Characterization of percutaneous absorption of calcium, magnesium, and potentially toxic elements in two tailored sulfurous therapeutic peloids: a comprehensive in vitro pilot study.

Pelotherapy treatments in thermal spas, which utilize peloids composed of clay minerals mixed with saltwater or mineral-medicinal water, can have various effects on spa users, ranging from therapeutic to potential adverse reactions. Despite the widespread use of peloids, comprehensive information on the penetration and permeation of essential and potentially toxic elements into deeper layers of the skin during pelotherapy is limited. Understanding the concentrations of these elements is crucial for evaluating therapeutic benefits and ensuring safety. This study investigates the in vitro availability and absorption of calcium, magnesium, and potentially toxic elements in two peloids, considering their formulation matrix. To replicate the pelotherapy methodology, an in vitro permeation experiment was conducted using a vertical diffusion chamber (Franz cells) and a biological system with human skin membranes from five Caucasian women, age range between 25 and 51 years. The experiment involved heating the peloids to 45℃. The results emphasize the possible transport properties of chemical elements in peloids, providing valuable information related to potential therapeutic efficacy and safety considerations. Despite no apparent differences between peloids' chemical composition, the method identified permeation variations among chemical elements. The methodology employed in this study adheres to the guidelines outlined by OECD for analyzing skin absorption through an in vitro approach. Furthermore, it aligns with the associated OECD guidance document for conducting skin absorption studies. The replicability of this methodology not only facilitates the analysis of peloids pre-formulation but also provides a robust means to evaluate the effectiveness of therapeutic elements during topical administration, particularly those with potential toxicity concerns.

Increasing Doses of Blueberry Polyphenols Alters Colonic Metabolism and Calcium Absorption in Ovariectomized Rats.

SCOPE: Blueberries are rich sources of bioactive polyphenols that may provide health benefits when consumed regularly, leading to their increased marketing as dietary supplements. However, the metabolic changes associated with consuming concentrated doses of purified polyphenols, as may be present in dietary supplements, are unknown, especially when considering the colonic metabolites formed. This study aimed to evaluate the pharmacokinetics of high doses of purified blueberry polyphenols. METHODS AND RESULTS: 5-month old, ovariectomized Sprague-Dawley rats are acutely dosed with purified blueberry polyphenols (0, 75, 350, and 1000 mg total polyphenols per kg body weight (bw)) and 45 Ca to measure calcium absorption. Blood and urine are collected for 48 h after dosing and phenolic metabolites measured via ultra high-pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The most prominent metabolites are colonically generated cinnamic and hippuric acids. Smaller amounts of other phenolic acids, flavonols, and anthocyanins are also detected. Most metabolites follow a dose-response relationship, though several show saturated absorption. Maximal metabolite concentrations are reached within 12 h for a majority of compounds measured, while some (e.g., hippuric acid) peaked up to 24 h post-dosing. Calcium absorption is significantly increased in the highest dose group (p = 0.03). CONCLUSION: These results indicate that increased doses of blueberry polyphenols induce changes in intestinal phenolic metabolism and increase calcium absorption.

Development of multi-layered gastric floating tablets based on konjac glucomannan: a modified calcium supplement with enhanced bioavailability.

This study developed a gastric-floating delivery system of calcium based on konjac glucomannan (KGM). The developed calcium tablets, consisting of one core layer coated with two barrier layers, were fabricated with a facile method. The role of KGM within the tablets was evaluated from characteristics including swelling behavior, hydrated gel properties, floating ability and release profiles of calcium (Ca). The results indicated that upregulating the KGM fraction accelerated the formation of a more compact gel network in gastric conditions, which prolonged both the floating lag time and floating duration, which resulted in a more sustained swelling behavior and a slower release of calcium. Among all the formulations, a core tablet containing 20% KGM (K20) was selected as the optimized one as it could quickly float up in 7.21 s, exhibited an almost linear release and obtained a release amount of 87.73% within 12 h. Finally, a comparison of in vivo calcium bioavailability between a KGM-based calcium tablet and a commercial calcium tablet (Caltrate®) was carried out by monitoring the serum calcium concentration after administration in rabbits. The results suggested that, after having the KGM-based calcium tablet, the changes of serum calcium levels were gentler due to a sustained-release property. The difference integral value between profile K20 and the baseline was 1.4358, larger than that of Caltrate® (1.1808), suggesting the higher absorption efficiency of KGM-based calcium tablets.

Home Fortification of Rice With Lime: A Novel Potential Way to Reduce Calcium Deficiency in Bangladesh.

BACKGROUND: In order to improve calcium status, fortified rice should have acceptable organoleptic properties of that food. OBJECTIVE: We aimed to assess whether home fortification of rice with slaked lime can increase calcium content of rice and whether this fortified rice is well tolerated in a nutritionally at-risk population. METHODS: This experimental study measured the calcium content of rice cooked with different concentration of lime and assessed the acceptability of fortified rice among 400 women and children. Each participant received fortified rice with one of five concentrations of lime (0, 2.5, 5, 7.5 or 10 gm per 500 gm of rice), with or without additional foods (lentil soup or fried green papaya). All participants were asked to score the organoleptic qualities on a hedonic scale. RESULTS: Analysis showed that rice calcium content increased in a dose- response manner with increased lime during cooking (76.03, 205.58, 427.55, 614.29 and 811.23 mg/kg for given lime concentrations). Acceptability of the meal was greater when additional foods were served with rice at all lime concentrations. In both groups, the 7.5M arm reported highest overall acceptability (children, 6.25; women 6.10). This study found significant association between overall acceptability (different concentrations of lime mixed rice; with/without additional foods) and between groups (women vs. children) (p value = < 0.001) where-as no association was found within groups. CONCLUSIONS: Lime-fortified rice can be feasible considering the calcium uptake of rice and organoleptic character. Further research on bioavailability can establish a solid foundation that will support design of an effective intervention to reduce calcium deficiency in this population.

Hypovitaminosis D: Is It Time to Consider the Use of Calcifediol?

Hypovitaminosis D is becoming a notable health problem worldwide. A consensus exists among several different medical societies as to the need for adequate levels of vitamin D for bone and general health. The correct method by which to restore normal vitamin D levels is still a matter of debate. Although cholecalciferol remains the most commonly distributed form of vitamin D supplementation worldwide, several drugs with vitamin D activity are available for clinical use, and making the correct selection for the individual patient may be challenging. In this narrative review, we aim to contribute to the current knowledge base on the possible and appropriate use of calcifediol-the 25-alpha-hydroxylated metabolite-in relation to its chemical characteristics, its biological properties, and its pathophysiological aspects. Furthermore, we examine the trials that have aimed to evaluate the effect of calcifediol on the restoration of normal vitamin D levels. Calcifediol is more soluble than cholecalciferol in organic solvents, due to its high polarity. Good intestinal absorption and high affinity for the vitamin-D-binding protein positively affect the bioavailability of calcifediol compared with cholecalciferol. In particular, orally administered calcifediol shows a much shorter half-life than oral cholecalciferol. Most findings suggest that oral calcifediol is about three- to five-fold more powerful than oral cholecalciferol, and that it has a higher rate of intestinal absorption. Accordingly, calcifediol can be particularly useful in treating diseases associated with decreased intestinal absorption, as well as obesity (given its lower trapping in the adipose tissue) and potentially neurological diseases treated with drugs that interfere with the hepatic cytochrome P-450 enzyme system, resulting in decreased synthesis of calcifediol. Up to now, there has not been enough clinical evidence for its use in the context of osteoporosis treatment.

Facile preparation of a Ca(ii) carboxymethyl cellulose complex with enhanced calcium bioavailability for treatment of osteoporosis.

At present, though calcium (Ca) reagents with high calcium contents are widely synthesized, their wide application is limited due to their low absorption rates and poor bioavailability. Here we use a carboxymethyl cellulose (CMC) derivative with high water solubility and biocompatibility as a ligand to bind Ca2+. The resulting CaCMC complex exhibits remarkable solubility and absorbability under both basic and acidic conditions as well as in stomach mimicking and the gastrointestinal tract. Importantly, this Ca reagent shows high in vivo calcium bioavailability. Data from osteoporosis mouse models show that the CaCMC complex is superior to calcium carbonate in the treatment of osteoporosis. Therefore, the resulting CaCMC complex is used as a new, highly effective and desirable Ca supplement for daily life and clinical applications.

Solving the calcium gluconate shortage in real-time: Mistakes made and lessons learned.

PURPOSE: During a national shortage of calcium gluconate, we switched to calcium chloride for routine supplementation for peripheral blood stem cell (PBSC) collections. Subsequently, we analyzed the postprocedure ionized calcium level, as we aimed for an equivalent result compared to before the shortage. METHODS: Pharmacy representatives helped us to find an "equivalent" substitute for calcium gluconate at 46.5 mEq in 500 mL normal saline, infused at 100 mL/hour. After instituting a presumably comparable protocol using calcium chloride (40.8 mEq in 250 mL normal saline at a rate of 100 mL/hour), we reviewed ionized calcium results post-PBSC procedures to compare with those obtained with calcium gluconate. Having noticed a difference in the mean values, we adjusted the rate of calcium chloride to reach our desired outcome. RESULTS: Twenty-seven procedures were analyzed on 15 unique patients. We used the Spectra OPTIA with a whole blood: anticoagulant ratio of 13:1. Ionized calcium levels post-PBSC collection with the first calcium chloride protocol were significantly higher (P = 0.003) in nine patients treated. Subsequently, we decreased the calcium chloride infusion rate to 75 mL/hour and achieved similar mean levels to calcium gluconate (P = 0.382). CONCLUSION: Changes in replacement fluids for apheresis procedures can be complex, particularly when dealing with electrolytes that could be clinically significant at critically high or low levels. Once we recognized the need to take into account the amount of elemental calcium infused, we achieved the desired postprocedure ionized calcium results. This study can serve as a lesson for future shortages of infusions used during apheresis procedures.

Effect of Adding a Galacto-Oligosaccharides/Fructo-Oligosaccharides (GOS/FOS®) Mixture to a Normal and Low Calcium Diet, on Calcium Absorption and Bone Health in Ovariectomy-Induced Osteopenic Rats.

Menopause is associated with bone loss. Prebiotics increase Ca, inorganic phosphorus (Pi), and Mg absorption, improving bone health. These increases would supply an extra amount of minerals, decreasing bone resorption and possibly reversing ovariectomy-induced bone loss. The present experimental study sought to evaluate the effect of adding a prebiotic GOS/FOS® mixture to a normal or a low Ca diet on Ca, Pi, and Mg absorption, in osteopenic rats. Four groups of n = 8 rats each were OVX, and 8 rats were SHAM operated. All rats were fed a commercial diet for 45 days. They were then fed one of the following diet for 45 days: C-0.5%: SHAM fed AIN 93 M containing 0.5%Ca; O-0.5% and O-0.3%: OVX rats fed AIN 93 M, containing 0.5% or 0.3%Ca, respectively; GF-0.5% and GF-0.3%: OVX rats fed AIN 93 M, containing 0.5% or 0.3%Ca+ 2.5% GOS/FOS®, respectively. At the end of the experimental time point, Ca, P, and MgAbs% was significantly higher in GF-0.5% and GF-0.3% as compared to the remaining groups (p < 0.01). Irrespective of diet Ca content, CTX decreased whereas femur Ca and P content, tibia BV/TV and GPC.Th, lumbar spine and proximal tibia BMD, bone strength, bone stiffness, and elastic modulus increased in the GF-0.5% and GF-0.3% groups as compared to O-0.5% and O-0.3%, respectively (p < 0.05). This prebiotic mixture would be a useful tool to prevent the increase in bone loss associated with menopause and aging.

Effects of the intake of white wheat bread added with garlic and resistant starch: action on calcium bioavailability and metabolic parameters of growing Wistar rats.

Wheat bread is a widely consumed food and is suitable for the introduction of functional ingredients. The aim of this work was to study the effects of bread with garlic and resistant starch as a fiber source on physiological, metabolic, and functional parameters using an in vivo Wistar rat model. Rats were fed with three diets: a control diet prepared according to the American Institute of Nutrition (C), and two semisynthetic diets containing wheat bread (B) and wheat bread with garlic, resistant starch and calcium citrate (BGR). Fresh feces were weighed and lactobacilli (L) and Enterobacteriaceae (E) were analyzed at different times: 1, 20, 45 and 60 days. The pH of the caecal content was recorded and at the end of the study changes in the bone mineral density of total skeleton (ts BMD), femur (F-BMD), spine (S-BMD) and tibia (T-BMD) were determined. Lipoprotein profile was assessed, atherogenic indexes were calculated and malonaldehyde content was measured in the serum and liver. In relation to gut microbiota, the BGR group showed an increase in the L/E ratio with respect to the other groups which was correlated with a lower cecal pH. Besides, the BGR group presented lower weight and a more favourable metabolic profile. In relation to bone measurements, the BGR group presented higher values of ts BMC, ts BMD, F-BMD, and T-BMD than the B group. Thus, bread with resistant starch, garlic and calcium citrate showed a prebiotic effect increasing calcium bioavailability and deposition in bones, compared with wheat bread. The observed beneficial health effects allow us to consider the design of healthier breads.

Preparation of a fermentation solution of grass fish bones and its calcium bioavailability in rats.

In this study, with grass fish bones as the substrate, after flavourzyme treatment, and fermentation with Leuconostoc mesenteroides, a fermentation solution with a high content of soluble calcium was obtained. High performance liquid chromatography and GC-MS analysis indicated that free calcium (11.29 mmol L-1) in the fermentation solution was composed of calcium lactate (3.89 mmol L-1), calcium acetate (6.21 mmol L-1), calcium amino acids and small peptide calcium. Animal experiments show that the fermentation solution of grass fish bones could promote the growth and development of calcium-deficient rats. Complex organic calcium could be well absorbed and utilized by rats so that serum calcium, alkaline phosphatase levels, femur weight and other indicators in calcium-deficient rats could be returned to normal levels. The fermentation solution of grass fish bones can avoid the waste of aquatic proteins and fish bone calcium, and it exhibited high calcium bioavailability. Therefore, the fermentation solution of grass fish bones might be used as a new efficient calcium supplement.

[Electronic probe analysis of enamel remineralization effect of casein phosphopeptide-amorphous calcium phosphate promoted by different concentrations of fluorine].

Objective: To evaluate the remineralization effect and mechanism of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) with different concentrations of fluorine on demineralized enamel using electronic probe. Methods: Extracted premolar teeth for orthodontic purpose were immersed into lactic acid gel to prepare artificial white spot lesions (10 teeth in each group). Then the specimens were randomly assigned to three groups: Control group, with 5% of the CPP-ACP+deionized water; Group A with 5% CPP-ACP+500 mg/L F(-) and Group B with 5% CPP-ACP+900 mg/L F(-). The teeth in each group were soaked in different solutions for 4 days and then were measured using electron probe tester. The changes of contents among the three groups were compared. Results: No statistically significant difference in the percentage of fluorine was found in the control group before and after treatment (P=0.06), and the difference in the percentage of fluorine quality in the other two groups was statistically significant (P<0.05). Statistically significant difference was found between calcium oxide and phosphorus peroxide in the three groups before and after mineralization (P<0.05). The percentage change of fluorine mass in group B [(0.107±0.035)%] was significantly greater than that in group A [(0.057±0.038)%] (P<0.05), while fluorine mass in group A was significantly greater than that in control group [(0.013±0.019)%] (P<0.05). In group A and group B, the change in quality of calcium oxide and phosphorus peroxide was significantly greater than that in control group (P<0.05), while no significant difference was found between group A and group B (P>0.05). Conclusions: The addition of fluorine in CPP-ACP increased the transport and penetration of calcium, phosphorus and fluorine on enamel surface.

Estudio comparativo de la absorción neta de calcio de dos formulaciones distintas de carbonato de calcio en mujeres posmenopáusicas / Comparative study of net calcium absorption of two different pharma¬ceutical formulations of calcium carbonate in posmenopausal women

La suplementación con calcio reduciría, sola o asociada a otra medicación para osteoporosis, la pérdida de masa ósea y el riesgo de fracturas. Sin embargo, su tasa de adherencia es baja debido a la poca tolerancia. Objetivo: comparar la tasa de absorción neta de calcio entre dos formulaciones distintas de carbonato de calcio (500 mg): comprimidos vs. mousse. Material y métodos: 11 pruebas fueron realizadas en mujeres posmenopáusicas de 58,9±3 años. El diseño fue exploratorio abierto, aleatorizado, prospectivo cruzado de fase 4. Intervención: las participantes fueron aleatorizadas en dos grupos para recibir las dos formulaciones previa suplementación con vitamina D3. La tasa de absorción neta de calcio fue estudiada por la prueba de inhibición de hormona paratiroidea (PTH). Se obtuvieron muestras de sangre: basal y en la 1a, 2a y 3a hora posadministración del calcio asignado, y de orina de 2 horas basal y al final de la prueba. Determinaciones bioquímicas: calcio, fósforo, albúmina, 25-hidroxivitamina D y hormona paratiroidea intacta y calciuria. Análisis estadístico: método de los trapecios para calcular el área bajo la curva (AUC) de la concentración de calcio en el tiempo (R Development Core Team (2008). http://www.Rp-project.org) y Anova con dos términos de error para evaluar el efecto secuencia, período y formulación. Resultados: la mayor inhibición de PTH se observó a dos horas de la toma de ambas formulaciones (comprimidos -39,2% vs. mousse -38,0%; p=ns), con similar AUC0-3 h (comprimidos 3,35; IC 95%: 3,32; 3,37 vs. mousse 3,36; IC 95%: 3,33; 3,38). Cuando analizamos tolerancia y preferencias no se observaron diferencias estadísticamente significativas entre ambas formulaciones. Conclusión: el carbonato de calcio en mousse mostró similar tasa de absorción intestinal, preferencia y tolerancia gastrointestinal que en comprimido. (AU)

Calcium supplementation, administered alone or in combination with a specific medication for osteoporosis, would reduce bone mass loss and fracture risk in postmenopausal women. However, the adherence rate to calcium supplements is low, mainly due to low tolerance. Objective: comparisson of net calcium absorption rate between two different pharmaceutical formulations of calcium carbonate (PFCa) in postmenopausal women. Materials and Methods: 11 tests were performed in postmenopausal women aged 58.9±3 yrs. Design: Comparative, randomized, prospective, open-label exploratory crossover study of calcium mousse versus calcium pills. Intervention: Participants were randomized in 2 groups to receive the 2 different PFCa (500mg): pills vs. mousse, with previous vitamin D3 supplementation. The parathyroid hormone (PTH) inhibition test and the area-under-thecurve (AUC) of calcium were analyzed. Blood samples were taken at baseline and 1, 2 and 3 hrs after intake of the assigned PFCa. Urine samples (2hs) were obtained at -baseline, after 2hs of PFCa intake and at the end of the test. Biochemical Determinations: Serum: calcium, phosphorus, albumin, 25-hydroxyvitamin D, and intact PTH. In urine: calcium. Statistical Analysis: The trapezoid rule was applied to assess AUC in time (R Development Core Team (2008). http://www.Rp-project.org). An ANOVA model with 2 error terms was used to assess the effect of sequence, period, and formulation. Results: The highest inhibition PTH rates were observed after 2 hrs of PFCa (pills -39.2% vs. mousse -38.0%; p=ns). The AUC0-3hrs for both PFCa was similar (pills 3.35; 95%CI: 3.32; 3.37 vs. mousse 3.36; 95%CI: 3.33; 3.38). No statistically significant differences were observed when we analyze tolerance and predilection. Conclusion: The calcium carbonate in mousse showed an adequate rate of intestinal absorption, similarly predilection and gastrointestinal tolerance than the pill presentation. (AU)

Effects of low phosphorus supply on the availability of calcium and phosphorus, and musculoskeletal development of growing dogs of two different breeds.

To investigate the impact of a selective reduction in dietary phosphorus (P) supply on healthy growing dogs, a total of 23 Beagles and 30 Foxhound crossbreds (FBI) were used in a feeding trial between 6 and 24 weeks of age. Sixteen Beagles and 19 FBI were fed with selectively reduced P concentrations (low phosphorus, LP). The remaining puppies received a completely balanced control diet (CON). With these diets, the P supply in the Beagles at the age of 12 weeks added up to 2.5 ± 0.6 (LP) and 9.8 ± 1.4 g P/kg DM (CON), and in the FBI 4.3 ± 0.9 (LP) and 13.0 ± 1.6 g P/kg DM (CON). Therefore, the LP Beagles received an average of 33 ± 11% of the recommended daily allowances (RDA) of P, the LP FBI 41 ± 11%. The calcium (Ca) concentration stayed unaltered and led to a Ca/P ratio above the recommended range of 1.3/1 to 2/1. The apparent digestibility (aD) of phosphorus was reduced in the LP Beagle; otherwise, the aD of both minerals was not affected by the P concentration of the diet. The renal excretion of P was reduced to zero in both LP groups while the renal calcium excretion increased significantly. Several of the puppies from both breeds showed impaired appetite, growth, skin and fur quality, and a few also clinically showed relevant signs of a disturbed musculoskeletal system after the LP feeding. A rapid loss of muscle strength and posture within hours led to severe deviation of the limb axis with hyperflexion of the joints but no radiological aberrations or signs of pain. Immediate transition of affected puppies to a balanced diet with sufficient phosphorus resulted in a complete recovery of the puppies in less than one month. The results demonstrate the importance of an adequate P supply on the healthy development of growing dogs.

Impact of the calcium form of ß-hydroxy-ß-methylbutyrate upon human skeletal muscle protein metabolism.

BACKGROUND & AIMS: ß-hydroxy-ß-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) - differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB. METHODS: Eight healthy young males received a primed constant infusion of 1,2 13C2 leucine and 2H5 phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting. RESULTS: Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 µM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 µmol Phe per leg min-1, Ca-HMB: 5.2 ± 0.8 µmol Phe per leg min-1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured. CONCLUSIONS: These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass.

In Vitro Bioavailability of Calcium, Magnesium, Iron, Zinc, and Copper from Gluten-Free Breads Supplemented with Natural Additives.

The aim of this study was to measure the content of calcium, magnesium, iron, zinc, and copper and determine the bioavailability of these ingredients in gluten-free breads fortified with milk and selected seeds. Due to the increasing prevalence of celiac disease and mineral deficiencies, it has become necessary to produce food with higher nutritional values which maintains the appropriate product characteristics. This study was designed for gluten-free breads fortified with milk and seeds such as flax, poppy, sunflower seeds, pumpkin seeds or nuts, and flour with amaranth. Subsequently, digestion was performed in vitro and the potential bioavailability of the minerals was measured. In the case of calcium, magnesium, iron, and copper, higher bioavailability was observed in rice bread, and, in the case of copper and zinc, in buckwheat bread. This demonstrated a clear increase in bioavailability of all the minerals when the bread were enriched. However, satisfactory results are obtained only for the individual micronutrients.

Hybrid spectral CT reconstruction.

Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 µm and 254 µm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral separation on the order of the energy resolution of the PCD hardware.

Calcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement.

OBJECTIVE: The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement. METHODS: A single-center, randomized controlled trial with a crossover design with 21 healthy men and women was conducted at the Institute of Food Science and Human Nutrition, Leibniz University Hannover. The participants consumed the 5 test products providing 300 mg of calcium each on 5 examination days with 1-week wash-out phases in between. Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC0-10h) and 24-hour urinary calcium excretion. RESULTS: In all groups, no significant differences in the AUC0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed. Likewise, mean changes in serum phosphate and urinary phosphate, as well as serum parathormone, showed no differences between the groups. CONCLUSION: Given an equivalent bioavailability of calcium in all test products, neither a high concentration of SO42- or of HCO3 influenced the bioavailability of calcium. Accordingly, the use of mineral water with high concentrations of calcium constitutes a calorie-free calcium source that can improve calcium supply.

Desalted Duck Egg White Peptides Promote Calcium Uptake and Modulate Bone Formation in the Retinoic Acid-Induced Bone Loss Rat and Caco-2 Cell Model.

Desalted duck egg white peptides (DPs) have been proven to promote calcium uptake in Caco-2 cells and rats treated with a calcium-deficient diet. The retinoic acid-induced bone loss model was used to evaluate the effect of DPs on calcium absorption and bone formation. Three-month-old Wistar female rats were treated with 0.9% saline, DPs (800 mg/kg), or alendronate (5 mg/kg) for three weeks immediately after retinoic acid treatment (80 mg/kg) once daily for two weeks. The model group was significantly higher in serum bone alkaline phosphatase than the other three groups (p < 0.05), but lower in calcium absorption rate, serum osteocalcin, bone weight index, bone calcium content, bone mineral density, and bone max load. After treatment with DPs or alendronate, the absorption rate increased and some serum and bone indices recovered. The morphology results indicated bone tissue form were ameliorated and numbers of osteoclasts decreased after supplementation with DPs or alendronate. The in vitro study showed that the transient receptor potential vanilloid 6 (TRPV6) calcium channel was the main transport pathway of both DPs and Val-Ser-Glu-Glu peptitde (VSEE), which was identified from DPs. Our results indicated that DPs could be a promising alternative to current therapeutic agents for bone loss because of the promotion of calcium uptake and regulation of bone formation.

Impact of Calcium and Two Doses of Vitamin D on Bone Metabolism in the Elderly: A Randomized Controlled Trial.

The optimal dose of vitamin D to optimize bone metabolism in the elderly is unclear. We tested the hypothesis that vitamin D, at a dose higher than recommended by the Institute of Medicine (IOM), has a beneficial effect on bone remodeling and mass. In this double-blind trial we randomized 257 overweight elderly subjects to receive 1000 mg of elemental calcium citrate/day, and the daily equivalent of 3750 IU/day or 600 IU/day of vitamin D3 for 1 year. The subjects' mean age was 71 ± 4 years, body mass index 30 ± 4 kg/m2 , 55% were women, and 222 completed the 12-month follow-up. Mean serum 25 hydroxyvitamin D (25OHD) was 20 ng/mL, and rose to 26 ng/mL in the low-dose arm, and 36 ng/mL in the high-dose arm, at 1 year (p < 0.05). Plasma parathyroid hormone, osteocalcin, and C-terminal telopeptide (Cross Laps) levels decreased significantly by 20% to 22% in both arms, but there were no differences between the two groups for any variable, at 6 or 12 months, with the exception of serum calcitriol, which was higher in the high-dose group at 12 months. Bone mineral density (BMD) increased significantly at the total hip and lumbar spine, but not the femoral neck, in both study arms, whereas subtotal body BMD increased in the high-dose group only, at 1 year. However, there were no significant differences in percent change BMD between the two study arms at any skeletal site. Subjects with serum 25OHD <20 ng/mL and PTH level >76 pg/mL showed a trend for higher BMD increments at all skeletal sites, in the high-dose group, that reached significance at the hip. Adverse events were comparable in the two study arms. This controlled trial shows little additional benefit in vitamin D supplementation at a dose exceeding the IOM recommendation of 600 IU/day on BMD and bone markers, in overweight elderly individuals. © 2017 American Society for Bone and Mineral Research.