Ca Intake Research Articles

Effect of calcium intake and the dietary cation-anion difference during early lactation on the bone mobilization dynamics throughout lactation in dairy cows.

This study investigated the consequences of a low supply of dietary Ca with or without a low dietary cation-anion difference (DCAD) during early lactation on bone mobilization and reconstitution during lactation and on the dynamics of milk Ca content. Fifteen multiparous Holstein cows were distributed among 3 treatments 5 weeks before their expected calving date. These treatments differed based on the provision of diets through the first 10 weeks of lactation. During this period, the control treatment (NCa) consisted of a diet providing 100% of the Ca requirement, with a DCAD of 200 mEq/kg dry matter (DM). The LCa (low Ca) and LCaLD (low Ca, low DCAD) treatments consisted of diets providing 70% of the Ca requirement, with a DCAD of 200 and 0 mEq/kg DM, respectively. After 10 weeks, all cows received the same total mixed ration, which was formulated to meet 100% of the Ca requirement. LCa and LCaLD tended to decrease the body retention of Ca at 3 weeks of lactation compared with NCa but affected neither the dynamics of the blood biomarkers of bone formation and resorption during lactation nor the body retention of Ca at 17 weeks of lactation. Cows almost entirely compensated for the decrease in Ca supply caused by LCa and LCaLD by increasing their apparent digestive absorption of Ca at 3 weeks of lactation, whereas their apparent digestive absorption was unaffected by the treatments at 17 weeks of lactation. Milk production tended to be lower throughout lactation with LCa and LCaLD compared with NCa, with a mean difference of 2 kg/d. The results of this study also indicated that measuring the dynamics of milk Ca content during lactation cannot be considered effective for indirectly estimating the dynamics of bone mobilization in cows. The results also suggested that limited Ca intake at the beginning of lactation may have deleterious effects on milk production.

Consumption of Very Low Mineral Water Is Associated with Lower Bone Mineral Content in Children

Our previous study found that consumption of very low mineral drinking water may retard height development in schoolchildren; however, its association with bone modeling remained unknown. The aim of this study was to investigate the influence of very low mineral water on biomarkers of bone modeling in children. A retrospective cohort study was conducted among 2 groups of 10-13-y-old children who had consumed drinking water with normal mineral contents (conductivity 345 μs/cm, the NW group including 119 boys and 110 girls) or very low mineral contents (conductivity 40.0 μs/cm, the VLW group including 223 boys and 208 girls) in school for 4 y. Differences in daily total mineral intakes, developmental parameters, serum biomarkers of osteoblast activity, and bone formation and resorption between the 2 groups were analyzed with independent t test and chi-square test. Associations of developmental parameters and serum biomarkers with Ca intake from drinking water were analyzed with multiple linear regression and binary logistic regression. Compared with the NW group, the VLW group had lower daily Ca intake, height increase, bone mineral content (BMC), osteoblast activity [serum bone alkaline phosphatase (BALP)] (means±SDs: 433±131 mg, 16.6±8.27 cm, 1.92±0.431 kg, and 9.28±1.42 μg/L compared with 497±155 mg, 22.3±8.45 cm, 2.14±0.354 kg, and 11.0±0.823 μg/L, respectively, P<0.001), and higher bone resorption [serum crosslinked C-telopeptide of type I collagen (CTX), mean±SD: 142±46.9 nmol/L compared with 130±40.6 nmol/L, P=0.001). Ca intake from drinking water was positively associated with height increase, BMC, and BALP (β: 0.0667, 95% CI: 0.0540, 0.0793; β: 3.22, 95% CI: 2.37, 4.08; and β: 23.9, 95% CI: 20.6, 27.2), respectively, P<0.001), and was negatively associated with CTX (β: -0.206, 95% CI:-0.321, -0.0904, P<0.001). These changes suggested that consumption of very low mineral water may be associated with osteoblast inhibition, bone resorption activation, bone mineral reduction, and height development retardation. The health risk of consuming very low mineral water should be considered in children.

Candidate genes of the transcellular and paracellular calcium absorption pathways in the small intestine of laying hens

ABSTRACTTo meet the high calcium (Ca) demand during eggshell biomineralization (2 g of Ca per egg), laying hens develop specific metabolic regulations to maintain Ca homeostasis. The intake of Ca, its solubilization, and absorption capacity are enhanced at sexual maturity (SM). A better knowledge of the intestinal Ca transporters involved in their variations at this stage could indicate new nutritional strategies to enhance Ca digestive utilization. Transcellular Ca absorption pathway and its major player calbindin-D 28 K (CALB1) mediate a saturable transport, which has been extensively described in this model. Conversely, a contribution by the paracellular pathway involving non-saturable Ca transport through intercellular tight junction has also been suggested. The aim of the present study was to identify candidate genes of these two pathways and their patterns of expression, in immature pullets (12, 15, and 17 wk old) and mature laying hens (23 wk old) in the duodenum, jejunum, and ileum. Using RT-qPCR, this study identifies 3 new candidate genes for transcellular, and 9 for paracellular Ca transport. A total of 5 candidates of the transcellular pathway, transient receptor potential cation channels subfamily C member 1 (TRPC1) and M member 7 (TRPM7); CALB1 and ATPase plasma membrane Ca2+ transporting 1 (ATP2B1) and ATPase plasma membrane Ca2+ transporting 2 (ATP2B2) were enhanced with age or after SM in the duodenum, the jejunum or all 3 segments. A total of 4 candidates of the paracellular pathway Claudin 2 (CLDN2) and tight junction proteins 1, 2, and 3 (TJP1, TJP2 and TJP3) increased in the small intestine after SM. Additionally, CALB1, ATP2B2, and CLDN2 were overexpressed in the duodenum or the jejunum or both segments after SM. The enhanced expression of candidate genes of the paracellular Ca pathway after SM, supports that the non-saturable transport could be a mechanism of great importance when high concentrations of soluble Ca are observed in the intestinal content during eggshell formation. Both pathways may work cooperatively in the duodenum and jejunum, the main sites of Ca absorption in laying hens.

Prospective associations between total, animal, and vegetable calcium intake and metabolic syndrome in adults aged 40 years and older.

Calcium (Ca) consumption may contribute to a decreased risk of developing metabolic syndrome (MetS). However, epidemiologic evidence on the association between Ca intake and MetS is limited. This study aimed to evaluate the association between dietary Ca intake (animal-based Ca and vegetable-based Ca separately, as well as total Ca intake) and the incidence risk of MetS and its components in the Korean Multi-Rural Communities Cohort (MRCohort). A total of 5509 participants who did not have MetS were enrolled. Dietary Ca intake was calculated using a food frequency questionnaire composed of 106 items. After 18,880 person-years of follow-up, 876 participants had developed de novo MetS. A significant inverse association between dietary total Ca intake and MetS were observed (incidence rate ratio (IRR)=0.62, 95% confidence interval (CI)=0.48-0.81, P for trend=0.002 for the highest quartile of total Ca intake compared with the lowest quartile). Trends for animal Ca (IRR=0.77, 95% CI=0.62-0.97, P for trend=0.039) and vegetable Ca (IRR=0.54, 95% CI=0.40-0.73, P for trend <0.001) were similar. The individual components of overall MetS were also inversely related to total, animal, and vegetable Ca. The tendency for an inverse association was more evident in the group with two of any of the metabolic abnormalities of MetS at baseline than in the group with no more than one MetS component. Our findings indicate that a relatively high dietary intake of Ca is associated with lower risk of MetS.

Severe calcium deficiency increased visceral fat accumulation, down-regulating genes associated with fat oxidation, and increased insulin resistance while elevating serum parathyroid hormone in estrogen-deficient rats

Menopause impairs calcium(Ca) metabolism and reduces bone mineral density (BMD), but the interaction of menopause with Ca deficiency in energy, glucose, lipid, and bone metabolism has not been studied. Herein we hypothesized that Ca deficiency at levels for post-menopausal women would impair energy, glucose, lipid, and bone metabolism in estrogen-deficient rats. This hypothesis was examined in ovariectomized (OVX) rats fed high-fat diets with different Ca levels for 12 weeks. OVX rats were allocated into either very low Ca (0.02%, VLCA), low Ca (0.7%, LCA), adequate Ca (1.18%, ACA, control), or excessive Ca (2.1%, EXCA). Sham-operated rats had the same diet as ACA (Normal-control). Ca intake was 37, 107, 190, and 311 mg/kg bw/d in the VLCA, LCA, ACA, and EXCA groups. The ACA group had higher serum parathyroid hormone concentrations than the Normal-control but were highest in VLCA. VLCA decreased BMD and lean body mass compared to ACA. Fasting serum glucose concentrations, even with higher serum insulin concentrations, were higher in the VLCA than ACA, indicating increased insulin resistance in VLCA. VLCA deteriorated glucose tolerance after oral glucose administration and impaired lipid profiles. LCA and EXCA had similar effects on metabolism as ACA, but LCA did not improve insulin sensitivity and lipid profiles as much as ACA. Expressions of hepatic genes related to fatty acid and cholesterol synthesis (FAS and SREBP-1c and HMGCR) were much higher in the VLCA than ACA and expressions of genes related fatty acid degradation(CPT1 and CYP7A1) were much lower in VLCA than ACA. In conclusion, we accepted the hypothesis. Very low Ca intake (350–400 mg/d as a human equivalent) exacerbated estrogen-deficiency-induced impairments of energy, glucose, and lipid metabolism by elevating serum parathyroid hormone levels and inducing visceral fat accumulation and insulin resistance in estrogen-deficient rats, but there was no added benefit of excessive Ca.

Association between Depressive Symptoms and Supplemental intake of Calcium and Vitamin D in Older Adults.

We explored the associations between depressive symptoms and supplemental calcium and vitamin D intake in older adults. This was a prospective cohort study. 8,527 older adults aged ≥60 years from Zhejiang Major Public Health Surveillance Program (ZPHS) without depressive symptoms at baseline survey. Participants were divided into non-supplementation, calcium (Ca), vitamin D, and calcium plus vitamin D (CaD) groups based on their supplemental intake during the past year. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9). Binary logistic regression analyses were performed to examine the association between depressive symptoms and supplemental intake. When compared to the non-supplementation group, the Ca group exhibited a significant odds ratio (OR) of 0.731 (95% CI: 0.552-0.967, P=0.028). After adjusting for age, sex, and Ca food sources, the OR was even smaller for the CaD group (OR: 0.326; 95% CI: 0.119-0.889, P=0.029). Additionally, our results indicated that taking Ca supplements ≥4 days/week yielded a significant OR of 0.690 (95% CI: 0.492-0.968) after full adjustment. Taking CaD supplements ≥4 days/week yielded a significant OR of 0.282 (95% CI: 0.089-0.898) after adjusting for age, sex, and Ca food sources. Supplemental intake of Ca or CaD ≥4 days/week can decrease the risk of depressive symptoms in older adults, although CaD supplements may be more effective.

Effects of pre-lay dietary calcium (2.5 vs. 4.0%) and pullet strain (Lohmann Brown vs. Selected Leghorn LSL-Lite) on calcium utilization and femur quality at 1st through to the 50th egg

To study the effects of pre-lay dietary Ca and strain on Ca utilization and femur quality at 1st through to 50th egg, 30 Lohmann Brown (LB) and 30 Lohmann Selected Leghorn-Lite (LSL) pullets (14 weeks of age, woa) reared under same management regimen were used. Six pullets/strain were necropsied for baseline femur samples and the rest (24 pullets/strain) placed in individual cages (65 × 30 × 45 cm3) and fed 1% Ca developer diet for 2 wk. At 16 woa, all pullets were weighed and allocated within strains to pre-lay diets (2.5vs. 4.0% Ca) effectively creating a 2 × 2 factorial arrangement. The pullets were offered pre-lay diets for 2 wk and switched to 4% Ca diet at 18 woa. The diets contained TiO2 to determine apparent retention (AR) of Ca. The age, BW, and feed intake (FI) at 1st, 25th, and 50th egg were recorded. Excreta samples were taken during pre-lay, at 1st and 25th egg and 4 hens per treatment were necropsied for femur samples at 1st, 25th, and 50th egg. There was no interaction (P > 0.05) between pre-lay Ca and strain on Ca intake, femur mineral density (FMD), mineral content (FMC), breaking strength (FBS), and ash (FA) content at 1st, 25th, and 50th egg. At 1st egg, pre-lay Ca interacted with strain on AR of Ca (P = 0.014) such that LB hens retained more Ca at 2.5vs. 4.0% Ca or LSL at 2.5% Ca. Pre-lay Ca had no effect (P > 0.05) on FMD, FMC, FBS, and FA at 1st, 25th, and 50th egg lay. Compared with LB hens, LSL hens had higher FMD (0.30vs. 0.19g/cm2; P = 0.010) and FA (51.9vs. 42.5%; P < 0.01) at 1st egg and FBS (259.4vs. 173.8N, P < 0.01) at 25th egg. In conclusion, except at 25th egg, pre-lay Ca and strain had independent effect on Ca utilization. Femur attributes to 1st egg suggested innate need for LSL birds to accumulate critical bone mass prior to first oviposition.

Calcium Intake and Serum Calcium Level in Relation to the Risk of Ischemic Stroke: Findings from the REGARDS Study.

Background and PurposeData on the association between calcium (Ca) and ischemic stroke are sparse and inconsistent. This study aimed to examine Ca intake and serum Ca levels in relation to risk of ischemic stroke. MethodsThe primary analysis included 19,553 participants from the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study. A subcohort was randomly selected to create a case-cohort study (n=3,016), in which serum Ca levels were measured. Ischemic stroke cases were centrally adjudicated by physicians based on medical records. Cox proportional hazards regression for the cohort and weighted Cox proportional hazard regression with robust sandwich estimation method for the case-cohort analysis with adjustment for potential confounders were performed. ResultsDuring a mean 8.3-year follow-up, 808 incident cases of ischemic stroke were documented. Comparing the highest quintile to the lowest, a statistically significant inverse association was observed between total Ca intake and risk of ischemic stroke (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.55 to 0.95; Plinear-trend=0.183); a restricted cubic spline analysis indicated a threshold effect like non-linear association of total Ca intake with ischemic stroke (Pnon-linear=0.006). In the case-cohort, serum Ca was inversely associated with the risk of ischemic stroke. Compared to the lowest, the highest quintile of serum Ca had a 27% lower risk of ischemic stroke (HR, 0.73; 95% CI, 0.53 to 0.99; Plinear-trend=0.013). Observed associations were mainly mediated by type 2 diabetes, hypertension, and cholesterol. ConclusionsThese findings suggest that serum Ca has inverse and Ca intake has threshold effect like association with risk of ischemic stroke.

Dietary habits of newcomer children in Canada.

To explore the dietary habits, nutrient adequacies and dietary change experiences of immigrant and refugee children. Mixed-methods cross-sectional design. Children completed three 24 h dietary recalls to determine nutrient inadequacies. Parents and service providers were interviewed to capture dietary practices. Healthy Immigrant Children study, Saskatchewan, Canada. Three hundred immigrant and refugee children aged 3-13 years and twenty-two parents who lived in Regina or Saskatoon for less than 5 years; twenty-four newcomer services providers. Immigrant children had higher mean intakes of meat and alternatives, milk and alternatives, and whole grains; and consumed more vitamin B12, folate, Ca, vitamin D, Fe and Zn compared with refugee children. Refugee children were at higher risk of having inadequate intakes of folate (37 %) and Fe (18 %). Both immigrant and refugee children were at high risk of inadequate vitamin D (87 and 93 %, respectively) and Ca intakes (79 and 80 %), and a substantial portion were at risk for inadequate Zn intake (21 and 31 %). Participants mentioned challenges with maintaining a healthy traditional diet in the midst of a busy schedule, while responding to their children's demands for foods high in fat and sugar. Newcomer children are at risk for inadequate intakes of vitamin D, Ca and Zn, while refugee children are at additional risk for inadequate folate and Fe intakes. Newcomers to Canada may experience subtle or drastic changes in their food environment leading to dietary acculturation that includes increased consumption of foods high in sugar, salt and fat.

178 A systematic review and meta-analysis of Ca digestibility and utilisation in growing and finishing pigs

Abstract The development of dietary recommendations based on digestible Ca values is an essential step to optimize pig performance and feed conversion because the present guidelines, expressed on total dietary Ca, are inadequate, as they ignore endogenous losses and the digestion process. A systematic review and meta-analysis of digestibility trials were performed to quantify factors affecting Ca absorption and retention, and to estimate endogenous Ca losses. Forty studies, corresponding to 201 dietary treatments performed on 1,204 growing pigs, were selected. Data analysis was performed in R using weighted linear mixed effects regression. The results indicated that while Ca absorption and retention (g/kg of BW/day) increased with increasing Ca (P &lt; 0.001), with non-phytate-P (P &lt; 0.001) and with exogenous phytase intakes (P &lt; 0.001), these responses decreased with increasing phytate-P intake (P &lt; 0.05). Interactions were detected between exogenous phytase and Ca intake (P &lt; 0.001), indicating reduced efficacy of this enzyme, and between phytate-P intake and exogenous phytase (P &lt; 0.05), indicating reversing of the direct negative effect of phytate-P on Ca absorption and retention. Based on the recommended Ca and P intake for a 25 kg pig, an exogenous phytase supplementation of 1,000 FTU/day could potentially improve Ca digestibility by 20–25%. There were no effects of animal characteristics (e.g. ‘genotype’) on Ca absorption and retention. The large amount of variance explained in Ca absorption (90%) and retention (91%) supported our a priori choice of independent variables. Estimated endogenous Ca losses were 239 mg/kg of DM (95% CI 114, 364). When scaled by bodyweight, the endogenous Ca excretion on Ca-and-P-free diets was 20.5 mg/kg of BW/day (95% CI 5.46, 36.5). These outcomes should contribute to a reassessment of Ca requirements, which should lead to a more accurate formulation of pig diets.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80–5.0%), accuracy (< 5%), recoveries of elements (97.4–105%), and their detection limits (0.075–1.1 μg L−1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)–40.7% (Ca) and 4.65% (Al)–46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Availability of feed sources and nutritional status of Hariana cattle in different seasons in the breeding tract

ABSTRACT The study was conducted to assess the availability of feed sources and nutritional status of Hariana cattle breed during different season in its breeding tract. The structed interview schedule was prepared to collect the information from 240 dairy farmers and the samples of available feed and fodder were collected during different season for proximate analysis. The results revealed that the fodder availibility varies according to season. The available green fodders were maize and jowar during rainy; berseem and oats during winter. The intake of nutrients were compared with requirements of Hariana cattle to find out the nutritional status during different season. The results revealed that the animals were underfed in different seasons. Dry matter intake (DMI) was deficit in all seasons; deficiency of DMI (%) was 21.46, 13.84 and 8.60 during summer, winter and rainy respectively. Total digestible nutrient intake was in excess during rainy and winter season and deficit during summer. Crude protein intake was in excess during winter; deficit in rainy and summer. The intake of Ca and P was less as compared to requirements. The information from the present study might be useful for formulation of balanced ration for Hariana breed of cattle.

Intravenous calcium infusion in a calving protocol disrupts calcium homeostasis compared with an oral calcium supplement

Hypocalcemia is a common postpartum condition in dairy cows, which negatively affects health and production. Intravenous Ca infusions are commonly included in calving protocols to prevent or mitigate the effect of hypocalcemia in multiparous cows. Thus, we sought to contrast the effect of intravenous Ca infusion against voluntary oral Ca intake on Ca metabolism. Serum total Ca (tCa) and whole-blood ionized Ca (iCa) were monitored in 24 multiparous Holstein cows after parturition. Precalving diets were formulated with a positive dietary cation-anion difference of 172 mEq/kg of DM and contained 4.1 g of Ca/kg of DM. At parturition, cows were blocked by calving sequence and calcemic status as either normocalcemic (cutoff threshold of iCa ≥1.10 mmol/L) or hypocalcemic (cutoff threshold of iCa <1.10 mmol/L). Cows in each block were randomly assigned to 1 of 2 treatments: either an oral source of Ca (Ca-Oral; n = 12) or an intravenous source of Ca (Ca-IV; n = 12). Cows in the Ca-Oral group were offered a 20-L commercial Ca suspension (48 g of Ca) for voluntary consumption. The supplement contained Ca carbonate, Ca formate, Ca propionate, and other minerals and vitamins (Farm-O-San Reviva, Trouw Nutrition, Amersfoort, the Netherlands). Cows in the Ca-IV group received a 450-mL intravenous Ca solution (13 g of Ca) that contained 298 mg/mL of Ca gluconate, 33 mg/mL of magnesium chloride, and 82 mg/mL of boric acid (AmosCAL, Kommer-Biopharm BV, Heiloo, the Netherlands). Both treatments were initiated within 25 ± 10 min after calving. The oral Ca suspension was offered to cows in a 25-L bucket and was available for 10 min. All cows in the Ca-Oral group voluntarily consumed the entire 20 L of the Ca suspension within 5 min. Blood samples for Ca analyses were collected at 0 (before treatment initiation), 1, 3, 10, and 18 h relative to treatment, and at 0700 and 1900 h for the next 2 consecutive days, to represent the 24-, 36-, 48-, and 60-h sampling time points. In Ca-IV cows, both iCa and tCa concentrations peaked at 1 h (1.54 mmol/L for iCa and 2.85 mmol/L for tCa) and declined to a nadir at 24 h following treatment initiation (0.94 mmol/L for iCa and 1.74 mmol/L for tCa). Although whole-blood iCa and serum tCa were higher at 1 and 3 h in Ca-IV cows, concentrations of iCa were greater for Ca-Oral cows at 18, 24, and 36 h and for tCa at 24 and 36 h. Our data indicate that intravenous Ca infusion immediately induced a state of hypercalcemia followed by lower whole-blood iCa and serum tCa concentrations 24 h later compared with oral Ca.

Dietary calcium intake and genetics have site-specific effects on peak trabecular bone mass and microarchitecture in male mice.

Trabecular bone (Tb) is used for rapid exchange of calcium (Ca) in times of physiologic need and the site-specific characteristics of Tb may explain why certain sites are more vulnerable to osteoporosis. We hypothesized that peak trabecular bone mass (PTBM) and Tb microarchitecture are differentially regulated by dietary Ca intake, genetics, or Gene-by-Diet (GxD) interactions at the distal femur and the fifth lumbar (L5) vertebra. Male mice from 62 genetically distinct lines were fed basal (0.5%) or low (0.25%) Ca diets from 4 to 12 wks of age. Afterwards, the right femur and L5 vertebra were removed and trabecular bone was analyzed by μCT. In mice fed the basal diet, bone volume fraction (BV/TV), trabecular number (Tb.N), and connectivity density (Conn.D) were significantly higher in the L5 vertebra than femur. Femur Tb had a weaker, more rod-like structure than the L5 vertebrae while mice fed the low Ca diet developed rod-like structures at both sites. Dietary Ca restriction also caused a greater relative reduction of Tb.N and Conn.D in the femur than L5 vertebra, i.e. it was more harmful to the integrity of Tb microarchitecture in femur. Genetics was a major determinant of Tb at both sites, e.g. heritability of BV/TV on the basal diet = 0.65 (femur) and 0.68 (L5 vertebra). However, while GxD interactions altered the impact of dietary Ca restriction on Tb parameters at both sites, the effect was not uniform, e.g. some lines had site-specific responses to Ca restriction. The significance of our work is that there are site-specific effects of dietary Ca restriction and genetics that work independently and interactively to influence the attainment of PTBM and Tb microarchitecture.

Bone turnover is altered during 72 h of sleep restriction: a controlled laboratory study.

The objective of the study was to evaluate how controlled, short-term sleep restriction (SR; 72 h) alters markers of bone formation and resorption and urinary calcium (Ca) output. Ten healthy, sleep-adequate, male soldiers were housed in the research facility one day prior to and for the duration of SR. Diet was controlled to provide adequate energy balance and macronutrient distribution, meeting the recommended dietary allowance (RDA) for Ca. Subjects engaged in light activities to maintain wakefulness and were allowed 2 h of sleep per night (0430-0630 hours). Blood samples were collected each morning at 0 h (baseline) and 24, 48, and 72 h of SR. Serum was assayed for parathyroid hormone (PTH), bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase (TRAP), and C-terminal telopeptide of type I collagen (CTX). Urine was collected in 24 h increments during SR for measurement of Ca and creatinine (Cr). BAP was reduced at 24 h (P= 0.015) and resorption markers TRAP and CTX were increased after 48 and 72 h of SR compared to baseline (P < 0.05). The ratio of BAP:TRAP was significantly lower (P= 0.017) at 48 and 72 h of SR. In contrast, total 24 h urinary Ca and Ca/Cr excretion were unchanged. Markers of bone formation and resorption are uncoupled in response to as little as 48 h of SR even when Ca intake is at the RDA. Sleep deprivation may be a risk factor for reduced bone health due to perturbations in bone turnover.

Could fructan sources in strawberry matrix be more effective as a tool for improvement of bone structure than these compounds added to diet alone? - Study on osteopenic rat model.

Osteoporosis, a disease associated with ovarian hormone deficiency following menopause, is the most common cause of age-related bone loss. Although an optimal intake of Ca is vital - both bone accretion during growth and maintenance in adult life - a great percentage of the population consumes far below the recommended amounts of this mineral. On the other hand, there are evidences that fructans enhance not only Ca absorption, but bone calcium as well. In the knowledge that estrogen deficiency and insufficient Ca in the diet during postmenopause cause serious problems with resultant osteoporosis, the aim of this study is to assess the effects of a diet enriched in fructan-containing sources alone, or in the "strawberry matrix", on the structure of bone in OVX rats under calcium hypoalimentation. Experimental animals were female Wistar rats, sham-operated or ovariectomized. The treatment with Ca-restricted diets also contained one of the sources of fructan (Jerusalem artichoke, yacon, Beneo Orafti Synergy1), in the amount providing 8% of fructans. Femur architecture of rats was assessed by tomography and Ca content by the AAS method. Ovariectomy led to a significant decrease in femoral Ca content, total mineral content and bone density of rats. This study shows that a diet containing inulin-type fructan (especially as a component of strawberry product) improved bone quality (i.e. increase in Ca content in femur, total density in middle part of bone, as well as decrease of endosteal circumference) in OVX rats under calcium hypoalimentation. These findings suggest that a fructan-enriched diet could be potentially useful for postmenopausal osteoporosis. It is important to determine an optimal dietary level of fructan with the long-term goal of developing a dietary strategy in osteoporosis prevention.

Effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions.

ObjectiveThis experiment aimed to investigate the effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions.MethodsA total of 480 Hy-Line Brown laying hens at 31 wk of age were randomly allotted to 1 of 5 experimental diets. The control diet contained 2,800 kcal/kg nitrogen-corrected apparent metabolizable energy with no fat addition. Four additional diets were prepared by adding 2.0% or 4.0% of animal fat (AF) or soybean oil (SO). Energy and nutrient concentrations were consistent among all diets. Diets were fed to hens for 4 weeks. Average daily room temperature and humidity were 26.7°C±1.52°C and 77.4%±4.50%. The heat stress index was approximately 76, indicating that hens were raised under heat stress conditions.ResultsFinal body weight (BW) was greater (p<0.05) for hens fed diets containing 2.0% or 4.0% AF than for those fed the control diet or diets containing 2.0% or 4.0% SO. The BW gain and feed intake were greater (p<0.05) for hens fed diets containing additional AF or SO than those fed the control diet. Eggshell thickness was the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO. Egg yolk color was the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO.ConclusionInclusion of supplemental fat (AF and SO) in diets exhibits preventative effects on BW loss for hens raised under hot environmental conditions when energy and nutrient concentrations in diets were maintained. The effects were greater for AF than for SO. However, inclusion of supplemental fat in diets decreases eggshell thickness and egg yolk yellowness, possibly due to a reduction in Ca absorption and intake of egg yolk colorants.

Dietary calcium intake and the risk of metabolic syndrome: evidence from observational studies.

Epidemiological investigations evaluating the association of dietary Ca intake with metabolic syndrome (MetS) risk have yielded controversial results. Therefore, a meta-analysis was conducted to quantitatively summarize the association between dietary Ca intake and the risk of MetS. PubMed, Embase and Web of Science were searched for relevant articles published up to October 2018. The pooled OR and 95 % CI were calculated with a random-effects model. Meta-analysis.ParticipantsNine cross-sectional studies. A total of nine articles with fifteen studies for dietary Ca intake were finally included in the meta-analysis. The combined OR with 95 % CI of MetS for the highest v. lowest category of dietary Ca intake was 0·80 (95 % CI 0·70, 0·91). For dose-response analysis, a non-linear relationship was found between dietary intake of Ca and risk of MetS (P non-linearity&lt;0·001). The threshold for dietary Ca intake was 280 mg/d (OR=0·87; 95 % CI 0·82, 0·93), reducing the risk of MetS by 13 %. The present meta-analysis suggests that dietary Ca intake might reduce the risk of MetS, which needs to be further confirmed by larger prospective cohort studies.

Associations of calcium and dairy product intakes with all-cause, all-cancer, colorectal cancer and CHD mortality among older women in the Iowa Women's Health Study.

Ca and dairy product intakes may be inversely associated with all-cause and cause-specific mortality, and non-Ca components of dairy products, such as insulin-like growth factor-1, may be independently associated with mortality. We investigated associations of Ca and dairy product intakes with all-cause, all-cancer, colorectal cancer (CRC) and CHD mortality among 35 221 55- to 69-year-old women in the prospective Iowa Women's Health Study, who were cancer-free in 1986. We assessed diet using a Willett FFQ, and associations using multivariable Cox proportional hazards regression. We estimated residuals from linear regression models of dairy products with dietary Ca to investigate total and specific dairy products independent of their Ca content. Through 2012, 18 687 participants died, including 4665 from cancer (including 574 from CRC) and 3603 from CHD. For those in the highest relative to the lowest quintiles of intake, the multivariable-adjusted hazard ratios (HR) and 95 % CI for total Ca (dietary plus supplemental) were 0·88 (0·83, 0·93; P trend=0·001) for all-cause mortality, 0·91 (0·81, 1·02; P trend=0·34) for all-cancer mortality, 0·60 (0·43, 0·83; P trend=0·002) for CRC mortality and 0·73 (0·64, 0·83; P trend &lt;0·0001) for CHD mortality. The corresponding HR for associations of whole milk, whole milk residuals, and low-/non-fat milk residuals with all-cause mortality were 1·20 (95 % CI 1·13, 1·27), 1·20 (95 % CI 1·13, 1·28) and 0·91 (95 % CI 0·86, 0·96), respectively. These results suggest that Ca may be associated with lower risk of all-cause, CRC and CHD mortality, and that non-Ca components of milk may be independently associated with mortality.

Interactive effects of calcium and top-dressed 25-hydroxy vitamin D3 on egg production, egg shell quality, and bones attributes in aged Lohmann LSL-lite layers

Calcium and vitamin D are critical in attenuating metabolic Ca insufficiency often observed in older hens. We investigated interactive effects of dietary Ca and top-dressed 25-hydroxy vitamin D3 (25OHD3) on egg production, eggshell quality (thickness, EST, and breaking strength, ESBS), serum Ca, kidney, liver, and bones attributes in 74-wk old Lohmann LSL-lite layers. A total of 4 levels of Ca (3.0, 3.5, 4.0, and 4.5%) and 3 levels of 25OHD3 (0, 69, and 138μg/kg) were tested. All diets had basal level of 3,300 IU of vitamin D3/kg, were allocated to 84 individually housed hens (n = 7), and fed to 81 wk of age. Dual-energy X-ray absorptiometry was used to measure bone mineral content (BMC) and density (BMD) in left ulna, femur, and tibia at week 74 (13 spare birds, baseline) and week 81. Birds fed diets containing 3.0, 3.5, 4.0, and 4.5% Ca consumed 3.4, 4.1, 4.2, and 4.8 Ca g/b/d. Interaction (P < 0.05) between Ca and 25OHD3 was such that 25OHD3 linearly increased egg weight and percentage of eggs graded as jumbo (≥70g) at 3.0, 3.5, and 4.5% Ca levels. There was no interaction (P > 0.05) between Ca and 25OHD3 on the rest of the parameters. Calcium increased EST and ESBS quadratically (P < 0.05), EST increased with Ca intake up to 4.1g of Ca/b/d whereas Ca intakes (3.4 and 4.8g of Ca/b/d) had poor ESBS relative to intermediate Ca intakes. Kidney ash concentration increased linearly (P = 009) with Ca intake. However, BMC and BMD in ulna, tibia, and femur declined (P < 0.05) at week 81 relative to baseline. In conclusion, top dressed 25OHD3 linearly increased egg weight at various Ca intakes with no negative effect on eggshell quality or bone attributes. Feeding 4.1 to 4.2g of Ca/b/d improved eggshell quality, however, higher intake deteriorated eggshell quality and increased renal ash accumulation with no benefit on skeletal integrity.