Calculation Of 3 Hours Calcium-Absorption From A Double Isotope Test - Simplified Method

For the rapid evaluation of calcium absorption in human subjects several isotopic tests have been proposed. Among them, the double isotope test based on the concurrent oral and intravenous administration of calcium isotopes seems the most reliable. However, the computations involved in this test, a deconvolution of the two specific-activity functions obtained, are quite extensive. By simulating these functions we developed a simple formula to calculate the absorption in the first three hours of the test. Applied to the data of 79 patiente the result differed less than the experimental error from the absorption computed with the more elaborate deconvolution method.