Ca Supplementation Research Articles

Vitamin D and Calcium in Osteoporosis, and the Role of Bone Turnover Markers: A Narrative Review of Recent Data from RCTs

Osteoporosis is a common disease, defined primarily by a low measured bone density, which is associated with an increased risk of fragility fractures. Low calcium intake and vitamin D deficiency seem to be positively correlated with the prevalence of osteoporosis. Although they are not suitable for the diagnosis of osteoporosis, the biochemical markers of bone turnover can be measured in serum and/or urine, enabling the assessment of the dynamic bone activity and the short-term effectiveness of the osteoporosis treatment. Calcium and vitamin D are essential for maintaining bone health. The aim of this narrative review is to summarize the effects of vitamin D and calcium supplementation separately and in combination, on bone density and circulating serum and blood plasma vitamin D, calcium, parathyroid hormone levels, markers of bone metabolism concentrations, and clinical outcomes, such as falls and osteoporotic fractures. We searched the PubMed online database to find clinical trials from the last five years (2016-April 2022). A total of 26 randomized clinical trials (RCTs) were included in this review. The present reviewed evidence suggests that vitamin D alone or in combination with calcium increases circulating 25(OH)D. Calcium with concomitant vitamin D supplementation, but not vitamin D alone, leads to an increase in BMD. In addition, most studies did not detect significant changes in circulating levels of plasma bone metabolism markers, nor in the incidence of falls. Instead, there was a decrease in blood serum PTH levels in the groups receiving vitamin D and/or Ca supplementation. The plasma vitamin D levels at the beginning of the intervention, and the dosing regimen followed, may play a role in the observed parameters. However, further study is needed to determine an appropriate dosing regimen for the treatment of osteoporosis and the role of bone metabolism markers.

Enhanced hydrogen production via staged catalytic gasification of rice husk using Ca(OH)2 adsorbent and Ce–Ni/γAl2O3 catalyst in a fluidized bed

Hydrogen production from rice husk was carried out via a two-stage system combining CLG (calcium looping gasification) using Ca(OH)2 adsorbent in a bubbling fluidized bed and catalytic reforming with Ce–Ni/γAl2O3 catalyst in a connected fixed bed. The results show that the maximum H2 concentration (69.16 vol%) and H2 yield (11.86 mmol g−1rice husk) are achieved at Ca/C (Ca(OH)2 to carbon molar ratio) = 1.5, H2O/C (H2O to carbon molar ratio) = 1.5, Tg (gasification temperature) = 500 °C, Tc (catalytic temperature) = 800 °C. The supplementation of fresh Ca(OH)2 at Ca/C of 0.5 during calcination helps to activate the regenerated CaO by hydration, maintaining its carbonation activity and CO2 adsorption. Ce–Ni/γAl2O3 catalyst promotes water gas shift (WGS), steam methane reforming (SMR), and C2–C3 hydrocarbons reforming, also exhibits excellent activity stability to maintain H2 concentration and H2 yield above 67.21 vol% and 11.67 mmol g−1rice husk, respectively, during 5 lifetime tests.

The Role of Calcium in Augmenting the Efficacy of Primary Homeostasis after Hemorrhagic Shock

Background: Traumatic Hemorrhagic Shock (THS) causes hypocalcemia (Ca). This study assesses how low Ca affects platelet (Plt) function. Study Design: A research registry was queried for 555 studies on 341 patients (pts) with THS requiring 14.2 units RBC, 8.4 units FFP, 3.6 units Plt, and 18.9 mEq Ca by end of O.R. (7.3 hours). Factors analyzed included Plt count, Ca, Bleeding Time (BT), Plt aggregation with ADP (PAadp) and collagen (PAcol), including Max PA, T1/2 PA, and rate PA, plus platelet release factors, beta thromboglobulin (BTG) and Plt PF-4. Studies were made in O.R. (26 pts) during fluid uptake phase II at 29 hours (216 pts), during fluid mobilization phase III at 56 hours (283 pts), and as outpatients (30 pts). Results: THS caused low Plts (1x10 SD) in O.R (107 ± 43), in phase II (96 ± 35), and in phase III (105 ± 59) and low Ca in O.R. (1.6 ± 0.3), in phase II (1.8 ± 0.2), and in phase III (2.1 ± 0.2). Low Plt and Ca correlated (p=<0.05) with PAadp and PAcol in O.R., phase II, and phase III. Ca correlated directly with Plt count, aggregation, BTG and PF-4, and inversely with BT. All outpatient studies were normal. Conclusion: THS causes Ca which leads to low Plt and impaired function. Routine Ca supplementation is recommended for THS.

The effects of concurrent increases in supplementation of calcium and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs

Abstract The objective of this study was to investigate the effects of concomitantly increasing supplementation of Ca and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs. There were eight experimental diets. The positive control (PC) one and two were formulated to contain 0.64% and 0.85% total Ca, respectively, whereas the dietary concentrations of other nutrients were identical and adequate. The negative control (NC) was deficient in total Ca (0.48%) and total P (0.41%). Five combinations of incremental levels of Ca and phytase (0.48% and 1,750 phytase units [FYT]/kg, 0.52% and 2,000 FYT/kg, 0.55% and 2,250 FYT/kg, 0.59% and 2,600 FYT/kg, and 0.63% and 3,000 FYT/kg) were added to the NC to establish the remaining five experimental diets. Each diet was fed to six pens of six pigs (three barrows and three gilts per pen). All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen during the trial. In the end, one pig per pen was euthanized to collect the right tibia and urine in bladder. The results showed that the pigs of NC gained less weight, consumed less feed, and utilized feed less efficiently than their counterparts fed the PC and the treatments with phytase (P < 0.01). With increasing supplementation of Ca and phytase, there was a tendency for gain:feed to decrease (P < 0.10). There was a significant reduction in bone dry weight; and in percentages, as well as weights of bone ash, Ca, and P; in pigs of NC compared with pigs of PC1, PC2, or phytase treatments. In comparison to PC2, PC1 and phytase treatments resulted in a higher percentage of bone P and greater weights of bone ash, Ca, and P (P < 0.05). There was no significant effect of concurrent supplementation of Ca and phytase on bone mineralization. The NC had significantly lower apparent total tract digestibility (ATTD) of Ca and P, lower concentrations of digestible Ca and P, but a higher ATTD Ca/ATTD P ratio than PC1, PC2, or the phytase treatments. The averages of ATTD of Ca and P in treatments with phytase were significantly higher than PC1 or PC2 (P < 0.01). With increasing addition of Ca and phytase, the ATTD of P, digestible Ca and P, and the ATTD Ca/ATTD P ratio increased linearly (P < 0.05), which contrasted with a linear reduction in ATTD of Ca (P < 0.05). Meanwhile, there was a linear (P < 0.01) increase in the concentration of urinary Ca. In conclusion, increasing the dietary supplementation of phytase in conjunction with the increasing dietary Ca level increased the dietary ATTD Ca/ATTD P ratio without damaging the absorption of P in the current study. The higher ATTD Ca/ATTD P ratio did not improve the bone mineralization markedly and thus the extra Ca was voided through urine.

The relationship between caffeine and its metabolites and bone mineral density in postmenopausal women: a cross-sectional analysis from the NHANES database.

We aim to explore the association between caffeine and its metabolites and bone mineral density (BMD) in postmenopausal women. Data of 4286 postmenopausal women were extracted from the National Health and Nutrition Examination Survey (NHANES) database in 2009-14 in this cross-sectional study. Weighted linear regression and stepwise regression analyses were used to screen the covariates. Weighted univariate and multivariate linear regression analyses were used to explore the associations between caffeine and its metabolites and BMD. The evaluation index was estimated value (β) with 95 % confidence intervals (CIs). We also explored these relationships in age subgroups. The median BMD level among the eligible women was 0⋅7 gm/cm2. After adjusting for covariates including age, body mass index (BMI), fat intake, Calcium (Ca) supplements, diabetes mellitus (DM), angina pectoris, parental history of osteoporosis (OP), anti-osteoporosis therapy, poverty income ratio (PIR), vitamin D (VD) supplements, coronary heart disease (CHD), and previous fracture, we found that caffeine intake was not significantly related to the BMD reduction (β = 0, P = 0⋅135). However, caffeine metabolites, including MethyluricAcid3, MethyluricAcid7, MethyluricAcid37, Methylxanthine3, and Methylxanthine37, were negatively associated with the BMD (all P < 0⋅05). In addition, MethyluricAcid37 and Methylxanthine37 were negatively associated with BMD in females aged <65 years old, while MethyluricAcid3 and Methylxanthine3 were noteworthy in those who aged ≥65 years old. The roles of caffeine and its metabolites in BMD reduction and OP in postmenopausal women needed further exploration.

Investing in Nutrition: A Global Best Investment Case

AbstractUndernutrition and micronutrient deficiencies are key drivers of infant and child mortality and are causes of impaired human potential for hundreds of millions of children every year. Investing in nutrition in the first 1,000 days from conception not only supports individual lifetime health, education, and productivity, but is also key to breaking the intergenerational cycle of malnutrition and enhance equitable development pathways for low- and middle-income countries. This paper provides a cost–benefit analysis of three nutrition interventions: 1) provision of preventive small-quantity lipid-based nutrient supplements (SQ-LNS) to children 6−23 months of age; 2) Complementary Feeding Promotion (CFP) for children 6−23 months of age; 3) provision of multiple micronutrient (MMN) and calcium (Ca) supplements to pregnant women. The benefit–cost ratios (BCRs) for MMN supplementation for pregnant women replacing iron and folic acid (37.5), as well as MMN and Ca combined (19-24), are the highest. The BCRs for CFP for children in the two highest socio-economic status (SES) quintiles and SQ-LNS for children in the three lowest SES quintiles are fairly similar at 16 and 14, respectively. The lowest BCR is for CFP for children in the three lowest SES quintiles due to the high cost of accomplishing behavioral change for improved complementary feeding in resource-poor households.

Efficient enhancement of calcium content in apple by calcium-encapsulated carbon dots

Efficient application of mineral nutrient supplements, such as calcium (Ca), is essential for ensuring crop yield and fruit quality. Calcium, however, usually has poor solubility, the tendency for calcification and element-antagonism, hindering its efficient absorption, which usually results in Ca deficiency in young leaves and fruits. Here, we developed Ca-encapsulated carbon dots (Ca-CDs) as nanofertilizers. These Ca-CDs have excellent solubility, great mobility, resistance to calcification, and no element-antagonism. Furthermore, this technique has an excellent capacity for being an efficient mode of Ca supplementation. Our results showed that the Ca-CDs promoted efficient Ca nutrition uptake and enhanced fruit Ca concentration. Furthermore, orchard applications proved that both foliar spraying and root irrigation of Ca-CDs could significantly enhance Ca content in apple fruit. This study informs the great agricultural application potential of nanomaterials in fruit calcium supplement.

The association of subclinical hypocalcemia at 4 days in milk with reproductive outcomes in multiparous Holstein cows

Delayed or persistent episodes of subclinical hypocalcemia (SCH) have been associated with reduced milk production and feed intake and they put cows at risk for additional disease development. However, little is known about the effect of delayed or persistent SCH on reproductive outcomes. The objectives of our study were to describe the association between SCH status at 4 d in milk (DIM) with the odds of pregnancy to first service and time to pregnancy through 150 DIM. Data were collected from multiparous Holstein cows (n = 697) from 4 farms in New York State that did not receive supplemental Ca during the first 5 DIM. Cows were classified into 1 of 2 SCH groups based on blood total Ca (tCa) at 4 DIM: normocalcemic (NC; n = 515) if tCa >2.2 mmol/L at 4 DIM or SCH (n = 182) if tCa ≤2.2 mmol/L at 4 DIM. We created a multivariable logistic regression model to assess the association between SCH group and pregnancy to first service and a time-to-event analysis to evaluate the effect of SCH group on the hazard of pregnancy by 150 DIM. Cows that were SCH at 4 DIM had lower odds of pregnancy to first service [odds ratio = 0.75, 95% confidence interval (CI) = 0.61 to 0.93, incidence = 18.1%] compared with their NC counterparts (incidence = 27.4%). Similarly, SCH cows tended to have a lower hazard of pregnancy by 150 DIM (hazard ratio = 0.82, 95% CI = 0.67 to 1.01, incidence = 65.4%) than NC cows (incidence = 70.7%). Our results indicate that delayed or prolonged reductions in blood Ca in the early postpartum period, resulting in SCH at 4 DIM, were associated with reduced reproductive outcomes in multiparous cows. Our findings, in conjunction with previous reports of the negative associations of delayed or persistent SCH on health and production, suggest that reductions in blood Ca beyond the first day of lactation might be indicative of maladaptation to lactation, and the ramifications can persist beyond the immediate postpartum period.

Increased Leaching Requirements Allow the Use of Source Water High in Salts for Plant Growth

Growers have different capabilities to alleviate salt stress in the growing substrate. One method to reduce substrate salt levels is to increase the volume of water applied during irrigation. This increases the leaching fraction (LF) which is the volume of water that drains from the growing substrate divided by the volume applied during irrigation. We can determine the leaching requirement (the minimum LF to maintain a desired substrate salt level) using the formula LF = ECw/5(ECe − ECw), where ECw is the electrical conductivity (EC) of the water and ECe is the desired EC of the substrate. We tested this formula to see if we could maintain an acceptable substrate EC of 4 dS⋅m−1 by modifying the LF for ‘Hope’ philodendron (Philodendron selloum) and ‘Tineke’ ficus (Ficus elastica) irrigated with tap water (EC 0.17 dS⋅m−1) or reclaimed wastewater (RWW) from Davie, FL, USA (EC 1.66 dS⋅m−1) and RWW from Hollywood, FL, USA (EC 2.93 dS⋅m−1). Shoot and root dry weight was greatest for both species with the tap water applied with a 5% LF. Increasing the LF to 15% for Davie RWW and a 55% for Hollywood RWW, produced acceptable growth for ‘Hope’ philodendron and ‘Tineke’ ficus. In our second experiment, we monitored the growth of ‘Looking Glass’ begonia (Begonia fibrous), ‘Freddie’ calathea (Calathea concinna), and ‘Déjà vu’ philodendron (Philodendron selloum) irrigated with tap water (EC 0.15 dS⋅m−1), salt water (EC 3.49 dS⋅m−1), or RWW (EC 3.48 dS⋅m−1) with LFs of 28%, 50%, or 65%. ‘Looking Glass’ begonia and ‘Freddie’ calathea growth was greater with 65% LF than 28% LF, respectively, for all three water sources. Philodendron growth was not different due to LF. However, philodendron, calathea, and begonia growth was greater with tap water and RWW than with saltwater. Although final leachate EC with saltwater and RWW was around 2 dS⋅m−1 using 50% LF, leachate sodium (Na) levels from salt watered plants was higher than for RWW or tap watered plants. We suspect that high Na levels in combination with lower potassium (K) and calcium (Ca) levels in the saltwater solution resulted in poor plant growth. Although the Na levels in leachate from RWW substrates was higher than tap watered substrates, Ca and K levels also were greater. Although we were able to use the salt equation to maintain substrate EC levels ranging from 2 to 4 dS⋅m−1, volumes of solution applied were two to three times higher when using RWW or salt water compared with tap water. We suspect that a balance between Na, Ca, and K supported better plant growth with RWW than salt water. However, additional work needs to be done on the benefits of supplemental Ca and K when using water high in salts or Na. This works suggests that in addition to monitoring EC, it also is important to monitor Na, Ca, and K concentrations.

The active core microbiota of two high-yielding laying hen breeds fed with different levels of calcium and phosphorus.

The nutrient availability and supplementation of dietary phosphorus (P) and calcium (Ca) in avian feed, especially in laying hens, plays a vital role in phytase degradation and mineral utilization during the laying phase. The required concentration of P and Ca peaks during the laying phase, and the direct interaction between Ca and P concentration shrinks the availability of both supplements in the feed. Our goal was to characterize the active microbiota of the entire gastrointestinal tract (GIT) (crop, gizzard, duodenum, ileum, caeca), including digesta- and mucosa-associated communities of two contrasting high-yielding breeds of laying hens (Lohmann Brown Classic, LB; Lohmann LSL-Classic, LSL) under different P and Ca supplementation levels. Statistical significances were observed for breed, GIT section, Ca, and the interaction of GIT section x breed, P x Ca, Ca x breed and P x Ca x breed (p < 0.05). A core microbiota of five species was detected in more than 97% of all samples. They were represented by an uncl. Lactobacillus (average relative abundance (av. abu.) 12.1%), Lactobacillus helveticus (av. abu. 10.8%), Megamonas funiformis (av. abu. 6.8%), Ligilactobacillus salivarius (av. abu. 4.5%), and an uncl. Fusicatenibacter (av. abu. 1.1%). Our findings indicated that Ca and P supplementation levels 20% below the recommendation have a minor effect on the microbiota compared to the strong impact of the bird’s genetic background. Moreover, a core active microbiota across the GIT of two high-yielding laying hen breeds was revealed for the first time.

Calcium chloride is a better calcium source rather than calcium carbonate for weanling pigs.

Two experiments were conducted to evaluate the effects of calcium (Ca) levels in weanling pigs (Landrace × Yorkshire × Duroc). In experiment 1, one hundred and eighty weanling pigs were randomly allotted to one of the three treatments. The treatments were low (Ca 0.60% in phase 1 and 0.50% in phase 2), standard (Ca 0.72% in phase 1 and 0.66% in phase 2), and high (Ca 0.84% in phase 1 and 0.72% in phase 2). In experiment 2, hundred and forty weanling pigs were randomly assigned to one of four treatments differing in Ca levels (high and low) and sources (CaCl2 and CaCO3) in a 2 × 2 factorial arrangement. There were 10 pigs per replicate in both experiments, with 6 replicates in each treatment, and they were conducted in two phases (phase 1, days 0–14; phase 2, days 15–28). In experiment 1, body weight (BW), average daily gain (ADG), and growth to feed ratio (G/F) increased as the Ca level decreased (p < 0.05). P digestibility was higher in the low-Ca diet group than in the high-Ca diet group (p <0.05). In experiment 2, the final BW, ADG, and G/F increased in the CaCl2 diet group compared with the case in the CaCO3 diet group (p < 0.05). The digestibility of crude protein (CP), Ca, and P was higher in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). Cl− levels were higher in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). The bicarbonate (HCO3−), base excess (BE), and electrolyte balance (EB) levels were lower in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). Hematocrit increased as the Ca level decreased (p < 0.05). The HCO3− interacted with the Ca sources and thus, affected the Ca levels (p < 0.05). Bone ash, Ca, and P were downregulated in the low-Ca diet group compared with the case in the high-Ca diet group. Overall, the low dietary Ca supplementation led to greater growth performance. Furthermore, CaCl2 appeared to be a better Ca source than CaCO3 because of the greater digestibility of CP, Ca, and P, and improved EB.

Optimum dietary calcium requirement of Hypophthalmichthys molitrix juveniles

A 13-week feeding trial was conducted to determine the optimum dietary calcium (Ca) requirement of juvenile silver carp, Hypophthalmichthys molitrix (3.20 ± 0.02 g). For this, five isonitrogenous semipurified diets containing 2.3, 5.3, 8.3, 11.1 and 14.2 g/kg Ca levels were formulated. The growth performance of juveniles was significantly affected by Ca supplementation with the maximum increase recorded at 8.3 g/kg Ca and stabilized thereafter (p < 0.05). Whole-body protein and ash contents were increased (p < 0.05) with increased dietary Ca up to 8.3 g/kg and then levelled off (p < 0.05). However, the moisture and fat contents in whole body were decreased (p < 0.05) with the increased Ca supplementation up to 8.3 g/kg and plateaued thereafter. Calcium and P concentration showed an increasing trend (p < 0.05) with the increasing Ca level up to 11.1 g/kg in whole body and 8.3 g/kg in bones and scales. However, Mg and Zn concentrations were decreased (p < 0.05) with increasing dietary Ca levels. The highest alkaline phosphatase (ALP) activity (p < 0.05) was recorded in the fish-fed diet containing 11.1 g/kg Ca diet; however, serum Ca, P and Ca/P ratio remained unaffected (p > 0.05). Broken line regression showed that 8.45 g/kg Ca is the optimal requirement for the growth of silver carp. Conclusively, an increase in Ca supplementation up to 8.3 g/kg significantly improved the overall performance of silver carp without urging the negative effects.

Effect of Dietary Supplementation with Calcium, Phosphorus and Vitamin D3 on Growth Performance, Nutrient Digestibility, and Serum Biochemical Parameters of Growing Blue Foxes.

Simple SummaryNutrient requirements have previously been established for minks and foxes, but not specifically for blue foxes. Over the past thirty years, an increase in body size was observed in the farmed blue fox because of the development of modern breeding technology. Hence, it is necessary to study the interaction mechanisms and requirements of calcium (Ca) and vitamin D3 (VD3) according to the body weights and conditions of farmed blue foxes to guide modern farms. The objective of the present study was to study the influence of dietary Ca and VD3 supplemental levels on the nutrient digestibility, growth performance, and serum biochemical indices of growing blue foxes. The results indicated that the Ca and VD3 doses showed promising effects on growth performance and nutrient digestibility in growing blue foxes and could reduce fecal nitrogen (N) and phosphorus (P) via improvement in protein and P utilization.Based on the randomized design, a 3 × 3 factorial experiment was designed to examine the effects of dietary calcium (Ca), phosphorus (P), and vitamin D3 (VD3) supplemental levels with a fixed 1.5/1 ratio of Ca to P on the growth performance, nutrient digestibility, and serum biochemical indices blue foxes’ growth. In total, 135 male blue foxes with the age of 60 days were randomly divided into 9 groups each with 15 blue foxes. The blue foxes belonging to the nine treatment groups were fed Ca supplementation (0%, 0.4%, or 0.8%) and VD3 supplementation (1000, 2000, or 4000 IU/kg DM). The base diet contained 0.8% Ca and 327 IU/kg VD3. The dosage of VD3 in blue foxes showed a significant impact on their growth performance (p < 0.05). The Ca dosage had a linear effect on the digestibility of the CP and carbohydrates (CHO) (p < 0.05). In conclusion, the results indicated that the Ca and VD3 doses showed promising effects on growth performance and nutrient digestibility in growing blue foxes and could reduce fecal N and P via improvement in protein and P utilization.

Role of Calcium Supplementation on Pregnancy Induced Hypertension Outcomes

Background: Pregnancy induced hypertension (PIH), is an important cause of both maternal and perinatalmorbidity and mortality. Low dietary calcium (Ca) intake represents a factor associated with an increasedincidence of hypertensive disease in general and in pregnant population in most low and middle income countries.Ca supplementation has the potential to reduce adverse gestational outcomes of PIH.Aim: To assess the effects of low-dose Ca supplementation on PIH outcomes.Method: A single- blind, randomized controlled trial was conducted in January through March, 2021. A totalnumber of 66 pregnant women with PIH at their 20th week of gestation attended maternal care outpatient inBaghdad Medical City were assigned randomly in two groups those received Ca supplementation 500 mg/day vsnone and follow up both groups till delivery for outcomes.Results: A significant reduction in diastolic blood pressure mean (93.28 mmHg vs. 88.62 mmHg, P= 0.015) andalmost significant reduction in systolic blood pressure mean (149.65 mmHg vs. 142.58 mmHg, P= 0.051) in theparticipants after receiving Ca supplements. Pre eclampcia (10.3% vs. 45.9%, P = 0.002), Low birth weight (6.9%vs. 40.5%, P = 0.002), Pre term delivery (10.3% vs. 43.2%, P=0.003), and admissions to neonatal intensive care unit(10.3% vs. 45.9%, P = 0.002) were significantly lower in the intervention group.Conclusion: Ca supplementation of 500 mg daily started at 20th week of gestation associated with reduction ofmaternal blood pressure, pre-eclampcia, preterm delivery, low birth weight and admission to neonatal intensivecare unit especially in a low dietary Ca intake mothers.

The role of environmental calcium in the extreme acid tolerance of northern banjo frog (Limnodynastes terraereginae) larvae.

Many aquatically respiring animals acutely exposed to low pH waters suffer inhibition of ion uptake and loss of branchial (gill) epithelial integrity, culminating in a fatal loss of body Na+. Environmental calcium levels ([Ca2+]e) are pivotal in maintaining branchial junction integrity, with supplemental Ca2+ reversing the negative effects of low pH in some animals. Tolerance of some naturally acidic environments by aquatic animals is further complicated by low [Ca2+]e, yet many of these environments are surprisingly biodiverse. How animals overcome the damaging actions of low pH and low environmental Ca2+ remains unknown. We examined the effects of [Ca2+]e on the response to low pH in larvae of the highly acid-tolerant frog Limnodynastes terraereginae. Acute exposure to low pH water in the presence of low (5 μmoll-1) [Ca2+]e increased net Na+ efflux. Provision of additional [Ca2+]e reduced net Na+ efflux, but the effect was saturable. Acclimation to both low and high (250 μmoll-1) [Ca2+]e improved the resistance of larvae to Na+ efflux at low pH. Exposure to the Ca2+ channel inhibitor ruthenium red resulted in an abrupt loss of tolerance in low pH-acclimated larvae. Acclimation to acidic water increased branchial gene expression of the intracellular Ca2+ transport protein calbindin, consistent with a role for increased transcellular Ca2+ trafficking in the tolerance of acidic water. This study supports a role for [Ca2+]e in promoting branchial integrity and highlights a potential mechanism via the maintenance of transcellular Ca2+ uptake in the acid tolerance of L. terraereginae larvae.

Effect of exogenous l-aspartate nano‑calcium on root growth, calcium forms and cell wall metabolism of Brassica napus L.

Currently, l-aspartate nano‑calcium (Ca(L-asp)-NPs) has been sued as a calcium supplement for humans, but its effects on plants are not well elucidated. This study aimed to investigate the effect of exogenous Ca(L-asp)-NPs on the growth of rapeseed (Brassica napus L.) for the first time. Different concentrations (0, 50, 100, 150, and 200 mg L−1) of Ca(L-asp)-NPs and 1.18 g L−1 Ca(NO3)2 were used in the nutrient solution. The results indicated that Ca2+ released from Ca(L-asp)-NPs were absorbed by the roots, and had a significant effect on plant height, root length, biomass accumulation, and root structure formation, especially on the growth and development of coarse roots at 100 mg L−1 Ca(L-asp)-NPs. Calcium (Ca) accumulation, Ca-pectinate, Ca-phosphate and Ca‑carbonate, and Ca-oxalate in plant roots and leaves were positively linked with Ca(L-asp)-NPs concentration. For cell wall, Ca(L-asp)-NPs treatment increased the content of pectin, and the activity of cell wall degrading enzymes in roots, such as pectin methyl-esterase (PME), cellulose enzyme (CE), polygalacturonase (PG), and β-galactosidase (β-Gal). For cell membrane osmotic regulation, Ca(L-asp)-NPs promoted the accumulation of soluble sugar and soluble protein. This finding suggests that 100 mg L−1 Ca(L-asp)-NPs had the best growth-promoting effect on rapeseed. This study provides a valuable reference for exogenous Ca(L-asp)-NPs as new nano Ca supplements for plant growth.

Influence of Calcium and Nonphytate Phosphorus (NPP) on Meat-Type Quail’s Growth, Carcass Features, and Tibia Indices

This study aimed to evaluate the role of increasing dietary calcium (Ca) and non-phytate phosphorus (NPP) supplementation on the growth, carcass, edible portions, and tibia indicators of growing quail. The current study was conducted in a 3×3 factorial design, for this, 360 1-wk-old quails were haphazardly assigned to nine groups, each group is with three gradual levels of Ca (0.60, 0.90, and 1.20 %) and NPP (0.20, 0.40 and 0.60 %). Each group was divided into five replicates with eight-quail each. Results of the study suggested that except at 2 and 6 weeks of age, dietary Ca level did not exhibit any significant (P &gt; 0.05) impact on body weight. Similarly, in the case of NPP, apart from the live weight at 2 and 3 weeks of age, NPP did not have a significant impact on live body weight. Further, in comparison to the low Ca level, the moderate or high Ca levels have higher values of body weight gain. During all the experiments, dietary Ca, NPP, or their mixtures had no significant (P &gt; 0.05) impact on feed consumption. Similarly, feed conversion rate and carcass metrics were also not affected by the individual or combined application of Ca or NPP supplementation Similarly, dietary intakes of Ca or P did not have any significant effect on the various tibia indicators (P &gt; 0.05). Results of the study can be concluded that the effect of the Ca and NPP levels in Japanese quail diets is lowered and it does not much affect the growth rate, feed utilization, carcass yields, edible components, or tibia indices.

Alleviation of cadmium toxicity in Zea mays L. through up-regulation of growth, antioxidant defense system and organic osmolytes under calcium supplementation.

Calcium (Ca) is a macronutrient and works as a modulator to mitigate oxidative stress induced by heavy metals. In this study, we investigated the role of Ca to ameliorate the Cd toxicity in Zea mays L. by modulating the growth, physio-biochemical traits, and cellular antioxidant defense system. Maize genotype Sahiwal-2002 was grown under a controlled glasshouse environment with a day/night temperature of 24 ± 4°C/14 ± 2°C in a complete randomized design with three replications and two Cd levels as (0 and 150 μM) and six regimes of Ca (0, 0.5, 1, 2.5, 5, and 10 mM). Maize seedlings exposed to Cd at 150 μM concentration showed a notable decrease in growth, biomass, anthocyanins, chlorophylls, and antioxidant enzymes activities. A higher level of Cd (150 μM) also caused an upsurge in oxidative damage observed as higher electrolyte leakage (increased membrane permeability), H2O2 production, and MDA accumulation. Supplementation of Ca notably improved growth traits, photosynthetic pigments, cellular antioxidants (APX, POD, and ascorbic acid), anthocyanins, and levels of osmolytes. The significant improvement in the osmolytes (proteins and amino acids), and enzymatic antioxidative defense system enhanced the membrane stability and mitigated the damaging effects of Cd. The present results concluded that exogenously applied Ca potentially improve growth by regulating antioxidants and enabling maize plants to withstand the Cd toxicity.

Amelioration of radiation-induced liver damage by p-coumaric acid in mice

Radiation-induced liver damage (RILD) is a spiny problem in radiotherapy or other circumstances that exposure to radiation. The need for radioprotective agent is increasing to protect liver tissue. This study aimed to explore the hepatoprotective effect of p-coumaric acid (CA) against RILD. C57BL/6 male mice were exposed to 4 Gy irradiation and administrated with CA for 4 days starting on the same day of irradiation. Mice were sacrificed to obtain blood and liver tissues on day 3.5 or 14 post irradiation, respectively. The blood and liver tissues were collected. As compared with the only irradiated group, CA supplementation improved liver morphology, decreased serum alanine aminotransferase and aspartate aminotransferase, inhibited BCL2-associated X (BAX) protein expression, and improved the mice hematopoietic function. CA at the dose of 100 mg/kg body weight showed better effect compared to the other doses. Thus, CA might possess potential to protect against RILD.

Calcium ion can alleviate ammonia inhibition on anaerobic digestion via balanced-strengthening dehydrogenases and reinforcing protein-binding structure: Model evaluation and microbial characterization

Experimental investigation and model simulation was combined to identify the effect of metal ions on mitigating ammonia inhibition during anaerobic digestion. Five metal ions (Ca, Mg, Cu, Zn, Fe) were tested in reactors with 1 g-glucose/L/d and 5 g-N/L under fed batch operation. Ca addition was considered the optimal approach with a 25% increment in methane production via balanced-strengthening dehydrogenases and reinforcing protein-binding structure. Gene-sequencing results suggested 50% and 15% increment in acetotrophic-related and hydrogenotrophic-related dehydrogenases, respectively, after Ca addition. The Anaerobic Digestion Model No.1 was modified by introducing lactate-related reactions, syntrophic acetate oxidation process, and kinetic equation of metal ions, with satisfactory predictions of methane and intermediates (R2 > 0.80). The lowest affinity constant KI_MI value was obtained with Ca supplement, indicating the highest conversion rate of substrates to methane. The model evaluation revealed the balanced ratio on the enzyme contribution of acetotrophic to hydrogenotrophic methanogenesis.