Calcium intake trends and health consequences from childhood through adulthood

Issues involving low calcium intake and dairy product consumption are currently the focus of much debate and discussion at both the scientific and lay community levels. In this review, we examine the following major areas of interest: (1). the role of calcium intake and dairy product consumption in chronic diseases, (2). nutritional qualities of milk and other dairy products, (3). trends in calcium intake and dairy product consumption, (4). current status of calcium intakes and dairy product consumption in children, (5). tracking of calcium intake and diary product consumption, (6). the impact of school meal participation on calcium intake and dairy product consumption, (7). concerns related to calcium-fortified foods and beverages and (8). factors influencing children's milk consumption. To date, the findings indicate that calcium intake and dairy product consumption have beneficial roles in a variety of chronic diseases; dairy products provide an abundant source of vitamins and minerals; calcium intakes of children have increased over time, yet intakes are not meeting the current adequate intake (AI) calcium recommendations; dairy consumption has decreased, and soft drink consumption and, possibly, consumption of calcium-fortified products have increased; consumption of dairy products have a positive nutritional impact on diets of children, particularly from school meals, and there are many factors which influence children's milk consumption, all of which need to be considered in our efforts to promote adequate calcium intakes by children. Based on this review, areas that need immediate attention and future research imperatives are summarized in an effort to further our understanding on what we already know and what we need to know to promote healthier eating habits early in life.     

Calcium Intake Trends and Health Consequences from Childhood through Adulthood

Issues involving low calcium intake and dairy product consumption are currently the focus of much debate and discussion at both the scientific and lay community levels. In this review, we examine the following major areas of interest: (1) the role of calcium intake and dairy product consumption in chronic diseases, (2) nutritional qualities of milk and other dairy products, (3) trends in calcium intake and dairy product consumption, (4) current status of calcium intakes and dairy product consumption in children, (5) tracking of calcium intake and diary product consumption, (6) the impact of school meal participation on calcium intake and dairy product consumption, (7) concerns related to calcium-fortified foods and beverages and (8) factors influencing children’s milk consumption. To date, the findings indicate that calcium intake and dairy product consumption have beneficial roles in a variety of chronic diseases; dairy products provide an abundant source of vitamins and minerals; calcium intakes of children have increased over time, yet intakes are not meeting the current adequate intake (AI) calcium recommendations; dairy consumption has decreased, and soft drink consumption and, possibly, consumption of calcium-fortified products have increased; consumption of dairy products have a positive nutritional impact on diets of children, particularly from school meals, and there are many factors which influence children’s milk consumption, all of which need to be considered in our efforts to promote adequate calcium intakes by children. Based on this review, areas that need immediate attention and future research imperatives are summarized in an effort to further our understanding on what we already know and what we need to know to promote healthier eating habits early in life.     

Dairy consumption and related nutrient intake in African-American adults and children in the United States: continuing survey of food intakes by individuals 1994-1996, 1998, and the National Health And Nutrition Examination Survey 1999-2000

OBJECTIVE: To establish the first baseline of dairy and related nutrient intake in African Americans, an at-risk population of public health concern in the United States. To document dairy consumption in African Americans by age and sex during 1994-1998 and 1999-2000 and compare it with concomitant dairy, calcium, and related nutrient intakes in non-African-American adults and children. DESIGN: Duplicate and single 24-hour recalls were analyzed to determine dietary intake during the Continuing Survey of Food Intakes by Individuals 1994-1996, 1998 (CSFII), and the National Health and Nutrition Examination Survey 1999-2000 (NHANES), respectively. SUBJECTS: African Americans and non-African Americans of all ages who participated in CSFII 1994-1996, 1998, and in NHANES 1999-2000; both surveys are a stratified random sample of the total civilian, noninstitutionalized US population. STATISTICAL ANALYSIS: Dairy food and nutrient intake per day were quantified according to age, sex, and ethnicity/race from CSFII 1994-1996, 1998, and NHANES 1999-2000. For NHANES, mean intakes from 1-day food records were sample-weighted, and standard errors estimated by the Taylor linearization method of SUDAAN (version 9.0, 2004, RTI International, Research Triangle Park, NC). Usual daily intakes of calcium, magnesium, and phosphorus were based on 2-day intake data from CSFII 1994-1996, 1998, and calculated using Software for Intake Distribution from Iowa State University. The percentage of individuals categorized as not meeting the Estimated Average Requirement for magnesium and phosphorus were calculated in the same way. RESULTS: CSFII 1994-1996, 1998, and NHANES 1999-2000 data both show that African Americans in all age groups consume fewer mean servings per day of total dairy, milk, cheese, and yogurt than non-African Americans, and have lower mean intakes of calcium, magnesium, and phosphorus. Significant differences were seen for men and women. CONCLUSIONS: In this analysis, young African-American women did not meet Dietary Reference Intakes for phosphorus, and all African Americans did not meet Dietary Reference Intakes for calcium and magnesium. African Americans in all age groups did not meet dairy recommendations from the 2005 US Dietary Guidelines and the 2004 National Medical Association Consensus Report on the role of dairy and dairy nutrients in the diet of African Americans.     

Nutrient contributions of dairy foods in the United States, Continuing Survey of Food Intakes by Individuals, 1994-1996, 1998

OBJECTIVE: This study was designed to quantify the impact of dairy foods on nutrient intakes in the United States. SUBJECTS: Data were from 17959 respondents to the 1994-1996, 1998 Continuing Survey of Food Intakes by Individuals (CSFII).Statistical analyses Nutrient intakes were quantified by quartile of dairy food intake. Also, dairy intakes were compared in people who met vs did not meet intake recommendations for select nutrients. Finally, the direct contribution of dairy foods/ingredients to calcium and lipid intakes was determined. SAS and SUDAAN software were used. Data were weighted. Energy intake was a covariable in regression models. RESULTS: Intake of all micronutrients examined, except vitamin C, was higher with increasing quartile of total dairy and milk intake, controlling for energy intake. Calcium was the only micronutrient positively associated with cheese intake. Fat intake either did not differ or was lower among people in quartile 2, 3, or 4 vs quartile 1 of total dairy and milk intake, whereas fat was higher as quartile of cheese intake increased. Dietary cholesterol was lower as intakes of any of the dairy categories increased; the opposite was true for saturated fat. Dairy foods/ingredients directly contributed an average of 51% of dietary calcium, 19% of total fat, 32% of saturated fat, and 22% of cholesterol. CONCLUSIONS: Total dairy and milk intakes were associated with higher micronutrient intakes without adverse impact on fat or dietary cholesterol. Results reinforce the strong nutritional profile of dairy-rich diets, although results with saturated fat and with cheese suggest that it would be useful to modify product composition and/or eating patterns to optimize nutritional contributions of dairy products.     

Children and adolescents' choices of foods and beverages high in added sugars are associated with intakes of key nutrients and food groups.

PURPOSE: To determine associations between intakes of the primary food and beverage sources of added sugars and intakes of key nutrients and food pyramid groups among U.S. children aged 6-17 years. METHODS: The 1994-96 and 1998 U.S. Department of Agriculture (USDA) Continuing Survey of Food Intakes by Individuals (CSFII) were used to examine the diets of U.S. children aged 6-17 years, who provided 2 full days of dietary data. The nationally representative sample (n = 3038) included children age 6-11 (n = 1913) and adolescents age 12-17 (n = 1125). Food codes for sweetened foods and beverages were selected from the USDA Food Coding Scheme and categorized into five food and beverage categories. The Statistical Analysis System software program was used to recode and format the data for statistical analysis and the Survey Data Analysis System was used to apply sample weights and generate statistical procedures. RESULTS: The consumption of sweetened dairy products was positively associated with calcium intakes for children and adolescents. Consumption of presweetened cereals increased the likelihood of the children and adolescents meeting recommendations for the essential shortfall micronutrients calcium, folate, and iron, whereas the consumption of sugar-sweetened beverages, sugars and sweets, and sweetened grains decreased the likelihood of meeting the Dietary Reference Intakes (DRI) for these nutrients. Only children who were nonconsumers of sugar-sweetened beverages had a mean calcium intake that met the adequate intakes (AI). Consumption of sweetened dairy products and presweetened cereals was positively associated with the number of dairy servings consumed per day for both age groups. CONCLUSIONS: On average, consumption of sweetened dairy foods and beverages and presweetened cereals had a positive impact on children and adolescents' diet quality, whereas sugar-sweetened beverages, sugars and sweets, and sweetened grains had a negative impact on their diet quality.     

Intake of Dairy Products in Relation to Periodontitis in Older Danish Adults

This cross-sectional study investigates whether calcium intakes from dairy and non-dairy sources, and absolute intakes of various dairy products, are associated with periodontitis. The calcium intake (mg/day) of 135 older Danish adults was estimated by a diet history interview and divided into dairy and non-dairy calcium. Dairy food intake (g/day) was classified into four groups: milk, cheese, fermented foods and other foods. Periodontitis was defined as the number of teeth with attachment loss ≥3 mm. Intakes of total dairy calcium (Incidence-rate ratio (IRR) = 0.97; p = 0.021), calcium from milk (IRR = 0.97; p = 0.025) and fermented foods (IRR = 0.96; p = 0.03) were inversely and significantly associated with periodontitis after adjustment for age, gender, education, sucrose intake, alcohol consumption, smoking, physical activity, vitamin D intake, heart disease, visits to the dentist, use of dental floss and bleeding on probing, but non-dairy calcium, calcium from cheese and other types of dairy food intakes were not. Total dairy foods (IRR = 0.96; p = 0.003), milk (IRR = 0.96; p = 0.028) and fermented foods intakes (IRR = 0.97; p = 0.029) were associated with reduced risk of periodontitis, but cheese and other dairy foods intakes were not. These results suggest that dairy calcium, particularly from milk and fermented products, may protect against periodontitis. Prospective studies are required to confirm these findings.     

Diet in a group of 18-month-old children in South West England, and comparison with the results of a national survey

OBJECTIVE: To investigate the normal range of nutrient intakes and food consumption patterns in 18 month old children. SUBJECTS: 1,026 children resident in South West England, forming part of the Children in Focus (CIF) research cohort. METHODS: Diet was assessed using a 3 day unweighed dietary record. Nutrient and food intakes were compared with the dietary reference values and with the results of a British survey of preschool children -- the National Diet and Nutrition Survey (NDNS). RESULTS: Intakes of energy and nearly all nutrients were significantly higher in boys than in girls. Intakes of energy were slightly above the estimated average requirements. For most nutrients the mean and median intakes were well above the Reference Nutrient Intakes (RNI). The exceptions were vitamin D, iron and zinc. Nutrient intakes in CIF were very similar to those in the NDNS except for carotene, calcium, vitamin D and iodine, where intakes were considerably higher in CIF, and sugar intake which was lower in CIF. Intakes of most foods were similar in the two surveys. However, consumption of milk, yoghurt and fromage frais and baby foods was higher in CIF, intakes of most fruit and vegetables was somewhat higher, and intakes of savoury snacks and sugar confectionery were lower. In addition, there were differences between the two groups in the types of meat and meat products consumed. CONCLUSIONS: These children are unlikely to be deficient in any nutrients, with the possible exceptions of iron, zinc, and vitamin D. The use of vitamin D supplements and the inclusion of iron- and zinc-rich foods in the diets of preschool children should be encouraged. These data will be important in assessing the influence of early diet on subsequent health and development.     

Dietary calcium intake in lactose maldigesting intolerant and tolerant African-American women

BACKGROUND: The relationship between lactose maldigestion, lactose intolerance, and calcium intake in premenopausal African American women is unknown. OBJECTIVE: To determine how intolerance of lactose and dairy products affects intake of calcium in lactose maldigesting premenopausal African American women. DESIGN: Dietary intake of calcium was assessed in 50 premenopausal lactose maldigesting African American women as determined by the breath hydrogen test. Twenty-six women were lactose intolerant and 24 were lactose tolerant by self-reports. RESULTS: The average intake of calcium in lactose maldigesting and intolerant women was significantly lower than in lactose tolerant women (388 +/- 150 mg/day vs. 763 +/- 333 mg/day, p < 0.0001, t test). Neither group reached the newly established Dietary Reference Intake (DRI) for calcium (1,000 mg/day). Major source of dietary calcium in lactose tolerant women were milk and dairy products (45%), and mixed foods containing calcium from non-dairy sources (30%). In lactose intolerant women, 46% of calcium was from mixed foods and only 12% was from milk and dairy products. Lactose intolerant women had higher body mass index (BMI) than lactose tolerant women (p = 0.008, t test), and calcium intake was negatively associated with BMI (R2 = 0.470). CONCLUSIONS: In African American premenopausal women, lactose tolerance facilitates the dietary intake of calcium when compared with their lactose intolerant counterparts. Low calcium intake is associated with higher BMI.     

Longitudinal calcium intake is negatively related to children's body fat indexes

OBJECTIVE: To determine if dietary calcium was negatively related to children's body fat (BF), if BF indexes and calcium intakes changed over time, and to identify variables related to BF and calcium intake. DESIGN: Percent BF and kg BF were assessed by dual energy x-ray absorptiometry (DEXA) in 8-year-old children. In a prospective design, height, weight, dietary intakes, and related variables were monitored longitudinally from ages 2 months to 8 years during in-home interviews. SUBJECTS: Fifty-two white children, (n=25 boys, 27 girls) participated in a longitudinal study with their mothers. At 8 years of age, mean BMI was 17.3+/-2.1 (standard deviation) for boys and 17.1+/-2.5 for girls. ANALYSES: Regression analysis of all variables, followed by further regression analysis on selected models. RESULTS: At 8 years, percent BF was 22.7+/-6.7 for boys and 26.2+/-7.9 for girls, as assessed by DEXA. Dietary calcium (mg) and polyunsaturated fat intake (g) were negatively related to percent BF (P=.02 to.04) in 3 statistical models, which predicted 28% to 34% of the variability in BF among children. Variables positively associated with percent BF were total dietary fat (g) or saturated fat (g), female gender, sedentary activity (hours/day), father's BMI, and mothers' percent BF. Calcium intakes were significantly correlated over time. Dietary variety was positively related to calcium intake, and intakes of carbonated beverages and other sweetened beverages were negatively related. APPLICATIONS/CONCLUSIONS: Children should be strongly encouraged to regularly include calcium-rich foods and beverages in their diets.     

Diet in a group of 18-month-old children in South West England, and comparison with the results of a national survey

Objective To investigate the normal range of nutrient intakes and food consumption patterns in 18-month-old children.
Subjects 1026 children resident in South West England, forming part of the Children in Focus (CIF) research cohort.
Methods Diet was assessed using a 3-day unweighed dietary record. Nutrient and food intakes were compared with the dietary reference values and with the results of a British survey of preschool children – the National Diet and Nutrition Survey (NDNS).
Results Intakes of energy and nearly all nutrients were significantly higher in boys than in girls. Intakes of energy were slightly above the estimated average requirements. For most nutrients the mean and median intakes were well above the Reference Nutrient Intakes (RNI). The exceptions were vitamin D, iron and zinc. Nutrient intakes in CIF were very similar to those in the NDNS except for carotene, calcium, vitamin D and iodine, where intakes were considerably higher in CIF, and sugar intake which was lower in CIF. Intakes of most foods were similar in the two surveys. However, consumption of milk, yoghurt and fromage frais and baby foods was higher in CIF, intakes of most fruit and vegetables was somewhat higher, and intakes of savoury snacks and sugar confectionery were lower. In addition, there were differences between the two groups in the types of meat and meat products consumed.
Conclusions These children are unlikely to be deficient in any nutrients, with the possible exceptions of iron, zinc and vitamin D. The use of vitamin D supplements and the inclusion of iron- and zinc-rich foods in the diets of preschool children should be encouraged. These data will be important in assessing the influence of early diet on subsequent health and development.     

Dairy and dairy-related nutrient intake during middle childhood

OBJECTIVE: To characterize patterns of dairy intake among girls in middle childhood. DESIGN: Longitudinal data were used to characterize girls' patterns of dairy intake at age 5, 7, 9, and 11 years. SUBJECTS: Participants were 151 girls from predominately middle-class and exclusively non-Hispanic white families living in central Pennsylvania. STATISTICAL ANALYSES: Intakes of dairy, energy, macronutrients, vitamin D, calcium, and phosphorus were assessed using three 24-hour dietary recalls in 151 non-Hispanic white girls at age 5, 7, 9, and 11 years. Analyses of changes over time were conducted using repeated measures analysis of variance. McNemar's chi(2) test was used to analyze change in percentage of dairy consumers over time. RESULTS: From age 5 to 11 years, girls' total dairy intake remained stable. Total milk consumption declined, due to a decline in intake of milk as a beverage, while intakes of cheese and dairy desserts increased. Much of the decline in milk intake from age 5 to 11 years, especially for milk as a beverage, was due to a reduction in the percentage of girls consuming milk as a beverage, not simply due to a decline in the servings of milk as a beverage consumed by consumers. On average, girls met vitamin D recommendations over time; however, by age 9 and 11 years girls failed to meet calcium and phosphorus recommendations. CONCLUSIONS: Although girls' dairy intake was stable over time, at age 7, 9, and 11 years girls did not meet the recommended three servings per day, leading to suboptimal intakes of calcium and phosphorus at age 9 and 11 years. Increasing milk intake among all children should continue to be a major focus of interventions.     

Diet quality in young children is influenced by beverage consumption

BACKGROUND: Replacement of milk with sugar-containing beverages could affect calcium intake and overall diet quality. OBJECTIVE: To describe dairy food, 100% juice and added sugar beverage intakes, contributions of dairy foods to diet quality, and effects of beverages on diet quality in young children. METHODS: We surveyed participants in the Iowa Fluoride Study (n = 645) at ages 1, 2, 3, 4 and 5 years and calculated intakes for 1-5 years (i.e. weighted averages). Nutrient, dairy food and beverage intakes were obtained from 3-day diaries; nutrient adequacy ratios were calculated as the nutrient intake to Recommended Dietary Allowance/Adequate Intake ratio; and dairy-dependent percentages were calculated as fractions of total diet nutrient adequacy ratios (truncated at 1) not met by non-dairy foods. RESULTS: Milk intakes were inversely associated with intakes of juice drinks (2, 4, 5 and 1-5 years), soda pop (2, 3, 4, 5 and 1-5 years) and added sugar beverages (2, 3, 4, 5 and 1-5 years). Dairy dependent fractions of 1-5 year nutrient adequacy ratios were 68% for calcium and 61% for vitamin D. Higher 1-5 year calcium adequacy was predicted by higher energy, higher other dairy and lower added sugar beverage intakes while higher vitamin D adequacy was predicted by higher energy and higher other dairy intakes. Overall diet quality was predicted by higher energy, higher other dairy, lower 100% juice and lower added sugar beverage intakes. CONCLUSIONS: Dairy foods remain an important source of calcium and vitamin D, while added sugar beverages and, to a lesser extent, 100% juice decrease diet quality of young children.     

Magnesium deficiency and its lack of association with asthma in Taiwanese elementary school children

The purpose of this study was to investigate magnesium nutritional status and its association with asthma in elementary school children (1277 boys and 1109 girls) participating in the Nutrition and Health Survey in Taiwan (NAHSIT children 2001-2002). Dietary magnesium intake was based on 24-hour dietary recalls. Serum magnesium was measured. Average magnesium intake was 247 mg and 228 mg for the boys and girls, respectively, which is equivalent to 135-123% of the relevant Taiwanese Dietary Reference Intakes (DRIs). Mean serum magnesium concentration was 0.87 mmol/L and 0.86 mmol/L, respectively. The prevalence of serum magnesium <0.8 mmol/L was 10.5-13.5% in both gender in our sample of elementary school children. In Taiwan, asthma was diagnosed in about 5.8% and 4.7% of boys and girls, respectively. In this study, there were no associations between asthma prevalence, dietary magnesium and serum magnesium concentration. In about 40% of our sample of school children, however, dietary magnesium may be suboptimal. This deficit should be targeted though improved intake of magnesium-rich foods such as whole grains, green vegetables and soybean products, particularly in Taiwanese school children whose dietary intakes are below the DRIs and/or who have low serum magnesium levels.     

12～17岁少年钙代谢实验研究

目的通过钙代谢平衡实验探讨中国青春期少年的钙参考摄入量。方法从320名参与1年补钙实验4组12～17岁的少年中,每组随机抽取男、女生各10人,共80人。采用钙代谢平衡实验的方法。实验期共10d,膳食适应3d后,开始7d的代谢试验。收集研究对象试验期内摄入的食品、排出的粪便和尿液样品,用电感耦合等离子体发射光谱法测定样品中的钙含量。结果不同水平钙摄入组间的钙吸收量、粪钙排出量、钙储留量存在差异。钙表观吸收率女生平均为46.4%,男生68.7%。进行曲线拟合后,男生钙吸收率最高时的钙摄入量为665mg/d,女生钙吸收率达到平台时的钙摄入量为650mg。为了达到每日最大储留量,男生钙摄入量要达到545mg/d,女生要达到1055mg/d。结论中国12～17岁男生和女生的钙适宜摄入量有很大差别,男生钙适宜摄入量约为600～700mg/d,女生为1000～1100mg/d。     

Dietary Intake and Associated Body Weight in Canadian Undergraduate Students Enrolled in Nutrition Education

The primary purpose of this study was to describe dietary intakes among Canadian undergraduate students enrolled in an Introductory Nutrition course. A secondary objective was to determine food group servings associated with meeting more Dietary Reference Intakes (DRIs) of select nutrients and with a lower body mass index (BMI). Participants (n = 124, 20.7±3.2yrs) provided output from a 3-day dietary record and completed a physical activity/demographics questionnaire. Linear regression showed that the dietary intake associated with meeting the most DRIs included vegetables, fruits, protein foods, and dairy (p = 0.001). Protein foods were a positive predictor and fruit a negative predictor of BMI (p = 0.001 and p = 0.023 respectively). Males consumed more grains (p = 0.001), dairy (p = 0.04), protein foods (p < 0.001), empty calories (p = 0.007) and total calories than females (p < 0.001). A diet characterized by greater intake of vegetables, fruits, protein foods, and dairy was associated with a Canadian undergraduate population meeting the greatest number of nutrient requirements.     

Positive effects of vegetable and fruit consumption and calcium intake on bone mineral accrual in boys during growth from childhood to adolescence: the University of Saskatchewan Pediatric Bone Mineral Accrual Study

BACKGROUND: Nutrition is an important modifiable factor in the development of bone mass during adolescence. Recent studies of children and adolescents examined the effects of foods such as milk products and fruit and vegetables on bone growth; however, few studies included both boys and girls. OBJECTIVE: The purpose was to ascertain the role of consumption of milk products and vegetables and fruit in the accrual of total-body bone mineral content (TBBMC) in boys and girls from childhood to late adolescence. DESIGN: Seven-year longitudinal data were obtained from 85 boys and 67 girls aged 8-20 y. Biological maturity was defined by the number of years from the age at peak height velocity. Dietary intake was assessed by serial 24-h recalls. Anthropometric measurements and physical activity were assessed every 6 mo. TBBMC assessed with dual-energy X-ray absorptiometry in the fall of each year was the indicator of bone mass. RESULTS: Most boys (87.8%) met Canadian recommendations for milk product intake. Few subjects (<30%) consumed vegetables and fruit in recommended amounts. Using a multilevel modeling statistical approach containing important biological and environmental factors, we found that vegetable and fruit intakes, calcium intake, and physical activity were significant independent environmental predictors of TBBMC in boys but not in girls. CONCLUSIONS: In addition to adequate dietary calcium intake, appropriate intakes of vegetables and fruit have a beneficial effect on TBBMC in boys aged 8-20 y. Underreporting of dietary intake by girls may explain why this effect was not apparent in girls.     

Meeting calcium recommendations during middle childhood reflects mother-daughter beverage choices and predicts bone mineral status

BACKGROUND: Longitudinal data regarding the influence of beverage intakes on calcium adequacy are lacking. OBJECTIVE: This study evaluated calcium intake from ages 5 to 9 y as a function of mother-daughter beverage choices and as a predictor of bone mineral status. DESIGN: Intakes of energy, calcium, milk, sweetened beverages, fruit juices, and non-energy-containing beverages were measured with the use of three 24-h dietary recalls in 192 non-Hispanic white girls aged 5, 7, and 9 y and their mothers. Calcium intakes from ages 5 to 9 y were categorized as either meeting or falling below recommended adequate intakes (AIs). The girls' bone mineral status was assessed with dual-energy X-ray absorptiometry at age 9 y. RESULTS: The mean 5-y calcium intake was related to bone mineral density at age 9 y (beta = 0.27, P < 0.001). The girls who met the AI for calcium were not heavier (P = 0.83) but had higher energy intakes (P < 0.0001) than did the girls who consumed less than the AI. Compared with the girls who consumed less than the AI, the girls who met the AI consumed, on average, almost twice as much milk (P < 0.0001), had smaller decreases in milk intake (P < 0.01), and consumed 18% less sweetened beverages (P < 0.01) from ages 5 to 9 y; the 2 groups did not differ significantly in juice and non-energy-containing beverage intakes. The girls who met the AI were also served milk more frequently than were the girls who consumed less than the AI (P < 0.0001) and had mothers who drank milk more frequently (P < 0.01) than did the mothers of the girls who consumed less than the AI. CONCLUSIONS: These findings provide new longitudinal evidence that calcium intake predicts bone mineral status during middle childhood and reflects mother-daughter beverage choice patterns that are established well before the rapid growth and bone mineralization observed in adolescence.     

Associations of adequate intake of calcium with diet, beverage consumption, and demographic characteristics among children and adolescents

OBJECTIVE: The objective of this study is to examine various factors associated with total calcium intake and percent adequate intake (% AI) of calcium by children and adolescents, with respect to age, gender, race/ethnicity, and diet and beverage choices. DESIGN: Data from the U.S. Department of Agriculture's Continuing Survey of Food Intake by Individuals 1994-96, 98 were used in the analyses. Age groupings (2-3, 4-8, 9-13, and 14-18 year olds) were based on the National Academy of Sciences recommendations for AI of calcium-500, 800, 1,300, and 1,300 mg calcium per day, respectively. RESULTS: Consumption of milk products was strongly and positively associated with calcium intake. Consumption of carbonated soft drinks and other non-dairy beverages was also positively associated with calcium intake, but this association was very weak. Beverage choices of African-American children and adolescents are significantly different than white and Hispanic children and adolescents. For example, African-American adolescent girls consume fewer milk products and more fruit drinks/ades. Average daily carbonated soft drink consumption is approximately 1.6 and 1.0 twelve ounce cans among 14-18 year old boys and girls, respectively. CONCLUSION: Carbonated soft drink consumption among adolescent girls is modest and does not appear to be linked to decreased calcium intake. The analyses in this paper show that creative effective, efficient, and targeted policies should be considered to help adolescent girls increase calcium intake. Making low-fat milk products, flavored milks, calcium-fortified beverages and foods more attractive and available will help encourage girls to consume more of this important mineral. When adequate calcium intake is not achieved through foods, health professionals should consider recommending calcium supplements.     

Dietary acid-base balance and intake of bone-related nutrients in Cambridge teenagers

OBJECTIVES: To evaluate the diet of 16-18-y-old boys and girls with particular reference to intakes of nutrients believed to affect bone health and dietary acid-base balance. DESIGN: A 7-day food diary was completed between the months of October and December. SETTING: Cambridge, UK. SUBJECTS: A total of 111 boys and 101 girls aged 16-18 y who were recruited into the Cambridge Bone Studies. MAIN OUTCOME MEASURES: Mean daily intakes of foods and selected nutrients (protein, calcium, phosphorus, magnesium, potassium, vitamins C and K) were calculated. Two estimates of acid-base balance were calculated from the diet using the formulae of Remer (net acid excretion, estimated indirectly; NAE(ind)) and Frassetto (protein/potassium ratio). RESULTS: Mean calcium and phosphorus intakes were above the UK Reference Nutrient intake (RNI). In all, 39% of the boys and 36% of the girls had vitamin K intakes lower than 1 microg/kg body weight/day. Calcium intake was positively correlated with all other nutrients except vitamins C and K. Boys had a significantly higher estimated net acid excretion (NAE(ind)) than girls (P<0.001). Although a strong correlation (r=0.76, P<0.001) was found between the two methods, at higher acid levels a divergence was observed. A significant positive correlation was found between NAE(ind) and the weight consumed per day of milk, cheese, meat and cereal foods and a negative correlation was found with the weight of potatoes and fruit. Diet composition is such that a lower NAE(ind) is accompanied by a lower calcium intake. CONCLUSIONS: The interpretation of the effects of calcium and other nutrients on bone cannot be considered in isolation from the other components of the diet. These results challenge some of the accepted perceptions about what constitutes an optimal diet for the promotion of bone health in adolescents.     

Parental Influences on Dairy Intake in Children,and Their Role in Child Calcium-fortified Food Use

ObjectiveTo understand how parental influences on dairy food intake relate to early adolescent children's use of calcium-fortified food.DesignContent analysis of qualitative interviews to identify parental influences on dairy intake; calcium-fortified food survey to identify children as either calcium-fortified food users or nonusers.Setting and ParticipantsA convenience sample of Asian (n = 56), Hispanic (n = 61), and white (n = 74) parents of children 10-13 years old, including boys (n = 86) and girls (n = 105).Variables Measured and AnalysisCluster analysis to identify groups with similar coded parental influences and chi-square analysis to determine associations between these groups and calcium-fortified food use.ResultsTwo dominant patterns of parental influences: Cluster 1 (n = 128), with positive parental influences related to availability of dairy, milk, and cheese; positive health beliefs for dairy, and child preferences for dairy and cheese, included parents whose children were more likely to use calcium-fortified food. Cluster 2 (n = 63), with positive influences for availability of dairy and milk, included parents whose children were equally likely to be either users or nonusers of calcium-fortified food (P < .05).ConclusionStrategies to improve parental influence on children's dairy intake might also encourage calcium-fortified food intake and improve calcium nutriture.