Apparent Absorption Of Calcium Research Articles

High Fiber Diets Slow Bone Turnover in Young Men but Have No Effect on Efficiency of Intestinal Calcium Absorption

Dietary fiber reduces the absorption of dietary calcium from a meal, but its impact on calcium kinetics is unknown. We therefore evaluated the effects of a high fiber diet on calcium balance and kinetics and on calcium-regulating hormones. Seven young men each participated in two 23-d experiments. In the low fiber period the controlled diet provided 6.5 g fiber/d and 530 mg calcium/d. In the high fiber period fiber was increased to 31.3 g/d and calcium to 586 mg/d by substituting high fiber cereal. Measured between d 7 and 12 of each period, the high fiber diet significantly lowered the apparent absorption of calcium (from 60.6 +/- 23.8% to 37.1 +/- 26.5%) and reduced calcium balance, although balance remained positive overall. Fiber had no effect on serum total or ultrafiltrable calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D or parathyroid hormone concentrations measured on d 1, 7, 12 and 20. Calcium kinetics was studied between d 17 and 23 by administering oral 44Ca and intravenous 42Ca to fasting subjects. Fractional absorption of calcium in the fasting state was unaffected by fiber. However, during the high fiber period, subjects had significantly lower bone accretion, resorption and turnover rates, and calcium flow to bone from the exchangeable pool than during the low fiber period. We conclude that the fiber-induced reduction in calcium absorption slowed down bone calcium turnover but did not increase the efficiency of intestinal absorption.

Preparation of synbiotic milk powder and its effect on calcium absorption and the bone microstructure in calcium deficient mice.

Calcium deficiency can lead to osteoporosis. Adequate calcium intake can improve calcium deficiency and prevent osteoporosis. Milk powder is the best source of dietary calcium supplements. Probiotics and prebiotics are considered to be beneficial substances for promoting calcium absorption. In this study, synbiotic milk powder (SMP) was prepared by combining the three, and its calcium supplementation effect and osteogenic activity were evaluated in calcium deficient mice. Through prebiotic screening experiments in vitro, after adding 1.2% iso-malto-oligosaccharide, the number of viable bacteria and the calcium enrichment of Lactobacillus plantarum JJBYG12 increased by 8.15% and 94.53% compared with those of the control group. Long-term calcium deficiency led to a significant reduction in calcium absorption and bone calcium content in mice, accompanied by structural deterioration of bone trabeculae. SMP significantly improved apparent calcium absorption, increased serum calcium and phosphorus levels, and decreased ALP activity and CTX-1 levels. In the meantime, the bone mineral density increased significantly, and the number of bone trabeculae and the proliferation and differentiation of osteoblasts also increased. SMP has good dietary calcium supplementation capacity and bone remodeling ability without significant side effects on major organs. These findings provide insights into using SMP as a dietary calcium source to improve bone health.

Impact of lentil-wheat bread on calcium metabolism, cecal and serum parameters in growing Wistar rats

The objective of this work was to evaluate the influence of bread with thermal treated lentil flour on metabolic and physiological parameters. Thirty-two Wistar rats fed for 60 days with different diets were studied: control (C), wheat bread (WB), wheat-lentil bread (LB), and lentil flour (LF). Food intake, weight gain, feces moisture, and apparent calcium absorption (AACa) were recorded during the experiment. The weight and pH of the cecum, as well as serum parameters, were evaluated after sacrifice. LB group showed higher intake and weight gain. Diets with lentil produced several positive effects: an increase in feces moisture, higher AACa, augmentation of cecum weight, and acidification in the cecum. Besides, an improvement in bone quality and a reduction of cholesterol was observed with lentil diets. Because of the named benefits, bread containing lentil flour could be considered a functional food.

Apparent calcium absorption of a novel calcium supplement – The RENEW study

Apparent calcium absorption of a novel calcium supplement – The RENEW study

The calcium supplementation effect of calcium-binding oligopeptides from bonito (Auxis thazard) hydrolysate in rats

Sixty Ca-deficient male Wistar rats were divided into six groups to investigate the effect of a calcium-binding bonito hydrolysate (PBH-Ca) on calcium bioavailability in rats, including the normal group, the control groups (PBH + CaCO3 group and the CaCO3 group), and three PBH-Ca groups with doses of 2,000 (PBH-Ca-H group), 1,000 (PBH-Ca-M group), and 500 (PBH-Ca-L group) mg/kg body wt/day. Each group was given the corresponding drug by intragastric administration for 4 weeks. The indices measured included the rate of increase in body weight and body length, apparent calcium absorption rate, serum calcium, serum phosphorus, alkaline phosphatase (ALP) activity, bone volume fraction (BV/TV), bone mineral density (BMD), and trabecular microstructure of the rats scanned by micro-computed tomography. The results showed that PBH-Ca promoted the growth of rats, significantly increased the apparent calcium absorption rate and the number of bone trabeculae, stabilized serum calcium and serum phosphorus content in serum, significantly inhibited ALP activity, decreased the separation of bone trabeculae, accelerated bone growth of rats, and raised the BV/TV and femoral BMD in the rats. These results illustrate that PBH-Ca has promising potential in a high-quality calcium diet.

Calcium Deficiency in Diet Decreases the Magnesium Content in Bone and Affects Femur Physicochemical Properties in Growing Rats.

This study evaluates the effect of three calcium levels in the diet (normal, moderate, and severe calcium depletion) on bone metabolism of male Wistar rats during their growth period. Bone mineral density (BMD) and femur length were determined in vivo during the growth stage using a single X-ray transmission system. The apparent calcium absorption was calculated in the rat adolescent and adulthood stages. At the end of the experiment, calcium concentrations in serum and urine were analyzed. The bones were evaluated postmortem to corroborate in vivo analyses. Microstructural properties of cortical and trabecular tissues of femurs bones were assessed using scanning electron microscopy. Bone mineral contents (Mg, Ca, P, and K) were quantified by inductively coupled plasma. Severe calcium depletion in the diets in the development stage affects the bone quality parameters such as bone mineral density and mineral content. Moreover, it was found thinner cortical and trabecular bone areas. Additionally, it was found that severe calcium depletion increased the apparent absorption of calcium as a defense mechanism, but with the decrease of the BMD peak, and the thickness of cortical bone as well as trabecular bone porosity. The severe calcium depletion increased the efficiency of apparent absorption calcium as a defense mechanism, but, even so, decreases the BMD peak as well as the thickness of cortical bone and trabecular bone porosity.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats.

Apparent calcium absorption, total bone mineral content and density, and mineral contents of the right femur were studied using a growing rat model. Twenty-four male Wistar rats were fed with diets based on extruded whole grain red (RSD) or white sorghum (WSD), and control diet (CD) up to 60 days. The animals fed with sorghum diets consumed less and gained less weight compared to those fed with CD, but the efficiency of all diets was similar. Calcium intake was lower in animals fed with sorghum diets, related to the lower total intake of these animals. Apparent calcium absorption in animals fed with RSD was lower than in those fed with CD (CD: 72.7%, RSD: 51.0%, WSD: 64.8%). No significant differences in bone mineral density of total body, spin, femur, distal femur, tibia and proximal tibia were observed among the groups. However, Ca and P contents in the right femur of the rats consuming RSD were lower, indicating a certain imbalance in the metabolism of these minerals.

Herring egg phosphopeptides as calcium carriers for improving calcium absorption and bone microarchitecture in vivo.

Phosphorylation may enhance the functional properties of proteins/peptides. Herring egg phosphopeptides (HEPPs) have been found to be more effective than the non-phosphorylated variant in calcium-binding activities due to the introduced phosphate groups. However, whether HEPPs as calcium carriers will be superior to herring egg peptides (HEPs) in improving calcium bioavailability in vivo, for the equivalent calcium intake prerequisite, remains to be clarified. This study aimed to evaluate the effect of HEPPs-calcium complex and HEPs-calcium complex on calcium absorption and bioavailability in calcium-deficient mice. Results showed that the remarkably lower calcium absorption and bone calcium deposition induced by long-term calcium deficiency were accompanied by deterioration of the trabecular bone microarchitecture (P < 0.05). The HEPPs-Ca supplements significantly improved the apparent calcium absorption, increased the serum calcium level, decreased the alkaline phosphatase activity, strengthened the bone biomechanical property, and increased bone volume/tissue volume (BV/TV) and trabecular number (Tb·N) in calcium-deficient mice (P < 0.05), as determined by micro-computed tomography (micro-CT) assay. The effect of HEPPs-Ca on calcium absorption and bioavailability was comparable to that of CPPs-Ca, but better than that of HEPs-Ca and CaCO3. This study brings new insights into the potential of HEPPs as an alternative to CPPs for use in calcium supplements.

Methodological study on endogenous calcium absorptivity using rats and 41Ca tracing

Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a 41Ca tracer technique in SD rats was conducted to measure the endogenous fecal calcium and true absorption of calcium. Apparent absorption of calcium was measured as a control to the endogenous calcium labeling experiment. These results show that by using 41Ca labeled endogenous calcium in vivo, researchers could obtain the true calcium absorption data without extrinsic labeling. Therefore, the method was not affected by the chemical structure or type of calcium supplement and might be used in evaluating the absorptivity of marketed calcium supplements.

Intestinal absorption of iron and calcium from soy and cow's milk-based infant formulas in weanling rats pups

ABSTRACT Objective: This study aimed to compare the intestinal absorption of iron and calcium between soy-based and cow's milk-based infant formulas in weanling rats. Methods: Twenty male Wistar rats, twenty-one days old on the first day of weaning, were used in this experiment, divided in two Groups, one Group was fed soy protein-based infant formula the other, cow's milk protein-based infant formula. During the study period (ten consecutive days) the animals received food and water ad libitum. Hematocrit and hemoglobin were evaluated on the first, fifth, and tenth days by the Wintrobe and cyanomethemoglobin methods. Feces and urine were collected, beginning on the fifth day, for three consecutive days. On the tenth day, hepatic iron content was also analyzed. Hepatic iron as well as fecal and urinary iron and calcium analyses were performed using an atomic absorption spectrophotometer. At thirty-one days of age, the animals were anesthetized with ketamine and xylazine and sacrificed by exsanguination via the vena cava. Results: The final concentration of hemoglobin in the group soy-based infant formula and milk-based infant formula were: 10.3±1.3g/dL and 10.9±1.0g/dL (p=0.310). The apparent absorption of iron and calcium, in that order, were: 73.4±10.2% and 70.2±9.5%; 97.2±0.7% and 97.6±1.0% (p=0.501; p=0.290). The apparent calcium retention was: 88.4% ±2.2 and 88.6±2.6% (p=0.848). Hepatic iron content was: 522.0±121.1mg/g and 527.8±80.5mg/g (p=0.907) . Conclusion: Intestinal iron and calcium absorption from soy-based infant formula is similar to that from milk-based infant formula in weanling rats.

Production of impure prebiotic galacto-oligosaccharides and their effect on calcium, magnesium, iron and zinc absorption in Sprague-Dawley rats

Prebiotic galacto-oligosaccharides (GOS) are important “functional foods” of current scenario and used for various health benefits including improved mineral absorption. In the present study, it was hypothesized that novel GOS mixture, produced through transgalactosylation, with significant amount of mono and disaccharides may enhance mineral absorption in Sprague-Dawley rats. The non-purified GOS having β-(1→6) and β-(1→3) glycosidic linkage, were evaluated for apparent absorption of calcium, magnesium, iron and zinc. The rats were divided into two main groups (n=12 per group, 6 male/6 female) fed on control and GOS (5g/100g) diet. The feces were collected after 7days interval for 28days. The weight gain, feed and water intake were statistically similar (p<0.05) in both groups irrespective of gender. Similarly, the absorption of minerals was statistically not different in both genders during whole study. The GOS diet significantly (p<0.05) improved absorption of Ca (34.55–39.93%), Mg (51.22–58.05%) and Fe (31.58–39.21%) as compared to control diet at the end of study. However, no impact on Zn absorption was observed during the whole study. It can be inferred that the use of non-purified GOS for 3–4 weeks may enhance Ca, Mg and Fe absorption.

Effect of feed grinding methods with and without expansion on prececal and total tract mineral digestibility as well as on interior and exterior egg quality in laying hens

The grinding of cereals by various milling methods as well as thermal treatment of feed may influence mineral digestibility and egg quality. The present study investigated the effect of feed produced by disc mill (D) and wedge-shaped disc mill (WSD), as mash (M) or expandate (E) on apparent ileal absorption (AIA) and apparent total digestibility (ATD) of calcium, phosphorus, magnesium, zinc, manganese, copper and iron, as well as on egg quality in laying hens. A total of 192 hens (Lohmann Brown) aged 19 wk, were assigned using a randomized design with a 2 × 2 factorial arrangement. Four experimental diets were offered ad libitum. Eggs were analyzed for weight, shape index, area, shell weight per unit surface area, yolk color, air cell, blood spot, Haugh unit, albumen and yolk measures (index, weight, height, width and length), shell measures (surface area, stability, density, thickness and membrane weight), as well as percent contents of albumen, yolk, shell, and shell membrane. The ATD for phosphorus, manganese, and copper was higher in WSD compared with D treatment (P = 0.028, P = 0.028 and P = 0.016, respectively). The interaction between milling methods and thermal treatment influenced ATD of copper (P = 0.033), which was higher in WSD+M group (41.0 ± 20.2) compared with D+E group (–3.21 ± 25.1), whereas no differences were observed for D+M (1.90 ± 37.8) and WSD+E (8.02 ± 36.2) groups. Egg stability tended to be higher in E compared with M treatment (P = 0.055). Albumen weight, percentage albumen weight, and albumen: yolk were higher and percentage yolk weight was lower in D compared with WSD treatment (P = 0.043, P = 0.027, P = 0.024, and P = 0.041, respectively). Number of blood spots was higher in E than M treatment (P = 0.053). In conclusion, use of a wedge-shaped disc mill resulted in higher ATD for phosphorus, manganese, and copper than use of a disc mill; however, digestibility for majority of minerals as well as egg quality parameters was comparable. Therefore, feed produced by either disc mill or wedge-shaped disc mill as mash or expandate may be used for laying hens without negative effects on egg quality.

Dietary protein derived from dried bonito fish improves type-2 diabetes mellitus-induced bone frailty in Goto-Kakizaki rats.

Type-2 diabetes mellitus (T2DM) induces bone frailty. Protein and polyunsaturated fatty acids (PUFA) contained in fish can be effective in enhancing bone quality, but the bone developing effect of fish protein containing less PUFA has not been evaluated in young animals with T2DM. We prepared a bonito fish (BF) and defatted BF (DBF) and hypothesized that protein contained in BF and DBF would be effective for mitigating the effects of T2DM-induced bone frailty. We mainly evaluated the effect of dietary BF and DBF on bone and apparent calcium absorption in young Goto-Kakizaki (GK) rats with T2DM. GK rats were divided into 3 groups based on diets (casein, BF, and DBF) and fed with each diet for 6 wk. Wistar rats were fed with the casein diet as a non-T2DM control. Bone mass, bone strength, apparent calcium absorption, and serum biochemical parameters were determined. The dry weight and strength of the femurs were lower in the GK rats than in the Wistar rats fed with the casein diet. Dietary intake of the BF and DBF diets enhanced the maximum load and dry weight of the femurs and suppressed the serum alkaline phosphatase activity although the apparent calcium absorption was lower in the GK rats fed with the BF and DBF diets than in those fed with the casein diet. These parameters were not different between the rats fed with the BF and DBF diets. Our data suggest that protein contained in the BF and DBF diets improved T2DM-induced bone frailty.

Prevention of osteoporosis by oral administration of phytate-removed and deamidated soybean β-conglycinin.

Phytate-removed and deamidated soybean β-conglycinin (PrDS) prepared by ion-exchange resins was supplemented to be 4% in the diet administered to ovariectomized rats to investigate its preventive effect on osteoporosis. The apparent calcium absorption rate decreased following ovariectomy and was not replenished by oral administration of phytate-removed soybean β-conglycinin (PrS) or casein. On the other hand, administration of PrDS restored the calcium absorption rate to the same level as the sham group. Markers of bone resorption, such as serum parathyroid hormone (PTH) and urinary deoxypyridinoline (DPD), increased, and the bone mineral density and breaking stress decreased following ovariectomy. However, PrDS supplementation suppressed the changes caused by the decrease in calcium absorption from the small intestine. Therefore, PrDS supplementation shows promise for the prevention of postmenopausal osteoporosis.

Zinc Deficiency Increases Serum Concentrations of Parathyroid Hormone through a Decrease in Serum Calcium and Induces Bone Fragility in Rats.

We hypothesized that a zinc-deficient diet alters the mineral (calcium, magnesium, and phosphorus) components of bones, as well as hormones related to bone remodeling, and negatively affects bone metabolism. Four-week-old male Wistar rats were randomly assigned to one of three groups for 4 wk: a zinc-adequate group (C, 30 ppm); a zinc-deficient group (ZD, 1 ppm); and a pair-fed group (PF, 30 ppm), which was pair-fed to the ZD group. Bone mineral density and bone mechanical properties were reduced in the ZD group compared to the C and PF groups. Compared with the C and PF groups, serum osteocalcin, a bone formation marker, was reduced in the ZD group. Conversely, urine deoxypyridinoline, a bone resorption marker, was increased in the ZD group compared to the C and PF groups. Calcium and phosphorus concentrations in bone were not different among all groups. The bone magnesium concentration was significantly higher in the ZD group than in the PF and C groups. Interestingly, compared with the C and PF groups, the ZD group showed a reduction in serum calcium concentration along with an increase in serum parathyroid hormone (PTH) concentration. Although serum 1,25-dihydroxycholecalciferol concentration was significantly higher in the ZD and PF groups than in the C group, the rate of apparent calcium absorption was significantly lower in the ZD group than in the C and PF groups. Therefore, zinc deficiency is suspected to cause an increase in serum PTH concentration owing to an inability to maintain calcium homeostasis, resulting in bone fragility.

Impact of thermal and organic acid treatment of feed on apparent ileal mineral absorption, tibial and liver mineral concentration, and tibia quality in broilers

Minerals play an important role for growth and bone stability in broilers. Thermal treatment and inclusion of organic acids in feed may affect the mineral absorption and tibial quality in broilers. The study was conducted to investigate the effect of thermal processing of feed including pelleting (P), long-term conditioning at 85°C (L), and expanding at 130°C (E) without and with 1.5% of an acid mixture containing 64% formic and 25% propionic acid on the apparent ileal absorption (AIA) of calcium, phosphorus, magnesium, potassium, sodium, iron, copper, manganese, and zinc, their concentrations in liver and tibia, as well as various tibial quality parameters in broilers. In total, 480 one-day-old Cobb broiler chicks were assigned using a completely randomized design with a 3 × 2 factorial arrangement. The ileal digesta, liver, and tibia were collected at d 35. The AIA of calcium and sodium was improved in group E compared with L (P ≤ 0.02 and P ≤ 0.01). Group P and E showed higher AIA for potassium than L (P ≤ 0.01). Bone ash content was increased in group E compared with L (P ≤ 0.04). The BW to bone weight ratio was lower and tibial zinc content was higher in group P compared with E (P ≤ 0.05). Tibial iron content was higher in group L than E (P ≤ 0.03). Acid addition did not affect AIA, mineral content in tibia, or tibial quality parameters. Thermal and acid treatment did not affect mineral concentrations in the liver, except an inconsistent interaction effect for DM content and sodium (P ≤ 0.03 and P ≤ 0.04, respectively). In conclusion, long-term thermal treatment reduced AIA of some minerals compared with short-term thermal treatments, but had no impact on tibia composition. Acid inclusion had no effect on AIA of minerals and tibia quality. Thermal treatment and the use of organic acids can therefore be considered as safe with regard to their impact on bone development in broilers.

Health-promoting effects in the gut and influence on lipid metabolism of Himanthalia elongata and Gigartina pistillata in hypercholesterolaemic Wistar rats

The intake of Himanthalia elongata and Gigartina pistillata from the Spanish Atlantic coasts was evaluated in Wistar rats. Both seaweed diets showed higher (p < 0.001) faecal excretion. Colonic fermentation increased (p < 0.001) total short-chain fatty acids (SCFAs) in Himanthalia-fed rats due to the higher (p < 0.001) levels of acetic, propionic and butyric acids. The intake of Gigartina increased (p < 0.001) propionic acid and decreased (p < 0.001) butyric acid. The apparent absorption and true retention of calcium and magnesium enhanced (p < 0.05) with Himanthalia diet, while Gigartina produced no significant effect. The serum concentration of HDL-C increased (p < 0.01), triglycerides (TGL) decreased (p < 0.001) and bile acids diminished (p < 0.001) in faeces of Himanthalia-fed rats. The Gigartina diet produced a decrease (p < 0.001) in TGL, total cholesterol (p < 0.01) and LDL-C (p < 0.05) in serum and reduced TGL in liver (p < 0.001). Thus, both seaweeds improved the lipid profile, and Himanthalia increased SCFA production and the absorption and retention of Ca and Mg as a result of the gut fermentation.

An Absorption Assessment of Eggshell Calcium Citrate Treated by PEF in Mice

Eggshell calcium citrate (ESCC) prepared by pulsed electric field (PEF) may be a new calcium resource to help treat and prevent calcium deficiency. An absorption assessment of ESCC prepared by PEF was performed in male mice with apparent calcium absorption. Compared with control group, ESCC prepared by PEF at doses of 133.0 mg/(kg•d) significantly improved the alkalinity phosphatase (ALP) activity (P &lt; 0.05) and decreased the levels of tartrate-resistant acid phosphatase (TRAP) (P &lt; 0.05). The ratio of calcium and phosphorus were in the normal range. Therefore, ESCC prepared by PEF could promote the absorption of calcium in mice.

Treatment of eggshell with casein phosphopeptide reduces the severity of ovariectomy-induced bone loss

It has been generally accepted that calcium intake prevents bone loss, and frequent fracture resulted from osteoporosis. However, it is still elusive as to how effective sole calcium intake is in preventing or attenuating the severity of osteoporosis. Here, we demonstrate the effects of eggshell-casein phosphopeptide (ES-CPP), and compared these effects those of calcium supplement, for restoring ovariectomy-mediated bone loss. CPP, synthesized from the hydrolysis of casein (0.5%) using trypsin, was added to the grinded ES and was then administered to the ovariectomized (OVX) rat at 100 mg/kg for 4 weeks. Urine and feces from each group were collected each day, and were used to calculate the apparent calcium absorption rate in a day. After 4 weeks incubation, blood and femoral bones were isolated for the analysis of parameters representing osteoporosis. The apparent calcium absorption rate was significantly increased in the ES-CPP treated groups, in comparison to both the OVX and the commercial calcium supplement (CCS) treated group. Notably, treatment with ES-CPP markedly enhanced the calcium content in femoral bone and the relative weight of femoral bone to body weight, though calcium content in serum was barely changed by treatment with ES-CPP. Parameters of osteoporosis, such as osteocalcin in serum and bone mineral density, were rescued by treatment with ES-CPP, compared to treatment with commercial calcium supplement. This finding strongly suggests the possible use of ES-CPP in preventing or attenuating the severity of postmenopausal osteoporosis.

Optimized extraction of calcium malate from eggshell treated by PEF and an absorption assessment in vitro

Under optimized pulsed electric field (PEF) treatment for production of eggshell calcium malate (ESCM) by one-factor-at-a-time test and ternary quadratic regression orthogonal combination design (TQROCD), an absorption assessment of ESCM treated by the best conditions of PEF were performed in male mice with apparent calcium absorption rate (ACAR), serum alkalinity phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP), serum calcium and serum phosphorus, length of femurs and skeletal calcium content were studied. The highest dissoluble calcium malate content (7.075mg/mL) was obtained with the 6.0% malic acid, the electric field intensity of 20kV/cm, and pulse duration of 24μs. In vitro, ESCM prepared by the best conditions of PEF at doses of 133.0mgkg−1d−1 for 70d not only significantly improve the ALP activity, the femur length and calcium content of bone of the mice (P<0.05) but also decreased the levels of TRAP (P<0.05). The ratio of calcium and phosphorus was in the normal range. PEF could be taken as a highly effective, environmentally friendly and energy-saving method for preparation of ESCM, which treated by PEF could promote the absorption of calcium in vitro, extraordinary can promote bone development and a healthy bone.