Publication Date:
2022-01-06
Description:
Calcium absorbtion was measured in fasting human beings after oral administration of Ca^45 in a solution containing 10 to 500mg stable calcium and an intravenous dose of Ca^47. Absorbtion was determined from the ratio of specific activities of the two isotopes (oral dose/intravenous dose) in calcium of urine collected more than 24 hours later. The accuracy of this calculation was confirmed by comparison with absorbtion calculated from recovery of the oral dose in stools (the completeness of collection being determined from recovery of simultaneously given Cr2O2or Cr^51 labeled protein and a correction for endogenous calcium being made from the fecal recovery of the intravenouse dose of Ca^47). In 20 tests, the average difference between the two calculations of per cent absorbtion was 2.2 and the coefficient of variation, 1.6. The Conditions under which the double isotope procedure gives an accurate result were evaluated and the results of its use with 3 different doses of calcium given to normal subjects are reported
Type:
Article
,
PeerReviewed
Format:
text
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