Calcium deficiency is associated with malnutrition risk in patients with inflammatory bowel disease.

BACKGROUND AND AIM: Patients with inflammatory bowel disease (IBD) often have the condition of malnutrition, which can be presented as sarcopenia, micronutrient deficiencies, etc. Trace elements (magnesium, calcium, iron, copper, zinc, plumbum and manganese) belonging to micronutrients, are greatly vital for the assessment of nutritional status in humans. Trace element deficiencies are also the main manifestation of malnutrition. Calcium (Ca) has been proved to play an important part in maintaining body homeostasis and regulating cellular function. However, there are still a lack of studies on the association between malnutrition and Ca deficiency in IBD. This research aimed to investigate the role of Ca for malnutrition in IBD patients. METHODS: We prospectively collected blood samples from 149 patients and utilized inductively coupled plasma mass spectrometry to examine their venous serum trace element concentrations. Logistic regression analyses were used to investigate the association between Ca and malnutrition. Receiver operating characteristic (ROC) curves were generated to calculate the cutoffs for determination of Ca deficiency. RESULTS: Except Ca, the concentrations of the other six trace elements presented no statistical significance between non-malnutrition and malnutrition group. In comparison with the non-malnutrition group, the serum concentration of Ca decreased in the malnutrition group (89.36 vs 87.03 mg/L, p = 0.023). With regard to ROC curve, Ca < 87.21 mg/L showed the best discriminative capability with an area of 0.624 (95% CI: 0.520, 0.727, p = 0.023). Multivariate analyses demonstrated that Ca < 87.21 mg/L (OR = 3.393, 95% CI: 1.524, 7.554, p = 0.003) and age (OR = 0.958, 95% CI: 0.926, 0.990, p = 0.011) were associated with malnutrition risk. Serum Ca levels were significantly lower in the malnutrition group than those in the non-malnutrition group among UC patients, those with severe disease state or the female group. CONCLUSIONS: In patients with IBD, Ca deficiency is an independent factor for high malnutrition risk.

Functional Characterization of Core and Unique Calcite-Dissolving Bacteria Communities from Peanut Fields.

Calcium deficiency is a leading cause of reduced peanut (Arachis hypogaea) seed quality and has been linked to increased disease susceptibility, specifically to soilborne fungal pathogens. Sufficient calcium at flowering time is critical to ensure proper pod development. Calcite-dissolving bacteria (CDB) isolated from farming fields can dissolve calcite (CaCO3) on plates and increase soluble calcium levels in soil. However, the phylogenetic diversity and geographic distribution of CDB is unclear. Here, we surveyed soil samples from 15 peanut-producing fields in three regions in southern Georgia, representing distinct soil compositions. We isolated CDB through differentiating media and identified 52 CDB strains. CDB abundance was not associated with any of the soil characteristics we evaluated. Three core genera, represented by 43 strains, were found in all three regions. Paenibacillus was the most common CDB found in all regions, making up 30 of the 52 identified strains. Six genera, represented by eight strains, are unique to one region. Members of the core and unique communities showed comparable solubilization indexes on plates. We conclude that a diversified phylogenetic population of CDB is present in Georgia peanut fields. Despite the phylogenetic diversity, as a population, they exhibit comparable functions in solubilizing calcite on plates.

Genome-Wide Identification and Characterization of CDPK Gene Family in Cultivated Peanut (Arachis hypogaea L.) Reveal Their Potential Roles in Response to Ca Deficiency.

This study identified 45 calcium-dependent protein kinase (CDPK) genes in cultivated peanut (Arachis hypogaea L.), which are integral in plant growth, development, and stress responses. These genes, classified into four subgroups based on phylogenetic relationships, are unevenly distributed across all twenty peanut chromosomes. The analysis of the genetic structure of AhCDPKs revealed significant similarity within subgroups, with their expansion primarily driven by whole-genome duplications. The upstream promoter sequences of AhCDPK genes contained 46 cis-acting regulatory elements, associated with various plant responses. Additionally, 13 microRNAs were identified that target 21 AhCDPK genes, suggesting potential post-transcriptional regulation. AhCDPK proteins interacted with respiratory burst oxidase homologs, suggesting their involvement in redox signaling. Gene ontology and KEGG enrichment analyses affirmed AhCDPK genes' roles in calcium ion binding, protein kinase activity, and environmental adaptation. RNA-seq data revealed diverse expression patterns under different stress conditions. Importantly, 26 AhCDPK genes were significantly induced when exposed to Ca deficiency during the pod stage. During the seedling stage, four AhCDPKs (AhCDPK2/-25/-28/-45) in roots peaked after three hours, suggesting early signaling roles in pod Ca nutrition. These findings provide insights into the roles of CDPK genes in plant development and stress responses, offering potential candidates for predicting calcium levels in peanut seeds.

The physio-biochemical characterization reflected different calcium utilization efficiency between the sensitive and tolerant peanut accessions under calcium deficiency.

Peanut yield in southern China is usually limited by calcium deficiency in soil. Most previous studies have found that small-seed varieties showed higher tolerance than large-seed varieties (e.g. Virginia type) under calcium deficiency, however, our preliminary research found that sensitive varieties also existed in small-seed counterparts. Few studies have been conducted to characterize low-calcium tolerance among small-seed germplasms with genetic diversity, and the differences in physiological characteristics between sensitive and tolerant varieties has not been reported yet. Thus, in order to better understand such differences, the current study firstly collected and characterized a diversity germplasm panel consisting of 50 small-seed peanut genotypes via a 2-year field trial, followed by the physiological characterization in sensitive (HN032) and tolerant (HN035) peanut genotypes under calcium deficiency. As a result, the adverse effects brought by calcium deficiency on calcium uptake and distribution in HN032 was much larger than HN035. In details, calcium uptake in the aboveground part (leaves and stems) was reduced by 16.17% and 33.66%, while in the underground part (roots and pods), it was reduced by 13.69% and 68.09% under calcium deficiency for HN035 and HN032, respectively; The calcium distribution rate in the pods of HN035 was 2.74 times higher than HN032. The utilization efficiency of calcium in the pods of HN035 was 1.68 and 1.37 times than that of HN032 under calcium deficiency and sufficiency, respectively. In addition, under calcium deficiency conditions, the activities of antioxidant enzymes SOD, POD, and CAT, as well as the MDA content, were significantly increased in the leaves of HN032, peanut yield was significantly reduced by 22.75%. However, there were no significant changes in the activities of antioxidant enzymes, MDA content, and peanut yield in HN035. Therefore, higher calcium absorption and utilization efficiency may be the key factors maintaining peanut yield in calcium-deficient conditions for tolerant genotypes. This study lays a solid foundation for selecting low-calcium tolerant varieties in future peanut breeding.

Inhibition of NPR1 Leads to Shoot Growth Improvement under Low-Calcium Conditions in Arabidopsis.

Under low-Ca conditions, plants accumulate salicylic acid (SA) and induce SA-responsive genes. However, the relationship between SA and low-Ca tolerance remains unclear. Here, we demonstrated that the inhibition or suppression of nonexpressor of pathogenesis-related 1 (NPR1) activity, a major regulator of the SA signaling pathway in the defense response, improves shoot growth under low-Ca conditions. Furthermore, mutations in phytoalexin-deficient 4 (PAD4) or enhanced disease susceptibility 1 (EDS1), which are upstream regulators of NPR1, improved shoot growth under low-Ca conditions, suggesting that NPR1 suppressed growth under low-Ca conditions. In contrast, growth of SA induction-deficient 2-2 (sid2-2), which is an SA-deficient mutant, was sensitive to low Ca levels, suggesting that SA accumulation by SID2 was not related to growth inhibition under low-Ca conditions. Additionally, npr1-1 showed low-Ca tolerance, and the application of tenoxicam-an inhibitor of the NPR1-mediated activation of gene expression-also improved shoot growth under low Ca conditions. The low-Ca tolerance of double mutants pad4-1, npr1-1 and eds1-22 npr1-1 was similar to that of the single mutants, suggesting that PAD4 and EDS1 are involved in the same genetic pathway in suppressing growth under low-Ca conditions as NPR1. Cell death and low-Ca tolerance did not correlate among the mutants, suggesting that growth improvement in the mutants was not due to cell death inhibition. In conclusion, we revealed that NPR1 suppresses plant growth under low-Ca conditions and that the other SA-related genes influence plant growth and cell death.

Calcium concentration of drinking water to improve calcium intake: A simulation study.

The risk of inadequate calcium intake is a worldwide problem. We performed a simulation exercise on the impact, effectiveness, and safety of increasing calcium levels in drinking water using the 2019 Health and Nutrition National Survey of Argentina, which provides water intake and water sources data at the individual level. We simulated the distribution of calcium intake assuming a calcium concentration of 100 mg of calcium per liter of tap water and 400 mg of calcium per liter of bottled water. After the simulation, all population groups had a slightly improved calcium intake. Higher impacts were observed in adults, as reported water intake was higher in adults 19-51 years old. In young adult women, the estimated calcium intake inadequacy decreased from 91.0% to 79.7% when calcium was increased in tap water and to 72.2% when calcium was increased in tap and bottled water. The impact was lower in adolescents and older adults who have higher calcium recommendations and reported lower water intake. Increased calcium concentration of water could improve calcium intake in Argentina, especially in adults as their reported water intake is higher. Combining more than one strategy to improve calcium intake might be required for countries like Argentina with low calcium intake.

Exogenous brassinosteroid alleviates calcium deficiency induced tip-burn by regulating calcium transport in Brassica rapa L. ssp. pekinensis.

Mini Chinese cabbage (Brassica rapa L. ssp. Pekinensis) plays an important role in the supply of summer vegetables on the plateau in western China. In recent years, tip-burn has seriously affected the yield, quality and commodity value of mini Chinese cabbage. Calcium (Ca2+) deficiency is a key inducer of tip-burn. As a new type plant hormone, brassinolide (BR) is involved in regulating a variety of biotic and abiotic stresses. To explore the alleviation role of BR in tip-burn caused by Ca2+ deficiency, a hydroponic experiment was conducted to study the relationship between BR and Ca2+ absorption and transport. The results showed that foliar spraying with 0.5 µM BR significantly reduced tip-burn incidence rate and disease index of mini Chinese cabbage caused by Ca2+ deficiency. Moreover, the dynamic monitoring results of tip-burn incidence rate showed that the value reached the highest on the ninth day after treatment. BR promoted the Ca2+ transport from roots to shoots and from outer leaves to inner leaves by increasing the activities of Ca2+-ATPase and H+-ATPase as well as the total ATP content, which provided power for Ca2+ transport. In addition, exogenous BR upregulated the relative expression levels of BrACA4, BrACA11, BrECA1, BrECA3, BrECA4, BrCAX1, BrCAS and BrCRT2, whereas Ca2+ deficiency induced down-regulation. In conclusion, exogenous BR can alleviate the Ca2+-deficiency induced tip-burn of mini Chinese cabbage by promoting the transport and distribution of Ca2+.

Cow's milk allergy in children impacts parental or caregiver calcium intake.

Food allergies have become a global epidemic, affecting more than 10% of the population and 8% of children worldwide. Eliminating or limiting a food group from the diet can adversely impact micronutrient consumption. Milk allergies can impact the amount of calcium consumed in the diet, serving as a barrier to meeting daily calcium needs. Previous research evaluates the nutritional impact food allergies may have on children diagnosed with food allergies; however, there is a marked gap in literature that investigates the impact that children's allergy may have on their parent or caregiver. We hypothesized that milk elimination in a child's diet resulting from a milk allergy is associated with inadequate calcium intake among parents. Study participants (n = 55) lived in the United States and included parents or caregivers of a child with a diagnosed milk allergy (experimental group) and parents of a child without a milk allergy (control group). Calcium intake was estimated by using the validated Calcium Assessment Tool. Results demonstrated that the experimental group consumed significantly less calcium (273 mg/d) than the control group (520 mg/d; P < .01). Notably, both groups consumed inadequate calcium relative to the calcium Recommended Dietary Allowance for adults of 1000 mg/d, although calcium supplementation was not assessed in this study. Key findings from this study indicate widespread inadequate dietary calcium intake and suggest a need for increased calcium consumption in this population.

G protein signaling and metabolic pathways as evolutionarily conserved mechanisms to combat calcium deficiency.

Calcium (Ca) deficiency causes necrotic symptoms of foliar edges known as tipburn; however, the underlying cellular mechanisms have been poorly understood due to the lack of an ideal plant model and research platform. Using a phenotyping system that quantitates growth and tipburn traits in the model bryophyte Marchantia polymorpha, we evaluated metabolic compounds and the Gß-null mutant (gpb1) that modulate the occurrence and expansion of the tipburn. Transcriptomic comparisons between wild-type and gpb1 plants revealed the phenylalanine/phenylpropanoid biosynthesis pathway and reactive oxygen species (ROS) important for Ca deficiency responses. gpb1 plants reduced ROS production possibly through transcriptomic regulations of class III peroxidases and induced the expression of phenylpropanoid pathway enzymes without changing downstream lignin contents. Supplementation of intermediate metabolites and chemical inhibitors further confirmed the cell-protective mechanisms of the phenylpropanoid and ROS pathways. Marchantia polymorpha, Arabidopsis thaliana, and Lactuca sativa showed comparable transcriptomic changes where genes related to phenylpropanoid and ROS pathways were enriched in response to Ca deficiency. In conclusion, our study demonstrated unresolved signaling and metabolic pathways of Ca deficiency response. The phenotyping platform can speed up the discovery of chemical and genetic pathways, which could be widely conserved between M. polymorpha and angiosperms.

Comparative Transcriptome and Co-Expression Network Analyses Reveal the Molecular Mechanism of Calcium-Deficiency-Triggered Tipburn in Chinese Cabbage (Brassica rapa L. ssp. Pekinensis).

Chinese cabbage tipburn is characterized by the formation of necrotic lesions on the margin of leaves, including on the insides of the leafy head. This physiological disorder is associated with a localized calcium deficiency during leaf development. However, little information is available regarding the molecular mechanisms governing Ca-deficiency-triggered tipburn. This study comprehensively analysed the transcriptomic comparison between control and calcium treatments (CK and 0 mM Ca) in Chinese cabbage to determine its molecular mechanism in tipburn. Our analysis identified that the most enriched gene ontology (GO) categories are photosynthesis, thylakoid and cofactor binding. Moreover, the KEGG pathway was most enriched in photosynthesis, carbon metabolism and carbon fixation. We also analyzed the co-expression network by functional categories and identified ten critical hub differentially expressed genes (DEGs) in each gene regulatory network (GRN). These DEGs might involve abiotic stresses, developmental processes, cell wall metabolism, calcium distribution, transcription factors, plant hormone biosynthesis and signal transduction pathways. Under calcium deficiency, CNX1, calmodulin-binding proteins and CMLs family proteins were downregulated compared to CK. In addition, plant hormones such as GA, JA, BR, Auxin and ABA biosynthesis pathways genes were downregulated under calcium treatment. Likewise, HATs, ARLs and TCP transcription factors were reported as inactive under calcium deficiency, and potentially involved in the developmental process. This work explores the specific DEGs' significantly different expression levels in 0 mM Ca and the control involved in plant hormones, cell wall developments, a light response such as chlorophylls and photosynthesis, transport metabolism and defence mechanism and redox. Our results provide critical evidence of the potential roles of the calcium signal transduction pathway and candidate genes governing Ca-deficiency-triggered tipburn in Chinese cabbage.

Role of GSL8 in low calcium tolerance in Arabidopsis thaliana.

Calcium (Ca) deficiency affects the yields and quality of agricultural products. Susceptibility to Ca deficiency varies among crops and cultivars; however, its genetic basis remains largely unknown. Genes required for low Ca tolerance in Arabidopsis thaliana have been identified. In this study, we identified a novel gene required for low Ca tolerance in A. thaliana. We isolated a mutant sensitive to low Ca concentrations and identified Glucan synthase-like (GSL) 8 as a gene responsible for low Ca tolerance. GSL8 is a paralog of the previously identified low Ca tolerance gene GSL10, which encodes ß-1,3 glucan(callose) synthase. Under low Ca conditions, the shoot growth of gsl8 mutants were inhibited compared to wild-type plants. A grafting experiment indicated that the shoot, but not root, genotype was important for the shoot growth phenotype. The ectopic accumulation of callose under low Ca conditions was reduced in gsl8 mutants. We further investigated the interaction between GSL8 and GSL10 by testing the gsl8 gsl10 double mutant for sensitivity to low Ca concentrations. The double mutant exhibited a more severe phenotype than the single mutant under 0.3 mM Ca, indicating additive effects of GSL8 and GSL10 with respect to low Ca tolerance. These results establish that GSL genes are required for low Ca tolerance in A. thaliana.

Improving Calcium Status of Women: Results of a Study of Bio-Availability of Calcium From Slaked Lime Fortified Rice.

BACKGROUND: Fortification of rice with slaked lime is an acceptable and inexpensive way to combat calcium (Ca) deficiency. However, bioavailability of calcium after intake of slaked lime fortified rice is yet to be investigated. OBJECTIVE: To measure the fractional absorption of Ca (FAC) from slaked lime fortified cooked rice. DESIGN: We conducted an experimental study using stable isotopes of Ca to measure FAC during a single morning test meal containing rice fortified with slaked lime. Participants (n = 22) were given slaked lime fortified rice 3 times a day for 4 days. On the morning of the fifth day, the participants were served the same amount of rice as previous the 4 days at the breakfast test meal with an accurately measured amount of 44Ca stable isotope oral tracer followed by an intravenous injection of 42Ca. Urine was collected over the next 24 hours in 3 consecutive 8-hour pools. Fractional absorption of Ca was calculated from the measurement of the relative enrichment of the of each administered tracer 44Ca and 42Ca using inductively coupled plasma mass spectrometry. RESULTS: The mean Ca concentration in the test meal was 879.5 ± 152.9 µg/g with a coefficient of variance (CV) of 17.2%. Although Ca absorption efficiency decreases with higher calcium intake, the total amount of calcium absorbed from test meal using FAC = 0.391 calculated from the third 8-hour urine pool was 69.0 (CV of 15.6) mg. CONCLUSIONS: We showed that one-fifth of daily calcium recommendation for women of reproductive age could be met by ingesting ∼200 g cooked slake fortified rice.

Nutritional rickets and vitamin D deficiency: consequences and strategies for treatment and prevention.

INTRODUCTION: Rickets is typically characterized by bone deformities due to defective bone mineralization and chondrocyte maturation in growing bones. However, infantile rickets often goes unrecognized, because the skeletal abnormalities are more subtle and often can only be detected radiologically. Nutritional rickets is a major public health concern in several regions worldwide. It is most commonly caused by vitamin D and/or calcium deficiency. AREA COVERED: We provide an overview of historical perspective, epidemiology, and pathophysiology of nutritional rickets. Additionally, we outline diagnostic approaches and highlight challenges in radiographic diagnosis of rickets. Finally, we present strategies for prevention and treatment of rickets. EXPERT OPINION: Despite the evidence from clinical databases that rickets is a rare disease, it is likely that rickets is clinically underdiagnosed as studies designed to screen healthy children for radiographic evidence of rickets reported surprisingly much higher prevalence. It has been reported that some of the radiologic features of rickets can be misinterpreted as fractures. To prevent nutritional rickets, most if not all infants and young children, should receive vitamin D from formulas and foods that are fortified with vitamin D or supplementation to achieve a serum 25-hydroxyvitamin D of at least 20 ng/mL as recommended by the Institute of Medicine. It has been recommended by the Endocrine Society that to achieve maximum bone health for children and adults, a serum concentration of 25-hydroxyvitamin D should be at least 30 ng/mL and preferably 40-60 ng/mL. Pregnant women who are unable to obtain an adequate amount of vitamin D from sunlight exposure and natural and fortified diets should take a vitamin D supplement of 1500-2000 IUs daily as recommended by the Endocrine Society since it has been demonstrated that 600 IUs daily will not maintain a circulating 25-hydroxyvitamin D of at least 20 ng/mL and most pregnant women. If lactating women take approximately 6400 IUs of vitamin D daily, they provide enough vitamin D in their milk to satisfy their infant's requirement thereby preventing rickets.

Arabidopsis Glucan Synthase-Like1 (GSL1) Is Required for Tolerance to Low-Calcium Conditions and Exhibits a Function Comparable to GSL10.

Crops that exhibit symptoms of calcium (Ca) deficiency constitute a major agricultural problem. Molecular breeding of resistant cultivars is a promising method for overcoming this problem. However, the involved genes must first be identified. Here, we show that the glucan synthase-like (GSL) 1 gene is essential for low-Ca tolerance in Arabidopsis thaliana. GSL1 is homologous to GSL10, which we previously showed was essential for low-Ca tolerance. Under low-Ca conditions, gsl1 mutants exhibit reduced growth and the onset of necrosis in new leaves. These symptoms are typical of Ca-deficient crops. A grafting experiment suggested that the shoot genotype, but not the root genotype, was important for the suppression of shoot necrosis. The ectopic accumulation of callose under low-Ca conditions was significantly reduced in gsl1 mutants compared with wild-type plants. Because the corresponding single-mutant phenotypes are similar, we investigated the interaction between GSL1 and GSL10 by testing the gsl1 gsl10 double mutant for sensitivity to low-Ca conditions. The double mutant exhibited a more severe phenotype than did the single mutants, indicating that the effects of GSL1 and GSL10 on low-Ca tolerance are additive. Because GSL genes are highly conserved within the plant kingdom, the GSL loci may be useful for breeding low-Ca tolerant crops.

Nutritional Calcium Supply Dependent Calcium Balance, Bone Calcification and Calcium Isotope Ratios in Rats.

Serum calcium isotopes (δ44/42Ca) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δ44/42Ca changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δ44/42CaSerum with bone histology are unknown. We analyzed Ca and δ44/42Ca by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.5%) and after four subsequent weeks of standard- and of low-Ca-diet (0.25%). In animals on a low-Ca-diet net Ca gain was 61 ± 3% and femur Ca content 68 ± 41% of standard-Ca-diet, bone mineralized area per section area was 68 ± 15% compared to standard-Ca-diet. δ44/42Ca was similar in the diets, and decreased in feces and urine and increased in serum in animals on low-Ca-diet. δ44/42CaBone was higher in animals on low-Ca-diet, lower in the diaphysis than the metaphysis and epiphysis, and unaffected by gender. Independent of diet, δ44/42CaBone was similar in the femora and ribs. At the time of sacrifice, δ44/42CaSerum inversely correlated with intestinal Ca uptake and histological bone mineralization markers, but not with Ca content and bone mineral density by µCT. In conclusion, δ44/42CaBone was bone site specific, but mechanical stress and gender independent. Low-Ca-diet induced marked changes in feces, serum and urine δ44/42Ca in growing rats. δ44/42CaSerum inversely correlated with markers of bone mineralization.

Analysis of miRNAs responsive to long-term calcium deficiency in tef (Eragrostis tef (Zucc.) Trotter).

MicroRNAs (miRNAs) play an important role in growth, development, stress resilience, and epigenetic modifications of plants. However, the effect of calcium (Ca2+) deficiency on miRNA expression in the orphan crop tef (Eragrostis tef) remains unknown. In this study, we analyzed expression of miRNAs in roots and shoots of tef in response to Ca2+ treatment. miRNA-seq followed by bioinformatic analysis allowed us to identify a large number of small RNAs (sRNAs) ranging from 17 to 35 nt in length. A total of 1380 miRNAs were identified in tef experiencing long-term Ca2+ deficiency while 1495 miRNAs were detected in control plants. Among the miRNAs identified in this study, 161 miRNAs were similar with those previously characterized in other plant species and 348 miRNAs were novel, while the remaining miRNAs were uncharacterized. Putative target genes and their functions were predicted for all the known and novel miRNAs that we identified. Based on gene ontology (GO) analysis, the predicted target genes are known to have various biological and molecular functions including calcium uptake and transport. Pairwise comparison of differentially expressed miRNAs revealed that some miRNAs were specifically enriched in roots or shoots of low Ca2+-treated plants. Further characterization of the miRNAs and their targets identified in this study may help in understanding Ca2+ deficiency responses in tef and related orphan crops.

Calcium deficiency worldwide: prevalence of inadequate intakes and associated health outcomes.

Dietary calcium deficiency is considered to be widespread globally, with published estimates suggesting that approximately half of the world's population has inadequate access to dietary calcium. Calcium is essential for bone health, but inadequate intakes have also been linked to other health outcomes, including pregnancy complications, cancers, and cardiovascular disease. Populations in low- and middle-income countries (LMICs) are at greatest risk of low calcium intakes, although many individuals in high-income countries (HICs) also do not meet recommendations. Paradoxically, many LMICs with lower calcium intakes show lower rates of osteoporotic fracture as compared with HICs, though data are sparse. Calcium intake recommendations vary across agencies and may need to be customized based on other dietary factors, health-related behaviors, or the risk of calcium-related health outcomes. The lack of standard methods to assess the calcium status of an individual or population has challenged efforts to estimate the prevalence of calcium deficiency and the global burden of related adverse health consequences. This paper aims to consolidate available evidence related to the global prevalence of inadequate calcium intakes and associated health outcomes, with the goal of providing a foundation for developing policies and population-level interventions to safely improve calcium intake and status where necessary.

Prothrombotic state and calcium deficiency in early pregnancy are risk factors for gestational diabetes mellitus: a retrospective cohort study.

OBJECTIVES: To investigate whether the prothrombotic state (PTS), calcium deficiency and iron deficiency anemia (IDA) in early pregnancy is associated with the risk of gestational diabetes mellitus (GDM). METHODS: We conducted a retrospective cohort study, including consecutive pregnant women tested for PTS, calcium deficiency and IDA before 20 weeks' gestation between September 1, 2017 and March 21, 2021. For routine prenatal care, pregnant women underwent a 75-g oral glucose tolerance test (OGTT) to make a GDM diagnosis during 24-28 weeks of gestation. Testing data and relevant clinical information were obtained from Shenzhen Baoan Women's and Children's Hospital. To estimate GDM risk of exposures (PTS, calcium deficiency and IDA) in early pregnancy, we used logistic regression to obtain odds ratio (OR) adjusted for maternal age, parity, family history of diabetes and pre-pregnancy body mass index. RESULTS: The cohort included 8396 pregnant women with complete data of exposures and GDM outcomes. Baseline characteristics were not comparable between exposure and control groups. PTS (adjusted OR 2.38, 95% CI 1.61-3.52) or calcium deficiency (adjusted OR 1.23, 95% CI 1.02-1.49) in early pregnancy was independently associated with increased GDM risk after adjusting covariates. There was no significant association between IDA status and GDM risk (adjusted OR 0.86, 95% CI 0.63-1.18). CONCLUSIONS: PTS and calcium deficiency in early pregnancy may be independent risk factors of GDM. These findings need further validation in well-designed prospective cohorts.

Nutritional rickets - Vitamin D and beyond.

Vitamin D deficiency has been considered to be the cause of nutritional rickets for most of the past century. During the past two decades, however, it has become clear that nutritional rickets may be caused by vitamin D deficiency or by dietary insufficiency of calcium. The combined deficiencies of calcium and vitamin D interact, and several other factors are also relevant in the pathogenesis of nutritional rickets.

Comparative physiological and transcriptomic analysis reveal MdWRKY75 associated with sucrose accumulation in postharvest 'Honeycrisp' apples with bitter pit.

BACKGROUND: Calcium (Ca) deficiency can cause apple bitter pit, reduce the quality and shelf life. WRKY transcription factors play essential role in plant response to multiple disorders. However, the underlying mechanisms causing bitter pit in apple fruit due to Ca deficiency during storage is extremely limited. RESULTS: In the present study, the nutritional metabolites and reactive oxygen species (ROS) were compared in Ca-deficient and healthy apple fruit (CK) during storage. Results showed that Ca-deficient apples sustained significantly higher production of ROS, PPO activity, flavonoids, total phenol, total soluble solids (TSS), and sucrose contents, but the contents of Ca, H2O2, titratable acids (TA), glucose and fructose were significantly lower than those of CK during storage. Principal component analysis (PCA) showed that TSS, •O2-, PPO, malondialdehyde (MDA) and Ca were the main factors, and TSS had a positive correlation with sucrose. Furthermore, transcriptome analysis revealed that WRKYs were co-expressed with sucrose metabolism-related enzymes (SWEETs, SS, SPS). qRT-PCR and correlation analysis indicated that MdWRKY75 was correlated positively with MdSWEET1. Moreover, transient overexpression of MdWRKY75 could significantly increase the sucrose content and promote the expression of MdSWEET1 in apple fruit. CONCLUSIONS: Calcium deficiency could decrease antioxidant capacity, accelerate nutritional metabolism and up-regulate the expression of WRKYs in apple with bitter pit. Overexpression of MdWRKY75 significantly increased sucrose accumulation and the expression of MdSWEET1. These findings further strengthened knowledge of the basic molecular mechanisms in calcium deficiency apple flesh and contributed to improving the nutritional quality of apple fruit.