Estimation of true calcium absorption.

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Measurements of true calcium absorption fraction in women were evaluated to see how closely calculations based on a single measurement of serum specific activity after administration of an oral calcium tracer might approximate the absorption value derived from the full, double-isotope absorption procedure. True absorption, body size, and miscible pool turnover could together explain better than 93% of the variance in serum calcium specific activity values 5 hours after a tracer-labeled test meal. Because measurement of pool turnover is not available routinely, it was dropped from the model, and a predictor equation was developed that allowed estimation of true absorption from the 5-hour serum specific activity value, height, and weight. These variables explained 90.8% of the variance in the 5-hour values and gave estimates of true absorption with a 95% confidence interval of +/- 0.055. This small range of uncertainty makes the procedure useful in estimating absorption efficiency for calcium therapy in routine clinical practice.

Original languageEnglish
Pages (from-to)516-521
Number of pages6
JournalAnnals of Internal Medicine
Issue number4
Publication statusPublished - Oct 1985
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Medicine(all)

Cite this

Estimation of true calcium absorption. / Heaney, R. P.; Recker, Robert R.

In: Annals of Internal Medicine, Vol. 103, No. 4, 10.1985, p. 516-521.

Research output: Contribution to journalArticle