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.

The Effect of Smoking on Salivary Calcium Levels, Calcium Intake, and Bleeding on Probing in Female

Introduction. Smoking is a bad habit that affects both systemic and oral conditions. Nicotine in cigarettes reduces estrogen production that can alter salivary calcium levels. Nicotine also causes vasoconstriction of the gingival blood vessels and decreases gingival bleeding. Low dietary calcium intake is also suspected to influence the low serum calcium levels in smokers. In this study, we evaluated the effect of smoking on salivary calcium levels, calcium intake, and BOP in women. Method. This was an analytical study using a cross-sectional approach. The subjects were 26 female smokers and 37 nonsmokers. Unstimulated saliva was collected by the spitting method. Salivary calcium levels were measured using an Atomic Absorption Spectrophotometer (AAS). The calcium intake was obtained by the Semiquantitative Food Frequency Questionnaire. BOP was measured by a gingival bleeding index by Ainamo and Bay in 1975. Results. All the basic characteristics including age, BMI, level of education, and occupation were statistically different between groups. The mean calcium level of female smokers was significantly lower than that of nonsmokers, whereas the mean BOP of female smokers was significantly higher. The total calcium intake per day of the two groups was not statistically different. The mean salivary calcium level and BOP decreased when the duration of smoking was longer. There was a positive correlation between salivary calcium level and BOP in the smokers’ group. Conclusion. A low level of education may be contributing to the smoking habit of subjects in this study. Salivary calcium levels were correlated with BOP in female smokers, which might be affected by the duration of smoking.

Dietary Calcium Intake and Fat Mass in Spanish Young Adults: The Role of Muscle Strength

Obesity is declared as a chronic multifaceted health problem, and young adults may be particularly vulnerable to weight gain. This study aims to identify the role of dietary calcium intake and the muscle strength index in handling excess of fat mass in young adults and to examine if the relationship between dietary calcium intake and fat mass percentage is mediated by muscle strength. A cross-sectional study including 355 Spanish college students (aged 21.05 ± 3.11) was performed during the 2017–2018 academic year. Pearson correlation coefficients were estimated to determine the relationship between dietary calcium intake, fat mass percentage, body mass index, muscle strength components, and total energy intake. ANCOVA models were used to analyze the differences in the muscle strength index by total dietary calcium intake categories, as well as the differences in % fat mass by total dietary calcium intake and muscle strength index categories, controlling for different sets of confounders. A mediator analysis was conducted to test if the relationship between dietary calcium intake and fat mass percentage was explained by muscle strength. Data on the fat mass percentage, dietary calcium intake, and muscle strength index as the sum of the standardized z-score of the standing long jump and z-score of handgrip/weight were collected. The muscle strength index was significantly better in young adults with higher dietary calcium intake. Moreover, the fat mass percentage was significantly lower in those with a higher dietary calcium intake and a better muscle strength index. Finally, the relationship between dietary calcium intake and fat mass percentage was fully mediated by muscle strength (z = −1.90; p < 0.05), explaining 33.33% of this relationship. This study suggests that both a major dietary calcium intake and muscle strength are associated with fat mass percentage. Moreover, muscle strength mediates the link between dietary calcium intake and fat mass percentage. Therefore, both high dietary calcium intake and exercise activities aimed at improving muscle strength levels may help to prevent the cardiometabolic risk associated with an excess of fat mass in young people.

Assessment of clinico-radiological and biochemical markers of rickets: A hospital based prospective follow up study

Background: Rickets is a disorder of defective mineralization due to deficiency of calcium and vitamin D and is more prevalent amongst the developing nations. Rickets has been ranked amongst the five most prevalent diseases in children of developing countries. The diagnosis of rickets is based on clinical features, biochemical studies and radiological signs and confirmed by response to treatment. Aims and Objectives: The purpose of this study is to evaluate the clinical, radiological and biochemical markers of the rickets by measuring the markers at the time of presentation, at 6 weekly intervals and after completion of treatment with standard regimen for rickets. Materials and Methods: 101 cases of nutritional rickets in age group 6 month to 18 years were allocated to receive combination therapy of calcium and vitamin-D according to their age and weight during a study period of 24 weeks. Radiographs (wrist and knee) and biochemical parameters (serum calcium, inorganic phosphate, alkaline phosphatase [ALP], and Vitamin-D), as well as clinical features, were evaluated at presentation, 6, 12, 18, and 24 weeks and response of treatment and markers were assessed at subsequent interval. clinical, radiological, biochemical parameters were evaluated statistically with Chi-square test for qualitative and 2 or more different variables by ANOVAs respectively. A P<0.05 was considered statistically significant analysis was done using Statistical Package for Social Sciences version 21.0. Results: At presentation, the mean dietary intake of calcium was low in all cases (6.11±0.78 mg/dl). Mean vitamin-D level was (23.05±8.14 ng/ml) indicative of vitamin-D deficiency. At the end of treatment (i.e., 24 weeks) clinical, radiological, and biochemical evidence of healing was observed. Normal serum ALP and complete radiological healing at 12 weeks was observed in 75% of subjects with the improvement of all markers. Conclusion: Children with rickets having low dietary calcium intake and low serum Vitamin-D levels have maximum number of markers at presentation. After intervention of combination regimen of calcium and Vitamin-D, remarkable improvement in clinical, radiological, and biochemical markers was found.

Non-inferiority of low-dose compared to standard high-dose calcium supplementation in pregnancy: study protocol for two randomized, parallel group, non-inferiority trials in India and Tanzania

Background Hypertensive disorders of pregnancy are important causes of maternal morbidity and mortality, as well as preterm birth, the leading cause of death for children under 5 years globally. The World Health Organization currently recommends that pregnant women receive high-dose calcium supplementation (1500–2000 mg elemental calcium) for prevention of preeclampsia in populations with low dietary calcium intake. Trials of low-dose calcium supplementation (< 1000 mg elemental calcium/day) during pregnancy have also shown similar reductions in the risk of preeclampsia; however, no trials to date have directly compared low-dose to the standard high-dose calcium supplementation. Our objective is to assess the non-inferiority of low-dose as compared to standard high-dose calcium supplementation in pregnancy. Methods/design We will conduct two independent trials in Bangalore, India (n = 11,000 pregnancies), and Dar es Salaam, Tanzania (n = 11,000 pregnancies). The trial designs are individually randomized, parallel group, quadruple-blind, non-inferiority trials of low-dose calcium supplementation (500 mg elemental calcium/day) as compared to standard high-dose calcium supplementation (1500 mg elemental calcium/day) among nulliparous pregnant women. Pregnant women will be enrolled in the trial before 20 weeks of gestation and will receive the randomized calcium regimen from randomization until the time of delivery. The co-primary outcomes are (i) preeclampsia and (ii) preterm birth; we will test non-inferiority of the primary outcomes for low-dose as compared to the standard high-dose supplementation regimen in each trial. The trials’ secondary outcomes include gestational hypertension, severe features of preeclampsia, pregnancy-related death, third trimester severe anemia, fetal death, stillbirth, low birthweight, small-for-gestational age birth, and infant death. Discussion The trials will provide causal evidence on the non-inferiority of low-dose as compared to the standard high-dose supplementation in India and Tanzania. A single tablet, low-dose calcium supplementation regimen may improve individual-level adherence, reduce programmatic costs, and ultimately expand implementation of routine calcium supplementation in pregnancy in populations with low dietary calcium intake. Trial registration ClinicalTrials.gov identifier: NCT03350516; registered on 22 November 2018. Clinical Trials Registry—India identifier: CTRI/2018/02/012119; registered on 23 February 2018. Tanzania Medicines and Medical Devices Authority Trials Registry identifier: TFDA0018/CTR/0010/5; registered on 20 December 2018.

Persistent hypercalcemia with similar familial Hypocalciuric hypercalcemia features: a case report and literature review

Background Primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcemia (FHH) are the most important differential diagnosis of parathyroid hormone (PTH)-dependent hypercalcemia. The clinical features of FHH and PHPT can overlap in some cases. Therefore, these two diseases must be differentiated to prevent unnecessary parathyroidectomy. Here, we present a case that was not entirely matched with any of the known differential diagnoses of hypercalcemia. Case presentation A 19-year-old girl with no history of any disease presented with persistent hypercalcemia without any specific musculoskeletal complaint. We found persistent hypercalcemia in her routine laboratory data from 3 years ago; while no data was available during the childhood period. Her dietary calcium intake was normal. She did not mention any history of renal stone, bone fracture as well as family history of hypercalcemia. Biochemical features showed normal values of serum creatinine, high normal serum calcium (range, 10.3–11.3 mg/dL; (normal range: 8.8–10.4)), and non-suppressed PTH levels (range, 37.2–58.1 pg/mL; (normal range: 10–65)). Serum 25 OH vitamin D level at the first visit was 16.1 ng/mL that treated by vitamin D supplementation. Since then, all 25 OH vitamin D levels were in the acceptable range. After correction of vitamin D deficiency during the follow-up period the calcium creatinine clearance ratio(s) (CCCR) were calculated in the range of 0.009 to 0.014 (means below 1%). The clinical and laboratory data indicate more FHH rather than PHPT. Genetic studies were negative for the common genes associated with FHH (CASR, GNA11, and AP2S1 genes) and multiple endocrine neoplasia type1 (MEN1). On the other hand, no evidence of autoimmunity was found in her to support an autoimmune FHH-like syndrome. Hence, the case did not match completely to any diagnosis of FHH and PHPT, so we decided to follow her. Conclusion We presented a patient with FHH phenotype whose common genetic tests were negative. Further research is needed to ascertain other causes leading to similar manifestations.

397A Meta-Analysis of Randomized Clinical Trials on Calcium Intake for Obesity Indices

Background There was no consistent finding of changes of obesity indices including fat mass by calcium supplements and dairy products intervention. Therefore, we conducted the meta-analysis of evidence on calcium supplements and dairy products (≥ 12 weeks) on changes in the obesity index (fat mass, as well as weight, body mass index, waist circumference) from randomized controlled trials (RCTs). Methods We searched for original articles during the last 10 years until August 19, 2019, using PubMed and EMBASE. The extracted data were analysed with random effects, inverse variance model using Review Manager 5.3 ver. Results Finally, ten RCTs with calcium supplements and fourteen RCTs with dairy products among adults aged 18 years old or over were selected. The intervention with calcium supplements showed significant change of fat mass (SMD, 95% CI; -0.21 [-0.37, -0.04], p = 0.02), but not in changes in body weight (p = 0.45), BMI (p = 0.14) and WC (p = 0.88). Dairy products also showed significant results in changes of fat mass (SMD, 95% CI; -0.51 [-0.90, -0.11], p = 0.01) as well as BMI (WMD, 95% CI; -0.46 [-0.67, -0.26], p &lt; 0.00001), but not in changes of body weight (p = 0.70) and WC (p = 0.27). Conclusions The fat mass may be reduced by both calcium supplements and dairy products intervention over 12 weeks among adults 18 years old or over. Dairy products may be beneficial for BMI reduction. Key messages Dietary calcium intake might reduce fat mass in adults (≥ 18 years).

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.