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Endocrinology and Metabolism Clinics of... Dec 2021Calcium plays a key role in skeletal mineralization and several intracellular and extracellular homeostatic networks. It is an essential element that is only available... (Review)
Review
Calcium plays a key role in skeletal mineralization and several intracellular and extracellular homeostatic networks. It is an essential element that is only available to the body through dietary sources. Daily acquisition of calcium depends, in addition to the actual intake, on the hormonally regulated state of calcium homeostasis through three main mechanisms: bone turnover, intestinal absorption, and renal reabsorption. These procedures are regulated by a group of interacting circulating hormones and their key receptors. This includes parathyroid hormone (PTH), PTH-related peptide, 1,25-dihydroxyvitamin D, calcitonin, fibroblast growth factor 23, the prevailing calcium concentration itself, the calcium-sensing receptor, as well as local processes in the bones, gut, and kidneys.
Topics: Bone and Bones; Calcium; Calcium, Dietary; Homeostasis; Humans; Parathyroid Hormone; Vitamin D
PubMed: 34774235
DOI: 10.1016/j.ecl.2021.07.005 -
Nature Reviews. Nephrology Sep 2020Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling,... (Review)
Review
Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling, these restrictions can result in a low intake of fruits and vegetables and a lack of diversity in the diet. Plant nutrients and plant-based diets could have beneficial effects in patients with CKD: increased fibre intake shifts the gut microbiota towards reduced production of uraemic toxins; plant fats, particularly olive oil, have anti-atherogenic effects; plant anions might mitigate metabolic acidosis and slow CKD progression; and as plant phosphorus has a lower bioavailability than animal phosphorus, plant-based diets might enable better control of hyperphosphataemia. Current evidence suggests that promoting the adoption of plant-based diets has few risks but potential benefits for the primary prevention of CKD, as well as for delaying progression in patients with CKD G3-5. These diets might also help to manage and prevent some of the symptoms and metabolic complications of CKD. We suggest that restriction of plant foods as a strategy to prevent hyperkalaemia or undernutrition should be individualized to avoid depriving patients with CKD of these potential beneficial effects of plant-based diets. However, research is needed to address knowledge gaps, particularly regarding the relevance and extent of diet-induced hyperkalaemia in patients undergoing dialysis.
Topics: Acid-Base Equilibrium; Diet, Healthy; Diet, Mediterranean; Diet, Vegetarian; Dietary Approaches To Stop Hypertension; Dietary Fats, Unsaturated; Dietary Fiber; Disease Progression; Humans; Hyperkalemia; Phosphorus, Dietary; Plant Proteins, Dietary; Potassium, Dietary; Renal Dialysis; Renal Insufficiency, Chronic
PubMed: 32528189
DOI: 10.1038/s41581-020-0297-2 -
Calcified Tissue International Jan 2021Phosphorus, a 5A element with atomic weight of 31, comprises just over 0.6% of the composition by weight of plants and animals. Three isotopes are available for studying... (Review)
Review
Phosphorus, a 5A element with atomic weight of 31, comprises just over 0.6% of the composition by weight of plants and animals. Three isotopes are available for studying phosphorus metabolism and kinetics. P is stable, whereas the radioactive isotope P has a half-life of 25 days and P has a half-life of 14 days. Phosphate ester and phosphoanhydride are common chemical linkages and phosphorus is a key element in organic molecules involved in a wide variety of essential cellular functions. These include biochemical energy transfer via adenosine triphosphate (ATP), maintenance of genetic information with nucleotides DNA and RNA, intracellular signaling via cyclic adenosine monophosphate (cAMP), and membrane structural integrity via glycerophospholipids. However, this review focuses on the metabolism of inorganic phosphorus (Pi) acting as a weak acid. Phosphoric acid has all three hydrogens attached to oxygen and is a weak diprotic acid. It has 3 pKa values: pH 2.2, pH 7.2, and pH 12.7. At physiological pH of 7.4, Pi exists as both HPO and HPO and acts as an extracellular fluid (ECF) buffer. Pi is the form transported across tissue compartments and cells. Measurement of Pi in biological fluids is based on its reaction with ammonium molybdate which does not measure organic phosphorus. In humans, 80% of the body phosphorus is present in the form of calcium phosphate crystals (apatite) that confer hardness to bone and teeth, and function as the major phosphorus reservoir (Fig. 1). The remainder is present in soft tissues and ECF. Dietary phosphorus, comprising both inorganic and organic forms, is digested in the upper gastrointestinal tract. Absorbed Pi is transported to and from bone, skeletal muscle and soft tissues, and kidney at rates determined by ECF Pi concentration, rate of blood flow, and activity of cell Pi transporters (Fig. 2). During growth, there is net accretion of phosphorus, and with aging, net loss of phosphorus occurs. The bone phosphorus reservoir is depleted and repleted by overall phosphorus requirement. Skeletal muscle is rich in phosphorus used in essential biochemical energy transfer. Kidney is the main regulator of ECF Pi concentration by virtue of having a tubular maximum reabsorptive capacity for Pi (TmPi) that is under close endocrine control. It is also the main excretory pathway for Pi surplus which is passed in urine. Transcellular and paracellular Pi transports are performed by a number of transport mechanisms widely distributed in tissues, and particularly important in gut, bone, and kidney. Pi transporters are regulated by a hormonal axis comprising fibroblast growth factor 23 (FGF23), parathyroid hormone (PTH), and 1,25 dihydroxy vitamin D (1,25D). Pi and calcium (Ca) metabolism are intimately interrelated, and clinically neither can be considered in isolation. Diseases of Pi metabolism affect bone as osteomalacia/rickets, soft tissues as ectopic mineralization, skeletal muscle as myopathy, and kidney as nephrocalcinosis and urinary stone formation. Fig. 1 Content of phosphorus in human adult: skeleton, soft tissue, and extracellular fluid (grams, log scale). Corresponding data for calcium are shown for comparison Fig. 2 Phosphate (Pi) transport to and from tissue compartments in mg/24 h. At a dietary phosphorus of 1400 mg, 1120 mg is absorbed in upper intestine to the ECF, 210 mg returned to intestine by endogenous secretion, resulting in 910 mg net Pi absorption and 490 mg fecal excretion. At bone, 180 mg is deposited by bone formation and 180 mg return to the ECF by bone resorption. At kidney, 5040 mg is filtered at the glomerulus and 4130 mg return to the ECF by tubular reabsorption with 910 mg excreted in the urine. In soft tissue, Pi is exchanged between ECF and cells.
Topics: Animals; Bone and Bones; Calcium, Dietary; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Kidney; Muscle, Skeletal; Parathyroid Hormone; Phosphates; Vitamin D
PubMed: 32266417
DOI: 10.1007/s00223-020-00686-3 -
Nephrology, Dialysis, Transplantation :... Jan 2024Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism,... (Review)
Review
Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism, signal transduction and pH buffering. In bone, Pi is essential for bone stability in the form of apatite. Intestinal absorption of dietary Pi depends on its bioavailability and has two distinct modes of active transcellular and passive paracellular absorption. Active transport is transporter mediated and partly regulated, while passive absorption depends mostly on bioavailability. Renal excretion controls systemic Pi levels, depends on transporters in the proximal tubule and is highly regulated. Deposition and release of Pi into and from soft tissues and bone has to be tightly controlled. The endocrine network coordinating intestinal absorption, renal excretion and bone turnover integrates dietary intake and metabolic requirements with renal excretion and is critical for bone stability and cardiovascular health during states of hypophosphataemia or hyperphosphataemia as evident from inborn or acquired diseases. This review provides an integrated overview of the biology of phosphate and Pi in mammals.
Topics: Animals; Humans; Phosphates; Phosphorus; Intestinal Absorption; Hyperphosphatemia; Minerals; Mammals
PubMed: 37660247
DOI: 10.1093/ndt/gfad188 -
Nutrients Apr 2021Phosphate is a key uremic toxin associated with adverse outcomes. As chronic kidney disease (CKD) progresses, the kidney capacity to excrete excess dietary phosphate... (Review)
Review
Phosphate is a key uremic toxin associated with adverse outcomes. As chronic kidney disease (CKD) progresses, the kidney capacity to excrete excess dietary phosphate decreases, triggering compensatory endocrine responses that drive CKD-mineral and bone disorder (CKD-MBD). Eventually, hyperphosphatemia develops, and low phosphate diet and phosphate binders are prescribed. Recent data have identified a potential role of the gut microbiota in mineral bone disorders. Thus, parathyroid hormone (PTH) only caused bone loss in mice whose microbiota was enriched in the Th17 cell-inducing taxa segmented filamentous bacteria. Furthermore, the microbiota was required for PTH to stimulate bone formation and increase bone mass, and this was dependent on bacterial production of the short-chain fatty acid butyrate. We review current knowledge on the relationship between phosphate, microbiota and CKD-MBD. Topics include microbial bioactive compounds of special interest in CKD, the impact of dietary phosphate and phosphate binders on the gut microbiota, the modulation of CKD-MBD by the microbiota and the potential therapeutic use of microbiota to treat CKD-MBD through the clinical translation of concepts from other fields of science such as the optimization of phosphorus utilization and the use of phosphate-accumulating organisms.
Topics: Animals; Chelating Agents; Chronic Kidney Disease-Mineral and Bone Disorder; Disease Models, Animal; Disease Progression; Gastrointestinal Microbiome; Holistic Health; Humans; Hyperphosphatemia; Mice; Parathyroid Hormone; Phosphorus, Dietary; Probiotics; Renal Insufficiency, Chronic; Th17 Cells
PubMed: 33924419
DOI: 10.3390/nu13041273 -
Frontiers in Veterinary Science 2021The sustainability of animal production relies on the judicious use of phosphorus (P). Phosphate, the mined source of agricultural phosphorus supplements, is a... (Review)
Review
The sustainability of animal production relies on the judicious use of phosphorus (P). Phosphate, the mined source of agricultural phosphorus supplements, is a non-renewable resource, but phosphorus is essential for animal growth, health, and well-being. P must be provided by efficient and sustainable means that minimize the phosphorus footprint of livestock production by developing precise assessment of the bioavailability of dietary P using robust models. About 60% of the phosphorus in an animal's body occurs in bone at a fixed ratio with calcium (Ca) and the rest is found in muscle. The P and Ca requirements must be estimated together; they cannot be dissociated. While precise assessment of P and Ca requirements is important for animal well-being, it can also help to mitigate the environmental effects of pig farming. These strategies refer to multicriteria approaches of modeling, efficient use of the new generations of phytase, depletion and repletion strategies to prime the animal to be more efficient, and finally combining these strategies into a precision feeding model that provides daily tailored diets for individuals. The industry will need to use strategies such as these to ensure a sustainable plant-animal-soil system and an efficient P cycle.
PubMed: 34901241
DOI: 10.3389/fvets.2021.734365 -
Nutrients Sep 2020Inorganic phosphate (P) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP... (Review)
Review
Inorganic phosphate (P) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP synthesis. P is the main source of dietary phosphorus. Reduced bioavailability of P or excessive losses in the urine causes rickets and osteomalacia. While critical for health in normal amounts, dietary phosphorus is plentiful in the Western diet and is often added to foods as a preservative. This abundance of phosphorus may reduce longevity due to metabolic changes and tissue calcifications. In this review, we examine how dietary phosphorus is absorbed in the gut, current knowledge about P sensing, and endocrine regulation of P levels. Moreover, we also examine the roles of P in different tissues, the consequences of low and high dietary phosphorus in these tissues, and the implications for healthy aging.
Topics: Biological Availability; Bone and Bones; Healthy Aging; Humans; Phosphates; Phosphorus, Dietary
PubMed: 33007883
DOI: 10.3390/nu12103001 -
Clinical Journal of the American... Oct 2019
Topics: Cross-Over Studies; Diet; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Phosphates; Phosphorus, Dietary; Renal Dialysis
PubMed: 31519551
DOI: 10.2215/CJN.09640819 -
The American Journal of Clinical... Feb 2022Recent observational studies have suggested that circulating phosphorus concentrations are positively associated with the risk of prostate cancer. However, little is...
BACKGROUND
Recent observational studies have suggested that circulating phosphorus concentrations are positively associated with the risk of prostate cancer. However, little is known about the causal direction of the association.
OBJECTIVES
To explore the potential causal relation between circulating phosphorus and risk of prostate cancer, we conducted a Mendelian randomization (MR) study.
METHODS
Summary statistics of prostate cancer were obtained from a meta-analysis of genome-wide association studies (GWASs) consisting of 79,148 cases and 61,106 controls. Single-nucleotide polymorphisms (SNPs) associated with serum phosphorus concentration were selected from a GWAS of 291,408 individuals from the UK Biobank. MR analysis was performed using the inverse variance weighted (IVW) method, supplemented with simple median method, weighted median method, maximum likelihood-based method, MR-Egger regression, and the MR pleiotropy residual sum and outlier test. We also performed a meta-analysis of observational studies to assess the associations of dietary phosphorus intake and serum phosphorus concentration with risk of prostate cancer.
RESULTS
In the MR analysis, a total of 125 independent SNPs associated with serum phosphorus concentrations were used as instrumental variables. Genetically predicted serum phosphorus concentrations were associated with a 19% increased risk of prostate cancer (95% CI: 9%, 31%) per 1-SD increment of serum phosphorus by IVW (P = 1.82 × 10-4). Sensitivity analyses using alternative MR methods produced similar positive associations, and no evidence of pleiotropy was detected by MR-Egger regression (P = 0.422). For meta-analysis, 8 studies for dietary phosphorus intake and 4 for serum phosphorus concentrations were included involving a total of 669,080 participants. Consistently, high dietary phosphorus intake and serum phosphorus concentrations were associated with an 8% (95% CI: 4%, 12%) and 7% (95% CI: 1%, 14%) increase in prostate cancer risk, respectively.
CONCLUSIONS
Our study suggested a potential causal relation between circulating phosphorus and risk of prostate cancer. Further studies are warranted to elucidate the underlying mechanism of phosphorus in the development of prostate cancer.
Topics: Biomarkers, Tumor; Genome-Wide Association Study; Humans; Likelihood Functions; Male; Mendelian Randomization Analysis; Meta-Analysis as Topic; Phosphorus; Polymorphism, Single Nucleotide; Prostatic Neoplasms
PubMed: 34617559
DOI: 10.1093/ajcn/nqab342 -
Brain Sciences Jul 2023Dietary constituents may affect the progression of Parkinson's disease (PD). This study aimed to assess the contribution of dietary intake of vitamins and minerals to...
BACKGROUND AND OBJECTIVE
Dietary constituents may affect the progression of Parkinson's disease (PD). This study aimed to assess the contribution of dietary intake of vitamins and minerals to the severity, motor and non-motor symptoms, and risk of PD.
METHODS
In this case-control study, 120 patients with PD and 50 healthy participants participated. Dietary intake of vitamins and minerals was determined using a 147-item food frequency questionnaire. The severity of PD was determined by the Unified Parkinson's Disease Rating Scale (UPDRS).
RESULTS
Patients with PD had lower intake of several vitamins and minerals including lycopene, thiamine, vitamin B6, vitamin B12, pantothenic acid, magnesium, zinc, manganese, selenium, chromium, and phosphorus, but had higher intake of α-tocopherol. High dietary intake of vitamin A, α-carotene, β-cryptoxanthin, vitamin C, and α-tocopherol were correlated with increased odds of PD. High intake of lycopene, thiamin, vitamin B6, pantothenic acid, magnesium, zinc, manganese, chromium, and phosphorous correlated with reduced odds of PD. The predictive power of α-tocopherol concerning the risk of PD was stronger relative to other vitamins. Dietary intake of pantothenic acid was negatively correlated with PD severity and symptoms of motor examination and complication. The severity and motor symptoms of PD were also negatively correlated with β-carotene, vitamin C, riboflavin, vitamin B6, and biotin intake. The UPDRS total score and motor symptoms in PD patients were negatively correlated with phosphorus, magnesium, zinc, manganese, and chromium, and strongly with potassium intake.
CONCLUSION
The findings indicate that adequate dietary intake of vitamins and minerals may have a preventive effect on developing PD and progression of motor decline.
PubMed: 37509049
DOI: 10.3390/brainsci13071119