Time course of calcium absorption in humans

Evidence for a colonic component

M. Janet Barger-Lux, Robert P. Heaney, Robert R. Recker

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

We examined the time course of calcium absorption (CaAbs) in 155 studies, using a double isotope technique. The subjects were 118 healthy peri-menopausal women (mean age 53.3 years), studied as impatients under metabolic balance conditions. We measured the ratio of radiolabeled calcium (oral:IV) in serum and urine for 144 hours after the oral dose, and generated a composite CaAbs curve for all 155 studies using normalized data. Although CaAbs was 80.9% complete at 3 hours, it was still only 95.8% complete at 7 hours; the remaining 4.2% was absorbed in a slower late component, and did not reach completion until about 26 hours. The rapid initial component probably represents mainly small intestinal absorption and the late component, colonic. At the dietary intakes of our subjects, we estimate the size of the late component at about 6.8 mg/day. For fully accurate measurements of CaAbs, it is necessary to allow for this small late component.

Original languageEnglish
Pages (from-to)308-311
Number of pages4
JournalCalcified Tissue International
Volume44
Issue number5
DOIs
StatePublished - Sep 1989

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Calcium
Intestinal Absorption
Isotopes
Urine
Serum

All Science Journal Classification (ASJC) codes

  • Endocrinology

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Time course of calcium absorption in humans : Evidence for a colonic component. / Barger-Lux, M. Janet; Heaney, Robert P.; Recker, Robert R.

In: Calcified Tissue International, Vol. 44, No. 5, 09.1989, p. 308-311.

Research output: Contribution to journalArticle

Barger-Lux, M. Janet ; Heaney, Robert P. ; Recker, Robert R. / Time course of calcium absorption in humans : Evidence for a colonic component. In: Calcified Tissue International. 1989 ; Vol. 44, No. 5. pp. 308-311.
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