The effect of calcium supplementation on bone calcium balance and calcium and bone metabolism during load carriage in women: a randomised controlled crossover trial.

Calcium supplementation before exercise attenuates the decrease in serum calcium and increase in PTH and bone resorption. This study investigated the effect of calcium supplementation on calcium and bone metabolism during load carriage in women. Forty-eight women completed two load carriage sessions (load carriage 1 n = 48; load carriage 2 n = 40) (12.

Calcimimetic AMG-416 induced short-term changes in calcium concentrations and calcium isotope ratios in rats.

Calcium (Ca) isotopes (δCa) in serum and urine have been suggested as novel sensitive markers of bone calcification. The response of δCa to acute changes in Ca homeostasis, has not yet been demonstrated. We measured serum Ca and δCa in rats maintained on a standard and a 50% Ca reduced diet for 4 weeks, and after injection of 1 mg/kg of the calcimimetic AMG-416, 24 h prior to sacrifice.

Nutritional Calcium Supply Dependent Calcium Balance, Bone Calcification and Calcium Isotope Ratios in Rats.

Serum calcium isotopes (δCa) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δCa changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δCa with bone histology are unknown. We analyzed Ca and δCa by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.

Naturally occurring stable calcium isotope ratios are a novel biomarker of bone calcium balance in chronic kidney disease.

Dysregulated calcium homeostasis is common in chronic kidney disease and causally associated with disorders of bone mineralization. However, radiological measures and biomarkers do not allow accurate evaluation of bone calcium balance. Non-radioactive calcium isotopes, Ca and Ca, are present in our diet and sequestered into body compartments following principles of kinetic isotope fractionation.

Calcium isotope fractionation by osteoblasts and osteoclasts, across endothelial and epithelial cell barriers, and with binding to proteins.

Timely and accurate diagnosis of osteoporosis is essential for adequate therapy. Calcium isotope ratio (δCa) determination has been suggested as a sensitive, noninvasive, and radiation-free biomarker for the diagnosis of osteoporosis, reflecting bone calcium balance. The quantitative diagnostic is based on the calculation of the δCa difference between blood, urine, and bone.

Naturally Occurring Stable Calcium Isotope Ratios in Body Compartments Provide a Novel Biomarker of Bone Mineral Balance in Children and Young Adults.

Serum calcium (Ca), bone biomarkers, and radiological imaging do not allow accurate evaluation of bone mineral balance (BMB), a key determinant of bone mineral density (BMD) and fracture risk. We studied naturally occurring stable (non-radioactive) Ca isotopes in different body pools as a potential biomarker of BMB. Ca and Ca are absorbed from our diet and sequestered into different body compartments following kinetic principles of isotope fractionation; isotopically light Ca is preferentially incorporated into bone, whereas heavier Ca preferentially remains in blood and is excreted in urine and feces.

Early effects of androgen deprivation on bone and mineral homeostasis in adult men: a prospective cohort study.

Objective: Long-term androgen deprivation therapy (ADT) negatively influences bone. The short-term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover.

Calcium Isotopes in Human Urine as a Diagnostic Tool for Bone Loss: Additional Evidence for Time Delays in Bone Response to Experimental Bed Rest.

The calcium (Ca) isotopic composition in urine during bed rest has been demonstrated to be systematically light, indicating a negative bone mineral balance (i.e., bone loss).

Biological fractionation of stable Ca isotopes in Göttingen minipigs as a physiological model for Ca homeostasis in humans.

In order to investigate fractionation of calcium (Ca) isotopes in vertebrates as a diagnostic tool to detect Ca metabolism dysfunction we analyzed the Ca isotopic composition (δ(44/40)Ca = [((44)Ca/(40)Ca)sample/((44)Ca/(40)Ca)reference]-1) of diet, faeces, blood, bones and urine from Göttingen minipigs, an animal model for human physiology. Samples of three groups were investigated: 1. control group (Con), 2.

Tracing copper derived from pig manure in calcareous soils and soil leachates by 65Cu labeling.

Copper is used as a growth promoter in animal husbandry, resulting in high Cu concentrations in animal manure. We tested whether Cu would be mobilized in soils receiving excessive loads of manure, both from recently added and from aged fractions. To discriminate between these Cu sources, manure was labeled with (65)Cu.

A pilot study on the use of natural calcium isotope (44Ca/40Ca) fractionation in urine as a proxy for the human body calcium balance.

We explored the possibility of using natural calcium (Ca) isotope variations in the urine (delta(44/40)Ca(urine)) as a proxy for the Ca balance in the human body. We chose two test persons extremely different in their health status, gender and age (4-year-old healthy boy and a 60-year-old woman known to suffer from osteoporosis). During a 5 day interval the Ca isotope composition of the individual diet (delta(44/40)Ca(diet)) was monitored for both test persons to be in general agreement to the Ca isotope composition of the normal western European diet ( approximately -1.