Estimation of total usual calcium and vitamin D intakes in the United States

Life-course approach to nutrition

This narrative review summarizes the role that nutrition plays in the development and maintenance of a healthy skeleton throughout the life-course. Nutrition has a significant influence on bone health throughout the life cycle. This narrative review summarizes current knowledge and guidance pertaining to the development and maintenance of a healthy skeleton. The primary objectives proposed for good bone health at the various stages of life are the following: Children and adolescents: achieve genetic potential for peak bone mass Adults: avoid premature bone loss and maintain a healthy skeleton Seniors: prevention and treatment of osteoporosis Findings from cohort studies, randomized controlled trials, systematic reviews and meta-analyses, in addition to current dietary guidelines, are summarized with the intention of providing clear nutritional guidance for these populations and pregnant women.

Intakes of Calcium and Phosphorus and Calculated Calcium-to-Phosphorus Ratios of Older Adults: NHANES 2005-2006 Data

Background: High intakes of dietary phosphorus (P), relative to calcium (Ca) intake, are associated with a lower calcium:phosphorus ratio (Ca:P) ratio which potentially has adverse health effects, including arterial calcification, bone loss, and death. A substantial percentage of older adults (50 to 70 and 71 plus years) who have a higher risk of fracture rate than younger adults typically have low intakes of dietary Ca that are dominated by higher intakes of dietary P from natural and fortified foods, and lower Ca:P ratios than desirable. Objective: This investigation was undertaken to examine Ca and P intakes and the resulting Ca:P ratios (by mass) across gender and older adult age groups, using data from the National Health and Nutrition Examination Survey (NHANES) 2005–2006. Design: NHANES data are based on a cross-sectional sample of the non-institutionalized United States (US) population within various regions. This sample is selected to be representative of the entire US population at all ages. National Cancer Institute (NCI) methods and SAS survey procedures were used for analyses. Ca:P ratios were calculated using total Ca from both foods and supplements, whereas P intakes were calculated from food composition values and supplements. The amounts of P additives in processed foods are not available. Results: Mean Ca and P intakes demonstrated lower intakes of Ca and higher intakes of P compared to current Recommended Dietary Allowances (RDAs). The Ca:P ratios in older male and female adults were influenced by both low-Ca and high-P dietary consumption patterns. Conclusions: Both low total Ca intakes and high P amounts contribute to lower Ca:P ratios, i.e., ~0.7:1.0, in the consumption patterns of older adults than is recommended by the RDAs, i.e., ~1.5:1.0. Whether Ca:P ratios lower than recommended contribute to increased risk of bone loss, arterial calcification, and all-cause mortality cannot be inferred from these data. Additional amounts of chemical P additives in the food supply may actually reduce even further the Ca:P ratios of older adults of both genders, but, without P additive data from the food industry, calculation of more precise ratios from NHANES 2005–2006 data is not possible.

Calcium phosphate supplementation increases faecal Lactobacillus spp. in a randomised trial of young adults

The aim of the studies was to determine the effects of calcium carbonate and calcium phosphate supplementation on faecal Lactobacillus spp., with and without a probiotic supplement, in healthy adults. Study 1 comprised of a randomised, double-blind, crossover design; participants (n=15) received 2 capsules/d of 250 mg elemental calcium as calcium carbonate (Ca1) and calcium phosphate (Ca2) each for 2-week periods, with 2-week baseline and washout periods. Study 2 was a randomised, double-blind, crossover design; participants (n=17) received 2 capsules/d of Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011 (probiotic) alone, the probiotic with 2 capsules/d of Ca1, and probiotic with 2 capsules/d of Ca2 each for 2-week periods with 2-week baseline and washout periods. In both studies, stools were collected during the baseline, intervention and washout periods for Lactobacillus spp. quantification and qPCR analyses. Participants completed daily questionnaires of stool frequency and compliance. In Study 1, neither calcium supplement influenced viable counts of resident Lactobacillus spp., genome equivalents of lactic acid bacteria or stool frequency. In Study 2, faecal Lactobacillus spp. counts were significantly enhanced from baseline when the probiotic was administered with Ca2 (4.83±0.30, 5.79±0.31) (P=0.02), but not with Ca1 (4.98±0.31) or with the probiotic alone (5.36±0.31, 5.55±0.29) (not significant). Detection of L. helveticus R0052 and L. rhamnosus R0011 was significantly increased with all treatments, but did not differ among treatments. There were no changes in weekly stool frequency. Calcium phosphate co-administration may increase gastrointestinal survival of orally-administered Lactobacillus spp.

Should we prescribe calcium or vitamin D supplements to treat or prevent osteoporosis?

Systematic reviews of randomized, controlled trials (RCTs) are considered the highest level of evidence to inform clinical practice. Meta-analyses of large RCTs of calcium and/or vitamin D supplements completed in the last 15 years provide strong evidence for clinical recommendations. These meta-analyses with data for > 50,000 older adults reported that calcium with or without vitamin D has only weak, inconsistent effects on fracture, and that vitamin D without calcium has no effect on fracture. Only one RCT of co-administered calcium and vitamin D in frail, institutionalized, elderly women with low dietary calcium intake and vitamin D levels showed significant reductions in fracture risk. These RCTs have also reported previously unrecognized adverse events of calcium supplements including kidney stones, myocardial infarction, hypercalcemia, and hospitalization with acute gastrointestinal symptoms. The small risk of these important adverse effects, together with the moderate risk of minor side-effects such as constipation, probably outweighs any benefits of calcium supplements on fracture. These data suggest the role for calcium and vitamin D supplements in osteoporosis management is very limited. Neither calcium nor vitamin D supplements should be recommended for fracture prevention in community-dwelling adults, although vitamin D should be considered for prevention of osteomalacia in at-risk individuals.

Egg Intake and Dietary Quality among Overweight and Obese Mexican-American Postpartum Women

Despite their low cost and high nutrient density, the contribution of eggs to nutrient intake and dietary quality among Mexican-American postpartum women has not been evaluated. Nutrient intake and dietary quality, as assessed by the Healthy Eating Index 2010 (HEI-2010), were measured in habitually sedentary overweight/obese (body mass index (BMI) = 29.7 ± 3.5 kg/m²) Mexican-American postpartum women (28 ± 6 years) and compared between egg consumers (n = 82; any egg intake reported in at least one of three 24-h dietary recalls) and non-consumers (n = 57). Egg consumers had greater intake of energy (+808 kJ (193 kcal) or 14%; p = 0.033), protein (+9 g or 17%; p = 0.031), total fat (+9 g or 19%; p = 0.039), monounsaturated fat (+4 g or 24%; p = 0.020), and several micronutrients than non-consumers. Regarding HEI-2010 scores, egg consumers had a greater total protein foods score than non-consumers (4.7 ± 0.7 vs. 4.3 ± 1.0; p = 0.004), and trends for greater total fruit (2.4 ± 1.8 vs. 1.9 ± 1.7; p = 0.070) and the total composite HEI-2010 score (56.4 ± 12.6 vs. 52.3 ± 14.4; p = 0.082). Findings suggest that egg intake could contribute to greater nutrient intake and improved dietary quality among postpartum Mexican-American women. Because of greater energy intake among egg consumers, recommendations for overweight/obese individuals should include avoiding excessive energy intake and incorporating eggs to a nutrient-dense, fiber-rich dietary pattern.

Vitamin D in Foot and Ankle Fracture Healing: A Literature Review and Research Design

Vitamin D is a generic name for a group of essential vitamins, or secosteroids, important in calcium homeostasis and bone metabolism. Specifically, efficacy of vitamin D with regard to bone healing is in question. A literature review was performed, finding mostly large studies involving vitamin D effects on prevention of fractures and randomized animal model studies consisting of controlled fractures with vitamin D interventions. The prevention articles generally focus on at-risk populations, including menopausal women and osteoporotic patients, and also most often include calcium in the treatment group. Few studies look at vitamin D specifically. The animal model studies often focus more on vitamin D supplementation; however the results are still largely inconclusive. While recent case reports appear promising, the ambiguity of results on the topic of fracture healing suggests a need for more, higher level research. A novel study design is proposed to help determine the efficacy on vitamin D in fracture healing.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Systematic Review.

Calcium intake and risk of fracture: systematic review

OBJECTIVE

To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures.

DESIGN

Systematic review of randomised controlled trials and observational studies of calcium intake with fracture as an endpoint. Results from trials were pooled with random effects meta-analyses.

DATA SOURCES

Ovid Medline, Embase, PubMed, and references from relevant systematic reviews. Initial searches undertaken in July 2013 and updated in September 2014.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials or cohort studies of dietary calcium, milk or dairy intake, or calcium supplements (with or without vitamin D) with fracture as an outcome and participants aged >50.

RESULTS

There were only two eligible randomised controlled trials of dietary sources of calcium (n=262), but 50 reports from 44 cohort studies of relations between dietary calcium (n=37), milk (n=14), or dairy intake (n=8) and fracture outcomes. For dietary calcium, most studies reported no association between calcium intake and fracture (14/22 for total, 17/21 for hip, 7/8 for vertebral, and 5/7 for forearm fracture). For milk (25/28) and dairy intake (11/13), most studies also reported no associations. In 26 randomised controlled trials, calcium supplements reduced the risk of total fracture (20 studies, n=58,573; relative risk 0.89, 95% confidence interval 0.81 to 0.96) and vertebral fracture (12 studies, n=48,967. 0.86, 0.74 to 1.00) but not hip (13 studies, n=56,648; 0.95, 0.76 to 1.18) or forearm fracture (eight studies, n=51,775; 0.96, 0.85 to 1.09). Funnel plot inspection and Egger's regression suggested bias toward calcium supplements in the published data. In randomised controlled trials at lowest risk of bias (four studies, n=44,505), there was no effect on risk of fracture at any site. Results were similar for trials of calcium monotherapy and co-administered calcium and vitamin D. Only one trial in frail elderly women in residential care with low dietary calcium intake and vitamin D concentrations showed significant reductions in risk of fracture.

CONCLUSIONS

Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures. Evidence that calcium supplements prevent fractures is weak and inconsistent.

Micronutrient Intake in Healthy Toddlers: A Multinational Perspective

Adequate nutrient intake during early childhood is of particular importance for optimal growth and future health. However, cross-national comparative research on nutrient intake of toddlers is still limited. We conducted a literature review to examine the nutrient intake in healthy toddlers from some of the world's most populous nations currently on different stages of socioeconomic development: Brazil, Germany, Russia and the United States. We aimed to identify national surveys reporting mean intakes of the following nutrients: vitamins A, D, E, folate, calcium, iron and zinc. To calculate the prevalence of inadequate nutrient intake, we used a modified version of the Estimated Average Requirement cut-point method. Overall, five studies with 6756 toddlers were eligible for inclusion in this review. In countries where data were available, a prevalence of inadequate intake higher than 20% was found for vitamins A, D, E and calcium. In Germany, folate intake also appeared to be inadequate. The results of our review indicate that inadequate micronutrient intake in toddlers might be a global challenge affecting also affluent countries. However, to explore the full scope of this important public health issue joint efforts of researchers worldwide are needed to combine existing data and fill in data gaps.

Delivery of a Vitamin D Intervention in Homebound Older Adults Using a Meals-on-Wheels Program: A Pilot Study

OBJECTIVES

To assess the feasibility of a vitamin D intervention delivered through a Meals-on-Wheels (MOW) program to improve 25-hydroxyvitamin D (25(OH)D) concentrations and reduce falls in homebound older adults.

DESIGN

Single-blind, cluster randomized trial.

SETTING

MOW, Forsyth County, North Carolina.

PARTICIPANTS

Community-dwelling homebound adults aged 65 to 102 (N = 68).

INTERVENTION

MOW clients were randomized to vitamin D3 (100,000 IU/month; n = 38) or active placebo (400 IU vitamin E/month; n = 30) according to MOW delivery route.

MEASUREMENTS

Serum 25(OH)D was assessed at baseline and 5-month follow-up; proportions of participants in 25(OH)D categories were compared using Fisher exact test. Falls were assessed using monthly fall calendars, and rate of falls was estimated using negative binomial generalized estimating equation models.

RESULTS

Mean ± standard deviation 25(OH)D concentrations were 20.9 ± 11.5 ng/mL at baseline, with 57% having 25(OH)D concentrations less than 20 ng/mL. Retention and adherence were high (>90%). After the 5-month intervention, only one of 34 participants randomized to vitamin D3 had 25(OH)D concentrations less than 20 ng/mL, compared with 18 of 25 participants randomized to placebo (P < .001). In unadjusted analyses, the rate of falls over 5 months was not significantly different according to intervention group (risk ratio (RR) = 0.48, 95% confidence interval (CI) = 0.19-1.19), but after adjustment for sex, race, season of year, baseline 25(OH)D status, and history of falls, participants randomized to vitamin D3 had a lower rate of falling than those randomized to placebo (RR = 0.42, 95% CI = 0.21-0.87).

CONCLUSION

A vitamin D intervention delivered through MOW was feasible, resulting in improvements in 25(OH)D concentrations and a lower rate of falls in adjusted analyses. Further research is needed to validate the reduction in falls from this type of intervention.

Effect of High-Calcium Diet on Coronary Artery Disease in Ossabaw Miniature Swine With Metabolic Syndrome

Background

Calcium is a shortfall essential nutrient that has been a mainstay of osteoporosis management. Recent and limited findings have prompted concern about the contribution of calcium supplementation to cardiovascular risk. A proposed mechanism is through the acceleration of coronary artery calcification. Determining causality between calcium intake and coronary artery calcification has been hindered by a lack of sensitive methodology to monitor early vascular calcium accumulation. The primary study aim was to assess the impact of high calcium intake on coronary artery calcification using innovative calcium tracer kinetic modeling in Ossabaw swine with diet-induced metabolic syndrome. Secondary end points (in vitro wire myography, histopathology, intravascular ultrasound) assessed coronary disease.

Methods and Results

Pigs (n =24; aged ≈15 months) were fed an atherogenic diet with adequate calcium (0.33% by weight) or high calcium (1.90% from calcium carbonate or dairy) for 6 months. Following 5 months of feeding, all pigs were dosed intravenously with ⁴¹Ca, a rare isotope that can be measured in serum and tissues at a sensitivity of 10⁻¹⁸ mol/L by accelerator mass spectrometry. Kinetic modeling evaluated early coronary artery calcification using ⁴¹Ca values measured in serial blood samples (collected over 27 days) and coronary artery samples obtained at sacrifice. Serum disappearance of ⁴¹Ca and total coronary artery ⁴¹Ca accumulation did not differ among groups. Secondary end points demonstrated no treatment differences in coronary artery disease or function.

Conclusion

There was no detectable effect of high calcium diets (from dairy or calcium carbonate) on coronary artery calcium deposition in metabolic syndrome swine.

Dietary intake of calcium and magnesium and the metabolic syndrome in the National Health and Nutrition Examination (NHANES) 2001-2010 data

Higher dietary intakes of Mg and Ca, individually, have been associated with a decreased risk for the metabolic syndrome (MetSyn). Experimental studies suggest that a higher intra-cellular ratio of Ca:Mg, which may be induced by a diet high in Ca and low in Mg, may lead to hypertension and insulin resistance. However, no previous epidemiological studies have examined the effects of the combined intake of Mg and Ca on MetSyn. Thus, we evaluated the association between dietary intakes of Ca and Mg (using 24-h recalls), independently and in combination, and MetSyn in the National Health and Nutrition Examination Study 2001-2010 data, which included 9148 adults (4549 men and 4599 women), with complete information on relevant nutrient, demographic, anthropometric and biomarker variables. We found an inverse association between the highest (>355 mg/d) v. the lowest (<197 mg/d) quartile of Mg and MetSyn (OR 0.70; 95% CI 0.57, 0.86). Women who met the RDA for both Mg (310-320 mg/d) and Ca (1000-1200 mg/d) had the greatest reduced odds of MetSyn (OR 0.59; 95% CI 0.45, 0.76). In men, meeting the RDA for Mg (400-420 mg/d) and Ca (1000-1200 mg/d), individually or in combination, was not associated with MetSyn; however, men with intakes in the highest quartile for Mg (≥ 386 mg/d) and Ca (≥ 1224 mg/d) had a lower odds of MetSyn (OR 0.74; 95% CI 0.59, 0.93). Our results suggest that women who meet the RDA for Mg and Ca have a reduced odds of MetSyn but men may require Ca levels higher than the RDA to be protected against MetSyn.

Self-reported calcium use in a cohort of postmenopausal women receiving osteoporosis therapy: results from POSSIBLE US™

Calcium use was common and remained high among women on osteoporosis therapy. Use of calcium-supplemented pharmacologic therapy increased from 65.1 to 76.0% in these women (mean follow-up, 27.5 months). Over 12 months, calcium discontinuation was fairly similar among women using calcium only (23.7%) and women supplementing pharmacologic therapy with calcium (22.5%).

INTRODUCTION

Calcium has an important role in bone health. This study describes calcium use and persistence in a postmenopausal osteoporosis treatment cohort.

METHODS

Subject-reported calcium use was analyzed for 3,722 participants of the Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US(TM)) who used calcium either as their sole osteoporosis treatment (calcium only) or to supplement pharmacologic osteoporosis therapy (supplementers). Descriptive analyses were conducted. Kaplan-Meier methods were used to estimate the probability of discontinuing calcium therapy, and logistic regression was used to assess associations (age-adjusted odds ratios) between healthy behaviors and calcium use.

RESULTS

At entry, there were 711 calcium-only subjects and 1,960 of 3,011 subjects on pharmacologic osteoporosis therapy also supplementing with calcium (supplementers). The percentage of supplementers increased from 65.1 to 76.0% during follow-up (mean, 27.5 months). During the first 12 months on study, the probability of calcium discontinuation was 23.7% (95 % confidence interval [CI], 20.7 - 27.0) among calcium-only subjects and 22.5% (95% CI, 20.7-24.5) among supplementers. Supplementers who discontinued pharmacologic therapy were more likely to discontinue calcium than supplementers who continued pharmacologic therapy (34.9 versus 14.8%). Overall 54.2% of calcium-only subjects who discontinued calcium and 42.3% of supplementers who discontinued calcium resumed calcium use during follow-up. Regular exercise was positively correlated with calcium use at study entry.

CONCLUSIONS

Calcium supplementation in pharmacologically treated subjects increased over time. Persistence with calcium was high. Discontinuation of pharmacologic osteoporosis therapy was associated with an increased likelihood of discontinuing calcium use.

Total, dietary, and supplemental calcium intake and mortality from all-causes, cardiovascular disease, and cancer: A meta-analysis of observational studies

AIMS

This systematic review and meta-analysis of observational studies was conducted to summarize the evidence on the association between calcium intake and mortality.

METHODS AND RESULTS

PubMed, Institute for Scientific Information (ISI) (Web of Science), SCOPUS, SciRUS, Google Scholar, and Excerpta Medica dataBASE (EMBASE) were searched to identify related articles published through May 2014. We found 22 articles that assessed the association between total, dietary, and supplementary intake with mortality from all-causes, cardiovascular disease (CVD), and cancer. Findings from this meta-analysis revealed no significant association between total and dietary calcium intake and mortality from all-causes, CVD, and cancer. Subgroup analysis by the duration of follow-up revealed a significant positive association between total calcium intake and CVD mortality for cohort studies with a mean follow-up duration of >10 years (relative risk (RR): 1.35; 95% confidence interval (CI): 1.09-1.68). A significant inverse association was seen between dietary calcium intake and all-cause (RR: 0.84; 95% CI: 0.70-1.00) and CVD mortality (RR: 0.88; 95% CI: 0.78-0.99) for studies with a mean follow-up duration of ≤10 years. Although supplemental calcium intake was not associated with CVD (RR: 0.95; 95% CI: 0.82-1.10) and cancer mortality (RR: 1.22; 95% CI: 0.81-1.84), it was inversely associated with the risk of all-cause mortality (RR: 0.91; 95% CI: 0.88-0.94).

CONCLUSIONS

We found a significant relationship between the total calcium intake and an increased risk of CVD mortality for studies with a long follow-up time and a significant protective association between dietary calcium intake and all-cause and CVD mortality for studies with a mean follow-up of ≤10 years. Supplemental calcium intake was associated with a decreased risk of all-cause mortality.

Vitamin D and Age-Related Health Outcomes: Movement, Mood, and Memory

It has long been recognized that vitamin D plays an important role in calcium homeostasis and musculoskeletal health. More recent evidence supports a role of vitamin D in physical and cognitive function and depressive symptoms through direct effects on skeletal muscle and the brain as well as indirectly through its reported roles in chronic conditions such as cardiovascular disease and diabetes, conditions that frequently lead to declines in physical and cognitive function and depressed mood. The purpose of this review is to summarize the prospective cohort and randomized controlled trial evidence for vitamin D on physical and cognitive function and depressed mood in older adults. Results from both prospective cohort studies and randomized controlled trials of vitamin D supplementation are mixed. Thus, controversy remains over the optimal vitamin D concentration for physical and cognitive function and depressed mood and whether vitamin D supplementation is beneficial for these outcomes.

Prevalence of Vitamin D Insufficiency and Deficiency among Young Physicians at University District Hospital in San Juan, Puerto Rico

Vitamin D has been attracting increased attention because of higher prevalences of vitamin D insufficiency and deficiency than expected in areas with sufficient sun exposure. Even though sunlight exposure and diet are the main determinants of vitamin D status, other factors, such as age, race, the use (or not) of sunscreen, medications, and malabsorptive conditions, also affect vitamin D levels. Recent studies have found high prevalences of vitamin D deficiency and insufficiency in different populations. However, there are limited data regarding the prevalence of vitamin D deficiency and insufficiency in Puerto Rico. To shed more light on the subject, we evaluated a sample of 51 internal medicine residents and research fellows, aged from 25 to 39 years at the University District Hospital in San Juan, Puerto Rico, doing so by means of a questionnaire that explored basic socio demographic and lifestyle characteristics and collected anthropometric data; in addition, we obtained blood samples in order to determine 25-hydroxyvitamin D levels. The median 25-hydroxyvitamin D level was 21 ng/mL (range, 7-38 ng/mL). Forty-five participants (88.2%) had 25-hydroxyvitamin D concentrations of lower than 30 ng/mL. We found vitamin D deficiencies in 43.1% of the population and insufficiencies in 45.1%. Contributory factors to our findings include limited exposure to sunlight during periods of high sun intensity, increased body mass index, and a limited area of the body being exposed to sunlight. A relationship between reduced physical activity levels and hypovitaminosis D was also found. Both calcium intake and vitamin D intake, which were markedly below recommended daily allowances, were positively correlated with 25-hydroxy vitamin D levels, but with a weak association.

Recommendations for Healthy Nutrition in Female Endurance Runners: An Update

The purpose of this review is to present the basic principles of a healthy nutrition in female endurance runner enriched by the latest scientific recommendations. Female endurance runners are a specific population of athletes who need to take specifically care of daily nutrition due to the high load of training and the necessity to keep a rather low body mass. This paradoxical situation can create some nutritional imbalances and deficiencies. Female endurance athletes should pay attention to their total energy intake, which is often lower than their energy requirement. The minimal energy requirement has been set to 45 kcal/kg fat free mass/day plus the amount of energy needed for physical activity. The usual recommended amount of 1.2–1.4 g protein/kg/day has recently been questioned by new findings suggesting that 1.6 g/kg/day would be more appropriate for female athletes. Although a bit less sensitive to carbohydrate loading than their male counterparts, female athletes can benefit from this nutritional strategy before a race if the amount of carbohydrates reaches 8 g/kg/day and if their daily total energy intake is sufficient. A poor iron status is a common issue in female endurance runners but iron-enriched food as well as iron supplementation may help to counterbalance this poor status. Finally, they should also be aware that they may be at risk for low calcium and vitamin D levels.

Consumption of calcium-fortified cereal bars to improve dietary calcium intake of healthy women: randomized controlled feasibility study

Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day) (intervention) to their usual diet and Group II continued their usual diet (control). At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d) when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001) or control diets (775 mg/d, P = 0.0001) periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01508689.

Changing Incidence of Serum 25-Hydroxyvitamin D Values Above 50 ng/mL: A 10-Year Population-Based Study

OBJECTIVE

To determine the incidence trend of 25-hydroxyvitamin D (25(OH)D) values above 50 ng/mL and associated toxicity.

PATIENTS AND METHODS

We conducted a retrospective population-based study in Olmsted County, Minnesota, in the 10-year period from January 1, 2002, through December 31, 2011, by using the Rochester Epidemiology Project. Individuals were eligible if they resided in Olmsted County during the study period and had a measured 25(OH)D value above 50 ng/mL. The date of the first 25(OH)D value above 50 ng/mL was considered the index date for incidence determination. Hypercalcemia, the primary vitamin D toxicity, was considered potentially associated with the 25(OH)D concentration if it was measured within 3 months of the 25(OH)D measurement, and such cases had a medical record review.

RESULTS

Of 20,308 total 25(OH)D measurements, 1714 (8.4%), 123 (0.6%), and 37 (0.2%) unique persons had 25(OH)D values above 50, 80 and above, and 100 ng/mL and above, respectively. The age- and sex-adjusted incidence of 25(OH)D values above 50 ng/mL increased from 9 to 233 cases per 100,000 person-years from 2002 to 2011 (P<.001), respectively, and was greatest in persons aged 65 years and older (P<.001) and in women (P<.001). Serum 25(OH)D values were not significantly related to serum calcium values (P=.20) or with the risk of hypercalcemia (P=.24). A medical record review identified 4 cases (0.2%) in whom 25(OH)D values above 50 ng/mL were temporally associated with hypercalcemia, but only 1 case had clinical toxicity associated with the highest observed 25(OH)D value of 364 ng/mL.

CONCLUSION

The incidence of 25(OH)D values above 50 ng/mL increased significantly between 2002 and 2011 without a corresponding increase in acute clinical toxicity.

Dietary calcium and Framingham Risk Score in vitamin D deficient male (KNHANES 2009-2011)

PURPOSE

The association between excess calcium intake and cardiovascular mortality has already been reported. In the present study, we investigated the relation between dietary calcium intake and Framingham Risk Score (FRS) according to serum 25-hydroxyvitamin D [25(OH)D] status.

MATERIALS AND METHODS

A total of 7809 subjects (3452 males and 4357 female) aged over 40 years were selected for this cross-sectional study from data obtained from the Korea National Health and Nutrition Examination Survey (2008-2011). Daily dietary calcium intake was categorized into <300, 300-600, 600-900, 900-1200, and >1200 mg/day and serum 25(OH)D concentration classified into <50, 50-75, >75 mmol/L. The FRS was compared by the daily dietary calcium intake categories according to 25(OH)D concentration after adjustment with relevant variables in both genders.

RESULTS

Higher FRS was observed in males with both <300 mg and >1200 mg of dietary calcium intake and females with <300 mg of dietary calcium intake without adjustment. The significantly higher FRS remained in the <300 mg and >1200 mg of dietary calcium intake groups in both genders after adjustments for relevant variables. FRS was significantly higher in the group with >1200 mg of dietary calcium intake and serum 25(OH)D <50 nmol/L, which was the male only vitamin D deficient group.

CONCLUSION

Very low (<300 mg/day) and excess (>1200 mg/day) dietary calcium intake were related with higher FRS in both genders. In particular, higher FRS was observed in the excess (>1200 mg/day) dietary calcium intake male group under vitamin D deficiency (<50 nmol/L).

Small Increments in Vitamin D Intake by Irish Adults over a Decade Show That Strategic Initiatives to Fortify the Food Supply Are Needed

BACKGROUND

Food fortification could be an effective method of increasing vitamin D intakes and preventing deficiency with minimal risk of excessive dosing.

OBJECTIVE

Secular trends in vitamin D intakes were examined over a 10-y period.

METHODS

We compared vitamin D intakes among 18- to 64-y-old adults from the base diet, fortified foods, and supplements in 2 nationally representative dietary surveys in 1999 and 2009 implemented using the same methodology.

RESULTS

There was a slight increase in the median (IQR) intake of vitamin D from 2.9 (3.2) to 3.5 (3.7) μg/d (mean ± SD, 4.3 ± 4.0 to 5.0 ± 6.4 μg). The median (IQR) intake from the base diet was 2.3 (1.6) μg/d in 1999 and 2.1 (1.8) μg/d in 2009. In vitamin D supplement users, median (IQR) intakes were 7.6 (6.7) and 8.7 (7.2) μg/d and the prevalence of inadequacy decreased from 67% to 57% in 2009. Although the consumption of vitamin D-containing supplements was similar in the 2 surveys (17% and 16%), the use of calcium-vitamin D supplements increased from 3% to 10% among women aged 50-64 y. The prevalence of fortified food consumption was also similar at 60%, and median (IQR) vitamin D intakes in consumers were 2.9 (2.2) and 3.7 (2.9) μg/d in 1999 and 2009, respectively. Mathematical modeling of food fortification using modified vitamin D composition data showed that there is potential to increase vitamin D intakes at the lower end of the distribution, without increasing the risk of exceeding the Tolerable Upper Intake Level.

CONCLUSIONS

We report small increases in vitamin D intakes among Irish adults over a decade of focus on vitamin D and in the context of a voluntary fortification policy. Strategic management of vitamin D in the food supply is required to yield measurable benefits.

Prevalence of 25-hydroxyvitamin D₂ in Western New York: a 3-year study

BACKGROUND

We evaluated the distribution of 25OH-D2 and 25OH-D3 in a general patient population in Western New York to provide insights into how common detectable vitamin D2 is among samples from a general patient population.

METHODS

Serum 25OH-D2 and 25OH-D3 results measured by LC-MS/MS from June 2009 to December 2012 were retrospectively analyzed.

RESULTS

A total of 266,269 serum tests were included for analysis. The percentage of tests with 25OH-D2 levels above the assay limit of quantitation (LoQ) decreased from 32% to 17% over the course of the study period. The percentage of tests with 25OH-D2 levels higher than those of 25OH-D3 decreased from 21% to 12%. Sixty-seven percent of the test results with 25OH-D2 levels above the LoQ had serum concentrations of 25OH-D2 higher than those of 25OH-D3.

CONCLUSION

Prevalence of tests with quantifiable 25OH-D2 decreased over time and yet 17% of them still had detectable levels of 25OH-D2, 67% of which had 25OH-D2 levels higher than 25OH-D3. To achieve accurate 25-hydroxyvitamin D measurement, clinical laboratories should assess the accuracy of their assays, and if necessary, determine the local prevalence of 25OH-D2 to determine if mass spectrometry is the platform of choice to assess vitamin D deficiency.

Acute effects of calcium citrate with or without a meal, calcium-fortified juice and a dairy product meal on serum calcium and phosphate: a randomised cross-over trial

Ca supplements, but not dietary Ca, have been associated with increased cardiovascular risk. This difference could be related to differences in their acute effects on serum Ca. We therefore examined the effects of Ca from different sources on serum Ca and phosphate in a randomised, cross-over trial of ten women (mean age of 69 years). Fasting participants received a single dose of 500 mg of Ca as citrate, citrate with a meal, fortified juice or a dairy product meal, with at least 6 d between each intervention. Blood was sampled before and 1, 2, 4 and 6 h after each intervention was ingested. Serum ionised and total Ca increased significantly from baseline over 6 h. Using calcium citrate fasting as a comparator, the elevations in ionised and total Ca were similar after fortified juice, delayed after calcium citrate with a meal and smaller after a dairy product meal. Serum phosphate and calcium-phosphate product increased from baseline after calcium citrate with a meal and after a dairy product meal, and they declined after calcium citrate fasting and after fortified juice. The elevations in serum Ca in the present study were only slightly different from those observed after the administration of 1000 mg of Ca in a previous study. These data indicate that different sources of Ca have different acute effects on serum Ca and support recommendations that dietary Ca might be safer than supplements. Whether these differences contribute to differences in cardiovascular risk requires further study.

Influence of calcium fortification on physical and rheological properties of sucrose-free prebiotic milk chocolates containing inulin and maltitol

In the present study, chocolates were investigated that had been prepared according to the composition specified as a result of this previous work (9.00 % w/w inulin and 34.0 % w/w maltitol) Certain physical (particle size distribution [PSD], brightness, chroma, water activity and hardness) and rheological features of the samples resulting from the addition of calcium carbonate in different quantities (300, 450, 600, 750 and 900 mg calcium carbonate to 100 mg milk chocolate) were studied. Both the Herschel-Bulkley and Casson models were used to investigate the rheological findings. It was determined by comparing certain rheological (rate index, Casson yield stress and Casson viscosity) and physical (chroma and hardness) parameters that samples containing 409.5 mg calcium (nearly 41.0 % of the RDA of calcium) per 100 g chocolate did not show significant differences from samples from the control group. Furthermore, these calcium-containing samples were shown to exhibit positive differences in other physical properties (brightness and water activity) that could be noteworthy and significant with respect to visual quality and shelf life.

Secular trends in the incidence of primary hyperparathyroidism over five decades (1965-2010)

Introduction of automated serum calcium measurements in the 1970s resulted in a sharp rise in primary hyperparathyroidism (PHPT) incidence. However, recent investigations suggest a significant rise in PHPT incidence for unclear reasons. Our objective was to update our population-based secular trends in PHPT incidence, to determine if there has been a significant rise in PHPT incidence as suggested by others, and, if possible, to identify changes in clinical practice that might be responsible. Rochester, Minnesota, residents who met the criteria for PHPT from 2002 through 2010 were identified through the medical records-linkage system of the Rochester Epidemiology Project and added to the historical cohort beginning in 1965. Incidence rates were adjusted to the 2010 US white population. Altogether, 1142 Rochester residents have been diagnosed with PHPT since 1965, including 341 in 2002-2010. Over time, two periods of increased PHPT incidence occurred, one beginning in 1974 (121.7 per 100,000 person-years) and a second peak (86.2 per 100,000 person-years) starting in 1998. The median age of PHPT subjects has increased significantly from 55 years in 1985-1997 to 60 years of age in 1998-2010 and more patients (36%) had a parathyroidectomy in 1998-2010. Although serum calcium measurement has declined since 1996, there was a progressive increase in parathyroid hormone testing between 1994 and 2008. There was also a rise in orders for bone mineral density measurements in women since 1998, which peaked in 2003-2004. A second sharp rise in PHPT incidence occurred in our community in 1998, simultaneously with the introduction of national osteoporosis screening guidelines, Medicare coverage for bone density measurement, and new medications for the treatment of osteoporosis. Case ascertainment bias from targeted PHPT screening in patients being evaluated for osteoporosis is the most likely explanation.

The risks and benefits of calcium supplementation

The association between calcium supplementation and adverse cardiovascular events has recently become a topic of debate due to the publication of two epidemiological studies and one meta-analysis of randomized controlled clinical trials. The reports indicate that there is a significant increase in adverse cardiovascular events following supplementation with calcium; however, a number of experts have raised several issues with these reports such as inconsistencies in attempts to reproduce the findings in other populations and questions concerning the validity of the data due to low compliance, biases in case ascertainment, and/or a lack of adjustment. Additionally, the Auckland Calcium Study, the Women's Health Initiative, and many other studies included in the meta-analysis obtained data from calcium-replete subjects and it is not clear whether the same risk profile would be observed in populations with low calcium intakes. Dietary calcium intake varies widely throughout the world and it is especially low in East Asia, although the risk of cardiovascular events is less prominent in this region. Therefore, clarification is necessary regarding the occurrence of adverse cardiovascular events following calcium supplementation and whether this relationship can be generalized to populations with low calcium intakes. Additionally, the skeletal benefits from calcium supplementation are greater in subjects with low calcium intakes and, therefore, the risk-benefit ratio of calcium supplementation is likely to differ based on the dietary calcium intake and risks of osteoporosis and cardiovascular diseases of various populations. Further studies investigating the risk-benefit profiles of calcium supplementation in various populations are required to develop population-specific guidelines for individuals of different genders, ages, ethnicities, and risk profiles around the world.

Associations between yogurt, dairy, calcium, and vitamin D intake and obesity among U.S. children aged 8-18 years: NHANES, 2005-2008

The aim of this study was to investigate associations of yogurt and dairy consumption with energy, macronutrient, calcium, and vitamin D intakes, and associations with indicators of overweight/obesity in U.S. children in the National Health and Nutrition Examination Survey (NHANES 2005–2008). Using 24-hour recall data, children 8–18 years of age were classified to dairy consumption groups of <1, 1 to <2, or 2+ dairy servings, and yogurt consumers were those who reported eating yogurt during at least one of two dietary intake interviews. NHANES anthropometric measurements were used, and BMI and BMI-for-age percentiles were calculated. Yogurt and dairy consumption were associated with higher intakes of calcium, vitamin D and protein. Yogurt intake was associated with lower total fat and saturated fat intakes and body fat as measured by subscapular skinfold thickness. This study supports consumption of yogurt and higher amounts of dairy as eating patterns associated with greater intake of specific shortfall nutrients, and lower body fat in U.S. children.

VITAL-Bone Health: rationale and design of two ancillary studies evaluating the effects of vitamin D and/or omega-3 fatty acid supplements on incident fractures and bone health outcomes in the VITamin D and OmegA-3 TriaL (VITAL)

RATIONALE

Although vitamin D is widely used to promote skeletal health, definitive data on benefits and risks of supplemental vitamin D alone on bone are lacking. Results from large, randomized controlled trials in the general population are sparse. Data on the effects of supplemental omega-3 fatty acids (FAs) on bone are also limited.

DESIGN

The VITamin D and OmegA-3 TriaL (VITAL) is a double-blind, placebo-controlled trial assessing the role of vitamin D3 (2000 IU/d) and omega-3 FA (1g/d) supplements in reducing risks of cancer and cardiovascular disease among U.S. men aged ≥50 and women aged ≥55. To comprehensively test effects of supplemental vitamin D and/or omega-3 FAs on skeletal health, the VITAL: Effects on Fractures ancillary study is determining the effects of these supplements on incident fractures among 25,875 participants enrolled in the parent trial. Study investigators adjudicate fractures through a detailed review of medical records and radiological images (hip and femur). In a complementary ancillary, VITAL: Effects on Structure and Architecture is determining the effects of supplemental vitamin D and/or omega-3 FAs on bone with detailed phenotyping during in-person visits. Comprehensive assessments of bone density, turnover, structure/architecture, body composition, and physical performance are being performed at baseline and 2 years post-randomization.

CONCLUSION

Results from these studies will clarify the relationship between supplemental vitamin D and/or omega-3 FAs on bone health outcomes, and inform clinical care and public health guidelines on the use of supplemental vitamin D for the primary prevention of fractures in women and men.

Proper Calcium Use: Vitamin K2 as a Promoter of Bone and Cardiovascular Health

Inadequate calcium intake can lead to decreased bone mineral density, which can increase the risk of bone fractures. Supplemental calcium promotes bone mineral density and strength and can prevent osteoporosis. Recent scientific evidence, however, suggests that elevated consumption of calcium supplements may raise the risk for heart disease and can be connected with accelerated deposit of calcium in blood-vessel walls and soft tissues. In contrast, vitamin K2 is associated with the inhibition of arterial calcification and arterial stiffening. An adequate intake of vitamin K2 has been shown to lower the risk of vascular damage because it activates matrix GLA protein (MGP), which inhibits the deposits of calcium on the walls. Vitamin K, particularly as vitamin K2, is nearly nonexistent in junk food, with little being consumed even in a healthy Western diet. Vitamin K deficiency results in inadequate activation of MGP, which greatly impairs the process of calcium removal and increases the risk of calcification of the blood vessels. An increased intake of vitamin K2 could be a means of lowering calcium-associated health risks.

Building healthy bones throughout life: an evidence-informed strategy to prevent osteoporosis in Australia

Osteoporosis imposes a tremendous burden on Australia: 1.2 million Australians have osteoporosis and 6.3 million have osteopenia. In the 2007–08 financial year, 82 000 Australians suffered fragility fractures, of which > 17 000 were hip fractures. In the 2000–01 financial year, direct costs were estimated at $1.9 billion per year and an additional $5.6 billion on indirect costs. Osteoporosis was designated a National Health Priority Area in 2002; however, implementation of national plans has not yet matched the rhetoric in terms of urgency. Building healthy bones throughout life, the Osteoporosis Australia strategy to prevent osteoporosis throughout the life cycle, presents an evidence-informed set of recommendations for consumers, health care professionals and policymakers. The strategy was adopted by consensus at the Osteoporosis Australia Summit in Sydney, 20 October 2011. Primary objectives throughout the life cycle are: to maximise peak bone mass during childhood and adolescence to prevent premature bone loss and improve or maintain muscle mass, strength and functional capacity in healthy adults to prevent and treat osteoporosis in order to minimise the risk of suffering fragility fractures, and reduce falls risk, in older people. The recommendations focus on three affordable and important interventions — to ensure people have adequate calcium intake, vitamin D levels and appropriate physical activity throughout their lives. Recommendations relevant to all stages of life include: daily dietary calcium intakes should be consistent with Australian and New Zealand guidelines serum levels of vitamin D in the general population should be above 50nmol/L in winter or early spring for optimal bone health regular weight-bearing physical activity, muscle strengthening exercises and challenging balance/mobility activities should be conducted in a safe environment.

Socioeconomic gradient in consumption of whole fruit and 100% fruit juice among US children and adults

BACKGROUND

The consumption of fruit is generally associated with better health, but also higher socioeconomic status (SES). Most previous studies evaluating consumption of fruits have not separated 100% fruit juice and whole fruit, which may conceal interesting patterns in consumption.

OBJECTIVE

To estimate demographic and socioeconomic correlates of whole fruit versus 100% juice consumption among children and adults in the United States.

DESIGN

Secondary analyses of two cycles of the nationally representative National Health and Nutrition Examination Survey (NHANES) from 2007-2010, by gender, age group, race/ethnicity and SES among 16,628 children and adults.

RESULTS

Total fruit consumption (population average of 1.06 cup equivalents/d) fell far short of national goals. Overall, whole fruit provided about 65% of total fruit, while 100% juice provided the remainder. Whereas 100% juice consumption was highest among children and declined sharply with age, whole fruit consumption was highest among older adults. Total fruit and whole fruit consumption was generally higher among those with higher incomes or more education. By contrast, the highest 100% juice consumption was found among children, racial/ethnic minorities and lower-income groups.

CONCLUSIONS

Consumption patterns for whole fruit versus 100% fruit juice showed different gradients by race/ethnicity, education, and income. The advice to replace 100% juice with whole fruit may pose a challenge for the economically disadvantaged and some minority groups, whose fruit consumption falls short of national goals.

SPADE, a new statistical program to estimate habitual dietary intake from multiple food sources and dietary supplements

BACKGROUND

For the evaluation of both the adequacy of intakes and the risk of excessive intakes of micronutrients, all potential sources should be included. In addition to micronutrients naturally present in foods, micronutrients can also be derived from fortified foods and dietary supplements. In the estimation of the habitual intake, this may cause specific challenges such as multimodal distributions and heterogeneous variances between the sources.

OBJECTIVE

We present the Statistical Program to Assess Dietary Exposure (SPADE) that was developed to cope with these challenges in one single program.

METHOD

Similar to other methods, SPADE can model habitual intake of daily and episodically consumed dietary components. In addition, SPADE has the option to model habitual intake from dietary supplements. Moreover, SPADE offers models to estimate habitual intake distributions from different sources (e.g., foods and dietary supplements) separately and adds these habitual intakes to get the overall habitual intake distribution. The habitual intake distribution is modeled as a function of age, and this distribution can directly be compared with cutoff values to estimate the proportion above or below. Uncertainty in the habitual intake distribution and in the proportion below or above a cutoff value is quantified with ready-for-use bootstrap and provides 95% CIs.

RESULTS

SPADE is implemented in R and is freely available as an R package called SPADE.RIVM. The various features of SPADE are illustrated by the estimation of the habitual intake distribution of folate and folic acid for women by using data from the Dutch National Food Consumption Survey 2007-2010. The results correspond well with the results of existing programs.

CONCLUSION

SPADE offers new features to existing programs to estimate the habitual intake distribution because it can handle many different types of modeling with the first-shrink-then-add approach.

Vitamin D insufficiency and insulin resistance in obese adolescents

Obese adolescents represent a particularly vulnerable group for vitamin D deficiency which appears to have negative consequences on insulin resistance and glucose homeostasis. Poor vitamin D status is also associated with future risk of type 2 diabetes and metabolic syndrome in the obese. The biological mechanisms by which vitamin D influences glycemic control in obesity are not well understood, but are thought to involve enhancement of peripheral/hepatic uptake of glucose, attenuation of inflammation and/or regulation of insulin synthesis/secretion by pancreatic β cells. Related to the latter, recent data suggest that the active form of vitamin, 1,25-dihydroxyvitamin D, does not impact insulin release in healthy pancreatic islets; instead they require an environmental stressor such as inflammation or vitamin D deficiency to see an effect. To date, a number of observational studies exploring the relationship between the vitamin D status of obese adolescents and markers of glucose homeostasis have been published. Most, although not all, show significant associations between circulating 25-hydroxyvitamn D concentrations and insulin sensitivity/resistance indices. In interpreting the collective findings of these reports, significant considerations surface including the effects of pubertal status, vitamin D status, influence of parathyroid hormone status and the presence of nonalcoholic fatty liver disease. The few published clinical trials using vitamin D supplementation to improve insulin resistance and impaired glucose tolerance in obese adolescents have yielded beneficial effects. However, there is a need for more randomized controlled trials. Future investigations should involve larger sample sizes of obese adolescents with documented vitamin D deficiency, and careful selection of the dose, dosing regimen and achievement of target 25-hydroxyvitamn D serum concentrations. These trials should also include clamp-derived measures of in vivo sensitivity and β-cell function to more fully characterize the effects of vitamin D replenishment on insulin resistance.

Canaries in the Phosphate-Toxicity Coal Mines

Phosphorus is an essential mineral for cell structure and function but, when consumed in excess of the body's requirements, has many adverse effects on metabolism and health. Recently published research has revealed that the average American consumes far more phosphorus than the recommended dietary allowance (RDA) (700 mg/d for adults). Some individuals' daily phosphorus intake exceeds even an adult's tolerable upper limit (4000 mg/d). Until now, understanding of the adverse effects caused by high phosphorus intake has come from patients with chronic kidney disease (CKD), in whom high levels of serum phosphates are strongly associated with increased cardiovascular and all-cause mortality. Due to their impaired renal function, CKD patients cannot clear excess phosphorus, for which reason they must avoid processed foods, virtually all of which are laden with phosphate-containing food additives. Recently, it has become apparent that CKD patients are our canaries in the phosphate-toxicity coal mines. Excessive phosphorus consumption has now been shown to be clearly associated with cardiovascular disease, osteoporosis, and all-cause mortality in the general, healthy population.

Attitudes, beliefs, and barriers related to milk consumption in older, low-income women

OBJECTIVE

To determine attitudes, beliefs, and barriers related to adequate milk consumption in low-income women ages ≥ 60 years.

METHODS

Nine focus groups were conducted with a convenience sample of 59 women at congregate meal sites in a metropolitan area. Grounded in Social Cognitive Theory, focus group questions were used to explore personal, behavioral, and environmental factors associated with milk consumption.

RESULTS

Key response themes indicated a positive attitude for the taste of milk (except for low-fat), a primary belief that milk was important for bones and health, and a primary barrier of gastrointestinal side effects.

CONCLUSIONS AND IMPLICATIONS

Knowledge regarding the benefits of milk and the dislike of its taste were not the primary reason for the lack of consumption. Instead, gastrointestinal side effects seemed to be the major barrier to adequate consumption. Future nutrition campaigns should test strategies for lactose intolerance management when communicating with low-income older women.

Perceptions of how parents of early adolescents will personally benefit from calcium-rich food and beverage parenting practices

OBJECTIVE

To identify and rank perceived personal benefits from parenting practices that promote intake of calcium-rich foods and beverages (CRF/B) by early adolescents.

METHODS

A convenience sample of parents/caregivers (n = 133) of early adolescents (10-13 years) from 6 states (CA, HI, MN, OH, OR, UT) participated in a qualitative study using a Nominal Group Technique process. Benefits identified by parents/caregivers were ranked by importance, given a score weight, and summed to create a total weighted score across states.

RESULTS

The top benefit from making CRF/B available was parent emotional rewards. The top benefit perceived by parents from role modeling intake of CRF/B and setting expectations for intake of CRB was child health promotion.

CONCLUSIONS AND IMPLICATIONS

Child health promotion and parent emotional rewards were important perceived benefits derived from CRF/B parenting practices, and thus, should be included as the focus of education to increase the frequency of these practices.

Calcium supplementation increases blood creatinine concentration in a randomized controlled trial

Background

Calcium supplements are widely used among older adults for osteoporosis prevention and treatment. However, their effect on creatinine levels and kidney function has not been well studied.

Methods

We investigated the effect of calcium supplementation on blood creatinine concentration in a randomized controlled trial of colorectal adenoma chemoprevention conducted between 2004–2013 at 11 clinical centers in the United States. Healthy participants (N = 1,675) aged 45–75 with a history of colorectal adenoma were assigned to daily supplementation with calcium (1200 mg, as carbonate), vitamin D₃ (1000 IU), both, or placebo for three or five years. Changes in blood creatinine and total calcium concentration were measured after one year of treatment and multiple linear regression was used to estimate effects on creatinine concentrations.

Results

After one year of treatment, blood creatinine was 0.013±0.006 mg/dL higher on average among participants randomized to calcium compared to placebo after adjustment for other determinants of creatinine (P = 0.03). However, the effect of calcium treatment appeared to be larger among participants who consumed the most alcohol (2–6 drinks/day) or whose estimated glomerular filtration rate (eGFR) was less than 60 ml/min/1.73 m² at baseline. The effect of calcium treatment on creatinine was only partially mediated by a concomitant increase in blood total calcium concentration and was independent of randomized vitamin D treatment. There did not appear to be further increases in creatinine after the first year of calcium treatment.

Conclusions

Among healthy adults participating in a randomized clinical trial, daily supplementation with 1200 mg of elemental calcium caused a small increase in blood creatinine. If confirmed, this finding may have implications for clinical and public health recommendations for calcium supplementation.

Trial Registration

ClinicalTrials.gov NCT00153816

Adequate dietary vitamin D and calcium are both required to reduce bone turnover and increased bone mineral volume

Clinical studies indicate that the combination of vitamin D and dietary calcium supplementation is more effective for reducing fracture risk than either supplement alone. Our previous dietary studies demonstrated that an adequate serum 25-hydroxyvitamin D3 (25D) of 80nmol/L or more reduces bone RANKL expression, osteoclastogenesis and maintains the optimal levels of trabecular bone volume (BV/TV%) in young rats. The important clinical question of the interaction between vitamin D status, dietary calcium intake and age remains unclear. Hence, 9 month-old female Sprague-Dawley rats (n=5-6/group) were pair-fed a semi-synthetic diet containing varying levels of vitamin D (0, 2, 12 or 20IU/day) and dietary calcium (0.1% or 1%) for 6 months. At 15 months of age, animals were killed, for biochemical and skeletal analyses. While changes to serum 25D were determined by both dietary vitamin D and calcium levels, changes to serum 1,25-dihydroxyvitamin D3 (1,25D) were consistently raised in animals fed 0.1% Ca regardless of dietary vitamin D or vitamin D status. Importantly, serum cross-laps levels were significantly increased in animals fed 0.1% Ca only when combined with 0 or 2 IUD/day of vitamin D, suggesting a contribution of both dietary calcium and vitamin D in determining bone resorption activity. Serum 25(OH)D3 levels were positively correlated with both femoral mid-diaphyseal cortical bone volume (R(2)=0.24, P<0.01) and metaphyseal BV/TV% (R(2)=0.23, P<0.01, data not shown). In multiple linear regressions, serum 1,25(OH)2D3 levels were a negative determinant of CBV (R(2)=0.24, P<0.01) and were not a determinant of metaphyseal BV/TV% levels. These data support clinical data that reduced bone resorption and increased bone volume can only be achieved with adequate 25D levels in combination with high dietary calcium and low serum 1,25D levels. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.

Optimizing bone health in children and adolescents

The pediatrician plays a major role in helping optimize bone health in children and adolescents. This clinical report reviews normal bone acquisition in infants, children, and adolescents and discusses factors affecting bone health in this age group. Previous recommended daily allowances for calcium and vitamin D are updated, and clinical guidance is provided regarding weight-bearing activities and recommendations for calcium and vitamin D intake and supplementation. Routine calcium supplementation is not recommended for healthy children and adolescents, but increased dietary intake to meet daily requirements is encouraged. The American Academy of Pediatrics endorses the higher recommended dietary allowances for vitamin D advised by the Institute of Medicine and supports testing for vitamin D deficiency in children and adolescents with conditions associated with increased bone fragility. Universal screening for vitamin D deficiency is not routinely recommended in healthy children or in children with dark skin or obesity because there is insufficient evidence of the cost-benefit of such a practice in reducing fracture risk. The preferred test to assess bone health is dual-energy x-ray absorptiometry, but caution is advised when interpreting results in children and adolescents who may not yet have achieved peak bone mass. For analyses, z scores should be used instead of T scores, and corrections should be made for size. Office-based strategies for the pediatrician to optimize bone health are provided. This clinical report has been endorsed by American Bone Health.

Female athletes: a population at risk of vitamin and mineral deficiencies affecting health and performance

Adequate vitamin and mineral status is essential for optimal human health and performance. Female athletes could be at risk for vitamin and mineral insufficiency due to inadequate dietary intake, menstruation, and inflammatory responses to heavy physical activity. Recent studies have documented poor iron status and associated declines in both cognitive and physical performance in female athletes. Similarly, insufficient vitamin D and calcium status have been observed in female athletes, and may be associated with injuries, such as stress fracture, which may limit a female athlete's ability to participate in regular physical activity. This review will focus on recent studies detailing the prevalence of poor vitamin and mineral status in female athletes, using iron, vitamin D, and calcium as examples. Factors affecting the dietary requirement for these vitamins and minerals during physical training will be reviewed. Lastly, countermeasures for the prevention of inadequate vitamin and mineral status will be described.

Calcium intake and serum calcium status in Mongolian children

Dietary calcium intake in relation to calcium status in Mongolian children was investigated. This survey was a cross-sectional survey. A total of 835 children were randomly selected from 4 economic regions and Ulaanbaatar city. Information on dietary intake was collected from 835 children in the 1-3, 4-7, and 8-14 year old groups by a 24-h recall method. The average daily intake of calcium from diet was calculated for individuals. Blood samples were collected from 104 children. The mean of daily calcium intakes as 273±30.0mg in 1-3-year old children, 309.0±30.0mg in 4-7 year old children, and 317.0±31.0mg in 8-14 year old children, respectively. There were statistically significant differences in calcium intakes between the age groups 1-3 years, 4-7 years, and 1-3 years, 8-14 years of children (p<0.001). Calcium intakes in all studied children of all age groups were lower (39%, 30.9%, and 24.4%) than the recommended level of calcium intakes. In 22.1% of studied children, the serum total calcium concentration levels were below the normal range. Based on the total serum calcium, the prevalence of hypocalcemia was higher among children in the age group 8-14 years (27.6%) than the prevalence among children in the age group <1 year (p<0.05). Based on the corrected serum calcium values, the prevalence of hypocalcemia was higher (52.4%, 63.6%, and 51.1%) among children in the age groups 1-3, 4-7, and 8-14 years. The mean level of corrected serum calcium were low (2.02±0.04, 2.05±0.73, and 1.99±0.64mg) in children in the age groups 1-3, 4-7, and 8-14 years. These findings suggest that low dietary calcium intakes may be reflected by hypocalcemia in Mongolian children. In conclusion, there is a need to improve a consumption of milk, dairy products in Mongolian children. In addition, there is need to use a vitamin D supplementation with a calcium supplementation in children with severe vitamin D deficiency rickets. This article is part of a Special issue entitled "16th Vitamin D Workshop".

Dietary calcium intake and mortality risk from cardiovascular disease and all causes: a meta-analysis of prospective cohort studies

BACKGROUND

Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy.

METHODS

We identified relevant studies by searching MEDLINE, Embase, and the Cochrane Library databases between 1 September 2013 and 30 December 2013. Reference lists of relevant articles were also reviewed. Observational prospective studies that reported relative risks and 95% confidence intervals for the association of calcium intake with cardiovascular and all-cause mortality were eligible. Study-specific relative risks were pooled using a random-effects model.

RESULTS

In this meta-analysis, 11 prospective studies with 12 independent cohorts, involving 757,304 participants, were eligible. There was evidence of a non-linear association between dietary calcium intake and risk of mortality from cardiovascular disease (P for non-linearity <0.01) and all causes (P for non-linearity <0.01). A dose-response analysis showed a U-shaped relationship between dietary calcium intake and cardiovascular mortality. Intakes that were lower and higher than around 800 mg/day were gradually associated with a higher risk of cardiovascular mortality. For all-cause mortality, we also observed a threshold effect at intakes around 900 mg/day. The risk of all-cause mortality did not decrease further at intakes above 900 mg/day.

CONCLUSIONS

This meta-analysis of prospective cohort studies suggests that dietary calcium intake is associated with cardiovascular mortality in a U-shaped manner and that high dietary calcium intake (>900 mg/day) is not associated with a decreased risk of all-cause mortality.

Effect of a combination GOS/FOS® prebiotic mixture and interaction with calcium intake on mineral absorption and bone parameters in growing rats

AIM

Increasing calcium intake is the most effective strategy for avoiding Ca deficit. However, if intake remains inadequate, improving Ca absorption becomes an important tool to optimize Ca homeostasis and bone health.

PURPOSE

The effect of a mixture of GOS/FOS(®) 9:1 added to a normal- or low-Ca diets on Ca absorption and bone mineralization, density and structure was investigated, in a model of growing rats. Several colonic parameters to help support the findings were also evaluated.

RESULTS

Weanling Wistar rats received one of the four experimental AIN-93G diets: C5: 0.5% Ca; C3: 0.3% Ca; P5: 0.5% Ca + 5.3% GOS/FOS(®); P3: 0.3% Ca + 5.3% GOS/FOS(®) until 50 days (T = 50). At T = 50, lactobacillus and cecum weights were higher, whereas cecum pH was lower in P5 and P3 versus C5 and C3 (p < 0.001). At T = 50, fecal Ca, Mg and P were lower and their absorptions (mg/dL) were higher in P5 and P3 versus C5 and C3, respectively (p < 0.05). Ca, Mg and P absorption % was higher in P5 and P3 versus C5 and C3 (p < 0.001). Femur Ca and P content, bone mineral content, trabecular bone mineral density, tibia length, bone volume, osteoblast surface, stiffness and elastic modulus were higher in P5 and P3 versus C5 and C3 (p < 0.05). Despite the lower Ca content, P3 group reached similar values than C5 in all these latter parameters.

CONCLUSIONS

Supplementing diets with the GOS/FOS(®) mixture increased bone mineralization, density and structure due to an increase in Ca, P and Mg absorptions. Thus, this prebiotic mixture may help to improve bone development in a period of high calcium requirements.

Paracellular calcium transport across renal and intestinal epithelia

Calcium (Ca(2+)) is a key constituent in a myriad of physiological processes from intracellular signalling to the mineralization of bone. As a consequence, Ca(2+) is maintained within narrow limits when circulating in plasma. This is accomplished via regulated interplay between intestinal absorption, renal tubular reabsorption, and exchange with bone. Many studies have focused on the highly regulated active transcellular transport pathways for Ca(2+) from the duodenum of the intestine and the distal nephron of the kidney. However, comparatively little work has examined the molecular constituents creating the paracellular shunt across intestinal and renal epithelium, the transport pathway responsible for the majority of transepithelial Ca(2+) flux. More specifically, passive paracellular Ca(2+) absorption occurs across the majority of the intestine in addition to the renal proximal tubule and thick ascending limb of Henle's loop. Importantly, recent studies demonstrated that Ca(2+) transport through the paracellular shunt is significantly regulated. Therefore, we have summarized the evidence for different modes of paracellular Ca(2+) flux across renal and intestinal epithelia and highlighted recent molecular insights into both the mechanism of secondarily active paracellular Ca(2+) movement and the identity of claudins that permit the passage of Ca(2+) through the tight junction of these epithelia.

Screening, diagnosis and treatment of osteoporosis: a brief review

Osteoporosis is a highly prevalent condition characterized by decreases in bone mass and microarchitectural alterations. Bone fractures, especially of the hip and vertebrae, are the most burdensome complications of osteoporosis, being associated with high risk of disability, institutionalization and mortality. The detection of osteoporosis relies on the quantification of bone mineral density via imaging techniques such as dual-energy X-ray absorptiometry. However, therapeutic decision-making should be based on a comprehensive fracture risk assessment, which may be obtained through validated algorithms. Once the decision of treating has been taken, non-pharmacological strategies should be implemented together with the prescription of anti-osteoporotic agents. Numerous drugs are currently available to treat osteoporosis and the choice of a specific compound should be guided by efficacy and safety considerations. The present review provides a concise synopsis of the current evidence in the management of osteoporosis, from screening to drug prescription. Novel anti-osteoporotic agents are also briefly presented.