Dietary calcium intake and overweight: An epidemiologic view

Objective: We evaluated the relation between overweight and calcium intake in adults living in the municipality of Sao Paulo, Brazil. Methods: This was a cross-sectional population-based Study on a sample of 1459 adults that was obtained by multistage cluster sampling. Dietary intake was measured by the 24-h recall method. Poisson`s and linear regression analyses were performed to evaluate the relation between overweight and quartiles of calcium intake adjusted for energy. Results: The prevalence of overweight was 43.1% and the average adjusted calcium intake was 448.6 mg. In the linear regression. analyses, the regression coefficient for adjusted calcium was significant and negative (P = 0.019, beta(1) = -0.0001). Although evaluated by quartiles, the prevalence ratio for overweight in the first quartile of calcium intake was 1.24 (95% confidence interval 1.00-1.54) and that in the second quartile was 1.24 (95% confidence interval 1.03-1.49). Conclusion: In the present study, calcium intake showed a significant negative association with body mass index. (C) 2008 Elsevier Inc. All rights reserved.

Calcium intake and its relationship with adiposity and insulin resistance in post-pubertal adolescents

Background Dietary calcium intake has been described as being a negative contributor to adiposity. In adolescents, this relationship is not well established. The objectives of the present study were to compare the calcium intake of normal-weight and obese adolescents and to evaluate its relationship with adiposity and insulin resistance. Methods A cross-sectional analysis of 96 post-pubertal adolescents; 47 normal weight and 49 obese, mean age 16.6 (SD +/- 1.3) years. Body composition was assessed by dual-energy X-ray absorptiometry. Dietary intake was evaluated using a 3-day dietary record. The biochemical evaluation comprised the measurements of serum lipids, lipoproteins, glucose and insulin. Insulin resistance was calculated using the Homeostasis Model Assessment of Insulin resistance (HOMA-IR). Results The mean calcium intake, adjusted for energy, was lower in obese adolescents, 585.2 (+/- 249.9) mg, than in normal weight adolescents, 692.1 (+/- 199.5) mg. Only 4% of adolescents had an adequate intake of calcium. Calcium intake was inversely associated with body trunk fat, insulin and HOMA-IR in the obese group. The quartile analysis of calcium intake provided evidence that girls in the highest quartile had decreased adiposity and insulin resistance. Conclusions This study showed a negative relationship between calcium intake and body fat and insulin resistance, mainly in obese girls, and demonstrates the importance of an increased dietary calcium intake.

Serum 25-Hydroxyvitamin D, calcium intake and risk of type 2 diabetes after 5 years : results from a national, population-based prospective study (the Australian Diabetes, Obesity and Lifestyle study)

OBJECTIVE To examine whether serum 25-hydroxyvitamin D (25OHD) and dietary calcium predict incident type 2 diabetes and insulin sensitivity.

RESEARCH DESIGN AND METHODS A total of 6,537 of the 11,247 adults evaluated in 1999–2000 in the Australian Diabetes, Obesity and Lifestyle (AusDiab) study, returned for oral glucose tolerance test (OGTT) in 2004–2005. We studied those without diabetes who had complete data at baseline (n = 5,200; mean age 51 years; 55% were women; 92% were Europids). Serum 25OHD and energy-adjusted calcium intake (food frequency questionnaire) were assessed at baseline. Logistic regression was used to evaluate associations between serum 25OHD and dietary calcium on 5-year incidence of diabetes (diagnosed by OGTT) and insulin sensitivity (homeostasis model assessment of insulin sensitivity [HOMA-S]), adjusted for multiple potential confounders, including fasting plasma glucose (FPG).

RESULTS During the 5-year follow-up, 199 incident cases of diabetes were diagnosed. Those who developed diabetes had lower serum 25OHD (mean 58 vs. 65 nmol/L; P < 0.001) and calcium intake (mean 881 vs. 923 mg/day; P = 0.03) compared with those who remained free of diabetes. Each 25 nmol/L increment in serum 25OHD was associated with a 24% reduced risk of diabetes (odds ratio 0.76 [95% CI 0.63–0.92]) after adjusting for age, waist circumference, ethnicity, season, latitude, smoking, physical activity, family history of diabetes, dietary magnesium, hypertension, serum triglycerides, and FPG. Dietary calcium intake was not associated with reduced diabetes risk. Only serum 25OHD was positively and independently associated with HOMA-S at 5 years.

CONCLUSIONS Higher serum 25OHD levels, but not higher dietary calcium, were associated with a significantly reduced risk of diabetes in Australian adult men and women.

Annual feedback is an effective tool for a sustained increase in calcium intake among older women

We aimed to optimize calcium intake among the 2,000+ older women taking part in the Vital D study. Calcium supplementation was not included in the study protocol. Our hypothesis was that annual feedback of calcium intake and informing women of strategies to improve calcium intake can lead to a sustained increase in the proportion of women who consume adequate levels of the mineral. Calcium intake was assessed on an annual basis using a validated short food frequency questionnaire (FFQ). Supplemental calcium intake was added to the dietary estimate. Participants and their nominated doctor were sent a letter that the participant’s estimated daily calcium intake was adequate or inadequate based on a cutoff threshold of 800 mg/day. General brief statements outlining the importance of an adequate calcium intake and bone health were included in all letters. At baseline, the median daily consumption of calcium was 980 mg/day and 67 percent of 1,951 participants had calcium intake of at least 800 mg per day. Of the 644 older women advised of an inadequate calcium intake at baseline (< 800 mg/day), 386 (60%) had increased their intake by at least 100 mg/day when re-assessed twelve months later. This desirable change was sustained at 24 months after baseline with almost half of these women (303/644) consuming over 800 mg calcium per day. This study devised an efficient method to provide feedback on calcium intake to over 2,000 older women. The improvements were modest but significant and most apparent in those with a low intake at baseline. The decreased proportion of these women with an inadequate intake of calcium 12- and 24-months later, suggests this might be a practical, low cost strategy to maintain an adequate calcium intake among older women.

Calcium intake and its relationship with risk of overweight and obesity in adolescents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of experimental osteoporosis and low calcium intake on postextraction sockets of rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A Pilot Study of the Relationship of Calcium Intake and Frequency of Injuries In High School Athletes

Little information is available related to adolescent calcium intake and relationships with injuries they might suffer from sport participation. To determine calcium intake of high school athletes, to assess their self reported injury rates, and to examine the relationship between the two over a 12 month period of time. Participants received a questionnaire at their school and completed it anywhere they found convenient. Adolescent athletes in the Lincoln Public School system (n=43) that participated in at least one sport in the past year. Four age groups participated in the study with sixteen year olds having a significantly higher calcium intake at 1297 mg that of fourteen year olds. A variety of sports were represented with largest number of respondents participating in baseball/or softball at (55%). The next most played sport was basketball at (18%). Median total diet calcium was 1144.5 mg with a mean of 1182 mg + 567 mg. For the frequency of injuries that caused a missed practice or game in the past year, ankle injuries were the most common (25%). Knee injuries were the second most common (17%), followed closely by hand injuries (8%). Mean total diet calcium of athletes with five or more injuries that caused a missed practice or game was significantly higher at 1966 mg (P<.05) than athletes mean diet calcium with zero, one, two, and three injuries. Total milk calcium of those who reported three injuries that resulted in broken or fractured bones or dislocated joints was significantly higher (P<.05) at 1286 mg of total milk calcium than those who reported having zero, one, or two breaks or fractures. Athletes with higher calcium intakes have a higher number of reported injuries. This may be the result of increased vigorous activity which leads to increased calorie and calcium consumption. More importantly, this increased activity leads to an increased chance of injury. The greater calcium intake correlated with greater number of injuries may also be because of third parties advising the athletes who get injured to drink more milk and get more calcium in their diets because they have been injuries already.

Psychosocial and environmental predictors of calcium intake, physical activity and bone health among adolescent girls

Objectives. The purpose of this study was to identify the psychosocial and environmental predictors and the pathways they use to influence calcium intake, physical activity and bone health among adolescent girls. Methods. A secondary data analysis using a cross-sectional and longitudinal study design was implemented to examine the associations of interest. Data from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study collected in 2001-2003 were utilized for the analyses. IMPACT was a 1½ year nutrition and physical activity intervention study conducted among 718 middle-school girls in central Texas. Hierarchical regression modeling and Structural Equation Modeling (SEM) were used to determine the psychosocial predictors of calcium intake, physical activity and bone health at baseline. Hierarchical regression was used to determine if psychosocial factors at baseline were significant predictors of calcium intake and physical activity at follow-up. Data was adjusted for included BMI, lactose intolerance, ethnicity, menarchal status, intervention and participation in 7th grade PE/athletics. Results. Results of the baseline regression analysis revealed that calcium self-efficacy and milk availability at home were the strongest predictors of calcium intake. Friend engagement in physical activity, physical activity self-efficacy and participation in sports teams were the strongest predictors of physical activity. Finally, physical activity outcome expectations, social support and participation in sports teams were significant predictors of stiffness index at baseline. Results of the baseline SEM path analysis found that outcome expectations and milk availability at home directly influenced calcium intake. Knowledge and calcium self-efficacy indirectly influenced calcium intake with outcome expectations as the mediator. Physical activity self-efficacy and social support had significant direct and indirect influence on physical activity with participation in sports teams as the mediator. Participation in sports teams had a direct effect on both physical activity and stiffness index. Results of regression analysis for baseline predicting follow-up showed that participation in sports teams, self-efficacy, outcome expectations and social support at baseline were significant predictors of physical activity at follow-up. Conclusion. Results of this study reinforce the relevance of addressing both, psychosocial and environmental factors which are critical when developing interventions to improve bone health among adolescent girls. ^

The effect of osteoporosis education on calcium intake and physical activity in a group of community-dwelling Black older adults

The unprecedented increase in the number of older adults is expected to increase the burden of osteoporosis on the individual and society. Blacks have been understudied in osteoporosis prevention education research. Although the risk of osteoporosis is low in this population, its consequences are significant. This study employs a two-group experimental design (experimental and wait-list control groups) to evaluate the effect of an osteoporosis education on two osteoporosis prevention behaviors (OPBs)—calcium intake (CI) and physical activity (PA), in a group of community-dwelling Black older adults, 50 years and older resident in South Florida. A final sample of 110 (mean age 70.15 years), 90% female and 10% male completed a battery of questionnaires at two assessment periods. The experimental group participated in six weekly education program sessions immediately following baseline assessment, and the wait-list control group received the education following end of program assessment by all participants. The weekly educational sessions were conducted in social settings (church or senior center) employing constructs of the Revised Health Belief Model. The sessions focused on improving CI; osteoporosis knowledge (OKT), self-efficacy (SE), health beliefs (HB) and PA. Findings revealed significantly greater increase in reported CI ( M = 556 mg, Wilks’ λ = .47, F (1,108)=122.97, p< .001, η2=.53), OKT (p< .001), and SE (p< .001) among participants in the experimental compared to the wait-list control group. There was no significant difference between the two groups for PA and most of the HB subscales. OKT and SE were the best predictors of CI, while perceived barrier was a predominant factor predicting PA. Over the study period, a change in SE was the only variable related to changes in both OPBs. Attrition rate was lower than expected, which can be attributed to the settings utilized for the study. These findings support the importance of utilizing a familiar social setting. These results suggested the effectiveness of a program offered in multiple short sessions among this underserved minority population to improve OKT and SE resulting in a change in OPBs (increase in CI). However, there is need to explore alternative strategies to improve PA in this population group.

The Effect of Osteoporosis Education on Calcium Intake and Physical Activity in a Group of Community-Dwelling Black Older Adults

The unprecedented increase in the number of older adults is expected to increase the burden of osteoporosis on the individual and society. Blacks have been understudied in osteoporosis prevention education research. Although the risk of osteoporosis is low in this population, its consequences are significant. This study employs a two-group experimental design (experimental and wait-list control groups) to evaluate the effect of an osteoporosis education on two osteoporosis prevention behaviors (OPBs) – calcium intake (CI) and physical activity (PA), in a group of community-dwelling Black older adults, 50 years and older resident in South Florida. A final sample of 110 (mean age 70.15 years), 90% female and 10% male completed a battery of questionnaires at two assessment periods. The experimental group participated in six weekly education program sessions immediately following baseline assessment, and the wait-list control group received the education following end of program assessment by all participants. The weekly educational sessions were conducted in social settings (church or senior center) employing constructs of the Revised Health Belief Model. The sessions focused on improving CI; osteoporosis knowledge (OKT), self-efficacy (SE), health beliefs (HB) and PA. Findings revealed significantly greater increase in reported CI (M = 556 mg, Wilks’ λ = .47, F(1,108)=122.97, p< .001, η2=.53), OKT (p< .001), and SE (p< .001) among participants in the experimental compared to the wait-list control group. There was no significant difference between the two groups for PA and most of the HB subscales. OKT and SE were the best predictors of CI, while perceived barrier was a predominant factor predicting PA. Over the study period, a change in SE was the only variable related to changes in both OPBs. Attrition rate was lower than expected, which can be attributed to the settings utilized for the study. These findings support the importance of utilizing a familiar social setting. These results suggested the effectiveness of a program offered in multiple short sessions among this underserved minority population to improve OKT and SE resulting in a change in OPBs (increase in CI). However, there is need to explore alternative strategies to improve PA in this population group.

Calcium Intake, Major Dietary Sources and Bone Health Indicators in Iranian Primary School Children

Background: Adequate calcium intake may have a crucial role with regards to prevention of many chronic diseases, including hypertension, hypercholesterolemia, different types of cancer, obesity and osteoporosis. In children, sufficient calcium intake is especially important to support the accelerated growth spurt during the preteen and teenage years and to increase bone mineral mass to lay the foundation for older age. Objectives: This study aimed to assess daily calcium intake in school-age children to ensure whether they fulfill the FGP dairy serving recommendations, the recommended levels of daily calcium intake and to assess the relationship between dietary calcium intake and major bone health indicators. Patients and Methods: A total of 501 Iranian school-age children were randomly selected. Calcium intake was assessed using a semi-quantitative food frequency questionnaire. Bone health indicators were also assessed. Results: Dairy products contributed to 69.3% of the total calcium intake of the children. Daily adequate intake of calcium was achieved by 17.8% of children. Only 29.8% met the Food guide pyramid recommendations for dairy intake. Dietary calcium intake was not significantly correlated with serum calcium and other selected biochemical indicators of bone health. Conclusions: The need for planning appropriate nutrition strategies for overcoming inadequate calcium intake in school age children in the city of Tehran is inevitable.

Evaluation of dietary intake of calcium in adult subjects with idiopathic arterial hypertension

The calcium-intake relationship with other alimentary and anthropometric variables was investigates in a group of 60 adult (19-75 year-old) subjects, 50 females and 10 males, with essential arterial hypertension (DAP > 90 mmHg). The calcium intake was assessed by three different protocols: 24-hour food intake recall, food-frequency questionnaire and 3 day self-food intake register, repeated along with anthropometric measurements on three different occasions (2-15 month-intervals). The calcium intake assessed by the three methods, as well as the anthropometric data, were statistically similar on all three occasions. The mean data were then compared with those form the control, composed of 75 healthy subjects matched with the hypertensive group by age and sex. The patients ingested less calcium (mean +/- SD) than the controls on the daily (517 +/- 271 x 740 +/- 353 mg/d) and body-weight (8.1 +/- 5.0 x 11.4 +/- 5.9 mg/kg/d) basis. Among the males the calcium intake was the only difference found between groups and could be attributed to the lower intake of calcium-rich foods. The hypertensive females showed also higher lean-body mass (Body-mass index and arm muscle circumference). Thus the calcium intake discriminated both groups being associated with changes in other nutritional parameters only in females.