Quantitation of stable isotopic tracers of calcium by fast atom bombardment mass spectrometry

Jiang, Xuxian; Smith, David L.

doi:10.1021/ac00148a009

Cited by 32 publications

(11 citation statements)

References 13 publications

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“…Calcium from wheat flour (National Bureau of Standards Wheat Flour 1567) averaged 266 Ϯ 3.7 ppm (coefficient of variation, 2.25%), compared with the certified value of 278 Ϯ 36 ppm. Calcium stable isotope ratios were determined by fast atombombardment mass spectrometry (23). Dietary composites were also analyzed for protein by Kjeldahl analysis, and fat by Soxhlet extraction (24).…”

Section: Discussionmentioning

confidence: 99%

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Bryant

Wastney

Martin³

et al. 2003

The Journal of Clinical Endocrinology & Metabolism

126

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Blacks develop a higher peak bone mass than whites which is associated with a reduced risk for bone fracture. The physiological basis for the difference in bone mass was investigated by metabolic balance and calcium kinetic studies in adolescent black and white girls. The hypothesis that the greater peak bone mass in blacks compared with whites is due to suppressed bone resorption was tested. Subjects were housed in a supervised environment for 3 wk during which time they consumed a controlled diet and collected all excreta. Subjects were given stable calcium isotopes orally and intravenously after 1 wk adaptation. Blacks have greater calcium retention (mean +/- SD, 11.5 +/- 6.1 vs. 7.3 +/- 4.1 mmol/d, P < 0.05) consistent with greater bone formation rates (49.4 +/- 13.5 vs. 36.5 +/- 13.6 mmol/d, P < 0.05) relative to bone resorption rates (37.4 +/- 13.2 vs. 29.4 +/- 10.9 mmol/d, P = 0.07), increased calcium absorption efficiency (54 +/- 19 vs. 38 +/- 18%, P < 0.05) and decreased urinary calcium (1.15 +/- 0.95 vs. 2.50 +/- 1.35 mmol/d, P < 0.001), compared with whites. The racial differences in calcium retention in adolescence can account for the racial differences in bone mass of adults.

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Section: Discussionmentioning

confidence: 99%

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Bryant

Wastney

Martin³

et al. 2003

The Journal of Clinical Endocrinology & Metabolism

126

View full text Add to dashboard Cite

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“…Following the method of Liu and others (1989), duplicate food and fecal samples diluted 1:10 with 1N HCl were analyzed for 44 Ca enrichment with a Kratos MS-50 Fast Atom Bombardment Mass Spectrometer (FABMS; Kratos Analytical Instruments, Ramsey, N.J., U.S.A.) which was equipped with a fast atom bombardment ion source. Precision (about 0.2%) and accuracy (RSD of natural abundance = 0.3%) of isotope ratios in biological samples by FABMS are given in the method's paper by Jiang and Smith (1987).…”

Section: Ca Isotope Measurementmentioning

confidence: 99%

Bioavailability of Calcium from Tofu as Compared with Milk in Premenopausal Women

Weaver¹,

Heaney²,

Connor³

et al. 2002

Journal of Food Science

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Using a cross-over design, two studies were conducted to measure calcium absorption from calcium-set tofu compared to milk in healthy, premenopausal women. In "study 1," calcium absorption from tofu set with CaCl 2 was determined in Caucasian women by fecal recovery of the stable isotope, 44 Ca. In "study 2," calcium absorption was determined in Asian women from tofu set with CaSO 4 by appearance of 45 Ca in serum after 5 h. Analysis of the studies, both separately and pooled, showed that calcium absorption was similar between calciumset tofu and milk. Calcium-set tofu is a concentrated source of bioavailable calcium.

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“…Compliance of urine and fecal collections was determined by creatinine and PEG recovery, as described previously (2). Calcium was determined in the samples by atomic absorption spectroscopy (5100 PC, PerkinElmer Corp., Norwalk, CT), and isotope ratios were determined by fast atom-bombardment mass spectrometry (11).…”

Section: Calcium Kineticsmentioning

confidence: 99%

Changes in Calcium Kinetics in Adolescent Girls Induced by High Calcium Intake¹

Wastney

Martin

Smith

et al. 2000

The Journal of Clinical Endocrinology & Metabolism

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To identify the mechanism/s whereby calcium retention is increased by calcium intake in adolescent girls, kinetic studies were performed using stable calcium isotope tracers. Girls (n ϭ 10; 12 Ϯ 1 yr old, mean Ϯ SD) were studied while on a controlled diet containing a low (21.2 mmol/day) and a high (47.4 mmol/day) calcium intake, in randomized order, using a cross-over design. Studies were separated by 1 month. Calcium tracers were administered after 1 week on the study diet, orally and iv; and serum, urine, and feces were collected for the following 14 days. Tracers were measured using fast atom bombardment mass spectrometry, and kinetic data were analyzed by compartmental modeling. Biochemical markers of bone turnover were measured in serum and urine samples. On high (compared with low) calcium intake, fractional absorption did not differ, absorbed calcium increased (19.6 Ϯ 7.5 vs. 8.0 Ϯ 2.5 mmol/day, mean Ϯ SD, P Ͻ 0.001), calcium excreted in urine increased (2.8 Ϯ 1.7 vs. 2.1 Ϯ 1.1 mmol/day, P Ͻ 0.01), calcium retained in bone increased (14.5 Ϯ 8.9 vs. 3.2 Ϯ 3.6 mmol/ day, P Ͻ 0.001), bone formation did not change, and bone resorption decreased by 32%. These changes, measured by kinetics, were corroborated by changes in markers of bone turnover. We conclude that increased bone retention of calcium, with high calcium intake in adolescent girls, is attributable to an increase in absorption and a decrease in bone resorption. (J Clin Endocrinol Metab 85: 4470 -4475, 2000)

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Quantitation of stable isotopic tracers of calcium by fast atom bombardment mass spectrometry

Cited by 32 publications

References 13 publications

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Bioavailability of Calcium from Tofu as Compared with Milk in Premenopausal Women

Changes in Calcium Kinetics in Adolescent Girls Induced by High Calcium Intake¹

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Quantitation of stable isotopic tracers of calcium by fast atom bombardment mass spectrometry

Cited by 32 publications

References 13 publications

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Racial Differences in Bone Turnover and Calcium Metabolism in Adolescent Females

Bioavailability of Calcium from Tofu as Compared with Milk in Premenopausal Women

Changes in Calcium Kinetics in Adolescent Girls Induced by High Calcium Intake1

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Changes in Calcium Kinetics in Adolescent Girls Induced by High Calcium Intake¹