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.

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.