were suggested for MSI subtypes (pheterogeneity = 0.02), with the corresponding HR being 0.86 (95% CI 0.77-0.95) for non-MSI-high and 1.10 (95% CI 0.92-1.32) for MSI-high. No differential associations were observed by BRAF, KRAS, or PIK3CA mutations. CONCLUSION: The inverse association between dietary calcium intake and colon cancer risk may be specific to CIMP-negative/low and possibly non-MSI-high subtypes.

Dietary calcium intake and adiposity in children and adolescents: Cross-sectional and longitudinal results from IDEFICS/I.Family cohort.

BACKGROUND AND AIMS: Studies in children and adolescents suggest that higher dairy consumption may exert a protective effect on adiposity. However, only few studies examined the association between dietary calcium intake and body mass measures with conflicting results. We evaluated the association between total dietary calcium, calcium from dairy and non-dairy sources and anthropometric indices in a large European cohort of children and adolescents. METHODS AND RESULTS: As many as 6,696 children belonging to the IDEFICS study were eligible for the cross-sectional analysis (Boys = 51%; age 6.0 ± 1.8 years; mean ± SD). Of these, 2,744 were re-examined six years later (Boys = 49.6%; age = 11.7 ± 1.8 years) in the framework of the I.Family study. The exposures were the baseline energy-adjusted total, dairy and non-dairy calcium intakes measured by a validated 24-h dietary recall. Multivariable linear regression was used to determine the association between calcium intake and z-scores of anthropometric indices (body mass index, BMI; waist circumference, WC; sum of skinfolds, SS; fat mass index, FMI) at baseline, and their variation over the 6 years follow-up. The association of dietary calcium with the incidence of overweight/obesity was also assessed. At baseline, an inverse association between total calcium intake and all the adiposity indices was consistently observed in boys, while only SS and FMI were significant in girls. The prevalence of overweight/obesity decreased significantly (P < 0.0001) across tertiles of calcium intake, in both sexes. Over the follow-up, boys with higher baseline calcium intake value showed significantly lower increase in BMI, WC and FMI z-scores, while in girls only a lower increase in WC z-score was observed. Only in boys, the risk to become overweight/obese decreased significantly across tertiles of calcium intake. Similar results were observed by analyzing only dietary calcium from dairy, while no association was observed between non-dairy calcium and adiposity indices. CONCLUSIONS: We showed in a large cohort of European children and adolescents that dietary calcium intake may play a role in the modulation of body fat in developmental age. The association between dietary calcium and adiposity indices was driven by dairy calcium, while no effect was observed for non-dairy calcium intake. The existence of a sex-related difference in the association deserves further investigations.

Supplemental calcium intake in the aging individual: implications on skeletal and cardiovascular health.

Adequate calcium intake during childhood is necessary to achieve optimal peak bone mass and this has the potential by increasing bone reserves, to modulate the rate of age-associated bone loss. However, data regarding the efficacy of calcium obtained either through the diet or in the form of medicinal supplementation, for prevention of bone loss and osteoporotic fractures in the elderly is conflicting. Calcium alone is unlikely to be of benefit for this purpose though the co-administration of calcium and vitamin D may have modest fracture risk benefits. Supplemental calcium with or without vitamin D has recently come into the spotlight after the publication of the findings from a controversial randomized controlled trial that associated calcium supplementation with an increased risk of myocardial infarction. Since then, multiple studies have explored this potential link. The data remains conflicting and the potential mechanistic link if any exists, remains elusive. This review examines the relationship between supplemental calcium intake and skeletal and cardiovascular health in the aging individual through an appraisal of studies done on the subject in the last three decades. It also briefly details some of the studies evaluating fractional absorption of calcium in the elderly and the rationale behind the current recommended dietary allowances of calcium.

Dietary calcium intake is associated with serum high-sensitivity C-reactive protein level in the general Japanese population.

The beneficial effects of dietary calcium intake on high-sensitivity C-reactive protein levels, a risk factor of cardiovascular disease, have not been fully elucidated. This study investigated the associations between dietary calcium intake and serum high-sensitivity C-reactive protein levels in the general Japanese population. We analyzed the data of 2,019 subjects (1,194 men and 825 women) aged 35 to 69 years in a cross-sectional study of the Japan Multi-Institutional Collaborative Cohort Study. Nutrients intake including calcium were estimated using a validated food-frequency questionnaire. Analysis using a general linear model revealed that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels (p for trend <0.001) after adjustment for age, sex, research group, leisure-time physical activity, smoking habit, drinking habit, dietary intakes (energy, dietary fiber, saturated fatty acids and vitamin D) and menopausal status. The association was slightly attenuated after additional adjustment for body mass index; however, remained significant (p for trend = 0.008). There were no significant interactions between dietary calcium intakes and sex, body mass index, or vitamin D intake for high-sensitivity C-reactive protein levels. This study have demonstrated that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels in the general population.

Global dietary calcium intake among adults: a systematic review.

Low calcium intake may adversely affect bone health in adults. Recognizing the presence of low calcium intake is necessary to develop national strategies to optimize intake. To highlight regions where calcium intake should be improved, we systematically searched for the most representative national dietary calcium intake data in adults from the general population in all countries. We searched 13 electronic databases and requested data from domain experts. Studies were double-screened for eligibility. Data were extracted into a standard form. We developed an interactive global map, categorizing countries based on average calcium intake and summarized differences in intake based on sex, age, and socioeconomic status. Searches yielded 9780 abstracts. Across the 74 countries with data, average national dietary calcium intake ranges from 175 to 1233 mg/day. Many countries in Asia have average dietary calcium intake less than 500 mg/day. Countries in Africa and South America mostly have low calcium intake between about 400 and 700 mg/day. Only Northern European countries have national calcium intake greater than 1000 mg/day. Survey data for three quarters of available countries were not nationally representative. Average calcium intake is generally lower in women than men, but there are no clear patterns across countries regarding relative calcium intake by age, sex, or socioeconomic status. The global calcium map reveals that many countries have low average calcium intake. But recent, nationally representative data are mostly lacking. This review draws attention to regions where measures to increase calcium intake are likely to have skeletal benefits.

Dietary calcium intake and rate of bone loss in men.

A high Ca intake has been recommended for osteoporosis prevention; however, little research has examined the relationship between dietary Ca and bone health in men. We examined associations between dietary Ca intake, bone mineral density (BMD) and change in BMD at the total body, hip and spine over 2 years in a cohort of men (mean age 57 years, BMI 26 kg/m2) from a trial. Data from the total cohort (n 323) were used in the analysis of Ca intake and BMD at baseline, and data from the placebo group (n 99) were used in the longitudinal analysis of Ca intake and change in BMD. Parathyroid hormone (PTH) and the markers of bone turnover serum total alkaline phosphatase activity, serum C-telopeptide and serum procollagen type-1 N-terminal propeptide were measured in a subset of participants at baseline (n 150), and associations with dietary Ca at baseline were examined. Mean Ca intake was 870 mg/d. Baseline BMD was not related to dietary Ca intake at any site, before or after adjustment for covariables. Similarly, bone loss over 2 years was not related to Ca intake at any site, before or after adjustment. Dietary Ca intake was inversely correlated with PTH at baseline (r -0·19, P=0·02), but was not associated with the markers of bone turnover. BMD and rates of bone loss were unrelated to Ca intake in these men. This suggests that strategies to increase Ca intake are unlikely to impact on the prevalence of and morbidity from male osteoporosis.

Dietary total, animal, vegetable calcium and type 2 diabetes incidence among Korean adults: The Korean Multi-Rural Communities Cohort (MRCohort).

BACKGROUND AND AIMS: Although a possible mechanism for developing type 2 diabetes in relation to calcium intake has been suggested, there is currently little epidemiological evidence on the association between dietary calcium and type 2 diabetes (T2D). This study aimed to evaluate the prospective association between dietary calcium and T2D incidence among adults 40 years of age or over, from the Multi-rural Communities Cohort (MRCohort), South Korea. METHODS AND RESULTS: In total, 8313 participants (3033 men and 5280 women) who did not have diabetes at baseline were recruited between 2005 and 2013. The incidence rate ratio (IRR) was estimated using a modified Poisson regression model with a robust error estimator. During follow-up (31,570 person-years), 322 T2D cases were newly diagnosed. Dietary calcium (total and vegetable calcium) were inversely associated with the risk of T2D incidence among women (IRR = 0.61, 95% CI = 0.43-0.86, P for trend = 0.007 in third tertile of baseline total calcium intake comparing to the first tertile; IRR = 0.57, 95% CI = 0.39-0.84, P for trend = 0.006 for baseline vegetable calcium intake), not for men. The tendency of those inverse associations remained in both the normal fasting blood glucose group and the impaired fasting blood glucose group and were independent of obesity, smoking, and magnesium intake. CONCLUSIONS: Total and vegetable calcium may be inversely associated with T2D incidence among women, regardless of impaired fasting blood glucose group or normal group. The associations may be potentially dose-responsive. Moderate dietary calcium may be related to lower risk of T2D incidence comparing to low intake group among women.

Nutritional Rickets and Osteomalacia in the Twenty-first Century: Revised Concepts, Public Health, and Prevention Strategies.

PURPOSE OF REVIEW: Nutritional rickets and osteomalacia are common in dark-skinned and migrant populations. Their global incidence is rising due to changing population demographics, failing prevention policies and missing implementation strategies. The calcium deprivation spectrum has hypocalcaemic (seizures, tetany and dilated cardiomyopathy) and late hypophosphataemic (rickets, osteomalacia and muscle weakness) complications. This article reviews sustainable prevention strategies and identifies areas for future research. RECENT FINDINGS: The global rickets consensus recognises the equal contribution of vitamin D and dietary calcium in the causation of calcium deprivation and provides a three stage categorisation for sufficiency, insufficiency and deficiency. For rickets prevention, 400 IU daily is recommended for all infants from birth and 600 IU in pregnancy, alongside monitoring in antenatal and child health surveillance programmes. High-risk populations require lifelong supplementation and food fortification with vitamin D or calcium. Future research should identify the true prevalence of rickets and osteomalacia, their role in bone fragility and infant mortality, and best screening and public health prevention tools.