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.

Prebiotic to Improve Calcium Absorption in Postmenopausal Women After Gastric Bypass: A Randomized Controlled Trial

Context The adverse skeletal effects of Roux-en-Y gastric bypass (RYGB) are partly caused by intestinal calcium absorption decline. Prebiotics, such as soluble corn fiber (SCF), augment colonic calcium absorption in healthy individuals. Objective We tested the effects of SCF on fractional calcium absorption (FCA), biochemical parameters, and the fecal microbiome in a post-RYGB population. Design, Setting, Participants : Randomized, double-blind, placebo-controlled trial of 20 postmenopausal women with history of RYGB mean 5 years prior. Intervention 2-month course of 20 g/day SCF or maltodextrin placebo orally. Main Outcomes Between-group difference in absolute change in FCA (primary outcome) was measured with a gold-standard dual stable isotope method. Other measures included tolerability, adherence, serum calciotropic hormones and bone turnover markers, and fecal microbial composition via 16S rRNA gene sequencing. Results Mean FCA ±SD at baseline was low at 5.5±5.1%. Comparing SCF to placebo, there was no between-group difference in mean (95% CI) change in FCA (+3.4 [-6.7,+13.6]%), nor in calciotropic hormones or bone turnover markers. The SCF group had a wider variation in FCA change than placebo (SD 13.4% vs. 7.0%). Those with greater change in microbial composition following SCF treatment had greater increase in FCA (r 2=0.72,p=0.05). SCF adherence was high, and GI symptoms similar between groups. Conclusions No between-group differences were observed in changes in FCA or calciotropic hormones, but wide confidence intervals suggest a variable impact of SCF that may be due to the degree of gut microbiome alteration. Daily SCF consumption was well-tolerated. Larger and longer-term studies are warranted.

THE USE OF A CALCIUM-CONTAINING VITAMIN-MINERAL COMPLEX IN CHRONIC GENERALIZED PERIODONTITIS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

Витамин Д является жирорастворимым витамином, который в организме человека вырабатывается только при определённых условиях, когда ультрафиолетовые лучи солнечного света попадают на кожу человека. В организм человека витамин Д поступает в ограниченном количестве 20- 30% от потребности , в таких продуктах питания как: лосось(200-800 МЕ на 100 г), сметана-50 МЕ, печень говяжья-45МЕ, масло сливочное-10-150 МЕ, молоко, обогащённое витамином Д, желтки яиц-45 МЕ. Витамину Д для активации в организме необходимо пройти два процесса гидроксилирования. Первый из них происходит в печени (до 90%) и превращает витамин Д в 25-гидроксивитамин Д-25(ОН)Д или кальцидиол. Второй этап происходит в почках (10%), в результате чего синтезируется активный 1,25 -дигидроксивитамин Д или кальцитриол. Уровень образования Д-гормона в организме взрослого человека составляет около 0,3-1,0 мкг/сут. Важнейшая реакция, в которой участвует витамин Д - абсорбция кальция в кишечнике и его реабсорбция в почках, поддержание необходимого уровня кальция и фосфатов в крови, он необходим для роста костей и процессов костного ремоделирования. Чтобы сохранить нормальный гомеостаз кальция и костного ремоделирования, организму необходимо получать витамин D3. В условиях физиологии его потребность варьирует в сутки от двухсот-четырёхсот МЕ (у взрослых людей), до шестисот-восьмисот МЕ (у людей пожилого возраста) и до одной тысячи МЕ у лиц, живущих в районах Крайнего Севера. Концентрация промежуточного метаболита [25-(OH)D3] в сыворотке крови считается самым надёжным показателем общего обмена витамина D, поэтому этот показатель может быть использован для определения обеспеченности организма витамином D. Также он необходим для выяснения причин патологических концентраций кальция в сыворотке крови пациентов. Адекватное содержание [25-(OH)D3] поддерживает абсорбцию кальция и костный метаболизм. Содержание же [25-(OH)D3] ниже целевого значения 30 нг/мл вызывает снижение кальция в плазме крови и повышение секреции ПТГ, и как следствие, остеокластическую резорбцию кости, нарушение процессов ремоделирования и минерализации костной ткани, снижение её плотности и изменение костной архитектуры Vitamin D is a fat-soluble vitamin that is produced in the human body only under certain conditions, when ultraviolet rays of sunlight fall on the human skin. The human body receives vitamin D in a limited amount of 20-30% of the need, in such food products as: salmon (200-800 IU per 100 g), sour cream-50 IU, beef liver-45 IU, butter-10-150 IU, milk enriched with vitamin D, egg yolks-45 IU. Vitamin D needs to undergo two hydroxylation processes to be activated in the body. The first of these occurs in the liver (up to 90%) and converts vitamin D to 25-hydroxyvitamin D-25(OH)D or calcidiol. The second stage occurs in the kidneys (10%), resulting in the synthesis of active 1,25 -dihydroxyvitamin D or calcitriol. The level of D-hormone formation in the adult body is about 0.3-1.0 mcg/day. The most important reaction in which vitamin D is involved is the absorption of calcium in the intestine and its reabsorption in the kidneys, maintaining the necessary level of calcium and phosphates in the blood, it is necessary for bone growth and bone remodeling processes. To maintain normal calcium homeostasis and bone remodeling, the body needs to receive vitamin D3. In the conditions of physiology, its need varies per day from two hundred to four hundred IU (in adults), to six hundred to eight hundred IU (in the elderly) and up to one thousand IU in people living in the Far North. The concentration of the intermediate metabolite [25-(OH)D3] in the blood serum is considered the most reliable indicator of the total vitamin D metabolism, so this indicator can be used to determine the body's vitamin D supply. It is also necessary to find out the causes of abnormal concentrations of calcium in the blood serum of patients. Adequate [25-(OH)D3] content supports calcium absorption and bone metabolism. The content of [25-(OH)D3] below the target value of 30 ng / ml causes a decrease in calcium in the blood plasma and an increase in PTH secretion, and as a result, osteoclastic bone resorption, a violation of the processes of bone remodeling and mineralization, a decrease in its density and a change in bone architecture

Identification and Classification of the Tea Samples by Using Sensory Mechanism and Arduino UNO

Tea is the most popular hot beverageworldwide. In 2020, the value of the global tea market was almost USD 200 billion, and is estimated to reach up to USD 318 billion by the year 2025. Tea has been included as part ofa regular diet for centuries because of its various health benefits. However, tea is acidic, and over-consumption causes heat problems, disturbance of the sleep cycle, tooth erosion, and low calcium absorption in the body. Strong tea concentration is very harmful and toxic. The safe consumption of tea should be guaranteed. The treatment applied in this research work is on sensory mechanisms and Arduino UNO. The objective of this paper is to find out community interest in a particular tea species and inform them about tea overdose.The acidity is mapped with tea taste in terms of strong, medium, and low flavors. Based on the data analysis, the results differentiatethe acidity level of black tea (pH: 3.89–4.08) as very high, green tea (pH: 4.68–4.70) is in the 2nd position, and the energy drink Herbalife Nutrition (pH: 5.59–5.64) is the least acidic comparatively, with a proportion ratio 1:10 of tea to water. Experimental analysis reveals that in the additives, lemon is most acidic, followed byginger, lemongrass, and Tulasi.

Vitamin D3 Protects Mice from Diquat-Induced Oxidative Stress through the NF-κB/Nrf2/HO-1 Signaling Pathway

Vitamin D3, as an indispensable and fat-soluble micronutrient, plays an important role in the health of humans and animals. At present, studies are focusing on the calcium absorption and immunoregulation function of vitamin D3; this study was aimed at exploring the antioxidative stress ability of vitamin D3 on diquat-induced intestinal dysfunction of ICR mice and the underlying mechanism. The results showed that oral gavage of vitamin D3 daily significantly improved the body weight gain and immune organ index and significantly reverted the abnormal changes of ALT, AST, SOD, GSH-Px, T-AOC, and MDA in the serum and jejunum induced by diquat. The addition of vitamin D3 also significantly reduced the concentration of DAO, D-LA, and certain proinflammatory cytokines in serum. Moreover, vitamin D3 improved the pathological morphology of the duodenum, jejunum, colon, liver, and kidney tissues, and it also largely attenuated the degree of inflammatory infiltration of macrophages and cell apoptotic index of jejunal epithelial tissue induced by diquat. The results demonstrated that vitamin D3 significantly recovered the intestinal barrier injury by enhancing the expression of mucins and tight junction proteins in the jejunum. In addition, the results indicated that vitamin D3 could significantly reduce the phosphorylation level of NF-κB (p65) and enhance the expression of Nrf2 and HO-1 in the jejunum compared with the diquat-induced group. This study suggested that oral administration of vitamin D3 can protect mice against oxidative damage by inhibiting the phosphorylation level of NF-κB (p65) and activating Nrf2-related signaling pathways.

Challenges Ahead for a Rational Analysis of Vitamin D in Athletes

Vitamin D is an essential vitamin for the normal formation of bones and calcium absorption. It is synthesized into our body through sunlight exposure and obtained by consuming foods rich in vitamin D (e.g., fatty fish, eggs yolk, dairy products). Its benefits on the health and performance of athletes are well documented. This article outlines some analytical challenges concerning the analytical quantification of vitamin D for its optimal intake, namely, a comprehensive study of the variability of the assay before categorizing any method as the golden standard, assurance of sample comparability to draw meaningful correlations, revision of the intake guidance based on appropriate statistical power analysis, and the implementation of rational strategies for preventing the underlying mechanism of preanalytical factors. Addressing these challenges will enable the effective management of vitamin D in the sports sector.

Elucidating the Calcium-Binding Site, Absorption Activities, and Thermal Stability of Egg White Peptide–Calcium Chelate

With the current study, we aimed to determine the characteristics and calcium absorption capacity of egg white peptide–calcium complex (EWP-Ca) and determine the effect of sterilization on EWP-Ca to study the possibility of EWP-Ca as a new potential calcium supplement. The results of SEM and EDS showed a high calcium chelating ability between EWP and calcium, and the structure of EWP-Ca was clustered spherical particles due its combination with calcium. The FTIR and Raman spectrum results showed that EWP could chelate with calcium by carboxyl, phosphate, and amino groups, and peptide bonds may also participate in peptide–calcium binding. Moreover, the calcium absorption of EWP-Ca measured by the intestinal everted sac model in rats was 32.38 ± 6.83 μg/mL, significantly higher than the sample with CaCl2, and the mixture of EWP and Ca (p < 0.05) revealed appropriate calcium absorption capacity. The fluorescence spectra and CD spectra showed that sterilization caused a decrease in the content of α-helix and β-sheet and a significant increase in β-turn (p < 0.05). Sterilization changed the EWP-Ca structure and decreased its stability; the calcium-binding capacity of EWP-Ca after sterilization was decreased to 41.19% (p < 0.05). Overall, these findings showed that EWP could bind with calcium, form a peptide–calcium chelate, and serve as novel carriers for calcium supplements.

Drug-induced hypocalcemia

Hypocalcemia (HCa) is one of the main water-electrolyte disturbances in clinical practice. An acute decrease in serum calcium levels can lead to seizures, ventricular arrhythmias, bronchospasm and laryngospasm. Chronic HCa can result in disorientation and confusion. To prevent these complications, the risk factors for low calcium levels must be carefully evaluated. One of these factors is drugs, in which case we are talking about drug-induced (DI) HCa. The list of drugs-inducers of DI HCa is quite extensive, but the leading role in this disorder is played by drugs for the treatment of osteoporosis, antineoplastic and antiepileptic drugs, as well as drugs for anti-tuberculosis therapy. When taking zoledronic acid, DI HCa is observed with a frequency of up to 39%. When taking imatinib, a targeted anticancer drug, a decrease in calcium levels was observed in 40% of cases. The pathophysiological mechanisms of DI HCa can be a decrease in bone resorption, a decrease in the concentration of vitamin D, inhibition of the action of parathyroid hormone and impaired calcium absorption. Risk factors in most cases of DI HCa are vitamin D deficiency and hypomagnesemia. An acute decrease in calcium levels leads to symptoms of neuromuscular excitability, abnormalities on the electrocardiogram (ECG) and electroencephalogram (EEG). The basis for the treatment of DI HCa is the drug withdrawal and the appointment of calcium. It is also necessary to prescribe vitamin D. The main methods of prevention of DI HCa are to determine the level of calcium and vitamin D before starting therapy with culprit medication, and to correct its level. It is also important to prescribe additional amounts of calcium and vitamin D during therapy with such drugs. Awareness of the attending physicians about the problem of DI HCa, a thorough assessment of its risk factors and the prophylactic administration of calcium and vitamin D preparations will help to effectively prevent those serious complications resulting from a decrease in calcium levels in clinical practice.

Hepcidin induces intestinal calcium uptake while suppressing iron uptake in Caco-2 cells

Abnormal calcium absorption and iron overload from iron hyperabsorption can contribute to osteoporosis as found in several diseases, including hemochromatosis and thalassemia. Previous studies in thalassemic mice showed the positive effects of the iron uptake suppressor, hepcidin, on calcium transport. However, whether this effect could be replicated in other conditions is not known. Therefore, this study aimed to investigate the effects of hepcidin on iron and calcium uptake ability under physiological, iron uptake stimulation and calcium uptake suppression. To investigate the potential mechanism, effects of hepcidin on the expression of iron and calcium transporter and transport-associated protein in Caco-2 cells were also determined. Our results showed that intestinal cell iron uptake was significantly increased by ascorbic acid together with ferric ammonium citrate (FAC), but this phenomenon was suppressed by hepcidin. Interestingly, hepcidin significantly increased calcium uptake under physiological condition but not under iron uptake stimulation. While hepcidin significantly suppressed the expression of iron transporter, it had no effect on calcium transporter expression. This indicated that hepcidin-induced intestinal cell calcium uptake did not occur through the stimulation of calcium transporter expression. On the other hand, 1,25(OH)2D3 effectively induced intestinal cell calcium uptake, but it did not affect intestinal cell iron uptake or iron transporter expression. The 1,25(OH)2D3-induced intestinal cell calcium uptake was abolished by 12 mM CaCl2; however, hepcidin could not rescue intestinal cell calcium uptake suppression by CaCl2. Taken together, our results showed that hepcidin could effectively and concurrently induce intestinal cell calcium uptake while reducing intestinal cell iron uptake under physiological and iron uptake stimulation conditions, suggesting its therapeutic potential for inactive calcium absorption, particularly in thalassemic patients or patients who did not adequately respond to 1,25(OH)2D3.