Safety and Feasibility of Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy With Calcium-Containing Solutions: A Randomized Controlled Trial.

BACKGROUND: Calcium-free (Ca-free) solutions are theoretically the most ideal for regional citrate anticoagulation (RCA) in continuous renal replacement therapy (CRRT). However, the majority of medical centers in China had to make a compromise of using commercially available calcium-containing (Ca-containing) solutions instead of Ca-free ones due to their scarcity. This study was designed to probe into the potential of Ca-containing solution as a secure and efficient substitution for Ca-free solutions. METHODS: In this prospective, randomized single-center trial, 99 patients scheduled for CRRT were randomly assigned in a 1:1:1 ratio to one of three treatment groups: continuous veno-venous hemodialysis Ca-free dialysate (CVVHD Ca-free) group, continuous veno-venous hemodiafiltration calcium-free dialysate (CVVHDF Ca-free) group, and continuous veno-venous hemodiafiltration Ca-containing dialysate (CVVHDF Ca-containing) group at cardiac intensive care unit (CICU). The primary endpoint was the incidence of metabolic complications. The secondary endpoints included premature termination of treatment, thrombus of filter, and bubble trap after the process. RESULTS: The incidence of citrate accumulation (18.2% vs. 12.1% vs. 21.2%) and metabolic alkalosis (12.1% vs. 0% vs. 9.1%) did not significantly differ among three groups (p > 0.05 for both). The incidence of premature termination was comparable among the groups (18.2% vs. 9.1% vs. 9.1%, p = 0.582). The thrombus level of the filter and bubble trap was similar in the three groups (p > 0.05 for all). CONCLUSIONS: In RCA-CRRT for CICU population, RCA-CVVHDF with Ca-containing solutions and traditional RCA with Ca-free solutions had a comparable safety and feasibility. TRIAL REGISTRATION: ChiCTR2100048238 in the Chinese Clinical Trial Registry.

Relación del consumo de calcio con el síndrome metabólico en adultos de la Amazonía Ecuatoriana / Relationship of calcium consumption with metabolic syndrome in adults from the Ecuadorian Amazon

Introducción. El Síndrome Metabólico (SM) comprende un conjunto de factores de riesgo cardiometabólico representado por obesidad central, dislipidemia, hipertensión arterial y glucosa alterada, se ha evidenciado que el consumo adecuado de calcio representa una disminución del riesgo para este síndrome. Objetivo. Analizar la relación entre el consumo de calcio total, de origen animal y vegetal con el SM y sus indicadores. Materiales y métodos. Estudio transversal de eje correlacional, con una muestra de 100 adultos de la región amazónica ecuatoriana, durante el último trimestre del 2020. La ingesta dietética de calcio se determinó mediante un recordatorio de 24 horas y el SM según los criterios de Adult Treatment Panel-IV (ATP-IV). Resultados. La población estuvo conformada por adultos maduros (40 a 60 años) que evidenciaron una ingesta de calcio deficiente (182,50 mg y 228,60 mg en mujeres y hombres respectivamente). Se evidenció, además, una relación directamente proporcional entre la circunferencia abdominal (r=0,391 ­ p=0,000), presión arterial sistólica (r=0,290 ­ p=0,000) y glucosa en ayuno (r=0,326 ­ p=0,000) con la edad. La ingesta de calcio total se relacionó positivamente con los triglicéridos, (r=0,221 ­ p=0,027). Conclusiones. La ingesta dietética de calcio en ambos sexos no alcanza el requerimiento diario y se relaciona positivamente con los triglicéridos(AU)

Introduction. The Metabolic Syndrome (MS) comprises a set of cardiometabolic risk factors represented by central obesity, dyslipidemia, high blood pressure and altered glucose, it has been shown that adequate calcium intake represents a decreased risk for this syndrome. Objective. To analyze the relationship between the consumption of total calcium, animal and vegetable origin, with MS and its indicators. Materials and methods. Cross-sectional study of correlational axis, with a sample of 100 adults from the Ecuadorian Amazon region, during the last quarter of 2020. Dietary calcium intake was determined through a 24-hour recall and the diagnosis of MS according to the Adult Treatment Panel- IV (ATP-IV) criteria. Results. The population consisted of mature adults (40 to 60 years) who showed a deficient calcium intake in both sexes (182.50 mg and 228.60 mg in women and men respectively). There is also evidence of a directly proportional relationship between abdominal circumference (r=0.391 - p=0.000), systolic blood pressure (r=0.290 - p=0.000) and fasting glucose (r=0.326 - p=0.000) with age. Total calcium intake was positively related to triglycerides (r=0.221 ­ p=0.027). Conclusions. Calcium dietary intake in both sexes does not reach the daily requirement and is positively related to triglycerides(AU)

Nutritional Approaches as a Treatment for Impaired Bone Growth and Quality Following the Consumption of Ultra-Processed Food.

The severe impairment of bone development and quality was recently described as a new target for unbalanced ultra-processed food (UPF). Here, we describe nutritional approaches to repair this skeletal impairment in rats: supplementation with micro-nutrients and a rescue approach and switching the UPF to balanced nutrition during the growth period. The positive effect of supplementation with multi-vitamins and minerals on bone growth and quality was followed by the formation of mineral deposits on the rats' kidneys and modifications in the expression of genes involved in inflammation and vitamin-D metabolism, demonstrating the cost of supplementation. Short and prolonged rescue improved trabecular parameters but incompletely improved the cortical parameters and the mechanical performance of the femur. Cortical porosity and cartilaginous lesions in the growth-plate were still detected one week after rescue and were reduced to normal levels 3 weeks after rescue. These findings highlight bone as a target for the effect of UPF and emphasize the importance of a balanced diet, especially during growth.

Metabolomics in liver injury induced by dietary cadmium exposure and protective effect of calcium supplementation.

The purpose of the study was to explore the effect of calcium (Ca) supplementation on liver injury induced by cadmium (Cd) in rats and its potential metabolic mechanisms through metabolomics analysis. Seventy rats were randomly allotted into 7 groups, including a control group, 3 groups with different levels of Cd exposed (1, 5, and 50 mg Cd/kg diet), and 3 corresponding Ca supplement groups (4 g Ca/kg diet) based on the Cd exposed groups. Dietary intake was simulated by giving Cd or Cd+Ca in the diets of rats. After 13-week feeding, serum biochemical parameters and liver histopathology were examined. Then the metabolic analysis of rat liver tissues was performed by ultra-performance liquid chromatography quadrupole-time-flight mass spectrometry (UPLC-Q-TOF-MS). It was demonstrated that Ca supplementation could reverse the abnormal alterations in TG, TC, GSH, MDA induced by Cd exposure, as well as the hepatic pathological changes in rats. Furthermore, the metabolomics analysis of liver samples revealed several distinct regulatory pathways, including energy, amino acid, and lipid metabolic pathways. In conclusion, it showed that Ca supplementation had an ameliorative effect on liver injury induced by Cd exposure in rats, which may be related to the role of Ca in regulating multiple metabolic pathways.

Effect of calcium and magnesium on inflammatory cytokines in accidentally multiple fracture adults: A short-term follow-up.

ABSTRACT: Calcium (Ca) and magnesium (Mg), which play an important role in several cellular processes, is essential for normal development of the skeleton and maintenance of tissue homeostasis. Deficiency of these elements might delay bone fracture recovery or accelerates bone loss. We aimed to examine whether supplementation of trace element (TE) promotes fracture healing in accidentally fracturing adults by involvement of inflammatory mechanism.A short-term follow-up in clinic was performed. Totally, 117 subjects diagnosed with multiple fractures by traffic accidents were recruited in this study. Serum Ca and Mg levels were measured by inductively coupled plasma atomic emission spectrophotometry. Short-term changes such as serum C-reactive protein, interleukin (IL)-1ß, IL-6, and tumor necrosis factor alpha in normal treatment and TE supplement groups were detected by enzyme-linked immunosorbent assay. Student t test and the Spearman correlation were performed to analyze the data.Significantly negative correlations between Ca (r = 0.7032; P < .001) and Mg (r = 0.2719; P < .05) and injury severity score were observed. Serum Ca and Mg were significantly increased at Day 5, 7, and 9 following TE supplements. After treatment, serum C-reactive protein, IL-1ß, IL-6, and tumor necrosis factor alpha were significantly reduced whereas cytokine levels of the TE supplement group were found to be lower than that of the normal treatment group after Day 3.These findings suggest that Ca and Mg levels are associated with the injury severity of multiple fractures, and the supplement could reduce the inflammation, which may be beneficial for the bone recovery and disease process.

Vitamin D repletion in primary hyperparathyroid patients undergoing parathyroidectomy leads to reduced symptomatic hypocalcaemia and reduced length of stay: a retrospective cohort study.

INTRODUCTION: Vitamin D deficiency co-exists with and can confuse the diagnosis of primary hyperparathyroidism (PHPT). Vitamin D replete (VDR) status may prevent significant postparathyroidectomy hypocalcaemia; however, reports from previous studies are conflicting. This study aimed to assess differences in early and/or late postoperative hypocalcaemia and length of stay (LOS) postparathyroidectomy between VDR and vitamin D non-replete (VDNR) PHPT patients. METHODS: This was a retrospective cohort study of a prospectively maintained single surgeon operative database. All records of patients who underwent parathyroidectomy over a four-year period (July 2014 to December 2018) were extracted. Data were collected on vitamin D and corrected calcium levels pre- and postoperatively as well as postoperative complications and LOS. RESULTS: On presentation, there were 91 (47.9%) VDR and 99 (52.1%) VDNR patients. Following vitamin D therapy there were 148 (77.9%) VDR and 42 (22.1%) VDNR. The multivariate analysis showed that vitamin D status was the only significant factor impacting on the hypocalcaemia symptoms (OR 4.9, 95% CI 1.8-13.7, p = 0.002) and the most significant factor for the calcium supplementation (OR 6.5, 95% CI 2.1-19.4, p = 0.001). Bilateral neck exploration was associated with increased likelihood of transient hypocalcaemia (p = 0.007) but no other post-op complication. Median LOS was significantly shorter for VDR (1 day) versus VDNR (1.5 days) patients (p = 0.001). CONCLUSION: There is a statistically significant increased likelihood of postoperative hypocalcaemia symptoms, requirement for calcium supplements and increased LOS in VDNR patients. This study suggests optimising preoperative vitamin D status improves patient experience and could reduce healthcare costs.

Neuroleptic Malignant Syndrome: A Potential Etiology of Multisystem Organ Failure in a Burn Patient.

Neuroleptic malignant syndrome (NMS) is described in the medical literature but rarely seen among acutely ill trauma patients. A 44-year-old man with burns to the hands and back after a chemical explosion was transported to an outside facility where he received treatment for presumed acute coronary syndrome after developing ventricular tachycardia and elevated serum troponins after the exposure. His cardiac catheterization was unremarkable, but an echocardiogram revealed severe cardiomyopathy, and he was also in multisystem organ failure. He was transferred to our facility after hospital day 2 for treatment of his multisystem organ failure and 2% total body surface area burns. His laboratory results were remarkable for a creatine kinase of >100 000 units/L, and he required 14 g of intravenous calcium. Upon further investigation, the patient reported taking ziprasidone for his bipolar disorder, and he had a core temperature of 103.5 °F on his initial presentation to the outside facility. As he convalesced, the unifying diagnosis was NMS. NMS is a side effect of antipsychotic therapy and is manifested by hyperpyrexia, rigidity, autonomic instability, and altered consciousness. An elevated creatine kinase >100 000 units/L is almost pathognomonic for NMS. Patients can also present with leukocytosis, organ failure, and electrolyte disturbances including hypocalcemia. We hypothesized that dehydration, the warm environmental conditions at our patient's job, and immense stress resulting in a catecholamine surge following his trauma were inciting triggers to this event. This case highlights the importance of considering alternate diagnoses in patients whose clinical presentation does not fit the most "obvious cause."

The effect of vitamin D and calcium supplementation on inflammatory biomarkers, estradiol levels and severity of symptoms in women with postpartum depression: a randomized double-blind clinical trial.

Objectives: Postpartum depression (PPD) is a major depressive disorder. Vitamin D deficiency may play a role in PPD pathogenesis. This study was designed to determine the effect of vitamin D and calcium supplementation on the severity of symptoms and some related inflammatory biomarkers in women with PPD.Materials and Methods: Eighty-one women with a PPD score >12 participated in this study. A total of 27 patients were randomly assigned into three groups (1:1:1 ratio) to receive either 50,000 IU vitamin D3 fortnightly + 500 mg calcium carbonate daily; or 50,000 IU vitamin D3 fortnightly + placebo of calcium carbonate daily, or placebo of vitamin D3 fortnightly + placebo of calcium carbonate daily (placebo group) for 8 weeks. At the baseline and end of the study, the severity score of PPD, levels of 25-hydroxy vitamin D, calcium, tumor necrosis factor-alpha (TNFα), interleukin 6 (IL6) and estradiol were measured.Results: The PPD score had more reduction in the vitamin D + calcium and vitamin D + calcium placebo groups than that of the placebo group (-1.7 ± 3.44, -4.16 ± 5.90 and 0.25 ± 2.81, respectively; p = 0.008). The effect of vitamin D on the PPD score was larger when vitamin D was given alone than given together with calcium (p = 0.042 and p = 0.004, respectively). No significant differences in estradiol, IL6 and TNFα were observed between the three groups.Discussion: Vitamin D may be effective in improving the clinical symptoms of PPD; however, the mechanism of the effect might not entirely operate through inflammatory and/or hormonal changes.

PaTH Forward: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial of TransCon PTH in Adult Hypoparathyroidism.

CONTEXT: Hypoparathyroidism is characterized by insufficient levels of parathyroid hormone (PTH). TransCon PTH is an investigational long-acting prodrug of PTH(1-34) for the treatment of hypoparathyroidism. OBJECTIVE: This work aimed to investigate the safety, tolerability, and efficacy of daily TransCon PTH in adults with hypoparathyroidism. METHODS: This phase 2, randomized, double-blind, placebo-controlled 4-week trial with open-label extension enrolled 59 individuals with hypoparathyroidism. Interventions included TransCon PTH 15, 18, or 21 µg PTH(1-34)/day or placebo for 4 weeks, followed by a 22-week extension during which TransCon PTH dose was titrated (6-60 µg PTH[1-34]/day). RESULTS: By Week 26, 91% of participants treated with TransCon PTH achieved independence from standard of care (SoC, defined as active vitamin D = 0 µg/day and calcium [Ca] ≤ 500 mg/day). Mean 24-hour urine Ca (uCa) decreased from a baseline mean of 415 mg/24h to 178 mg/24h by Week 26 (n = 44) while normal serum Ca (sCa) was maintained and serum phosphate and serum calcium-phosphate product fell within the normal range. By Week 26, mean scores on the generic 36-Item Short Form Health Survey domains increased from below normal at baseline to within the normal range. The Hypoparathyroidism Patient Experience Scale symptom and impact scores improved through 26 weeks. TransCon PTH was well tolerated with no treatment-related serious or severe adverse events. CONCLUSION: TransCon PTH enabled independence from oral active vitamin D and reduced Ca supplements (≤ 500 mg/day) for most participants, achieving normal sCa, serum phosphate, uCa, serum calcium-phosphate product, and demonstrating improved health-related quality of life. These results support TransCon PTH as a potential hormone replacement therapy for adults with hypoparathyroidism.

Vitamin D Supplementation Improves Fasting Insulin Levels and HDL Cholesterol in Infertile Men.

CONTEXT: Vitamin D has been linked with glucose and lipid metabolism. Men with impaired gonadal function have a higher risk of metabolic syndrome and mortality, and vitamin D status may be a reversible modulator. OBJECTIVE: This work aimed to determine the effect of daily vitamin D and calcium supplementation for 150 days on glucose and lipid homeostasis in infertile men. METHODS: A single-center, double-blinded, randomized clinical trial (NCT01304927) was conducted. A total of 307 infertile men were randomly assigned (1:1) to a single dose of 300 000 IU cholecalciferol followed by 1400 IU cholecalciferol + 500 mg of calcium daily (n = 151) or placebo (n = 156) for 150 days. Reported metabolic parameters including fasting plasma glucose, glycated hemoglobin A1c, fasting serum insulin, homeostatic model assessment of insulin resistance (HOMA-IR), fasting plasma cholesterols, and triglycerides were secondary end points. The primary end point semen quality has previously been reported. RESULTS: Men receiving vitamin D supplementation improved their vitamin D status, whereas vitamin D status was aggravated in the placebo group characterized by higher serum parathyroid hormone. At the end of the trial, men receiving vitamin D supplementation had 13% lower fasting serum insulin concentrations compared with the placebo-treated group (65 vs 74 pmol/L, P = .018) and 19% lower HOMA-IR (2.2 vs 2.7, P = .025). Moreover, men in the vitamin D group had higher high-density lipoprotein (HDL) cholesterol levels (1.38 vs 1.32 mmol/L, P = .008) compared with the placebo group. CONCLUSION: High-dose vitamin D supplementation has beneficial effects on glucose homeostasis and HDL cholesterol levels in infertile men.

Calcium and Vitamin D Supplementation and Their Association with Kidney Stone Disease: A Narrative Review.

Kidney stone disease is a multifactorial condition influenced by both genetic predisposition and environmental factors such as lifestyle and dietary habits. Although different monogenic polymorphisms have been proposed as playing a causal role for calcium nephrolithiasis, the prevalence of these mutations in the general population and their complete pathogenetic pathway is yet to be determined. General dietary advice for kidney stone formers includes elevated fluid intake, dietary restriction of sodium and animal proteins, avoidance of a low calcium diet, maintenance of a normal body mass index, and elevated intake of vegetables and fibers. Thus, balanced calcium consumption protects against the risk for kidney stones by reducing intestinal oxalate availability and its urinary excretion. However, calcium supplementation given between meals might increase urinary calcium excretion without the beneficial effect on oxalate. In kidney stone formers, circulating active vitamin D has been found to be increased, whereas higher plasma 25-hydroxycholecalciferol seems to be present only in hypercalciuric patients. The association between nutritional vitamin D supplements and the risk for stone formation is currently not completely understood. However, taken together, available evidence might suggest that vitamin D administration worsens the risk for stone formation in patients predisposed to hypercalciuria. In this review, we analyzed and discussed available literature on the effect of calcium and vitamin D supplementation on the risk for kidney stone formation.

Thresholds of Basal- and Calcium-Stimulated Calcitonin for Diagnosis of Thyroid Malignancy.

Since medullary thyroid carcinoma is an aggressive cancer, it is important to have an early detection based on stimulated calcitonin (CT), especially when basal-CT is slightly elevated. The objective of this work was to set specific thresholds for basal-CT- and calcium-stimulated calcitonin for prediction of thyroid malignancy in female population. The study included 2 groups: group A-women with elevated basal-CT (>9.82 pg/ml) and group B-women with normal basal-CT (control group). After calcium stimulation test precise protocol, histopathological reports of those that required surgery were correlated with both basal and stimulated calcitonin. The best basal and stimulated calcitonin cut-offs for distinguishing female patients with medullary thyroid carcinoma or C-Cell-hyperplasia from other pathologies or normal cases were: 12.9 pg/ml, respectively 285.25 pg/ml. For basal-CT above 30 pg/ml, malignancy was diagnosed in 9/9 patients (100%): 9 MTC. For stimulated calcitonin above 300 pg/ml, malignancy was diagnosed in 17/21 patients (80.95%): 12 MTC and 5 papillary thyroid carcinomas. The smallest nodule that proved to be medullary thyroid carcinoma had only 0.56/0.34/0.44 cm on ultrasound, with no other sonographic suspicious criteria. In conclusion, we have identified in Romanian female population basal and stimulated calcitonin thresholds to discriminate medullary thyroid carcinoma or C-Cell-hyperplasia from other cases. We recommend thyroid surgery in all women with stimulated calcitonin above 285 pg/ml. Further studies on larger groups are necessary to establish and confirm male and female cut-offs for early diagnosis of medullary thyroid carcinoma, and interestingly, maybe for macro-papillary thyroid carcinomas alike. The calcium administration has minimum side-effects, but continuous cardiac monitoring is required.

Micronutrients and athletic performance: A review.

Optimising nutrition intake is a key component for supporting athletic performance and supporting adaption to training. Athletes often use micronutrient supplements in order to correct vitamin and mineral deficiencies, improve immune function, enhance recovery and or to optimise their performance. The aim of this review was to investigate the recent literature regarding micronutrients (specifically iron, vitamin C, vitamin E, vitamin D, calcium) and their effects on physical performance. Over the past ten years, several studies have investigated the impacts of these micronutrients on aspects of athletic performance, and several reviews have aimed to provide an overview of current use and effectiveness. Currently the balance of the literature suggests that micronutrient supplementation in well-nourished athletes does not enhance physical performance. Excessive intake of dietary supplements may impair the body's physiological responses to exercise that supports adaptation to training stress. In some cases, micronutrient supplementation is warranted, for example, with a diagnosed deficiency, when energy intake is compromised, or when training and competing at altitude, however these micronutrients should be prescribed by a medical professional. Athletes are encouraged to obtain adequate micronutrients from a wellbalanced and varied dietary intake.

Membrane-based therapeutic plasma exchange: Hemodynamics and operational characteristics leading to procedure failure.

BACKGROUND AND OBJECTIVES: Therapeutic plasma exchange (TPE) is a blood purification treatment capable of removing large molecular weight substances from plasma. It is commonly used for the removal of circulating pathogenic immunoglobulins presumed to be the cause of many autoimmune diseases. TPE can be performed with a membrane-based system (mTPE) or a centrifugal-based system (cTPE). When plasma separation is performed with a membrane, filter clotting can lead to longer treatment time, higher cost and can negatively impact patient satisfaction. In this study, we examine the operational characteristics that might influence filter life. DESIGN, SETTING, PARTICIPANTS, & MEASURES: We report on 24 patients, with a total of 135 mTPE treatments in a single tertiary care academic center using the NxStage machine. The study focuses on treatment specific parameters that may lead to procedure failure. The main parameters of interest were transmembrane pressure (TMP) and the filtration fraction as displayed on the machine (FFd) compared to the calculated filtration fraction (FFc). Primary outcome was to measure whether TMP, FFc, and FFd influenced filter survival. Secondary outcomes included factors that might have indirectly resulted in filter failure, including hematocrit (Hct), platelet count, heparin use, and intra-treatment calcium administration. RESULTS: In this study, we demonstrated that machine displayed filtration fractions (FFd) were lower than FFc and this difference was significantly larger in TPE sessions that experienced a clotting event (7.58 vs 6.22, P = .031). TPE sessions that clotted had a higher mean TMP (57.48 mmHg vs 44.43 mmHg, P = .001) and clotting events tended to have a lower mean blood flow rate (175.83 mL/min vs 189.55 mL/min, P = .002). In TPE sessions that received prefilter calcium administration, a higher mean dose of calcium gluconate was found in the sessions that experienced clotting (3.27 g vs 2.70 g, P = .013). Patients who experienced at least one clotting event were noted to be heavier than those patients without any clotting events (91.52 kg vs 72.15 kg, P = .040). Prefilter heparin administration was not associated with a lower incidence of filter clotting. We did not find a statistically significant difference in clotting events based upon type of intravenous access, pretreatment hematocrit, or pretreatment platelet counts. CONCLUSION: Among patients undergoing mTPE, machine FFd on the NxStage system are consistently lower than FFc. Treatments where there was a greater difference between displayed and FFc had a greater likelihood of filter clotting. Treatments with higher TMP were associated with failed treatments. Prefilter calcium administration during treatment was associated with increased filter clotting. Lower blood flow rates and higher patient weight were also associated with increased filter clotting. Prefilter heparin administration did not reduce the incidence of filter clotting.

Assessment of the Methods Used to Develop Vitamin D and Calcium Recommendations-A Systematic Review of Bone Health Guidelines.

BACKGROUND: There are numerous guidelines developed for bone health. Yet, it is unclear whether the differences in guideline development methods explain the variability in the recommendations for vitamin D and calcium intake. The objective of this systematic review was to collate and compare recommendations for vitamin D and calcium across bone health guidelines, assess the methods used to form the recommendations, and explore which methodological factors were associated with these guideline recommendations. METHODS: We searched MEDLINE, EMBASE, CINAHL, and other databases indexing guidelines to identify records in English between 2009 and 2019. Guidelines or policy statements on bone health or osteoporosis prevention for generally healthy adults aged ≥40 years were eligible for inclusion. Two reviewers independently extracted recommendations on daily vitamin D and calcium intake, supplement use, serum 25 hydroxyvitamin D [25(OH)D] level, and sunlight exposure; assessed guideline development methods against 25 recommended criteria in the World Health Organization (WHO) handbook for guideline development; and, identified types identified types of evidence underpinning the recommendations. RESULTS: we included 47 eligible guidelines from 733 records: 74% of the guidelines provided vitamin D (200~600-4000 IU/day) and 70% provided calcium (600-1200 mg/day) recommendations, 96% and 88% recommended vitamin D and calcium supplements, respectively, and 70% recommended a specific 25(OH)D concentration. On average, each guideline met 10 (95% CI: 9-12) of the total of 25 methodological criteria for guideline development recommended by the WHO Handbook. There was uncertainty in the association between the methodological criteria and the proportion of guidelines that provided recommendations on daily vitamin D or calcium. Various types of evidence, including previous bone guidelines, nutrient reference reports, systematic reviews, observational studies, and perspectives/editorials were used to underpin the recommendations. CONCLUSIONS: There is considerable variability in vitamin D and calcium recommendations and in guideline development methods in bone health guidelines. Effort is required to strengthen the methodological rigor of guideline development and utilize the best available evidence to underpin nutrition recommendations in evidence-based guidelines on bone health.

Gellan gum/alginate-based Ca-enriched acellular bilayer hydrogel with robust interface bonding for effective osteochondral repair.

The treatment of osteochondral (OC) defects remains challenging because of the lack of economical and feasible therapeutic strategies for OC repair and reconstruction. In this study, we report an integrated bilayer hydrogel with robust interface binding force (40 kPa) by facilitating the diffusion of calcium ions to the secondary crosslink of the bilayer hydrogel, in which gellan gum and sodium alginate acted as the chondral layer, gellan gum and hydroxyapatite acted as subchondral layer. This integrated construct has high cytocompatibility, and can seed with mesenchymal stem cells (MSCs) related to different functional protein expression for cartilage and bone formation, respectively. Furthermore, in the rabbit critical-sized osteochondral defect model (4.0 mm in diameter and 8.0 mm in depth), the calcium enriched hydrogel act as a calcium reservoir, promote neovascularization at week 4, and repair the critical defect at week 8, demonstrating the feasible preparation of an acellular hydrogel for OC repair.