An investigation of sources of variation in calcium absorption efficiency

M. J. Barger-Lux, R. P. Heaney, Stephen J. Lanspa, J. C. Healy, H. F. DeLuca

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Abstract

To examine putative sources of interindividual variation in calcium absorption efficiency, we studied 41 healthy premenopausal women (mean age, 36.4 yr). About half were randomized to pretreatment with supplemental 25- hydroxyvitamin D (25OHD; 20 mg/day for ~34 days) before testing. We measured dietary factors, humoral regulators, intestinal motility, mucosal histology, mucosal vitamin D receptor levels, and calcium absorption efficiency. In winter tests, but not in summer tests, calcium absorption fraction was significantly higher in the pretreated group (mean, 0.465 vs. 0.387). Serum 25OHD, intestinal transit, and urinary calcium to creatinine ratio were all significantly and positively correlated to calcium absorption efficiency. However, neither the level of 1,25-dihydroxyvitamin D receptors in duodenal mucosa nor circulating 1,25-dihydroxyvitamin D was related to calcium absorption efficiency. These findings, which are consistent with other published human data, suggest that 25OHD plays a more prominent role in the regulation of calcium absorption than is generally believed. In a multiple regression model, serum 25OHD, mouth to cecum transit time, and fasting urinary calcium/creatinine ratio explained 44% of the observed variation in calcium absorption efficiency.

Original languageEnglish
Pages (from-to)406-411
Number of pages6
JournalJournal of Clinical Endocrinology and Metabolism
Volume80
Issue number2
StatePublished - 1995

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All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Cite this

Barger-Lux, M. J., Heaney, R. P., Lanspa, S. J., Healy, J. C., & DeLuca, H. F. (1995). An investigation of sources of variation in calcium absorption efficiency. Journal of Clinical Endocrinology and Metabolism, 80(2), 406-411.