Calcium Bioavailability in Relation to Bone Health

2002 ◽  
Vol 72 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Susan J. Fairweather-Tait ◽  
Birgit Teucher
Keyword(s):  
Bone Health ◽  
Bone Growth ◽  
Intervention Studies ◽  
Dietary Intervention ◽  
Calcium Absorption ◽  
Dietary Calcium ◽  
Whole Body ◽  
Calcium Balance ◽  
Calcium Bioavailability

A well established stable isotope technique exists for measuring calcium absorption from single foods and meals, but the long term effects of calcium on bone health cannot be assessed from acute bioavailability studies. Bone health depends primarily on the degree of mineralization, measured as bone mineral density (BMD), and phenotypic variations depend on genetic and environmental factors including calcium supply. Since almost all retained calcium is used for bone mineralization and remodeling, BMD can be used as a long-term (> six months) marker of dietary calcium bioavailability. However, BMD is a very insensitive marker of calcium bioavailability, so its use in dietary intervention studies is restricted to periods of significant bone growth or loss. Biochemical markers of bone metabolism may be used to predict the overall bioavailability of dietary calcium over a shorter time period (> four weeks), but they have a high coefficient of variation, so may not be appropriate for some dietary intervention studies. A group of European laboratories is currently developing an alternative approach using a long-lived radioisotope (41Ca) to label bone calcium and to directly measure the rate of calcium loss from urinary excretion data. The efficiency of calcium absorption is inversely related to intake; whole body balance of the mineral is dependent on rates of absorption and excretion and limited by calcium-binding substances in the gut. Dietary data and indirect measures of bone health indicate that bioavailability is important when habitual intakes are low, especially during periods of bone growth or loss. Further research is required to quantify the effects of major dietary modulators of calcium balance on bone health and to understand their relationship with genetic and physiological variables.

scholarly journals Dietary protein and bone health: towards a synthesised view

2020 ◽  
pp. 1-8
Author(s):  
Andrea L. Darling ◽  
D. Joe Millward ◽  
Susan A. Lanham-New
Keyword(s):  
Amino Acids ◽  
Bone Health ◽  
Dietary Protein ◽  
Bone Growth ◽  
Calcium Absorption ◽  
Health It ◽  
Cereal Products ◽  
Sulphur Amino Acids ◽  
The Relationship

The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.

Regulation of calcium balance in the sturgeon Acipenser naccarii: a role for PTHrP

2007 ◽  
Vol 293 (2) ◽  
pp. R884-R893 ◽  
Author(s):  
Juan Fuentes ◽  
Christophe Haond ◽  
Pedro M. Guerreiro ◽  
Nádia Silva ◽  
Deborah M. Power ◽  
...  
Keyword(s):  
Calcium Transport ◽  
Calcium Uptake ◽  
Dietary Calcium ◽  
Calcium Deficiency ◽  
Cell Number ◽  
The Body ◽  
Whole Body ◽  
Calcium Balance ◽  
Parathyroid Hormone Related Protein ◽  
Juvenile Sturgeon

Calcium regulation in sturgeon is of special interest because they are a representative of the ancient fishes possessing mainly cartilaginous skeletons and a supposedly low calcium demand. The present study aimed to characterize the effect of a chronic absence of dietary calcium and the effect of parathyroid hormone-related protein (PTHrPA) (1-34) ( 7 ) on calcium balance in juvenile sturgeon ( Acipenser naccarii). At rest, sturgeon juveniles are in net positive calcium balance, since whole body calcium uptake is significantly higher than efflux and calcium accumulates in the body. To study the importance of dietary calcium, the sturgeon were kept on a calcium-free diet for 8 wk. This manipulation impaired growth as measured by failure to gain weight or increase in length and indicates that dietary calcium is important for growth in sturgeon. An increased whole body calcium uptake partially compensated dietary calcium deficiency and was associated with increased gill chloride cell number in lamellae and filaments in parallel with increased gill Na+K+-ATPase activity. In addition, a single injection of piscine PTHrP(1-34) significantly increased whole body calcium uptake and decreased whole body calcium efflux. Administration of PTHrP significantly increased circulating plasma calcium 4–24 h postinjection. The increase in net calcium transport and increased plasma levels of calcium is consistent with the actions of a hypercalcemic factor. It would appear that the sturgeon rely on calcium for growth and tightly regulate calcium transport. The action in calcium balance is consistent with PTHrP acting as a hypercalcemic factor in sturgeon.

scholarly journals Caloric Substitution of Diets with Apple Pomace was Determined to be Safe for Renal and Bone Health Using a Growing Rat Model

2019 ◽  
pp. 248-259 ◽  
Author(s):  
R. Chris Skinner ◽  
Joseph C. Gigliotti ◽  
Katherine H. Taylor ◽  
Derek C. Warren ◽  
Vagner A. Benedito ◽  
...  
Keyword(s):  
Bone Health ◽  
Calcium Absorption ◽  
Apple Pomace ◽  
Western Diet ◽  
Histological Evaluation ◽  
Calcium Balance ◽  
Sprague Dawley ◽  
Growing Rat ◽  
Growing Age ◽  
And Function

Aims: To determine the safety of caloric substitution with 10% (g/kg) apple pomace to a healthy or Western diet. Study Design: Growing (age 22-29 days) female Sprague-Dawley rats were randomly assigned (n=8 rats/group) to consume a purified standard rodent diet (AIN-93G), AIN-93G/10% g/kg apple pomace (AIN/AP), Western diet, or Western/10% g/kg apple pomace (Western/AP) diets for 8 weeks. Results: Histological evaluation showed renal interstitial hypercellularity in rats fed AIN/AP, Western, and Western/AP diets. However, there were no effects on renal expression of oxidative stress and inflammatory genes or serum measures of kidney damage and function among diet groups. Apple pomace was also high in calcium which can affect calcium balance. Dietary calcium consumption was highest (P < .001) in rats consuming Western/AP. However, there were no significant differences in calcium absorption and retention among diet groups. Further, there was no evidence of renal calcification. There were also no impacts on femoral calcium, total mineral content, size or strength. Conclusions: Based on the results, apple pomace consumption was safe for renal and bone health in a rodent model, regardless of diet quality. Future preclinical studies should be conducted to further determine the efficacy and safety of apple pomace.

Calcium Balance in Osteoporotic Patients on Long-Term Oral Calcium Therapy with and without Sex Hormones

1982 ◽  
Vol 62 (2) ◽  
pp. 221-226 ◽  
Author(s):  
N. C. Thalassinos ◽  
D. H. Gutteridge ◽  
G. F. Joplin ◽  
T. R. Fraser
Keyword(s):  
Calcium Intake ◽  
Calcium Absorption ◽  
Concomitant Administration ◽  
Urinary Calcium ◽  
Calcium Balance ◽  
Total Calcium ◽  
High Calcium Intake ◽  
Oral Calcium ◽  
High Calcium

1. The effect of a high calcium intake (1 mmol day−1 kg−1) alone or with the concomitant administration of oestradiol and testosterone derivatives was monitored by serial calcium balances in 48 patients with osteoporosis of various types. 2. On high calcium alone there was an increase (P < 0.001) in both total calcium balance and net calcium absorption as compared with values on a simulated home intake. This effect was sustained for periods up to 10 years (mean 3.5 years) by the addition of the hormones. 3. Discontinuation of the hormones (only) produced a significant decrease in both calcium balance and nett absorption but both were still increased when compared with the initial values under simulated home calcium intake. 4. No significant change in the urinary calcium output was observed under any of the regimens.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats

2020 ◽  
Vol 11 (1) ◽  
pp. 508-513
Author(s):  
María Gimena Galán ◽  
Adriana Weisstaub ◽  
Angela Zuleta ◽  
Silvina Rosa Drago
Keyword(s):  
Sorghum Bicolor ◽  
Bone Health ◽  
Wistar Rats ◽  
Calcium Absorption ◽  
Bone Mineralization ◽  
Grain Sorghum ◽  
Whole Grain ◽  
Calcium Bioavailability ◽  
Health Promoting ◽  
Sorghum Bicolor L

Sorghum is a valuable cereal due to its antioxidant health-promoting properties. However, whole grain sorghum contains phytates and phenolics which can act as anti-nutrients, decreasing calcium bioavailability and affecting bone mineralization.

scholarly journals The effect of ‘fibre-filler’ (F-plan diet) on iron, zinc and calcium absorption in rats

1985 ◽  
Vol 54 (3) ◽  
pp. 585-592 ◽  
Author(s):  
Susan J. Fairweather-Tail ◽  
A. J. A. Wright
Keyword(s):  
Calcium Absorption ◽  
Ferrous Sulphate ◽  
Whole Body ◽  
Fibre Filler ◽  
Long Term Effect ◽  
Blood Haemoglobin ◽  
Body Counting ◽  
Whole Body Counting ◽  
Zn Availability

1. The availability of iron, zinc and calcium in a diet containing 400 g ‘fibre-filler’ (a mixture of bran, fruit and nuts, used in the F-plan diet)/kg diet (HF diet) was measured by whole-body counting in rats, using 59Fe, 66Zn and 47Ca as extrinsic labels, and compared with a diet of similar mineral content but no ‘fibre-filler’ (LF diet). Absorption of Fe and Ca was significantly higher from the HF than from the LF diet but there was no difference in Zn availability between the two diets.2. The ability of rats given LF or HF diets for 3 or 28 d to absorb Fe, Zn and Ca was measured using ferrous sulphate, zinc chloride and calcium chloride in a cooked starch-sucrose (1: 1 w/w) paste, extrinsically-labelled with the appropriate isotope. There was no difference in Fe absorption between the HF- and LF-fed groups but both Zn and Ca absorption were higher in LF- than in HF-fed animals after 3 and 28 d.3. The mineral status of the animals given HF or LF diets for 28 d was examined, and there were no differences in blood haemoglobin, liver and bone Zn and plasma and bone Ca levels. The total liver Fe was significantly lower (P < 0.05) in the HF-fed animals.4. It was concluded that ‘fibre-filler’did not have an adverse effect on Fe, Zn or Ca metabolism in rats although the long-term effect on Fe status warrants more detailed investigation. Further work is required to extend these studies to man.

Gastric Acid, Calcium Absorption, and Their Impact on Bone Health

2013 ◽  
Vol 93 (1) ◽  
pp. 189-268 ◽  
Author(s):  
Sascha Kopic ◽  
John P. Geibel
Keyword(s):  
Gastric Acid ◽  
Bone Health ◽  
Gastric Acidity ◽  
Calcium Uptake ◽  
Calcium Absorption ◽  
Neuroendocrine Regulation ◽  
Calcium Balance ◽  
Physiological Basis ◽  
Physiological Processes ◽  
Potential Link

Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.

Preventing Long-Term Reading Difficulties through Kindergarten and First Grade Intervention: The Case for Early Intervention

2008 ◽  
Vol 15 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Frank R. Vellutino ◽  
Haiyan Zhang
Keyword(s):  
Early Intervention ◽  
Reading Disability ◽  
Intervention Studies ◽  
Intervention Study ◽  
Reading Difficulties ◽  
First Grade

Abstract This article reviews recent intervention studies that have provided the foundation for a variety of RTI approaches to reading disability classification and remediation. The three-tier model of RTI is defined and discussed. Selected findings from a kindergarten and first grade intervention study are summarized.

Studies of Calcium Absorption in Man Using a CD-2 Whole-Body Counter

1977 ◽  
Vol 16 (04) ◽  
pp. 163-167
Author(s):  
K. Bakos ◽  
Věra Wernischová
Keyword(s):  
Calcium Absorption ◽  
Whole Body ◽  
Control Group ◽  
Absorption Process ◽  
Whole Body Counter ◽  
Absorption Studies ◽  
Body Counting ◽  
Calcium Load ◽  
Calcium Malabsorption ◽  
Whole Body Counting

SummaryWhole-body counting makes an important contribution of radioisotope techniques to ȁEin vivo“ absorption studies, in comparison with other methods. In a large number of subjects, the method was tested for its usefulness in the diagnosis of calcium malabsorption. The effects of drugs, of the calcium load in the gut and of the whole-body content of calcium on the absorption process were studied in a control group.

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