Association between Daily Dietary Calcium Intake and the Risk of Cardiovascular Disease (CVD) in Postmenopausal Korean Women.

We aimed to evaluate the association between daily dietary calcium intake and the risk of cardiovascular disease (CVD) in postmenopausal women using data from the Korean National Health and Nutrition Examination Survey (KNHANES). This cross-sectional study included 12,348 women aged 45-70 years who had reached natural menopause. They were classified into three groups according to daily dietary calcium intake: <400 mg, 400-800 mg, and >800 mg. The risks of CVD, stroke, angina, and myocardial infarction were assessed in each group. Further, we performed subgroup analysis according to the post-menopause duration (≤10 vs. >10 postmenopausal years). We performed logistic regression analysis with adjustment for age, menopausal age, income, urban area, education, insulin use, body mass index, hypertension, diabetes mellitus, dyslipidemia, high alcohol intake, smoking, exercise, oral contraceptive use, and hormonal therapy use. Calcium intake level was not significantly associated with the risk of CVD in the total population and the ≤10 postmenopausal years subgroup. However, in the >10 postmenopausal years subgroup, daily calcium intake >800 mg was associated with significantly decreased risks of all CVD (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.11-0.64), stroke (OR, 0.06; 95% CI, 0.01-0.42), and myocardial infarction (OR, 0.27; 95% CI, 0.11-0.64). Our findings suggest that a dietary calcium intake of >800 mg/day decreases the risk of CVD events in women who have been menopausal for >10 years.

Dietary calcium is inversely associated with hepatitis B virus infection: an analysis of US National Health and Nutrition Examination Survey (NHANES) 2007-2020.

BACKGROUND: There have been studies on the relationship between hepatitis B virus (HBV) infection and diet. We hypothesized HBV infection is related to dietary calcium intake, but the evidence is limited. This study aimed to examine whether dietary calcium intake is independently related to HBV infection in the United States population. METHODS: A total of 20,488 participants aged over 20 years from the National Health and Nutrition Examination Survey (NHANES), conducted from 2007 to 2020, were included in this study. Pearson correlation was used to test the association between dietary calcium and serum calcium. The relationships of HBV infection with dietary calcium and serum calcium were assessed by logistic regression models. RESULTS: There was a weak correlation between dietary calcium and serum calcium (r = 0.048). Logistic regression models indicated that HBV infection had a linear negative correlation with dietary calcium (OR 0.37; 95%CI 0.19, 0.76). For each additional 10 mg dietary calcium, the possibility of HBV infection was reduced by 63%. Hepatitis B positive participants had lower serum calcium content than negative participants. Stratified analysis shown the linear relationship between calcium and HBV infection varied among sex, race/ethnicity, and body mass index. CONCLUSION: Our findings demonstrated HBV infection was linearly and inversely correlated with dietary calcium. The current study is expected to offer a fresh perspective on reducing HBV infection.

Association between dietary calcium intake and severe abdominal aorta calcification among American adults: a cross-sectional analysis of the National Health and Nutrition Examination Survey.

BACKGROUND: Evidence regarding the relationship between dietary calcium intake and severe abdominal aortic calcification (AAC) is limited. Therefore, this study aimed to investigate the association between dietary calcium intake and severe AAC in American adults based on data from the National Health and Nutrition Examination Survey (NHANES). METHODS: The present cross-sectional study utilized data from the NHANES 2013-2014, a population-based dataset. Dietary calcium intake was assessed using two 24-h dietary recall interviews. Quantification of the AAC scores was accomplished utilizing the Kauppila score system, whereby severe AAC was defined as having an AAC score greater than 6. We used multivariable logistic regression models, a restricted cubic spline analysis, and a two-piecewise linear regression model to show the effect of calcium intake on severe AAC. RESULTS: Out of the 2640 individuals examined, 10.9% had severe AAC. Following the adjustment for confounding variables, an independent association was discovered between an augmented intake of dietary calcium and the incidence of severe AAC. When comparing individuals in the second quartile (Q2) of dietary calcium intake with those in the lowest quartile (Q1), a decrease in the occurrence of severe AAC was observed (odds ratio: 0.66; 95% confidence interval: 0.44-0.99). Furthermore, the relationship between dietary calcium intake and severe AAC demonstrated an L-shaped pattern, with an inflection point observed at 907.259 mg/day. Subgroup analyses revealed no significant interaction effects. CONCLUSION: The study revealed that the relationship between dietary calcium intake and severe AAC in American adults is L-shaped, with an inflection point of 907.259 mg/day. Further research is required to confirm this association.

Consumo de calcio en mujeres jóvenes y factores de riesgo que favorecen la osteoporosis en la postmenopausia / Calcium consumption in young women and risk factors that favor osteoporosis in postmenopause

Fundamentos: La osteoporosis es una enfermedad crónica ósea considerada un problema de salud pública, cuya prevalencia es mayor en mujeres que en hombres. Debido a ello el objetivo fue evaluar el consumo de calcio diario en 138 mujeres jóvenes de la localidad de Makallé, Chaco, teniendo en cuenta sus requerimientos y señalar los factores de riesgo. Métodos: Estudio descriptivo de corte transversal, una vez obtenido el consentimiento de los encuestados, se aplicó una encuesta online estructurada con preguntas cerradas y abiertas dividida en dos secciones, para determinar elnivel de conocimiento de calcio y su frecuencia de consumo. Se analizó la distribución de frecuencias y se realizaron análisis de varianza para ver las diferencias entre grupos. Resultados: Se obtuvieron 136 respuestas, que evidenciaron que el 60% de las mujeres conoce la importancia del consumo de calcio y el momento fundamental de su consumo; el 82% conoce los alimentos fuentes del mineral y sus factores inhibidores como el alcohol el 42% y las bebidas cola el 39%. Por otra parte, demostraron desconocer cómo prevenir pérdidas del mineral un 40% siendo solo el 28% de respuestas correctas. El 50% conocía la enfermedad de osteoporosis y el 49% cómo prevenirla. Conclusiones: Se pudo determinar en las encuestadas que muchas mujeres no cubren el requerimiento diario promedio de calcio a través de la alimentación, teniendo en cuenta los factores que inhiben su absorción lo cual predispone a mayor riesgo de osteoporosis a edad avanzada. Esto señala la necesidad de establecer un programa de prevención sobre la osteoporosis. (AU)

Background: Osteoporosis is a chronic bone disease considered a public health problem and being more prevalent in women than in men. Therefore, the importance of studying young women in the age range in which they are closeto the maximum bone peak since it is a preventable disease. Due to this problem, the main objective is to evaluate the daily calcium consumption in 138 young women from the town of Makallé, Chaco, taking into account their requirements and pointing out the risk factors. Methods: Descriptive cross-sectional study, once the consent of the respondents was obtained, a structured online survey with closed and open questions was applied, divided into two sections, to determine the level of knowledge of calcium and its frequency of consumption. The results are presented in tables and graphs of frequency distribution and being significant when the value of p was less than 0.05. Results: 136 responses were obtained, which showed that 60% of the women know the importance of calciumconsumption and the fundamental moment of its consumption; 82% know the food sources of the mineral and its inhibitory factors such as alcohol 42% and cola drinks 39%. In addition, they demonstrated not knowing how to prevent mineral losses by 40%, with only 28% being correct. 50% know about osteoporosis disease and 49% know how to prevent it. Conclusions: It was determined that the surveyed women do not meet their average daily calcium requirementthrough food, taking into account the factors that inhibit its absorption, which predisposes them to a higher risk of osteoporosis in advanced age. This point to the need to establish a prevention program on osteoporosis since it iscurrently considered a public health problem. (AU)

Lower Dietary Calcium Intake is Associated with a Higher Risk of Mortality in Korean Adults.

BACKGROUND: Calcium, one of the most abundant minerals in the human body, has a pivotal role in human physiology. However, only a few studies have examined the association of dietary calcium intake with mortality in a population with low calcium intake. OBJECTIVE: The aim of this study was to examine the association of dietary calcium intake with risk of all-cause and cause-specific mortality among Korean adults with low calcium intake. DESIGN: This study was a prospective cohort study. PARTICIPANTS/SETTING: The analysis was conducted using data from 44,327 eligible Korean adults aged 19 years and older who participated in the Korea National Health and Nutrition Examination Survey 2007-2015. Dietary calcium intake was assessed using 1-day 24-hour recall data. MAIN OUTCOME MEASURES: The main outcomes of this study were mortality from all causes, cancer, cardiovascular disease, respiratory disease, and all other causes combined. The outcome was ascertained through linkage to the death registry compiled by Statistics Korea with the use of the resident registration number. STATISTICAL ANALYSES PERFORMED: Weighted Cox proportional hazard models were used to estimate the hazard ratios and 95% CIs of the all-cause and cause-specific mortality according to dietary calcium intake. RESULTS: During a mean follow-up of 7.28 person-years, 1,889 deaths were ascertained. After multivariable adjustment, the hazard ratios for all-cause mortality for the second quintile to the highest quintile of dietary calcium intake, respectively, compared with the first quintile were 0.86 (95% CI 0.73 to 1.00), 0.82 (95% CI 0.69 to 0.98), 0.85 (95% CI 0.69 to 1.03), and 0.78 (95% CI 0.64 to 0.96) (P for trend from the lowest to the highest quintile = .04). There were no statistically significant associations between dietary calcium intake and risk of mortality from cancer, cardiovascular, or respiratory disease. CONCLUSIONS: In this large prospective cohort study of Korean adults, lower dietary calcium intake was associated with a higher risk of all-cause mortality.

Complex Modulating Effects of Dietary Calcium Intake on Obese Mice.

BACKGROUND/AIM: Οverweight and obesity are risk factors for chronic diseases. Dietary calcium has been reported to exert anti-obesity effects. However, the complex modulating effects of calcium intake on obese mice have not been clarified. MATERIALS AND METHODS: The effects of calcium intake on body weight/visceral fat mass were examined in the obese mouse model, KK-Ay Results: Body weight gain decreased in mice fed a diet containing 0.4 to 3.2% calcium at the age of 11 and 13 weeks, but not at 12 weeks after normalization for food intake. Calcium intake also decreased serum insulin levels and increased the amount of feces excreted. Fecal deoxycholate levels were lower in the high-calcium group than in the normal diet control group. Furthermore, the ratio of the deoxycholate-producing microbiome in feces decreased. CONCLUSION: Dietary calcium has anti-obesity effects in obese KK-Ay mice. Inhibition of insulin production and an increased amount of feces excreted with calcium intake may affect body weight.

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.

Calcium-Alkali Syndrome: Historical Review, Pathophysiology and Post-Modern Update.

Milk-alkali syndrome or calcium-alkali syndrome (CAS) is the triad of hypercalcemia, metabolic alkalosis and renal impairment. It is often related to ingestion of high amounts of calcium carbonate, which was used historically for the treatment of peptic ulcer disease. The incidence of the syndrome decreased dramatically after the introduction of newer peptic ulcer medications such as proton pump inhibitors and histamine blocking agents. However, a resurgence was seen in the late 1980s with the wide use of over-the-counter calcium supplements, mainly by females for osteoporosis prophylaxis. The modern version of the syndrome continues to evolve along with medical management. This review focuses on the historical context of CAS, pathogenesis, resurgence of the condition with variable presentations, and contemporary management.

Association of Dietary Calcium Intake With Bone Health and Chronic Diseases: Two Prospective Cohort Studies in China.

Background: Calcium is an essential element in our diet and the most abundant mineral in the body. A high proportion of Chinese residents are not meeting dietary calcium recommendations. The purpose of this study was to investigate the relationship between calcium intake and the health of residents in two longitudinal studies of Chinese residents. Methods: This study used nationally representative data from the Harbin Cohort Study on Diet, Nutrition, and Chronic Non-communicable Disease Study (HDNNCDS) and China Health Nutrition Survey (CHNS), including 6,499 and 8,140 Chinese adults, respectively, who were free of chronic diseases at recruitment, with mean values of 4.2- and 5.3-year follow-up. Cox's proportional-hazards regression was conducted to explore the relationship between dietary calcium intake and the incidence of obesity, type 2 diabetes, hypertension, and cardiovascular disease (CVD) with adjustment for covariates. Results: Calcium intakes were 451.35 ± 203.56 and 484.32 ± 198.61 (mean ± SD) mg/day in HDNNCDS and CHNS. After adjusting the covariates, the relationship between dietary calcium intake and bone mineral density (BMD) was not statistically significant (p = 0.110). In the multivariate-adjusted Cox's proportional-hazards regression model, dietary calcium intakes were inversely associated with obesity incidence in both cohorts (HR [95% CI]: 0.61 [0.48-0.77] and p trend < 0.001 in fixed-effects model); nevertheless, there was no correlation between dietary calcium intake and the risk of type 2 diabetes (p trend = 0.442 and 0.759) and CVD (p trend = 0.826 and 0.072). The relationship between dietary calcium intake and the risk of hypertension in the two cohorts was inconsistent (p trend = 0.012 and 0.559). Additionally, after further adjusting the vegetable intake in the original multivariate model, both cohorts found no association between dietary calcium intake and the risk of developing obesity (p trend = 0.084 and 0.444). Conclusions: Our data suggest that the current calcium intake of Chinese residents was inversely associated with obesity, which may be related to consumption of vegetables. Meanwhile, the current calcium intake does not increase the risk of type 2 diabetes, CVD, and bone health burden. This research suggested that the Chinese current calcium intake level may have met the needs of the body.

Childhood and long-term dietary calcium intake and adult cardiovascular risk in a population with high calcium intake.

BACKGROUND & AIMS: The influence of dietary calcium intake in childhood on adult cardiovascular health is unknown, particularly in those with long-term high intake. To examine both linear and non-linear associations of childhood and long-term (between childhood and adulthood) dietary calcium intake with adult cardiovascular risk outcomes. METHODS: A population-based prospective cohort study in Finland (n = 1029, aged 3-18 years at baseline). Dietary calcium intake was assessed in childhood (1980, baseline) and adulthood (mean of available data from 2001, 2007 and 2011). Long-term dietary calcium intake was calculated as the mean between childhood and adulthood. Outcomes were measured in 2001, 2007, and/or 2011, and the latest available data were used for analyses, including high carotid intima-media thickness, hypertension, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol and triglycerides, arterial pulse wave velocity (PWV), carotid artery compliance (CAC), Young's elastic modulus (YEM), and stiffness index (SI). RESULTS: There were no significant non-linear or linear associations between childhood or long-term dietary calcium intake with any adult cardiovascular outcomes, after adjustment for age, sex, and childhood and adulthood confounders (e.g., body mass index, systolic blood pressure, smoking, physical activity, fruit and vegetable consumption). CONCLUSIONS: Childhood or long-term dietary calcium intake that is higher than the recommended level is not associated with increased cardiovascular risk in adulthood.

Poor sleep quality among young adults: The role of anxiety, depression, musculoskeletal pain, and low dietary calcium intake.

PURPOSE: This study examined the relationships between sleep quality, anxiety, depression, musculoskeletal pain (MSP), and calcium intake. DESIGN AND METHODS: In this cross-sectional study (N = 1422), sleep was assessed using the Pittsburgh Sleep Quality Index, anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, and calcium intake and MSP were assessed by self-reporting. FINDINGS: Poor sleep quality was reported by 62.66% of the participants. The participants with poor sleep quality reported lower calcium intake, higher anxiety and depression levels, more severe MSP, and multisite pain. Anxiety, depression, low calcium intake, and multisite pain were significant predictors of poor sleep quality. Anxiety was predicted by poor sleep quality, depression, multisite pain, and sex (ie, female). Depression was predicted by anxiety, poor sleep quality, and low calcium intake. PRACTICAL IMPLICATIONS: The findings underscore the role of low calcium intake in the development of sleep problems, anxiety, depression, and MSP. Individuals with these conditions should be advised to increase their calcium intake.

Association between Dietary Calcium Intake and Adiposity in Male Adolescents.

The aim was to investigate the possible association of dietary calcium intake with adiposity, insulin resistance, and adipocytokine values in adolescent boys. In this cross-sectional study, participants were 123 adolescent boys aged 13-15 years, who were divided into tertiles according to their dietary calcium intake. Dietary calcium intake was assessed using three 24 h dietary recalls. In addition, energy intake, body composition, physical activity (PA), and blood biochemical values were also measured. Mean body fat%, fat mass (FM), trunk FM, trunk fat%, and leptin differed between high and low tertiles of calcium intake after adjustment for age, pubertal stage, and PA. For the entire cohort, mean calcium intake was 786 ± 380 mg/day and was related to body mass index (BMI), FM, and trunk fat% but not to insulin resistance or adipocytokine values after adjusting for possible confounders. In addition, only 15.4% of the participants obtained or exceeded their mean dietary calcium intake requirements. These subjects who met their dietary calcium intake had significantly lower body fat% in comparison with subjects not meeting their dietary calcium intake. Odds ratio of being in the highest tertile of FM, trunk FM, and trunk fat% was 3.2-4.4 (95% confidence interval 1.19-12.47; p < 0.05) times higher for boys in low calcium intake tertile, compared to those boys in high calcium intake tertile. In conclusion, dietary calcium intake is inversely associated with total body and abdominal adiposity values in a specific group of healthy male adolescents with different body mass values.

Serum calcium level among pregnant women and its association with pre-eclampsia and delivery outcomes: A cross-sectional study from North India.

BACKGROUND: Calcium requirement increases during pregnancy, thereby increasing the chances of developing hypocalcaemia. Hypocalcaemia may be associated with pregnancy-related complications. Therefore, we planned this study to estimate the prevalence of hypocalcaemia among pregnant women attending secondary care hospital, and to study the association between hypocalcaemia and pregnancy outcomes. MATERIALS AND METHODS: This study was conducted in a secondary level hospital at Ballabgarh, district Faridabad, Haryana, India. Consecutive pregnant women with gestation period more than 28 weeks were enrolled. Dietary calcium intake was ascertained using 24-hour dietary recall method. Serum calcium estimation was done by Biolis 24i auto analyser. Outcome of pregnancy (preterm delivery, low birth weight (LBW) babies, and neonatal mortality) was assessed telephonically 3 months after the enrolment. RESULTS: A total of 696 pregnant women were enrolled in the study. Mean (SD) dietary calcium intake and serum calcium level was 796.4 (360.4) mg/day and 9.56 (0.94) mg/dl respectively. Prevalence (95% CI) of hypocalcaemia was 23.9% (20.8 - 27.2%). Serum total calcium level was not associated with dietary calcium intake (p-value = 0.36). Mean serum calcium level was significantly lower in mothers who had LBW babies. Pre-eclampsia, preterm delivery, and neonatal mortality were not associated with serum calcium level. CONCLUSION: Serum calcium level may not be related to dietary calcium level. Hence, the current recommendation of calcium supplementation during antenatal period appears to be inconclusive among our study population.

Association of Habitually Low Intake of Dietary Calcium with Blood Pressure and Hypertension in a Population with Predominantly Plant-Based Diets.

This study aimed to assess the association of habitually low dietary calcium intake with blood pressure or hypertensive risk using data from the China Health and Nutrition Survey (CHNS) in 2009. We included 6298 participants (2890 men and 3408 women) aged 18 years or older in this analysis. Food intakes were measured by 3-day 24-h individual recalls combined with a weighing and measuring of household food inventory. The participants were divided into normotensive, pre-hypertensive and hypertensive groups according to their mean blood pressure of three repeated measurements. Six intake levels were decided by percentiles of gender-specific dietary calcium intakes (P0⁻10, P10⁻30, P30⁻50, P50⁻70, P70⁻90, and P90⁻100). Average dietary calcium intakes were 405 mg/day for men and 370 mg/day for women, 80% and 84% of which were derived from plant-based food in men and women, respectively. Multiple linear regression analyses showed that dietary calcium intakes were not related with blood pressure in both genders (all P > 0.05). Logistic regression analyses showed a lower risk of pre-hypertension with higher dietary calcium intakes in women (all Pfor trend < 0.001), but not in men; no association between dietary calcium intake and hypertensive risk was found in both genders (all Pfor trend > 0.05). This study suggests that there are no conclusive associations of habitually low dietary calcium intake with blood pressure or hypertensive risk in Chinese individuals consuming predominantly plant-based diets.

Dietary calcium intake and physical activity levels among people living in Karnataka, India - An observational hospital-based study.

BACKGROUND: Calcium is the most abundant mineral in our body with varied functions, and its dietary deficiency leads to osteoporosis. Various studies have shown that adequate dietary calcium intake (DCI) and moderately increased physical activity if maintained for long term prevent osteoporosis. The data regarding DCI of people living in Karnataka, south India, are limited. Thus, we aimed to assess DCI, physical activity, and their predictors among people living in Karnataka. METHODOLOGY: A cross-sectional study was done among 250 inpatients and normal relatives of orthopedics department of a tertiary care teaching hospital. Multistage random sampling was performed. DCI and physical activity were measured using validated questionnaires. RESULTS: The mean (standard deviation) DCI was 499.94 (251.5). The prevalence [95 confidence interval (CI)] of poor intakers of DCI [DCI < Recommended Dietary Allowance (RDA)] was 76.6% (70.9, 81.7). However, only 43.52% of all participants with poor DCI were on supplements. Male gender [2.189 (1.125, 4.257)], elderly [1.988 (1.067, 3.705)], and low knowledge score [1.240 (1.093, 1.407)] were significant predictors of low DCI. The proportion (95 CI) of patients who were categorized as having low physical activity (LPA) was 44.0% (37.8, 50.4). The predictors for LPA [adjusted odds ratio (95 CI)] were marital status, being single [1.853 (1.047, 3.282)], and low socioeconomic status class [1.209 (1.002, 1.458)]. CONCLUSION: DCI was below the RDA for three-fourths of our patients with nearly half of them being physically inactive, indicating the need for better education regarding DCI and improving physical activity, all of which can prevent osteoporosis.

A systemic review on global dietary calcium intake in adults / 中华内分泌代谢杂志

Low calcium intake may impose adverse impacts on bone health. The current paper is the Chinese translation for a systemic review article published in December, 2017 in Osteoporosis International with open access [ Balk EM, Adam GP, Langberg VN, et al. Global dietary calcium intake among adults: a systematic review. Osteoporos Int. 2017;28 ( 12 ):3315-332 ] . Through searching 13 electronic databases and requesting data from domain experts, an interactive global calcium map was developed. Average national dietary calcium intake ranges from 175 to 1233 mg/day. Many Asia countries 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. This review draws attention to regions where measures to increase calcium intake are likely to have skeletal benefits.

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.

A 51-item calcium-focused food frequency questionnaire is a reliable tool to assess dietary calcium intake in postmenopausal women.

Given the lack in a valid biomarker to assess dietary calcium intake (dCai), reproducible estimation of usual dCai is crucial for better understanding of its interaction with health outcomes in specific populations. This study tested the hypothesis that a calcium-focused food frequency questionnaire (FFQ) may be used to estimate dCai of women ≥50 years residing in a multicultural environment (Montreal, Canada). One hundred and eight women (age, 63.1±7.7 years; 98% postmenopausal) completed the FFQ twice and 4 nonconsecutive 24-hour recalls (24HRs) over 1 month. Medians of dCai were compared by Wilcoxon signed rank test. Reproducibility and relative validity of the FFQ were assessed by Spearman correlation (rs) and Cohen's weighted kappa (κw). Agreement was further assessed by cross-classification by quartiles, Bland-Altman plot, and sensitivity and specificity analyses. The median (interquartile range) dCai estimated by the FFQ and 24HRs were 723 (524-1033) mg/d and 854 (666-1068) mg/d, respectively (P<.001). The FFQs had a strong correlation (rs=0.72, P<.001) and moderate agreement (κw=0.55). The FFQ and 24HRs were moderately correlated (rs=0.65, P<.001). Cross-classification showed moderate agreement (κw=0.42), with 85% of the participants classified into identical or contiguous quartiles and 2.8% into extreme opposite quartiles. According to the Bland-Altman plot, the FFQ underestimated dCai with a bias of 99 mg/d (95% limits of agreement, -677 to +480 mg/d). Sensitivity and specificity of identifying intakes <1000 mg/d were 90% and 57%, respectively. This FFQ is a useful tool to discriminate dCai <600 and ≥1000 mg/d in postmenopausal women and to rank dCai in epidemiological studies.

The effect of increasing dairy calcium intake of adolescent girls on changes in body fat and weight.

Background: Overweight is epidemic in adolescents and is a major concern because it tracks into adulthood. Evidence supports the efficacy of high-calcium, high-dairy diets in achieving healthy weight in adults. However, no randomized controlled trials of the effect of dairy food on weight and body fat in adolescents have been reported to our knowledge.Objective: The aim was to determine whether increasing calcium intake to recommended amounts with dairy foods in adolescent girls with habitually low calcium intakes would decrease body fat gain compared with girls who continued their low calcium intake. Participants had above-the-median body mass index (BMI; in kg/m2).Design: We enrolled 274 healthy postmenarcheal 13- to 14-y-old overweight girls who had calcium intakes of ≤600 mg/d in a 12-mo randomized controlled trial. Girls were randomly assigned in a 1:1 ratio to 1 of 2 groups within each of 3 BMI percentiles: 50th to <70th, 70th to <85th, and 85th to <98th. The assignments were 1) dairy, which included low-fat milk or yogurt servings providing ≥1200 mg Ca/d or 2) control, which included the usual diet of ≤600 mg Ca/d.Results: We failed to detect a statistically significant difference between groups in percentage of body fat gain over 12 mo (mean ± SEM: dairy 0.40% ± 0.53% > control; P < 0.45). The effect of the intervention did not differ by BMI percentile stratum. There was no difference in weight change between the 2 groups.Conclusion: Our findings that the dairy group gained body fat similar to the control group provide no support for dairy food as a stratagem to decrease body fat or weight gain in overweight adolescent girls. This trial was registered at clinicaltrials.gov as NCT01066806.

Dietary Calcium Intake, Serum Calcium Level, and their Association with Preeclampsia in Rural North India.

BACKGROUND: Preeclampsia in pregnancy has been shown to be associated with low serum calcium level. Though the evidence is abundant, it is equivocal. OBJECTIVES: The study aimed to estimate the dietary calcium intake and serum calcium status among pregnant women, and to document the association of the dietary calcium intake and serum calcium status with incidence of preeclampsia in the 3rd trimester of pregnancy. MATERIALS AND METHODS: A community-based cross-sectional study was conducted in the Health and Demographic Surveillance System (HDSS) site, Ballabgarh, Haryana, India. All pregnant women between 28 weeks and 36 weeks of gestation were interviewed. A semi-structured interview schedule and a 24-h dietary recall questionnaire were administered to assess the dietary calcium intake. AutoAnalyser (Biolis 24i) was used for measuring serum calcium. RESULTS: We enrolled 217 pregnant women. The mean [standard deviation (SD)] dietary calcium intake was 858 (377) mg/day. The mean (SD) serum calcium level was 9.6 mg/dL (0.56). Incidence of preeclampsia was 13.4%. Preeclampsia was not associated with hypocalcemia [odds ratio (OR) = 1.2 95% confidence interval (CI); 0.27-3.98]. CONCLUSION: The majority of pregnant women had inadequate dietary calcium intake. The prevalence of hypocalcemia was low. Low serum calcium level was not associated with preeclampsia. Calcium supplementation may not reduce preeclampsia in this population.