Effect of energy density and fat level of milk formulas on subsequent food and energy intake in preschool children

The aim of this study was to examine the effects of two levels of energy intakes and two levels of fat at breakfast, on the food and energy intakes in subsequent meal (lunch). The study was performed in 51 children both genders, with ages ranging from 24 to 48 months, attending a day care center. The children selected had normal nutritional status (weight/height index) according to the NCHS standards. The food intake was determined by differential weighing and energy intake was calculated from proximal analysis. The energy densities of the cow's milk formula used were 0.8 and 1.2 kcal/g, resulting in a total energy offer (breakfast) of 267.5 and 367.5 kcal respectively, the fat levels were 6.3 and 0.9 g/250 g of formula, using the design 2 x 2 factorial. In the study, 720 observations of food intake were conducted in those children consuming higher than 75% of the total food offered at breakfast. In the lunch-time were offered in alternated form two preparations with an 0.97 kcal/g of energy density. The results demonstrated that the children consumed significantly higher energy amounts in the subsequent meal, after being fed the high fat and lower energy-content breakfast. When the total energy intake (breakfast + lunch) was compared these results show that the caloric difference of breakfast was reduced and the degree of reduction was influenced by the fat level. These results show evidence for partial caloric compensation of 67% in the higher-fat level, and only 34% for the children with the lower of fat-level. It is conclude that the energy intake and fat intake at breakfast influences the energy intake at the subsequent meal. These findings are important to the preschool children's feeding with risk of malnutrition.     

Effects of lactation and lifestyles including food intake on bone density of lactating women

Ultrasonic bone densities were measured in 131 lactating women, aged 21 to 42 years, at 6-590 days postpartum. STIFFNESS Calculated from the combined value of speed of sound and broadband ultrasound attenuation at the calcaneus was used as an index of bone density. The relationships of STIFFNESS with period of lactation, current and past consumption of cow's milk, various food intake frequency, history of participating in sports, daily physical activity, using calcium drugs and sun exposure were examined using stepwise multiple regression analysis, including age and weight as independent variables. 1) The mean (SD) of STIFFNESS was 79.8 (11.9). Thirty-three women (25% of subjects) showed STIFFNESS less than 70. 2) Period of lactation showed a significant negative effect on STIFFNESS (p < 0.05). However, no such effect appeared for women with cow's milk intake of less than 100 ml per day. This result suggests a protection of calcium levels in bone. 3) Current daily cow's milk intake showed significant positive effect on STIFFNESS (p < 0.05). For women lactating less than 150 days, this relation between cow's milk intake and STIFFNESS was clear (r = 0.44, p < 0.01). 4) Significant relation between STIFFNESS and food intake frequencies was found in milk and milk products only among various foods. This result indicates that cow's milk and milk products are important sources of calcium during lactation.     

Effect of topical butyrate on rectal epithelial kinetics and mucosal enzyme activities

Public awareness and misunderstandings of lactose intolerance are at an all-time high. Many people erroneously believe they are lactose intolerant or develop gastrointestinal symptoms after intake of lactose. Consequently, lactose-containing foods such as milk and other dairy foods may be eliminated unnecessarily from the diet. Because these foods are a major source of calcium, low intake of them can compromise calcium nutriture. This, in turn, can increase the risk of major chronic diseases such as osteoporosis (porous bones) and hypertension. This review is intended to help dietetics professionals alleviate clients' fears about lactose intolerance and recommend dietary strategies to improve tolerance to lactose. Scientific findings indicate that the prevalence of lactose intolerance is grossly overestimated. Other physiologic and psychologic factors can contribute to gastrointestinal symptoms that mimic lactose intolerance. Scientific findings also indicate that people with laboratory-confirmed low levels of the enzyme lactase can consume 1 serving of milk with a meal or 2 servings of milk per day in divided doses at breakfast and dinner without experiencing symptoms. Several dietary strategies are available to help lactose maldigesters include milk and other dairy foods in their diet without experiencing symptoms.     

Association of nucleoside diphosphate kinase nm23-H2 with human telomeres

In this study, the effect of dietary calcium and vitamin D on serum parathyroid hormone and vitamin D metabolites was measured in 376 free-living women aged 65-77 y. Mean calcium intake in both groups was close to the recommended dietary allowance of 800 mg/d. Mean vitamin D intake in the 245 women not taking vitamin D supplements was 3.53 microg/d (141 IU/d), which is below the recommended dietary allowance of 5 microg/d (200 IU/d). To test the hypothesis that vitamin D is more important than calcium in reducing serum parathyroid hormone, the source of dietary calcium intake was subdivided into milk, which is fortified with vitamin D, and nonmilk sources. The serum parathyroid hormone concentration was inversely correlated with calcium intake derived from milk (r = -0.20, P < 0.01) but not from nonmilk sources (r = -0.06). Furthermore, serum calcidiol correlated with milk calcium intake (r = 0.35, P < 0.001) but not with nonmilk calcium intake (r = 0.10). Multivariate analysis showed a significant effect of season on serum calcidiol but not on serum parathyroid hormone. Serum parathyroid hormone was inversely correlated with serum calcidiol (r = -0.33, P < 0.001) and the regression predicted that mean serum parathyroid hormone would be reduced in the elderly to concentrations considered normal in the young when serum calcidiol is 122 nmol/L (49 ng/mL); this would require a much higher recommended dietary allowance for vitamin D than 5 microg/d (200 IU/d).     

Calcium, vitamin D, and dairy foods and the occurrence of colon cancer in men

To examine the associations between intakes of calcium, Vitamin D, and dairy foods and the risk of colon cancer, the authors analyzed data from a prospective study of 47,935 US male professionals, 40-75 years of age and free of cancer in 1986. Within this cohort, 203 new cases of colon cancer were documented between 1986 and 1992. After adjusting for age and total energy intake, the authors found that the intake of calcium from foods and supplements was inversely associated with colon cancer risk (relative risk (RR) = 0.58, 95% confidence interval (CI) 0.39-087 between high and low intakes of calcium). However, after adjusting for confounding variables, they found that the trend was no longer statistically significant (p = 0.22), and the relative risk for the highest quintile group of intake was attenuated: 0.75 (95% CI 0.48-1.15). Similar results were observed for total vitamin D intake; the age- and energy-adjusted relative risk was 0.54% (95% CI 0/34-0/85) for the highest versus lowest quintile group, and this was attenuated in the multivariate model (RR = 0.66, 95% CI 0.42-1.05). The inverse association was weaker for dietary vitamin D (RR highest vs. lowest quintile = 0.88. 95% CI 0.54-1.42) and strongest for vitamin D arising from vitamin supplements (RR = 0.48, 95% CI 0.22-1.02). Thus, it is possible that other components of multivitamin use rather than vitamin D accounted for the reduction in risk. Consumption of milk and fermented dairy products was not significantly associated with the risk of colon cancer; individuals consuming two or more glasses of "whole" or skim milk per day had a relative risk of 1.09 (95% CI 0.69-1.72), compared with those who consumed "whole or skim milk less than once a month. These prospective data do not support the hypothesis that calcium intake is strongly protective against colon cancer risk, although a modest association cannot be excluded.     

Calcium and magnesium balance in 9-14-y-old children

Few data are available regarding calcium and magnesium absorption and endogenous fecal excretion in children. We used a multitracer stable isotope technique to assess calcium and magnesium balance in 12 boys and 13 girls aged 9-14 y (mean weight: 42 kg) maintained on relatively high calcium intakes (mean: 1310 +/- 82 mg/d). There were no significant differences in absorption of calcium or magnesium from milk between boys and girls. Calcium retention (balance) correlated positively with calcidiol (25-hydroxyvitamin D) concentration (r = 0.48, P = 0.02) and serum alkaline phosphatase activity (r = 0.44, P = 0.03). There was no significant relation between magnesium balance and concentration. When data from this study were combined with our previously reported data, an increase in total calcium absorption was seen for pubertal (Tanner stages 2-4) but not prepubertal (Tanner stage 1) white children over the range of intakes from approximately 750 to 1350 mg/d. Despite intakes similar to the 1989 recommended dietary allowance for magnesium (mean intake: 6.4 +/- 1.2 mg.kg-1.d-1), 11 of the 25 subjects (6 girls and 5 boys) were in negative magnesium balance. We conclude that benefits from higher calcium intakes, < or = 1350 mg/d, were most apparent in pubertal children. In addiction, higher magnesium intakes should be considered for children.     

Zinc content of selected foods

Selected food items appearing on 24-hr. dietary recalls of nineteen volunteers were analyzed for zinc by atomic absorption spectrophotometry. Consistent and reproducible results were obtained for the zinc content of the foods. Values ranged from 0.02 +/- 0.01 mg. zinc per 100 gm. for fruit cocktail to 6.77 +/- 0.03 mg. per 100 gm. for London broil. Foods in the meat group had the highest zinc values (0.40 to 6.77 mg. per 100 gm.), followed by the breads and cereals (0.30 to 2.54 mg. per 100 gm.); milk and milk products (0.36 to 0.49 mg. per 100 gm.); vegetables (0.12 to 0.60 mg. per 100 gm.); and fruits (0.02 to 0.26 mg. per 100 gm.)--in that order. When comparisons with published values for zinc content of foods were possible, there was good agreement with the values obtained in this study. Using the zinc content of the analyzed foods, dietary zinc intakes based on 24-hr. recall records were calculated for the nineteen volunteers. Mean dietary zinc intake was 13.3 +/- 7.6 mg. and showed a high positive correlation to dietary energy (r = 0.85) and protein (r = 0.90) intakes. Analyzed zinc content of two food composites containing beef was twice that of four food composites not containing beef.     

Do exclusively breast-fed infants require extra protein?

It has been argued that the growth rate of exclusively breast-fed infants may be limited by their protein intake. This issue was examined using data from an intervention study in Honduras in which infants were randomly assigned to be exclusively breast-fed for the first 6 mo (EBF; n = 50), or to receive preprepared solid foods (including egg yolk) in addition to breast milk beginning at 4 mo (n = 91). Neither weight gain nor length gain from 4 to 6 mo differed between groups despite a 20% higher protein intake (as well as significantly higher intakes of iron, zinc, calcium, vitamin A, and riboflavine) in the latter group. The 20 infants with the highest protein intakes in that group were matched to 20 EBF infants on the basis of energy intake; protein intake was 1.46 +/- 0.09 versus 1.10 +/- 0.17 g/kg/d, respectively (p < 0.001), but growth rate did not differ between groups. Similarly, the 20 infants with the lowest protein intakes in the EBF group were matched (by energy intake) to 20 infants given solid foods; protein intake was very low in the former compared with the latter (0.81 +/- 0.13 versus 1.04 +/- 0.20 g/kg/d; p < 0.001), yet there was still no difference in growth. Infant morbidity was relatively low and did not influence the results. These analyses indicate that protein intake is not likely to be a limiting factor with regard to growth of breast-fed infants from 4 to 6 mo of age.     

The infrarenal aortic diameter in relation to age: only part of the population in older age groups shows an increase

The aim of the present investigation was to study the relationship between ascorbic acid status during the third trimester of pregnancy and levels of this vitamin in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation). To this end, the pregnancies and lactation periods of fifty-seven healthy women between 18 and 35 years of age (27 (SD 3.7) years) were monitored. Vitamin intake during the third trimester was determined by recording the consumption of foods over 5 d, and by registering the quantities provided by dietary supplements. Ascorbic acid levels in maternal serum during this stage of pregnancy, and in transition and mature milk samples, were determined by spectrophotometry. Those subjects with ascorbic acid intakes below that recommended (80 mg/d) (group L) showed lower consumption of fruit and vegetables than did those with greater intakes (group H). The consumption of ascorbic acid supplements was very low, and was only seen in three group H subjects. The difference in ascorbic acid intake was reflected at serum level. Group L subjects showed significantly lower serum values than did group H subjects (30.1 (SD 36.3) mumol/l compared with 101.1 (SD 168.1) mumol/l). Vitamin intake also influenced the composition of transition milk. Group L subjects showed significantly lower levels of ascorbic acid in milk than did group H subjects (255.5 (SD 220.3) mumol/l compared with 437.8 (SD 288.4) mumol/l). The results of the present study reveal the need to increase the consumption of fruits and vegetables during pregnancy and to monitor maternal ascorbic acid intake and vitamin C status.     

Biochemical markers of calcium and bone metabolism during 18 months of lactation in Gambian women accustomed to a low calcium intake and in those consuming a calcium supplement

The effect of 18 months of lactation on indexes of calcium and bone metabolism was studied in 60 Gambian women accustomed to a very low calcium intake. Half the women consumed a calcium supplement from 10 days postpartum for 52 weeks (supplement, 714 mg Ca/day; total Ca intake, 992 +/- 114 mg/day), and half consumed placebo (total Ca intake, 288 +/- 128 mg/day). Fasting blood and 24-h urine samples were collected at 1.5, 13, 52, and 78 weeks of lactation and analyzed for calciotropic hormones (intact PTH, 1,25-dihydroxyvitamin D, and calcitonin), bone turnover markers (osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline), and plasma minerals (calcium and phosphate). The first months of lactation were associated with increased bone turnover and plasma phosphate, and decreased PTH and 1,25-dihydroxyvitamin D. These effects diminished by 52 weeks, although breast milk volumes remained high. The Gambians had higher PTH, 1,25-dihydroxyvitamin D, and bone formation than British women with a greater customary calcium intake. None of the biochemical indexes was affected by calcium supplementation, with the possible exception of bone alkaline phosphatase (-29% at 52 weeks; P = 0.015). These data demonstrate that lactation-associated changes in calcium and bone metabolism are physiological and are independent of dietary calcium supply in women with very low calcium intakes.     

Relation of calcium, vitamin D, and dairy food intake to ischemic heart disease mortality among postmenopausal women

To investigate whether greater intakes of calcium, vitamin D, or milk products may protect against ischemic heart disease mortality, the authors analyzed data from a prospective cohort study of 34,486 postmenopausal Iowa women 55-69 years old and without a history of ischemic heart disease who completed a dietary questionnaire in 1986. Through 1994, 387 deaths due to ischemic heart disease were documented (International Classification of Diseases, Ninth Revision, codes 410-414, 429.2). The multivariate-adjusted relative risks for the highest versus the lowest quartiles of total calcium, vitamin D, and milk product intakes were as follows: 0.67 (95% confidence interval (CI) 0.47-0.94; p for trend = 0.09) for calcium, 1.41 (95% CI 0.93-2.15; p for trend = 0.12) for vitamin D, and 0.94 (95% CI 0.66-1.35; p for trend = 0.68) for milk products. The relative risk was 0.63 (95% CI 0.40-0.98) for high dietary calcium but no supplemental calcium intake and 0.66 (95% CI 0.36-1.23) for high supplemental calcium but low dietary calcium intake. These results suggest that a higher intake of calcium, but not of vitamin D or milk products, is associated with reduced ischemic heart disease mortality in postmenopausal women, and reduced risk may be achievable whether the higher intake of calcium is attained by diet, supplements, or both.     

Lactose in human nutrition

The disaccharide lactose is naturally present as a component of foods in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. In most people lactase activity decreases at the age of approximately 2 years of age. After this lactose intake can cause symptoms of bloating, flatulence, abdominal pain and diarrhoea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended that these people abandon the consumption of milk and dairy products. However, most lactose-intolerant people are able to digest small amounts of milk (approximately 200 ml). They can also consume cheese without (hard and semi-hard cheese) or only low lactose content (only present in 10% of soft cheese). These products are a very important source of calcium.     

Effect of exercise and dietary restraint on energy intake of reduced-obese women

Self-selected food intake of 15 reduced-obese women living in a metabolic ward was studied for 14 consecutive days to determine the effect of exercise and other metabolic and behavioral variables on energy intake. A choice of prepared food items were offered at breakfast, lunch and dinner, and a variety of additional food items were available continuously 24 h/day. Subjects performed either moderate intensity aerobic exercise (A-EX) (n = 8) expending 354 +/- 76 kcal/session or low intensity resistance weight training (R-EX)(n =7) expending 96 +/- kcal/session, 5 days/week. Mean energy intakes (kcal/day, +/- SEM) of the exercise groups were similar: 1867 +/- 275 for A-EX, 1889 +/- 294 for R-EX. Mean energy intakes of individuals ranged from 49 to 157% of the predetermined level required for weight maintenance. Resting metabolic rate per kg 0.75 and the Eating Inventory hunger score contributed significantly to the between subject variance in energy intake, whereas exercise energy expenditure did not. Regardless of exercise, eight women consistently restricted their energy intake (undereaters), and seven other consumed excess energy (overeaters). Overeaters were distinguished by higher Eating Inventory disinhibition (P = 0.023) and hunger (p = 0.004) scores. The overeaters' diet had a higher fat content 34 +/- 1% (p = 0.007). Also, overeaters took a larger percentage of their daily energy, than that of undereaters, 27 +/- 1 energy intake in the evening, 13 +/- 2%, compared to undereaters, 7 +/- 1% (p = 0.005). We conclude that the Eating Inventory is useful for identifying reduced-obese women at risk of overeating, and these individuals may benefit from dietary counseling aimed at reducing fat intake and evening snacking.     

Impact of breakfast consumption on nutritional adequacy of the diets of young adults in Bogalusa, Louisiana: ethnic and gender contrasts

OBJECTIVE: To evaluate the impact of breakfast consumption patterns on the nutritional adequacy of diets of young adults and determine possible ethnic and gender differences. DESIGN AND SETTING: Cross-sectional survey of young adults in Bogalusa, La. SUBJECTS: Twenty-four-hour dietary recalls were collected from October 1988 through October 1991 on 504 young adults (mean age=23 years, 58% women, 70% white). STATISTICS: Analysis of variance and logistic regression techniques were used to investigate the relationship of breakfast consumption, ethnicity, and gender on dietary adequacy. The P values are from an analysis of variance model that adjusted for gender and ethnicity. RESULTS: Thirty-seven percent of young adults skipped breakfast. Of those who ate breakfast, 75% ate at home, 10% ate a fast-food breakfast, and 15% reported other sources. Mean energy intake from breakfast was 485 kcal; men consumed more energy than women (P<.001), and blacks consumed more energy than whites (P<.01). The breakfast meal provided an average of 13% of energy from protein, 55% from carbohydrate, 14% from sucrose, 34% from fat, and 12% from saturated fat. Whites consumed a breakfast higher in carbohydrate and sucrose than blacks, who consumed a breakfast higher in fat and saturated fat. Variations in breakfast foods consumed explained the racial differences in the nutrient composition of the breakfast meal. Young adults who skipped breakfast had lower total daily intakes of energy (P<.0001), protein per 1,000 kcal (P<.05), and saturated fat per 1,000 kcal (P<.01) than those who consumed breakfast. For all vitamins and minerals studied, a higher percentage of young adults who skipped breakfast did not meet two thirds of the Recommended Dietary Allowance than those who consumed a breakfast. APPLICATIONS: Encouraging consumption of breakfast, along with selection of more healthful breakfast food choices or snacks that are culturally appropriate, may be important strategies for improving the nutritional quality of young adults' diets.     

Energy density of foods affects energy intake in normal-weight women

This study examined the effect of energy density, independent of fat content and palatability, on food and energy intakes. With use of a within-subjects design, normal-weight women (n = 18) were provided with meals for 2 d during each of three test sessions. During lunch, dinner, and an evening snack, subjects were given free access to a main entree varying in energy density (low, medium, or high). The manipulated main entrees were similar in palatability to their counterparts across conditions. Low-energy compulsory (consumption required) side dishes accompanied each meal. Subjects also consumed a standard, compulsory breakfast. Results showed that subjects consumed a similar amount of food (by weight) across the three conditions of energy density. Thus, significantly more energy was consumed in the condition of high energy density (7532 +/- 363 kJ, or 1800 +/- 86 kcal) than in the medium- (6356 +/- 281 kJ, or 1519 +/- 67 kcal) and low- (5756 +/- 178 kJ, or 1376 +/- 43 kcal) energy-density conditions (P < 0.0001). There were no differences in hunger or fullness before meals, after meals, or over the 2 d across conditions. The results from this study indicate that energy density affects energy intake independent of macronutrient content or palatability, suggesting that the overconsumption of high-fat foods may be due to their high energy density rather than to their fat content.     

Consumption of calcium-rich food in the adult population of French-speaking Switzerland and of Tessin

Food intake high in calcium content is important in the development of skeleton and the prevention of osteoporosis. From a public health perspective, it is therefore important to know the dietary calcium intake of a population. Two population surveys in the French and Italian parts of Switzerland (MONICA, 1988-1989, and Geneva, 1991), were combined to study nutritional habits related to calcium intake. A random population sample, aged 35 et 65 years, answered to a 24 hour recall questionnaire, either self-administered (MONICA, cantons of Vaud, Fribourg and Tessin, N = 2734) or by phone (canton of Geneva, N = 475). In the 4 cantons, for the previous day, 60% of participants ate dairy products, particularly whole milk and cheese. They drunk 3-4 dl/day of milk. A significant proportion (10%) of french and italian speaking Swiss did not consume any food high in calcium content. In Geneva, the mean daily calcium intake was 656 mg in men and 489 mg in women. In conclusion 1) eating habits related to calcium intake are similar across cantons; 2) women consume dairy products more frequently than men, but in smaller quantities; 3) about 60% of men and 80% of women do not get the daily amount of calcium recommended for the prevention of osteoporosis.     

The influence of thermic effect of food on satiety

OBJECTIVES: To evaluate energy expenditure after three isoenergetic meals of different nutrient composition and to establish the relationship between the thermic effect of food (TEF), subsequent energy intake from a test meal and satiety sensations related to consumption. DESIGN: The study employed a repeated measures design. Ten subjects received, in a randomized order, three meals of 2331+/-36 kJ (557+/-9 kcal). About 68% of energy from protein in the high protein meal (HP), 69% from carbohydrate in the high carbohydrate meal (HC) and 70% from fat in the high fat meal (HF). SETTING: The experiments were performed at the University of Milan. Subjects: Ten normal body-weight healthy women. METHODS: Energy expenditure was measured by indirect calorimetric measurements, using an open-circuit ventilated-hood system; intake was assessed 7h later by weighing the food consumed from a test meal and satiety sensations were rated by means of a satiety rating questionnaire. RESULTS: TEF was 261+/-59, 92+/-67 and 97+/-71 kJ over 7 h after the HP, HC and HF meals, respectively. The HP meal was the most thermogenic (P < 0.001) and it determined the highest sensation of fullness (P=0.002). There were no differences in the sensations and thermic effect between fat and carbohydrate meals. A significant relationship linked TEF to fullness sensation (r=0.41, P=0.025). Energy intake from the test meal was comparable after HP, HC and HF meals. CONCLUSIONS: Our results suggest that TEF contributes to the satiating power of foods.     

A highly polymorphic microsatellite within intron 5 of the porcine 54/56 kDa vacuolar H(+)-ATPase subunit gene (V-ATPase)

OBJECTIVE: To assess the validity of a short calcium food frequency questionnaire (FFQ) for use in young children. DESIGN: Calcium intake from an estimated 4 d diet record (4DDR) was compared with the calcium intake from a 35 item FFQ specifically designed to assess habitual calcium intake and previously validated for adult women. SUBJECTS: Forty-one girls and 26 boys aged 3-6 y recruited by advertisement for studies of nutrition and bone health. RESULTS: Mean (s.d.) calcium intakes were 798 mg (271) and 942 mg (419) for the 4DDR and FFQ respectively, (r = 0.52). Mean difference (s.d. of difference) in calcium intake between the two methods was 144 mg (355), showing that the FFQ may estimate calcium intakes 565 mg below to 854 mg above diet record values. 84% of subjects when classified by the 4DDR fell into the same or adjacent quartiles when classified by the FFQ. Only two subjects were classified in extreme quartiles for the two methods. The FFQ correctly identified 68% of children with recorded intakes less than 800 mg. CONCLUSIONS: The short calcium FFQ tended to overestimate actual calcium intakes in young children, and would not be appropriate for determining calcium intake of individuals. However, the FFQ demonstrated good ability to classify subjects into extremes of calcium intake. Moreover, the predictive value of the FFQ in identifying children with intakes below the current recommended intake of 800 mg was reasonably high (79%).     

Calcium intake and the incidence of forearm and hip fractures among men

High calcium intakes are thought to be associated with strong bones and lower risk of fractures. However, findings from epidemiologic studies have not been consistent. In addition, the vast majority of such studies were conducted among women, leading to a relative lack of data concerning men. The objective of this study therefore was to investigate the relation between adult calcium intake and risk of fractures among men in the Health Professionals Follow-up Study (HPFS). During 331,234 person-years of follow-up over an 8-y period, 201 forearm and 56 hip fractures due to low or moderate trauma were reported among 43,063 men 40-75 y of age in 1986 when they first completed a questionnaire about diet and lifestyle factors. After controlling for age, smoking status, body mass index (BMI), physical activity, alcohol consumption and total energy intake, the relative risk (RR) of forearm fractures for men in the highest quintile of calcium intake (from foods plus supplements) compared with those in the lowest quintile was 0.98 [95% confidence interval (CI) = 0.59-1.61; P for trend = 0.78]; for hip fractures, the comparable RR was 1.19 (95% CI = 0.42-3.35; P for trend = 0.58). Relative risks for consuming >2.5 glasses (600 mL) of milk per day compared with one (240 mL) or fewer per week were 1.06 (95% CI = 0.69-1.62; P for trend = 0.82) for forearm fractures and 0.97 (95% CI = 0.39-2.42; P for trend = 0.56) for hip fractures. In conclusion, these results do not support a relation between calcium intake and the incidence of forearm or hip fractures in men.     

Dietary calcium, calcium supplementation, and blood pressure in African American adolescents

BACKGROUND: Intake of calcium from the diet is inversely associated with blood pressure in observational studies and animal models but randomized trials in humans have found only small effects of calcium supplementation on blood pressure. A blood pressure-lowering effect of calcium supplementation may thus be restricted to persons with a low intake of calcium from the diet and specific genetic or other characteristics. OBJECTIVE: A randomized trial was conducted to assess the effect of calcium supplementation on blood pressure in African American adolescents. Rapid growth during adolescence may increase calcium requirements, and avoidance of milk and milk products by some African Americans can result in low intake of calcium. DESIGN: One hundred sixteen adolescents (65 girls, 51 boys; mean age: 15.8 y) were given calcium (1.5 g/d) or placebo for 8 wk in a randomized, double-blind, crossover design. Blood pressure was measured after 2, 4, and 8 wk. Dietary calcium was determined with a validated food-frequency questionnaire. RESULTS: The net effect (+/-SE) of calcium supplementation on diastolic blood pressure was a reduction of 1.9 +/- 1.1 mm Hg (P = 0.04, one-tailed t test). Blood pressure reduction was greater in adolescents with lower intake of calcium from the diet (P = 0.003, one-tailed t test for interaction): -4.9 +/- 1.6, -2.3 +/- 1.6, and 1.4 +/- 1.8 mm Hg for change in the lower (0.024-0.067 g Ca/MJ), middle (0.069-0.091 g Ca/MJ), and upper (0.093-0.217 g Ca/MJ) tertiles, respectively. No main effect on systolic blood pressure was detected. CONCLUSION: These findings suggest that calcium supplementation may lower diastolic blood pressure in African American adolescents with low dietary intakes of calcium.