No description available.

In recent years, dietary calcium intake among children and adolescents has fallen sharply. This trend is alarming because childhood and adolescence are the primary ages for building bone mass. Therefore, an interactive website, Clueless in the Mall (http://calcium.tamu.edu) was developed targeting youth to increase knowledge, improve attitudes, and equip them to incorporate calcium-rich foods into their diets. This website was created with the help of adolescents at every stage of development and has been pilot tested with adolescents at home and in school, showing improvements in knowledge and attitudes. However, the website has not been tested for effectiveness in changing behaviors, specifically for increasing calcium intake. The present study was conducted to measure the effectiveness of the website for changing knowledge, attitudes, and behaviors. The hypothesis of this investigation was that the website intervention would significantly improve attitudes and knowledge about calcium and increase dietary calcium intake among adolescents and pre-adolescents who took part in the study. After the group-administered Food Frequency Questionnaire (FFQ) was validated among a local church youth group, a total of 126 middle school and high school students were recruited from 12 local public school classes to participate. Each student took three questionnaires during class time to measure baseline knowledge, attitudes, and behaviors (including calcium intake using the FFQ). Then each student took one class period to view the calcium website. Four to six weeks later, the investigators returned to administer the same three tests to each student. Demographic information was collected, and data were analyzed using paired samples t-tests and analyses of variance (ANOVA). Results demonstrated that the website alone was sufficient to improve knowledge scores; however, it was not enough to change attitudes and behaviors significantly. In conclusion, the website should be used to promote and reinforce health behaviors, but should not be expected to stand alone as an intervention.

In recent years, dietary calcium intake among children and adolescents has fallen sharply. This trend is alarming because childhood and adolescence are the primary ages for building bone mass. Therefore, an interactive website, Clueless in the Mall (http://calcium.tamu.edu) was developed targeting youth to increase knowledge, improve attitudes, and equip them to incorporate calcium-rich foods into their diets. This website was created with the help of adolescents at every stage of development and has been pilot tested with adolescents at home and in school, showing improvements in knowledge and attitudes. However, the website has not been tested for effectiveness in changing behaviors, specifically for increasing calcium intake. The present study was conducted to measure the effectiveness of the website for changing knowledge, attitudes, and behaviors. The hypothesis of this investigation was that the website intervention would significantly improve attitudes and knowledge about calcium and increase dietary calcium intake among adolescents and pre-adolescents who took part in the study. After the group-administered Food Frequency Questionnaire (FFQ) was validated among a local church youth group, a total of 126 middle school and high school students were recruited from 12 local public school classes to participate. Each student took three questionnaires during class time to measure baseline knowledge, attitudes, and behaviors (including calcium intake using the FFQ). Then each student took one class period to view the calcium website. Four to six weeks later, the investigators returned to administer the same three tests to each student. Demographic information was collected, and data were analyzed using paired samples t-tests and analyses of variance (ANOVA). Results demonstrated that the website alone was sufficient to improve knowledge scores; however, it was not enough to change attitudes and behaviors significantly. In conclusion, the website should be used to promote and reinforce health behaviors, but should not be expected to stand alone as an intervention.

<p>Osteoporosis and fractures are debilitating skeletal problems. Accumulating the highest peak bone mass in both cortical and trabecular bone (Tb) as well as developing strong Tb microarchitecture play an integral role in preventing bone loss and osteoporotic fractures later in life. Because Tb is modulated by genetics (G) and environment (e.g. diet, D), my dissertation research focuses on the influence of dietary calcium (Ca) intake, genetics as well as GxD interaction controlling Tb phenotypes in two clinically relevant skeletal sites, i.e. the femur and the L5 vertebra. Male mice from 11 in bred lines and 51 BXD recombinant inbred (RI) lines were fed either adequate (Basal, 0.5%) or low (0.25%) Ca diets from 4-12 weeks of age. We used micro-computed tomography to measure Tb mass and microarchitecture phenotypes. We systematically proved that there are site-specific effects of diet, genetic, and GxD interactions influencing Tb phenotypes. This indicates that there are unique genetic effects modulating Tb at each bone site. Therefore, we conducted a genetic mapping experiment using the 51 BXD RI lines separately for each bone site. We coupled genetic mapping analysis with bioinformatics analysis to identify novel genetic variation and candidate genes accounting for the variation in each phenotypes. The findings from this work serve as a foundation for future research to identify novel pathways and genes underlying the development of Tb as well as an adaptation to Ca insufficiency.</p> <br> <p> </p>

Osteoporosis literally means 'porous bone" and is characterized by an increase in bone fragility and susceptibility to fracture, which typically involves the wrist, spine and hip (South African Medical Association (SAMA) Working Group, 2000). In South Africa osteoporosis and fractures are more common in whites than in blacks. African-American men experience hip fractures at a rate of only half of that of Caucasian men. The bone mass in Africans were found to be 6 - 12 % higher than in Caucasians at all ages. A higher peak bone density at skeletal maturity in African-Americans were found, so that despite comparable age related bone loss, African Americans reach the fracture threshold less frequently than whites. Age-related bone loss that begins later, is less severe, or occurs in different skeletal sites in African-Americans than whites (Luckey et al., 1996). American whites have a higher bone turnover than American blacks, but in contrast to this American data. South African blacks may have a higher bone turnover and lower bone density than whites (Daniels et a/., 1995). If it is compared with Caucasians a lower rate of hip fracture in South African blacks were found, despite lower bone density at all ages (Villa, 1994). The lower fracture rate in blacks than in whites is because of greater bone mass and higher bone turnover leading to more frequent renewal of damaged bone. Blacks excrete less urinary calcium, and show no skeletal sensitivity towards the parathyroid hormone. Few studies focus on older black South African men and osteoporosis. Objectives The aim of this study was to investigate the relationship of calcium intake, vitamin D status, anthropometry and physical activity and bone density in black South African men. Methods A case-control study design was used, in which variables associated with bone density were compared. The case group were men with fractures of the proximal femur, the proximal humerus or the distal radius and an equal number of age-matched healthy black men (with not more than a 5-year age difference) with no fracture (the proximal femur and humerus and distal radius) previously, was recruited as a control group. Bone density was measured with DEXA. Fat percentage was measured with a Tanita scale. Biochemical analyses were done. Questionnaires were used to gather demographic, activity and dietary information. To our knowledge, this is the first case-control study on osteoporotic fractures in South African black men. Results Both the groups' bone mineral densities were lower than recommended. The bone density of the case group for lumbar and hip regions was 0.86 and 0.88 and the control group's bone density for lumbar region was 0.95 and hip region 0.91. The control group was more physically active and had a better nutritional status than the case group. The control group's calcium intake was higher but the vitamin D status was lower than the case group. Both calcium and vitamin D status were not statistically significant (pc0.5), between the two groups. Body mass indices of the groups were the same. The serum albumin was higher in the control group than in the case group. The case group serum calcium was higher than the control group. Both serum albumin and serum calcium were statistical significant between the two groups. There were no statistically significant differences in any of the other biochemical variables between the two groups. Serum phosphate and serum vitamin D were statistical significant for bone density of the hip and lumbar regions. Conclusion To conclude it seems logical to suggest a healthy diet with optimal macro- and micro nutrient intake. Maintain ideal body weight and body fat percentage and recommend regular but moderate-weight-bearing exercise from a young age throughout adult life, as part of a strategy to prevent and treat osteoporosis. In the present study black South African men present with low bone mineral density, but other studies indicated a lower rate of hip fracture in South African blacks, despite lower bone density at all ages. It can be recommended that other factors may play a role in black South African men with osteoporosis. Factors such as serum phosphorus, 25-hydroxy-vitamin D, body mass index (BMI), physical activity index (PAI), animal protein, total fat intake and dietary calcium are important determinants of BMD in older South African blacks, as shown in the present study. Osteoporosis is a multi factorial problem and must be treated that way. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2004.

No description available.

Osteoporosis literally means 'porous bone" and is characterized by an increase in bone fragility and susceptibility to fracture, which typically involves the wrist, spine and hip (South African Medical Association (SAMA) Working Group, 2000). In South Africa osteoporosis and fractures are more common in whites than in blacks. African-American men experience hip fractures at a rate of only half of that of Caucasian men. The bone mass in Africans were found to be 6 - 12 % higher than in Caucasians at all ages. A higher peak bone density at skeletal maturity in African-Americans were found, so that despite comparable age related bone loss, African Americans reach the fracture threshold less frequently than whites. Age-related bone loss that begins later, is less severe, or occurs in different skeletal sites in African-Americans than whites (Luckey et al., 1996). American whites have a higher bone turnover than American blacks, but in contrast to this American data. South African blacks may have a higher bone turnover and lower bone density than whites (Daniels et a/., 1995). If it is compared with Caucasians a lower rate of hip fracture in South African blacks were found, despite lower bone density at all ages (Villa, 1994). The lower fracture rate in blacks than in whites is because of greater bone mass and higher bone turnover leading to more frequent renewal of damaged bone. Blacks excrete less urinary calcium, and show no skeletal sensitivity towards the parathyroid hormone. Few studies focus on older black South African men and osteoporosis. Objectives The aim of this study was to investigate the relationship of calcium intake, vitamin D status, anthropometry and physical activity and bone density in black South African men. Methods A case-control study design was used, in which variables associated with bone density were compared. The case group were men with fractures of the proximal femur, the proximal humerus or the distal radius and an equal number of age-matched healthy black men (with not more than a 5-year age difference) with no fracture (the proximal femur and humerus and distal radius) previously, was recruited as a control group. Bone density was measured with DEXA. Fat percentage was measured with a Tanita scale. Biochemical analyses were done. Questionnaires were used to gather demographic, activity and dietary information. To our knowledge, this is the first case-control study on osteoporotic fractures in South African black men. Results Both the groups' bone mineral densities were lower than recommended. The bone density of the case group for lumbar and hip regions was 0.86 and 0.88 and the control group's bone density for lumbar region was 0.95 and hip region 0.91. The control group was more physically active and had a better nutritional status than the case group. The control group's calcium intake was higher but the vitamin D status was lower than the case group. Both calcium and vitamin D status were not statistically significant (pc0.5), between the two groups. Body mass indices of the groups were the same. The serum albumin was higher in the control group than in the case group. The case group serum calcium was higher than the control group. Both serum albumin and serum calcium were statistical significant between the two groups. There were no statistically significant differences in any of the other biochemical variables between the two groups. Serum phosphate and serum vitamin D were statistical significant for bone density of the hip and lumbar regions. Conclusion To conclude it seems logical to suggest a healthy diet with optimal macro- and micro nutrient intake. Maintain ideal body weight and body fat percentage and recommend regular but moderate-weight-bearing exercise from a young age throughout adult life, as part of a strategy to prevent and treat osteoporosis. In the present study black South African men present with low bone mineral density, but other studies indicated a lower rate of hip fracture in South African blacks, despite lower bone density at all ages. It can be recommended that other factors may play a role in black South African men with osteoporosis. Factors such as serum phosphorus, 25-hydroxy-vitamin D, body mass index (BMI), physical activity index (PAI), animal protein, total fat intake and dietary calcium are important determinants of BMD in older South African blacks, as shown in the present study. Osteoporosis is a multi factorial problem and must be treated that way. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2004.

Menopause is an important period for bone health in women. Objective: To assess the determinants of bone mineral density (BMD) changes in women transitioning to menopause. Method: A secondary data analysis of the MONET (Montreal-Ottawa New Emerging Team) study. Outcome measures included yearly assessment of menopause status, body composition, BMD, physical activity energy expenditure (PAEE) and dietary calcium and vitamin D intakes. Results: 84 of the original 102 women had complete data for the purpose of the present study. Repeated measures analysis revealed significant decreases in lumbar spine and femoral neck BMD (P< 0.01). Regression analysis revealed that baseline femoral neck BMD, changes in PAEE and trunk fat explained 31% of the variation of BMD changes at the femoral neck, while changes in both PAEE and trunk fat account for 27% of BMD change at lumbar spine. Conclusion: Baseline femoral neck and changes in physical activity energy expenditure and trunk fat are determinants of the reduction of bone mineral density in women transitioning to menopause.

Menopause is an important period for bone health in women. Objective: To assess the determinants of bone mineral density (BMD) changes in women transitioning to menopause. Method: A secondary data analysis of the MONET (Montreal-Ottawa New Emerging Team) study. Outcome measures included yearly assessment of menopause status, body composition, BMD, physical activity energy expenditure (PAEE) and dietary calcium and vitamin D intakes. Results: 84 of the original 102 women had complete data for the purpose of the present study. Repeated measures analysis revealed significant decreases in lumbar spine and femoral neck BMD (P< 0.01). Regression analysis revealed that baseline femoral neck BMD, changes in PAEE and trunk fat explained 31% of the variation of BMD changes at the femoral neck, while changes in both PAEE and trunk fat account for 27% of BMD change at lumbar spine. Conclusion: Baseline femoral neck and changes in physical activity energy expenditure and trunk fat are determinants of the reduction of bone mineral density in women transitioning to menopause.

Dietary calcium has been classified as one of the minerals frequently limiting in the American diet (FAO, 1962) . Bone demineralization has been observed as a result of calcium deficient diets (Salomon et al., 1972), partial gastrectomies (Eddy, 1971) and inadequate hormonal balance (Albright et al., 1948). Although bone demineralization, or osteoporosis, has been attributed to many factors, the interrelationship of gastric acidity and the utilization of dietary calcium may be a key to the etiology of osteoporosis. Eighty weanling male albino rats were divided into eight groups. All animals had their stomachs exposed through a mid-line incision. Control rats were sham-operated while the treatment animals had their stomachs X-irradiated to destroy the secretory cells. Four diets were prepared containing calcium carbonate, calcium chloride, tri-calcium phosphate or calcium gluconate as calcium sources. For a three-week experimental period, ten control and ten X-irradiated rats were fed each diet. In vitro data suggests that the solubility of each calcium salt, except calcium gluconate, increased in an acid media. Saturated viii ix solutions of calcium carbonate and tri-calcium phosphate had low quantities of calcium ion in solution in neutral pH's, but as the acidity was changed from pH 4 to pH 3 the calcium ion concentration increased as much as eight times. This demonstrates that the presence of acid with insoluble forms of calcium salts will generally increase calcium ion concentration in solution. All X-irradiated animals had an average fasting gastric pH of over 6, while the control rats averaged pH 2.5. The calcium absorption data demonstrates that X-irradiated rats fed diets containing soluble calcium salts (calcium chloride, 18.5 percent and calcium gluconate, 25.13 percent) had increased absorption values over those fed diets containing calcium salts of low solubility (calcium carbonate, 12.94 percent and tri-calcium phosphate, -7.06 percent). Femur strength and bone calcium data reflected similar evidence. Both femur strength and bone calcium of the X-irradiated rats fed the less soluble forms of calcium salt were significantly lower than the controls, while X-irradiated rats fed the more soluble forms of calcium had femur strength and bone calcium similar to the controls. Achlorhydric, or X-irradiated, animals were observed to have decreased iron stores in comparison with the control rats. Hemoglobin levels, liver iron and iron absorption were all significantly reduced in the x-irradiated animals. From the results of these experiments, it is apparent that gastric acidity and the solubility of the dietary calcium source play an important role in the utilization of calcium.