The bioavailability of dietary calcium

Isolation and differential structure characteristics of calcium-binding peptides derived from Pacific cod bones by hydroxyapatite affinity

Calcium-chelating peptides were found in Pacific cod bone, but their binding structure and properties have not been elucidated. Novel calcium-binding peptides were isolated by hydroxyapatite affinity chromatography (HAC), and their binding structure and properties were investigated by isothermal titration calorimetry (ITC), multispectral techniques, and mass spectrometry. Based on multiple purifications, the calcium binding capacity (CBC) of Pacific cod bone peptides (PBPs) was increased from 1.71 ± 0.15 μg/mg to 7.94 ± 1.56 μg/mg. Peptides with a molecular weight of 1-2 kDa are closely correlated with CBC. After binding to calcium, the secondary structure of peptides transitioned from random coil to β-sheet, resulting in a loose and porous microstructure. Hydrogen bonds, electrostatic interaction, and hydrophobic interaction contribute to the formation of peptide‑calcium complexes. The F21 contained 42 peptides, with repeated "GE" motif. Differential structure analysis provides a theoretical basis for the targeted preparation of high CBC peptides.

Membrane capacitive deionization (MCDI): A flexible and tunable technology for customized water softening

There is a growing demand for water treatment systems for which the quality of feedwater in and product water out are not necessarily fixed with "tunable" technologies essential in many instances to satisfy the unique requirements of particular end-users. For example, in household applications, the optimal water hardness differs for particular end uses of the supplied product (such as water for potable purposes, water for hydration, or water for coffee or tea brewing) with the inclusion of specific minerals enhancing the suitability of the product in each case. However, conventional softening technologies are not dynamically flexible or tunable and, typically, simply remove all hardness ions from the feedwater. Membrane capacitive deionization (MCDI) can potentially fill this gap with its process flexibility and tunability achieved by fine tuning different operational parameters. In this article, we demonstrate that constant-current MCDI can be operated flexibly by increasing or decreasing the current and flow rate simultaneously to achieve the same desalination performance but different productivity whilst maintaining high water recovery. This characteristic can be used to operate MCDI in an energy-efficient manner to produce treated water more slowly at times of normal demand but more rapidly at times of peak demand. We also highlight the "tunability" of MCDI enabling the control of effluent hardness over different desired ranges by correlating the rates of hardness and conductivity removal using a power function model. Using this model, it is possible to either i) soften water to the same hardness level regardless of the fluctuation in hardness of feed waters, or ii) precisely control the effluent hardness at different levels to avoid excessive or insufficient hardness removal.

Fish Bones as Calcium Source: Bioavailability of Micro and Nano Particles

The amount of by-products/waste in the fish industry is roughly 50%. Fish bones could be used to produce nanoparticles, which may have potential use in the food industry as a novel calcium source and at the same time, contribute to reduce waste production. The objective of this study was to evaluate the bioavailability of nano-size salmon fish bone particles compared to micro-size salmon fish bone particles, and calcium carbonate. The study was carried out in 21-28-day-old C57BL/6 male mice fed for 21 days with the experimental diets. The groups were as follows: CaCO3 0.5% Ca (CN 0.5); CaCO3 1.0% Ca (CN 1.0); salmon fish bone (SFB) microparticles 0.5% Ca (MP 0.5); SFB microparticles 1.0% Ca (MP 1.0); SFB nanoparticles 0.5% Ca (NP 0.5); and SFB nanoparticles 1.0% Ca (NP 1.0). Calcium bioavailability, defined as the percent calcium in femur showed an increasing trend from CN 0.5 to NP 1.0 group. According to ANCOVA, the greatest Ca content was observed in the NP 1.0 group compared with all groups but NP 0.5. In conclusion, in a murine model, salmon fish bone nanoparticles present higher calcium bioavailability than salmon fish bone microparticles, and both, in turn, have better bioavailability than calcium carbonate.

Fermented foods and gastrointestinal health: underlying mechanisms

Although fermentation probably originally developed as a means of preserving food substrates, many fermented foods (FFs), and components therein, are thought to have a beneficial effect on various aspects of human health, and gastrointestinal health in particular. It is important that any such perceived benefits are underpinned by rigorous scientific research to understand the associated mechanisms of action. Here, we review in vitro, ex vivo and in vivo studies that have provided insights into the ways in which the specific food components, including FF microorganisms and a variety of bioactives, can contribute to health-promoting activities. More specifically, we draw on representative examples of FFs to discuss the mechanisms through which functional components are produced or enriched during fermentation (such as bioactive peptides and exopolysaccharides), potentially toxic or harmful compounds (such as phytic acid, mycotoxins and lactose) are removed from the food substrate, and how the introduction of fermentation-associated live or dead microorganisms, or components thereof, to the gut can convey health benefits. These studies, combined with a deeper understanding of the microbial composition of a wider variety of modern and traditional FFs, can facilitate the future optimization of FFs, and associated microorganisms, to retain and maximize beneficial effects in the gut.

Dairy Matrix Effects: Physicochemical Properties Underlying a Multifaceted Paradigm

When food products are often considered only as a source of individual nutrients or a collection of nutrients, this overlooks the importance of interactions between nutrients, but also interactions between nutrients and other constituents of food, i.e., the product matrix. This product matrix, which can be defined as 'The components of the product, their interactions, their structural organization within the product and the resultant physicochemical properties of the product', plays a critical role in determining important product properties, such as product stability, sensory properties and nutritional and health outcomes. Such matrix effects can be defined as 'the functional outcome of specific component(s) as part of a specific product matrix'. In this article, dairy matrix effects are reviewed, with particular emphasis on the nutrition and health impact of dairy products. Such matrix effects are critical in explaining many effects of milk and dairy products on human nutrition and health that cannot be explained solely based on nutrient composition. Examples hereof include the low glycemic responses of milk and dairy products, the positive impact on dental health, the controlled amino acid absorption and the absence of CVD risk despite the presence of saturated fatty acids. Particularly, the changes occurring in the stomach, including, e.g., coagulation of casein micelles and creaming of aggregated fat globules, play a critical role in determining the kinetics of nutrient release and absorption.

An Algorithm to Assess Calcium Bioavailability from Foods

BACKGROUND

The recommended calcium intakes to meet calcium requirements at various ages are based on average population absorption values. Absorption is altered by physiology, the calcium load, and type of food. The calcium intake necessary, therefore, to meet requirements depends upon diet composition, through bioavailability.

OBJECTIVE

The objectives of this study was to improve predictions of calcium bioavailability on the basis of the food matrix.

METHODS

We modeled calcium absorption data from individual foods, beverages, and fortified foods that were determined with calcium isotopic tracers and compared with milk as a referent to adjust for physiologic differences of the host.

RESULTS

Data from 496 observations were modeled to develop a predictive algorithm for calcium bioavailability in adults on the basis of calcium load and oxalate and phytate loads, which represent the 2 main inhibitors of calcium absorption.

CONCLUSIONS

This algorithm will be helpful in assessing calcium availability from the food supply, for developing diets for individuals and research cohorts, and for designing policies and interventions to address inadequate calcium intake for populations.

Bioaccessibility and Digestibility of Proteins in Plant-Based Drinks and Cow's Milk: Antioxidant Potential of the Bioaccessible Fraction

During the last years, a strong increase in the sales volume and consumption of plant-based drinks was observed, which were partly used as an alternative to cow's milk. As milk is a relevant protein source in many countries, we have investigated the protein bioaccessibility and digestibility of soy, almond, and oat drinks in comparison to milk using the tiny-TIMsg gastrointestinal model. The relative protein digestibility of all products was between 81% (soy drink) and 90% (milk). The digestible indispensable amino acid score (DIAAS) in vitro method was used to estimate the protein nutritional quality. The highest DIAAS values were obtained for milk in tryptophan (117%) and soy drink in sulfur containing amino acids (100%). Oat drink was limited in lysine (73%), almond drink in lysine (34%) and the sulfur containing amino acids (56%). Additionally, the antioxidant activity of the bioaccessible fractions was analyzed using Trolox equivalent antioxidative capacity and oxygen radical absorbance capacity assays, revealing a higher antioxidative potential of milk and soy drink compared to oat and almond drink.

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

Calcium - a scoping review for Nordic Nutrition Recommendations 2023

The aim of this scoping review was to conduct evidence-based documentations between calcium (Ca) intake and health outcomes for updating dietary reference values (DRVs) and food-based dietary guidelines (FBDGs) in the sixth edition of Nordic Nutrient Recommendations (NNR2023). The systematic literature search was limited to reviews on human data published between 2011 and June 2021. Systematic reviews (SRs) and original publications of relevance for this scoping review were included. A common practice of designing studies on health outcomes related to Ca supplement intake is to examine combined Ca and vitamin D, and therefore, a combination of Ca with vitamin D (CaD) was included in this review. In total, 27 studies addressing the association between dietary or supplemental Ca on bone health, bone mineral density (BMD), pregnancy-related outcomes, cardiovascular diseases (CVD), cancers, obesity, and mortality were reviewed. SRs showed that both dietary and supplemental Ca intakes were positively associated with BMD, but evidence did not support the benefit in fracture prevention. Current evidence did not support that Ca or CaD supplementation increases risk of coronary heart disease or all-cause mortality in older adults, but that Ca may be beneficial for hypertension, especially in young people. Increasing Ca intake may be beneficial during pregnancy, especially for those at high risk of pre-eclampsia due to ethnicity, age, high BMI, and those with low baseline Ca intake. The associations between high Ca intake and cancers were varied, with strong evidence that high consumption of dairy products is protective against colorectal cancer and limited-suggestive evidence that dairy products and diets high in Ca might also be protective against breast cancer. Moreover, there is limited-suggestive evidence that dairy products and diets high in Ca increase the risk of prostate cancer. Based on current evidence, Ca intake is beneficial or neutral in relation to most of the outcomes evaluated in this review. Data from the Nordic countries show that average Ca intake is around the same as previously recommended by NNR. However, the average Ca intake in the Baltic countries is below the recommendations.

The Postprandial Calcium Absorption of a Milk-Derived Calcium Permeate - The Acute RENEW Double-Blinded Randomized Controlled Cross-Over Study

BACKGROUND

Studies suggest that dairy-derived calcium supplements have additional beneficial properties compared with other calcium supplements in relation to bone health.

OBJECTIVES

We investigated the postprandial calcium absorption from a milk-derived calcium permeate (CP) compared with calcium carbonate (CC).

METHODS

In this randomized double-blinded cross-over study, 10 healthy postmenopausal females (age 50-65 y) received maltodextrin (placebo), 800 mg calcium from CP or from CC provided in 6 capsules on separate days. A fasting blood sample was collected at baseline, 60, 120, 240, and 360 min after ingestion. At baseline and 360 min, spot-urine samples were collected. Serum-ionized calcium, intact parathyroid hormone, phosphorus, and magnesium were analyzed, as were urinary calcium, phosphorus, and magnesium. A linear mixed model was applied.

RESULTS

Serum-ionized calcium concentration after the CC supplement was higher at 240 min compared with the CP supplement [between-group difference; 95% confidence interval (CI): 0.039 mmol/L; 95% CI: 0.017-0.061; P = 0.00078]. Serum-ionized calcium concentration after the CC supplement was significantly higher than placebo at all postprandial time points except at 60 min. Urinary calcium concentration in 360 min spot urine was higher after intake of CC compared with CP [between-group difference; 95% CI: 2.47 mmol/L; 95% CI: 1.90-3.03; P = 0.0042].

CONCLUSIONS

Postprandial calcium absorption from CP was lower than that of CC, and concurrently, urinary concentration reflected increased serum appearance by CC compared with CP, highlighting different metabolic responses. The long-term and clinical implications should be studied further.

Importance of binary and ternary complex formation on the functional and nutritional properties of legume proteins in presence of phytic acid and calcium

Nowadays, legumes are considered as a good source of plant-based proteins to replace animal ones. They are more favorable regarding environmental aspects and health benefits, therefore many people consider moving toward a greener diet. Interestingly, recent consumer trends are promoting pea and faba bean as alternatives to soybean. Both are rich in protein and a good source of essential nutrients and minerals (calcium). However, these advantages can be partially impaired due to their high phytic acid content. This natural polyphosphate is a major antinutrient in plant-based foods, as it can bind minerals (particularly calcium) and proteins, thereby reducing their digestibility and subsequent bioavailability. Indeed, complexes formed are insoluble and limiting the absorption of nutrients, thus lowering the nutritional value of pulses. To understand and overcome these issues, the present review will refine specific mechanisms involved in assemblies between these three essential compounds in legumes as soluble/insoluble binary or ternary complexes. Molecular interactions are influenced by the environmental medium including pH, ionic strength and molar concentrations modulating the stability of these complexes during protein extraction. Protein/phytic acid/calcium complexes stability is of high relevance for food processing affecting not only structure but also functional and nutritional properties of proteins in legume-based foods.

Physiology of intracellular calcium buffering

Calcium signaling underlies much of physiology. Almost all the Ca2+ in the cytoplasm is bound to buffers, with typically only ∼1% being freely ionized at resting levels in most cells. Physiological Ca2+ buffers include small molecules and proteins, and experimentally Ca2+ indicators will also buffer calcium. The chemistry of interactions between Ca2+ and buffers determines the extent and speed of Ca2+ binding. The physiological effects of Ca2+ buffers are determined by the kinetics with which they bind Ca2+ and their mobility within the cell. The degree of buffering depends on factors such as the affinity for Ca2+, the Ca2+ concentration, and whether Ca2+ ions bind cooperatively. Buffering affects both the amplitude and time course of cytoplasmic Ca2+ signals as well as changes of Ca2+ concentration in organelles. It can also facilitate Ca2+ diffusion inside the cell. Ca2+ buffering affects synaptic transmission, muscle contraction, Ca2+ transport across epithelia, and the killing of bacteria. Saturation of buffers leads to synaptic facilitation and tetanic contraction in skeletal muscle and may play a role in inotropy in the heart. This review focuses on the link between buffer chemistry and function and how Ca2+ buffering affects normal physiology and the consequences of changes in disease. As well as summarizing what is known, we point out the many areas where further work is required.

Pantoprazole-Induced Bone Loss through Gastrin Secretion: A Stereological Study

Background

Recent researches have failed to uncover a clear explanation for proton pump inhibitors' bone-loss effects. In light of pantoprazole's effects on gastrin secretion, the goal of this study was to see if it caused bone loss through gastrin secretion.

Methods

Forty male rats were divided into control, octreotide (Oct), pantoprazole (Pan), and pantoprazole plus octreotide (Pan+Oct) groups. Serum calcium, phosphorous, alkaline phosphatase, parathyroid hormone, and gastrin were measured before and three months after the treatment, and bone densitometry was examined. The rats' femoral bones were examined stereologically at the end of the investigation.

Results

The Pan group had considerably greater levels of serum alkaline phosphatase, parathyroid hormone (PTH), and gastrin, but this was prevented in the presence of Oct, a gastrin secretion inhibitor. All parameters of femoral bone densitometry in the Pan group were significantly lower than the control after treatment which was considerably inhibited in the presence of Oct. Furthermore, when compared to the control and Oct groups, the rats in the Pan group had a lower trabecular volume, femur bone weight, and volume, as well lower number of osteocytes. The amount of osteoclasts, on the other hand, was much higher in the Pan group than in the other groups.

Conclusion

Overall findings revealed that pantoprazole caused bone loss, which could be prevented by adding octreotide. Because these detrimental effects were not detected in rats given both Oct and Pan, it was suggested that the effect of Pan on bone was produced by a hypergastrinemic condition.

The impact of age-related digestive disorders on in vitro digestibility of macronutrients and bioaccessibility of minor components of chia seeds

Gastrointestinal (GI) functions deteriorate with age, primarily affecting protein digestion. The consumption of chia seeds may be helpful for the elderly because they offer a vegetable-based source of proteins, healthy lipids, fibre and micronutrients. The impact of common age-related GI deterioration on chia seed digestibility was assessed using in vitro digestion models. The goal was to study the potential of chia seeds as part of the diet of seniors. Deterioration in the oral, gastric and intestinal stages of digestion was cumulatively assessed in three digestion models: E1 (deterioration in oral conditions), E2 (deterioration in oral and gastric conditions) and E3 (deterioration in oral, gastric and intestinal conditions). Less efficient chewing (E1) decreased proteolysis, lipolysis and antioxidant capacity (p < 0.05). In contrast, deterioration in gastric functions seemed to affect only total polyphenolic content. Finally, in the model simulating the greatest deterioration in digestive functions (E3), all measured variables were negatively affected (proteolysis, lipolysis, amino acid release, total phenolic content, antioxidant capacity and calcium). Calcium bioaccessibility fell by 24 % with a decrease in pancreatic enzymes and bile secretion (E3). Age-related reduced digestive function did not affect the ratio of essential to non-essential amino acids in the digested samples in any case. However, under suboptimal GI conditions (E3), amino acids such as valine, leucine and isoleucine, which are important for sarcopenia prevention in the elderly, fell by 39 %, 49 % and 44 %, respectively. These findings might be helpful for further in vitro studies of chia seeds as a possible food ingredient. They may also be useful for the development of more targeted nutrition strategies in the elderly.

Effects of time and temperature of storage on chemical and nutritional characteristics of raw milk for Provolone Valpadana PDO cheesemaking: a multivariate approach

We evaluated the possibility of increasing the storage temperature of raw milk for Provolone Valpadana cheesemaking, to identify the most suitable conditions of time and temperature for a pre-maturation process. We used Principal Component Analysis (PCA) to analyze the overall effects of different storage conditions on chemical, nutritional and technological characteristics of the raw milk. Four different thermal storage cycles, two at fixed temperature/time (6 and 12°C for 60 h) and two with two-phase thermal cycle (10 and 12°C for 15 h, followed by refrigeration at 4°C for 45 h) were studied. Although a moderate heterogeneity among raw milks from the 11 producers of Provolone Valpadana cheese was observed, PCA revealed the critical aspects of the extreme storage conditions (60 h of refrigeration). Some samples resulted in anomalous behaviors, probably related to unexpected fermentation phenomena occurring with increasing storage temperature. The acidification and the increase in the contents of lactic acid, soluble calcium, and degree of retinol isomerization observed in the anomalous samples can compromise the technological functionality of milk. Conversely, the storage with a two-phase thermal cycle did not lead to variations in any measured characteristic, suggesting that mild refrigeration conditions (10 or 12°C for 15 h followed by 4°C for 45 h) could be a good compromise in favoring milk pre-maturation without altering its quality characteristics.

Adherence to Mediterranean-Style Dietary Pattern and Risk of Bladder Cancer: A Case-Control Study in Iran

Few dietary patterns are related to reduce the Bladder Cancer (BC) risk. One of the well-known dietary patterns is the Mediterranean diet (MD). This case-control study investigated the association between MD and the odds of BC among Iranian population. The present case-control study was performed on 103 eligible cases and 200 controls age 45 to 92 years. Diet of participants was assessed by a validated 168-item food frequency questionnaire (FFQ). Adherence to MD was measured by Mediterranean-Style Dietary Pattern Score (MSDPS). Multivariate logistic regression was used to estimate the relationship between MSDPS and risk of BC. After controlling for potential confounders, a negative association was observed between MSDPS and risk of BC (OR = 0.22; 95%CI = 0.09-0.52; p trend = 0.001). Furthermore, significant negative associations were observed for dairy, fish and other seafood, whole-grain, bread intake and risk of BC (p for trend < 0.05). In contrast, the risk of BC increased for high intake of poultry (OR = 1.09; 95%CI = 1.03-1.15; p trend = 0.003), sweets (OR = 1.24; 95%CI = 1.03-1.48; p trend = 0.018) and egg (p for trend = 0.01). Our results suggested that dietary habit in concordance with the principles of the Mediterranean dietary pattern may protect against BC.

Association between Dairy Consumption and Psychological Symptoms: Evidence from a Cross-Sectional Study of College Students in the Yangtze River Delta Region of China

BACKGROUND

Assessing the dairy consumption and psychological symptoms of Chinese college students as a reference for the mental health of Chinese college students.

METHODS

A three-stage stratified whole-group sampling method was used to investigate dairy consumption and psychological symptoms among 5904 (2554 male students, accounting for 43.3% of the sample) college students in the Yangtze River Delta region. The mean age of the subjects was 20.13 ± 1.24 years. Psychological symptoms were surveyed using the Brief Questionnaire for the Assessment of Adolescent Mental Health. The detection rates of emotional problems, behavioral symptoms, social adaptation difficulties and psychological symptoms among college students with different dairy consumption habits were analyzed using chi-square tests. The association between dairy consumption and psychological symptoms was assessed using a logistic regression model.

RESULTS

College students from the "Yangtze River Delta" region of China participated in the study, of which 1022 (17.31%) had psychological symptoms. The proportions of participants with dairy consumption of ≤2 times/week, 3-5 times/week, and ≥6 times/week were 25.68%, 42.09%, and 32.23%, respectively. Using dairy consumption ≥6 times/week as a reference, multifactor logistic regression analysis showed that college students with dairy consumption ≤2 times/week (OR = 1.42, 95% CI: 1.18, 1.71) were at higher risk of psychological symptoms (p < 0.001).

CONCLUSION

During the COVID-19 pandemic, Chinese college students with lower dairy consumption exhibited higher detection rates of psychological symptoms. Dairy consumption was negatively associated with the occurrence of psychological symptoms. Our study provides a basis for mental health education and increasing knowledge about nutrition among Chinese college students.

Calcium bioaccessibility increased during gastrointestinal digestion of α-lactalbumin and β-lactoglobulin

Calcium bioaccessibility depends on the amount of soluble calcium under intestinal digestion. The changes in calcium during in vitro static digestion of α-lactalbumin and β-lactoglobulin in presence of calcium chloride (0 mM, 20 mM and 50 mM) were followed by combining electrochemical determination of free calcium with the determination of soluble calcium by inductively coupled plasma optical emission spectroscopy. α-Lactalbumin and, more evident, β-lactoglobulin were found to increase calcium bioaccessibility with increasing intestinal digestion time by around 5% and 10%, respectively, due to the complex binding of calcium to peptides formed from protein hydrolysis by gastrointestinal enzymes. In vitro digested samples of β-lactoglobulin in presence of CaCl₂ had nearly twice as much complex bound calcium as α-lactalbumin samples. The calcium bioaccessibility decreased significantly with the increasing concentration of added calcium chloride, although the amount of calcium chloride had little effect on the extension of digestion of α-lactalbumin and β-lactoglobulin. Simulated digestion fluids were found to have a negative effect on calcium bioaccessibility, especially the presence of hydrogen phosphate, and the amount of precipitated calcium increased significantly with increasing amount of added calcium chloride. Based on analysis and visualization by sequences of the peptides formed during digestion of α-lactalbumin and β-lactoglobulin, it was observed that peptides containing aspartic acid and glutamic acid acting as calcium chelators, may prevent precipitation of calcium in the intestines and increase calcium bioaccessibility. These results provide knowledge for the design of new dairy based functional foods to prevent calcium deficiency.

Cow's Milk in Human Nutrition and the Emergence of Plant-Based Milk Alternatives

Cow's milk is considered a complete food, providing high-quality protein and essential micronutrients, including vitamins and minerals. For medical reasons or as a lifestyle choice, consumers are replacing cow's milk with plant-based milk alternatives (PBMA); some perceive them as healthier alternatives to cow's milk due to their low saturated fatty acid content and no cholesterol content. However, the nutritional composition of PBMA is quite variable between different types and even within, which makes a comparison with cow's milk a complex issue. Furthermore, the consumption of PBMA has been associated with the development of some diseases in infants and children. Meanwhile, the consumption of cow's milk in human health is a controversial issue since it has been associated with a favorable effect in some diseases (such as obesity, type 2 diabetes, and Alzheimer's) and a negative effect in others (such as prostate cancer risk and Parkinson's disease); while in some diseases, there is no consensus in the cow's milk consumption effect. The aim of this review is to make a nutritional comparison of cow's milk with PBMA and to clarify the potential health issues related to their consumption.

Calcium is a noncompetitive inhibitor of DMT1 on the intestinal iron absorption process: empirical evidence and mathematical modeling analysis

Iron absorption is a complex and highly controlled process where DMT1 transports nonheme iron through the brush-border membrane of enterocytes to the cytoplasm but does not transport alkaline-earth metals such as calcium. However, it has been proposed that high concentrations of calcium in the diet could reduce iron bioavailability. In this work, we investigate the effect of intracellular and extracellular calcium on iron uptake by Caco-2 cells, as determined by calcein fluorescence quenching. We found that extracellular calcium inhibits iron uptake by Caco-2 cells in a concentration-dependent manner. Chelation of intracellular calcium with BAPTA did not affect iron uptake, which indicates that the inhibitory effect of calcium is not exerted through intracellular calcium signaling. Kinetic studies performed, provided evidence that calcium acts as a reversible noncompetitive inhibitor of the iron transport activity of DMT1. Based on these experimental results, a mathematical model was developed that considers the dynamics of noncompetitive inhibition using a four-state mechanism to describe the inhibitory effect of calcium on the DMT1 iron transport process in intestinal cells. The model accurately predicts the calcein fluorescence quenching dynamics observed experimentally after an iron challenge. Therefore, the proposed model structure is capable of representing the inhibitory effect of extracellular calcium on DMT1-mediated iron entry into the cLIP of Caco-2 cells. Considering the range of calcium concentrations that can inhibit iron uptake, the possible inhibition of dietary calcium on intestinal iron uptake is discussed.

A comprehensive review on preparation, structure-activities relationship, and calcium bioavailability of casein phosphopeptides

Calcium is one of the important elements for human health. Calcium deficiencies can lead to numerous diseases. Calcium chelating peptides have shown potential application in the management of calcium deficiencies. Casein phosphopeptides (CPP) are phosphoseryl-containing fragments of casein by enzymatic hydrolysis or fermentation during manufacture of milk products as well as during intestinal digestion. An increasing number of CPP with the ability to facilitate and enhance the bioavailability of calcium are being discovered and identified. In this review, 249 reported CPP derived from four types of bovine casein (αs1, αs2, β and κ) were collected, and the amino acid sequence and phosphoserine group information were sorted out. This review outlines the current enzyme hydrolysis, detection methods, purification, structure-activity relationship and mechanism of intestinal calcium absorption in vitro and in vivo as well as application of CPP.

The contribution of regulated colonic calcium absorption to the maintenance of calcium homeostasis

Calcium absorption and secretion can occur along the length of the small and large intestine. To date, the focus of research into intestinal calcium absorption has been the small intestine, the site contributing the majority of intestinal calcium absorption. However, evidence that the colon contributes as much as 10% of enteral calcium transport has been available for decades. Transcellular calcium absorption and bidirectional paracellular calcium flux contributing to either net absorption or secretion have been observed in the colon, depending on the physiological state. Moreover, the calcium transport pathways contributing to colonic absorption or secretion are regulated by a variety of hormones, including calcitriol, plasma calcium and dietary factors, including prebiotics. Herein we review historical and recent research highlighting the role of colonic calcium transport in overall maintenance of calcium balance, and suggest these data are consistent with the colon being a site of significant regulated transepithelial calcium transport.

Discovery of calcium-binding peptides derived from defatted lemon basil seeds with enhanced calcium uptake in human intestinal epithelial cells, Caco-2

It is anticipated that calcium-chelating peptides may serve to enhance the absorption of calcium. This research examined defatted lemon basil seeds (DLBS) which had been treated with Alcalase under optimized parameters for the degree of hydrolysis for proteolysis, discovering that the activity for calcium-binding in a competitive condition with phosphate ion was 60.39 ± 1.545%. The purification of the hydrolysates was performed via ultrafiltration along with reversed-phase high performance liquid chromatography (RP-HPLC). Determination of the purified peptide amino acid sequence was confirmed for both peptides and reported as Ala-Phe-Asn-Arg-Ala-Lys-Ser-Lys-Ala-Leu-Asn-Glu-Asn (AFNRAKSKALNEN; Basil-1), and Tyr-Asp-Ser-Ser-Gly-Gly-Pro-Thr-Pro-Trp-Leu-Ser-Pro-Tyr (YDSSGGPTPWLSPY; Basil-2). The respective activities for calcium-binding were 38.62 ± 1.33%, and 42.19 ± 2.27%. Fluorescence spectroscopy, and fourier transform infrared spectroscopy were employed in order to assess the chelating mechanism between calcium and the peptides. It was found that the calcium ions took place through the activity of the amino nitrogen atoms and the oxygen atoms on the carboxyl group. Moreover, both of these peptides served to improve calcium transport and absorption in Caco-2 cell monolayers, depending on the concentration involved. It was revealed that the peptide-calcium complexes offered an increased calcium absorption percentage when compared to free calcium at similar concentrations. It might be concluded that the peptide within the peptide-calcium complex can promote calcium absorption through both active and passive transport pathways by increasing calcium concentration and promoting cell membrane interaction. Accordingly, DLBS protein can be considered a strong potential source of protein which can be used to produce calcium-binding peptides and might therefore play a role in the production of nutraceutical foods as a bioactive ingredient.

Is dietary deficiency of calcium a factor in rickets? Use of current evidence for our understanding of the disease in the past

OBJECTIVE

Rickets is considered an indicator of vitamin D deficiency in palaeopathology, but a strand of biomedical thought maintains that dietary calcium deficiency may sometimes play a part in its causation. Our aim is to evaluate the extent to which low calcium intake should be considered as a factor in biocultural interpretations of rickets.

METHODS

We assess published modern epidemiological studies that provide primary data to support claims for a role for dietary calcium deficiency in rickets. We also consider how we might identify, via indicators of calcium intake, populations at risk of calcium deficiency in the past.

RESULTS

Support for dietary calcium deficiency as a cause of rickets is equivocal. Direct measurement of dietary calcium in the past is not possible, but exposure to risk factors for low calcium intake can to some extent be identified.

CONCLUSION

Whilst there is little evidence to alter the view that rickets is essentially an indicator of a population's vitamin D status, occasionally, in very low calcium intake groups, dietary calcium deficiency may play a synergistic role by accentuating the need for vitamin D.

SIGNIFICANCE

The notion that dietary calcium deficiency may be a cause of rickets appears to be gaining currency in bioarchaeological studies. This paper shows that it is unusual for this to be the case, and even then the role of vitamin D remains crucial.

LIMITATIONS

This paper attempts to summarise the current state of biomedical study in an area that is subject to continuing investigation.

Relationships between Dairy and Calcium Intake and Mental Health Measures of Higher Education Students in the United States: Outcomes from Moderation Analyses

Background: The prevalence of mental health concerns among university students in the United States (U.S.) continues to increase, while current treatments, including medication and counseling, present shortcomings. Higher dairy and calcium intakes are associated with protective effects on mental health; however, previous studies have focused on investigating singular relationships between dairy and calcium intakes and mental health measures. A more complex exploration of these relationships is warranted to better examine whether increasing dairy and calcium intakes could serve as an intervention to improve mental health. The present study sought to further characterize the relationships between dairy and calcium intake, perceived stress, and a variety of mental health measures using linear regression and moderation analyses. Methods: The present cross-sectional study involved students studying at three large U.S. universities, and data collection occurred from April to May 2020 when students were learning remotely due to the COVID-19 pandemic. An online survey comprising validated tools was distributed among students to assess dairy and calcium intake, perceived stress, anxiety, negative and positive moods, rumination, and resilience, sleep quality and duration, dietary risk, and physical activity. Results: A total of 1233 students completed the study. Higher dairy and calcium intake was coincident with lower perceived stress and higher positive mood scores, while higher calcium intake was also coincident with lower anxiety, rumination, and higher resilience scores. Additionally, as calcium intake increased, the relationship between perceived stress and anxiety and the relationship between perceived stress and negative mood weakened. Dairy intake did not have this effect. Conclusions: Based on the results, and considering that calcium is a shortfall nutrient, universities should consider initiating programs and public health campaigns to promote dairy and calcium intake among this population.

Effects of Calcium Source, Inulin and Lactose on Gut-Bone Associations in an Ovarierectomized Rat Model

SCOPE

Osteoporosis poses a health challenge especially for postmenopausal women. This study aimed to explore nutritional strategies to counteract bone demineralization in ovarierectomized (OVX) rats.

METHODS AND RESULTS

OVX rats (n = 49) were fed with one of six different diets, where two different calcium sources (dairy calcium or calcium carbonate) were provided alone or in combination with either inulin (5%) or lactose (0.5%). In addition, a calcium-deficient diet was included. Calcium supplementation increased intestinal concentrations of short-chain fatty acids (SCFAs) and the abundance of fecal Acinetobacter and Propionibacterium. Accompanied with these effects, rats fed with calcium-fortified diets had higher bone mineral density, bone mineral content and femur mechanical strength, lower serum levels of bone markers and lower expression of calcium absorption-related genes (CaBP and Trpv6) compared with control. Inulin supplementation resulted in a markedly increased production of intestinal SCFAs, a decreased intestinal pH, an increased abundance of Allobaculum and Bifidobacterium, and an increased expression of Trpv6. Inulin and lactose showed beneficial effects on spine bone.

CONCLUSION

Calcium modulated gut microbiome composition and function. A pronounced effect of inulin on metabolic activity in the gastrointestinal tract was evident, and lactose supplementation decreased jejunal pH that might be associated with slightly enhanced bone mineralization. This article is protected by copyright. All rights reserved.

Calcium Absorption from Food Products: Food Matrix Effects

This article reviews physicochemical aspects of calcium absorption from foods. Notable differences are observed between different food products in relation to calcium absorption, which range from <10% to >50% of calcium in the foods. These differences can be related to the interactions of calcium with other food components in the food matrix, which are affected by various factors, including fermentation, and how these are affected by the conditions encountered in the gastrointestinal tract. Calcium absorption in the intestine requires calcium to be in an ionized form. The low pH in the stomach is critical for solubilization and ionization of calcium salts present in foods, although calcium oxalate complexes remain insoluble and thus poorly absorbable. In addition, the rate of gastric transit can strongly affect fractional absorption of calcium and a phased release of calcium into the intestine, resulting in higher absorption levels. Dairy products are the main natural sources of dietary calcium in many diets worldwide, which is attributable to their ability to provide high levels of absorbable calcium in a single serving. For calcium from other food products, lower levels of absorbable calcium can limit contributions to bodily calcium requirements.

Nutritional Status and Serum Levels of Micronutrients in an Elderly Group Who Participate in the Program for Complementary Food in Older People (PACAM) from the Metropolitan Region, Santiago de Chile

The increase in the Chilean elderly population has promoted public policies to favor an adequate nutrition in later life. This study evaluated the nutritional status, micronutrients intake and serum micronutrients levels of an elderly group beneficiary of the PACAM from the Metropolitan Region, Santiago de Chile. Anthropometric and dietary survey (24 h food recalls) were assessed in 182 elderly individuals (60 and 80 years old). Blood serum collection was used to measure the micronutrient status. The sample was comprised by 12.6%, 46.1%, 28.0% and 13.2% of underweight, normal weight, overweight and obese subjects, respectively. Women presented 11% of underweight, 45% of normal weight and 44% of overweight and obese, while men—18%, 50% and 32%, respectively. Only the 63% of the elderlies consumed PACAM foods, reaching average daily intakes below (50%) the recommended daily serving. Serum deficiencies of 25-hydroxyvitamin D (88%), vitamin B₁₂ (33%) and calcium (36%) were observed, being the highest ones in the PACAM foods women (60–75 years old). Chilean elderlies presented mainly a normal weight; however, an important proportion of overweight/obese subjects was observed. Although PACAM foods consumption significantly increased the micronutrient intake, it was not enough to ensure an adequate serum micronutrient levels in the elderly.

Calcium and vitamin D supplementation: when and why

Osteoporosis is a common disease, with fragility fractures representing its dreaded complications. The role of calcium and vitamin D supplementation needs to be addressed in the context of a heavy health burden, with a massive impact on individuals, healthcare systems, and societies as a whole. Calcium and vitamin D are often discussed together as interventions for promoting bone health. Still, it is essential to remember that they are quite distinct entities that play different roles in mineral metabolism. Insufficient calcium intake and vitamin D deficiency are common and widespread. Furthermore, a strong association between vitamin D deficiency and extra-skeletal outcomes has emerged over the last decades. When dietary intake is insufficient, with little room for improvement, several supplementation strategies have proved to be effective and safe. Adequate calcium intake and vitamin D serum levels should be pursued efficiently in the general population, and deficiency should be considered unacceptable in subsets particularly at risk. The aim of this narrative review was to present an overview of calcium and vitamin D intake and their supplementation.

Animal and plant-sourced nutrition: complementary not competitive

Debate on the sustainability of the global food system often compares the environmental, economic and health impacts of plant- and animal-sourced foods. This distinction can mask the considerable variation in impacts across and within these food groups. Moreover, the nutritional benefits of these food groups are insufficiently discussed. In this review, we highlight the nutritional contribution to the current global food system of both plant- and animal-sourced foods and place their impacts on human health in the global context. We highlight how the comparison of the environmental impacts of foods via life cycle analyses can change on the basis of the functional unit used, particularly the use of mass as opposed to nutrient content or nutrient richness. We review the literature on the affordability of nutrient-adequate diets, demonstrating the presence of both plant- and animal-sourced foods in affordable nutritious diets. Finally, we address the potential of alternative food sources that are gaining momentum, to ask where they may fit in a sustainable food system. We conclude that there is a clear place for both plant- and animal-sourced foods in future sustainable food systems, and a requirement for both for sustainable global nutrition; as such, the two groups are complementary and not competitive.

Influence of Dairy Products on Bioavailability of Zinc from Other Food Products: A Review of Complementarity at a Meal Level

In this paper, we reviewed the role of dairy products in dietary zinc absorption. Dairy products can have a reasonable contribution for dietary zinc intake in Western diets, where dairy consumption is high. However, the co-ingestion of dairy products can also improve zinc absorption from other food products. Such improvements have been observed when dairy products (e.g., milk or yoghurt) were ingested together with food such as rice, tortillas or bread products, all of which are considered to be high-phytate foods with low inherent zinc absorption. For foods low in phytate, the co-ingestion of dairy products did not improve zinc absorption. Improved zinc absorption of zinc from high-phytate foods following co-ingestion with dairy products may be related to the beneficial effects of the citrate and phosphopeptides present in dairy products. Considering that the main dietary zinc sources in areas in the world where zinc deficiency is most prevalent are typically high in phytate, the inclusion of dairy products in meals may be a viable dietary strategy to improve zinc absorption.

A comprehensive review of calcium and ferrous ions chelating peptides: Preparation, structure and transport pathways

Calcium and iron play crucial roles in human health, deficiencies of which have globally generated public health risks. The poor solubility, low bioavailability and gastrointestinal irritation of existing commercial mineral supplements limit their further application. As an emerging type of mineral supplement, mineral chelating peptides have drawn plenty of attention due to their advantages in stability, absorptivity and safety. A majority of calcium and ferrous ions chelating peptides have been isolated from food processing by-products. Enzymatic hydrolysis combined with affinity chromatography, gel filtration and other efficient separation techniques is the predominant method to obtain peptides with high calcium and ferrous affinity. Peptides with small molecular weight are more likely to chelate metals, and carboxyl, amino groups and nitrogen, oxygen, sulfur atoms in the side chain, which can provide lone-pair electrons to combine with metallic ions. Unidentate, bidentate, tridentate, bridging and α mode are regarded as common chelating modes. Moreover, the stability of peptide-mineral complexes in the gastrointestinal tract and possible transport pathways were summarized. This review is to present an overview of the latest research progress, existing problems and research prospects in the field of peptide-mineral complexes and to provide a more comprehensive theoretical basis for their exploitation in food industry.

Multiple Breeds and Countries' Predictions of Mineral Contents in Milk from Milk Mid-Infrared Spectrometry

Measuring the mineral composition of milk is of major interest in the dairy sector. This study aims to develop and validate robust multi-breed and multi-country models predicting the major minerals through milk mid-infrared spectrometry using partial least square regressions. A total of 1281 samples coming from five countries were analyzed to obtain spectra and in ICP-AES to measure the mineral reference contents. Models were built from records coming from four countries (n = 1181) and validated using records from the fifth country, Austria (n = 100). The importance of including local samples was tested by integrating 30 Austrian samples in the model while validating with the remaining 70 samples. The best performances were achieved using this second set of models, confirming the need to cover the spectral variability of a country before making a prediction. Validation root mean square errors were 54.56, 63.60, 7.30, 59.87, and 152.89 mg/kg for Na, Ca, Mg, P, and K, respectively. The built models were applied on the Walloon milk recording large-scale spectral database, including 3,510,077. The large-scale predictions on this dairy herd improvement database provide new insight regarding the minerals' variability in the population, as well as the effect of parity, stage of lactation, breeds, and seasons.

Promoting the Calcium-Uptake Bioactivity of Casein Phosphopeptides in vitro and in vivo

Casein phosphopeptides have been studied widely for their ability to chelate calcium. However, systematic studies on the effects of casein phosphopeptides (CPP) on calcium absorption in vitro and in vivo are scarce. The purities of two commercially available products, CPP1 and CPP2, are 18.37 and 25.12%, respectively. Here, the in vitro calcium binding capacity of CPP2 was 142.56 ± 7.39 mg/g, which was higher than that of CPP1 (107.15 ± 6.27 mg/g). The calcium transport results in a Caco-2 monolayer model indicated that, relative to controls, CPP1 and CPP2 increased calcium transport by 21.78 and 53.68%, respectively. Subsequent animal experiments showed that the CPP2-Ca-H group (1% Ca, 0.4% CPP2) had significant increases in the femur index, serum Ca²⁺ and serum osteocalcin levels, and femoral Ca content. The CPP2-Ca-H animal also had decreased serum alkaline phosphatase levels, parathyroid hormone content, and urinary pyridinoline content. Overall, our results demonstrated that CPP2 had stronger effects on promoting calcium uptake than CPP1.

KFP-1, a Novel Calcium-Binding Peptide Isolated from Kefir, Promotes Calcium Influx Through TRPV6 Channels

INTRODUCTION

Kefir is an acidic and alcoholic fermented milk product with multiple health-promoting benefits. A previous study demonstrated that kefir enhanced calcium absorption in intestinal Caco-2 cells. In this study, kefir-fermented peptide-1 (KFP-1) is isolated from the kefir peptide fraction, and its function as a calcium-binding peptide is characterized.

METHODS AND RESULTS

KFP-1 was identified as a 17-residue peptide with a sequence identical to that of κ-casein (residues 138-154) in milk protein. KFP-1 is demonstrated to promote calcium influx in Caco-2 and IEC-6 small intestinal cells in a concentration-dependent manner. TRPV6, but not L-type voltage-gated calcium channels, is associated with the calcium influx induced by KFP-1. An in vitro calcium binding assay indicates that the full-length KFP-1 peptide has a higher calcium-binding capacity than the two truncated KFP-1 peptides, KFP-1∆C5 and KFP-1C5. Alexa Fluor 594 labeling shows that KFP-1 is taken up by Caco-2 cells and interacts with calcium ions and TRPV6 protein. Moreover, KFP-1 is found moderately resistant to pepsin and pancreatin digestions and enhanced calcium uptake by intestinal enterocytes in vivo.

CONCLUSION

These data suggest that KFP-1, a novel calcium-binding peptide, binds extracellular calcium ions and enters Caco-2 and IEC-6 cells, and promotes calcium uptake through TRPV6 calcium channels. The present study is of great importance for developing kefir-derived metal ion-binding peptides as functional nutraceutical additives.

Review on the extraction of calcium supplements from eggshells to combat waste generation and chronic calcium deficiency

When faced with a plethora of issues, the possibility of one problem becoming the solution of another is a rare, yet beneficial scenario. This report explores the prospect of viewing the accumulation of organic waste matter in India as a potential calcium reservoir to relieve the issue of calcium deficiency in the population. Waste generation has seen gradual growth, and it has created a problem of waste disposal. A large segment of the generated waste primarily consists of food waste which contains significant amounts of nutrients. Food waste such as eggshells, waste from shellfish, bones, and fish scales contain good amounts of bioavailable calcium, and large quantities of this discarded bioavailable calcium remain unused. Global studies show India to have significantly lower levels of calcium intake than the global average, thus increasing the risk of calcium deficiency-related diseases. Furthermore, research shows that for over the past half of the century, the intake of dietary calcium has declined drastically throughout India. This has led to chronic calcium deficiency-related diseases throughout most of the Indian population. Hence, development of calcium supplements from calcium-rich waste material has the potential to not only reduce the strain on waste management, but also to provide the calcium-deficient population with a cheaper alternative to traditional supplements. Owing to the abundance and ease of separation, eggshells have been chosen as the focus of the review. This review highlights and compares their extraction methods of providing cheap calcium supplements while reducing the amount of eggshell waste.

Authenticity assessment of dairy products by capillary electrophoresis

Milk and derivatives are a very important part in the diet of the world population. Products from goat, buffalo, and sheep species have a greater economic value than the cow ones, therefore, authenticity frauds by improperly adding cow's milk occur frequently: dairy products are among the seven more attractive foods for adulteration. Milk from each of the above-cited animal species has its own definite profile of whey proteins (variants of α-lactalbumin and β-lactoglobulin) and its definite profile of caseins (variants of α_S1 -, α_S2 -, β-, and κ-casein). Such proteins can be usefully exploited as markers of authenticity by using capillary electrophoresis which is the technique of choice for the analysis of proteins. Due to the multiple adjustable parameters that are unknown to other analytical techniques, capillary electrophoresis is able to detect frauds in milk mixtures and cheese with little use of solvents, fast analysis time, and ease of operation. This makes it attractive and competitive for routine checks that are very important to fight the adulteration market. Advantages and limitations are discussed.

Ruminant Milk-Derived Extracellular Vesicles: A Nutritional and Therapeutic Opportunity?

Milk has been shown to contain a specific fraction of extracellular particles that are reported to resist digestion and are purposefully packaged with lipids, proteins, and nucleic acids to exert specific biological effects. These findings suggest that these particles may have a role in the quality of infant nutrition, particularly in the early phase of life when many of the foundations of an infant's potential for health and overall wellness are established. However, much of the current research focuses on human or cow milk only, and there is a knowledge gap in how milk from other species, which may be more commonly consumed in different regions, could also have these reported biological effects. Our review provides a summary of the studies into the extracellular particle fraction of milk from a wider range of ruminants and pseudo-ruminants, focusing on how this fraction is isolated and characterised, the stability and uptake of the fraction, and the reported biological effects of these fractions in a range of model systems. As the individual composition of milk from different species is known to differ, we propose that the extracellular particle fraction of milk from non-traditional and minority species may also have important and distinct biological properties that warrant further study.

The Safety of a Vegan Diet During Pregnancy

There is an increasing number of people who go vegetarian. Some young parents also switch to this diet. The safety of vegetarian diets, especially vegan diets, is very important, especially during pregnancy. Unfortunately, reference publications do not provide coherent data on the safety of vegetarian diets during pregnancy. On the one hand, the vegan diet has advantages because it reduces the risk of heart disease and gestational diabetes. On the other hand, vegetarians/vegans should be aware of potential deficiencies of some nutrients (iron, zinc, vitamin B12, vitamin D, omega-3 fatty acids, calcium, iodine) and the clinical consequences for the fetus. For example, iron deficiency may affect cognitive abilities, behavior, intelligence and increase the risk of preterm birth and low birth weight of infants. Plant food contains non-haem iron with variable absorption. Therefore, the vegan diet should include nutrients increasing the bioavailability of iron, e.g. ascorbic acid, carotene and retinol. Due to the fact that animal food is the main source of vitamin B12, vegans are at a very high risk of vitamin B12 deficiency, which will affect the infant’s weight at birth. Low level of vitamin D, which is prevalent in animal food, is the most common deficiency among vegans and lacto-ovo vegetarians. This vitamin prevents gestational diabetes, reduces insulin resistance and guarantees normal function of the musculoskeletal system. Zinc deficiency during pregnancy may lead to preterm birth, neural tube defects or even miscarriage. In view of the clinical consequences of potential deficiencies of nutrients, the vegetarian/vegan diet should be well balanced.

Drug-Encapsulated Cyclodextrin Nanosponges

To date, a number of nanocarriers, either inorganic or organic, have been developed to improve the delivery and therapeutic efficacy of various drugs. Drug delivery systems have attempted to overcome the undesirable pharmacokinetic problems encountered. Among the various nanomaterials that have been designed as potential nanocarriers, cyclodextrin-based polymers are of particular interest in this review.Cyclodextrins (CD) are a class of cyclic glucopyranose oligomers, obtained from starch by enzymatic action, with a characteristic toroidal shape that forms a truncated cone-shaped lipophilic cavity. The main common native cyclodextrins are named α, β, and γ which comprise six, seven, and eight glucopyranose units, respectively. Cyclodextrins have the capability to include compounds whose size and polarity are compatible with those of their cavity.Cyclodextrin-based cross-linked polymers, often referred to as "cyclodextrin nanosponges" (CDNSs), attract great attention from researchers for solving major bioavailability problems such as inadequate solubility, poor dissolution rate, and limited stability of some agents, as well as increasing their effectiveness and decreasing unwanted side effects.Registered patents about this novel system in various fields, different pharmaceutical applications, and classes of drugs encapsulated by CDNSs are detailed. The features outlined make CDNSs a promising platform for the development of innovative and advanced delivery systems.

Invited review: Maintaining and growing fluid milk consumption by children in school lunch programs in the United States

Fluid milk consumption among children has declined for decades. Adequate consumption of milk and dairy products, especially during childhood, has beneficial health outcomes for growth, development, and reduced risk of osteoporosis, hypertension, obesity, and cancer during adulthood. Satisfaction with milk flavor, perceived health benefits derived from milk, and habit are primary drivers of lifelong milk consumption. Child preferences and attitudes for milk may differ from those of adults, and as such, understanding and fulfilling the needs of children is crucial to reverse the decline in milk consumption. School meal programs make fluid milk accessible to millions of children each day; however, regulations and school lunch procurement systems in the United States sometimes make it difficult to provide novel or value-added milk products in these programs. Total consumption of all milk types in US schools declined by 14.2% from 2008 to 2017, and the percentage of children participating in the school lunch program has also declined. This decline has also been driven by declining average daily participation in the school meal program and may also reflect children's dissatisfaction with the sensory characteristics and the form of milk offered in schools. The change in form of milk offered in schools to lower fat and lower added sugar content in the United States has been driven by government-mandated school lunch calorie and fat requirements. This review describes the current milk consumption trends among children; the structure and basic requirements of the school lunch program in total and for milk; and the intrinsic, extrinsic, and environmental factors that influence child perception, preference, and consumption of fluid milk in the US school system.