Skip to main content
PMC home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1988 Jan;81(1):126–132. doi: 10.1172/JCI113283

Role of vitamin D-dependent and vitamin D-independent mechanisms in absorption of food calcium.

M S Sheikh 1, A Ramirez 1, M Emmett 1, C Santa Ana 1, L R Schiller 1, J S Fordtran 1
PMCID: PMC442483  PMID: 3335630

Abstract

We measured net calcium absorption and the calcium content of the digestive glands secretions in people with widely different serum concentrations of 1,25 dihydroxy vitamin D (hereafter referred to a 1,25-D). Patients with end stage renal disease on hemodialysis served as a model of human 1,25-D deficiency; they were also studied when they had abnormally high serum 1,25-D concentrations as a result of short periods of treatment with exogenous 1,25-D. Normal subjects were studied for comparison. The amount of calcium secreted into the duodenum by the digestive glands was found to be trivial compared to the calcium content of normal or even low calcium meals; therefore, values for net and true net calcium absorption differed only slightly. There was a linear correlation between true net calcium absorption and serum 1,25-D concentration. By extrapolating the short distance to a zero value for serum 1,25-D, D-independent true net calcium absorption was estimated. By subtracting D independent from true net calcium absorption, values for D-dependent absorption were obtained. For a given level of meal calcium intake, D-dependent calcium absorption was found to be directly proportional to serum 1,25-D concentration. At any given value for serum 1,25-D, absorption via the D-dependent mechanism was approximately the same with a low (120 mg) calcium meal as it was when meal calcium intake was increased to 300 mg. We interpret this to mean that the D-dependent mechanism is saturated or nearly saturated by low calcium meals. The D-independent absorption/secretion mechanism resulted in secretion (a loss of body calcium in the feces) when intake was low (120 mg per meal) and absorption when intake was normal. All of the increment in calcium absorption that occurs when low or normal calcium meals are supplemented with extra calcium is mediated by the D-independent mechanism.

Full text

PDF
126

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bo-Linn G. W., Davis G. R., Buddrus D. J., Morawski S. G., Santa Ana C., Fordtran J. S. An evaluation of the importance of gastric acid secretion in the absorption of dietary calcium. J Clin Invest. 1984 Mar;73(3):640–647. doi: 10.1172/JCI111254. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bo-Linn G. W., Santa Ana C. A., Morawski S. G., Fordtran J. S. Purging and calorie absorption in bulimic patients and normal women. Ann Intern Med. 1983 Jul;99(1):14–17. doi: 10.7326/0003-4819-99-1-14. [DOI] [PubMed] [Google Scholar]
  3. Bo-Linn G. W., Santa Ana C. A., Morawski S. G., Fordtran J. S. Starch blockers--their effect on calorie absorption from a high-starch meal. N Engl J Med. 1982 Dec 2;307(23):1413–1416. doi: 10.1056/NEJM198212023072301. [DOI] [PubMed] [Google Scholar]
  4. FORDTRAN J. S., LEVITAN R., BIKERMAN V., BURROWS B. A., INGELFINGER F. J. The kinetics of water absorption in the human intestine. Trans Assoc Am Physicians. 1961;74:195–206. [PubMed] [Google Scholar]
  5. HEANEY R. P., SKILLMAN T. G. SECRETION AND EXCRETION OF CALCIUM BY THE HUMAN GASTROINTESTINAL TRACT. J Lab Clin Med. 1964 Jul;64:29–41. [PubMed] [Google Scholar]
  6. Halloran B. P., DeLuca H. F. Calcium transport in small intestine during early development: role of vitamin D. Am J Physiol. 1980 Dec;239(6):G473–G479. doi: 10.1152/ajpgi.1980.239.6.G473. [DOI] [PubMed] [Google Scholar]
  7. Hansky J. Calcium content of duodenal juice. Am J Dig Dis. 1967 Jul;12(7):725–733. doi: 10.1007/BF02238282. [DOI] [PubMed] [Google Scholar]
  8. Lohse J., Pfeiffer A. Duodenal total and ionised calcium secretion in normal subjects, chronic alcoholics, and patients with various stages of chronic alcoholic pancreatitis. Gut. 1984 Aug;25(8):874–880. doi: 10.1136/gut.25.8.874. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Norman D. A., Fordtran J. S., Brinkley L. J., Zerwekh J. E., Nicar M. J., Strowig S. M., Pak C. Y. Jejunal and ileal adaptation to alterations in dietary calcium: changes in calcium and magnesium absorption and pathogenetic role of parathyroid hormone and 1,25-dihydroxyvitamin D. J Clin Invest. 1981 Jun;67(6):1599–1603. doi: 10.1172/JCI110194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Pansu D., Bellaton C., Roche C., Bronner F. Duodenal and ileal calcium absorption in the rat and effects of vitamin D. Am J Physiol. 1983 Jun;244(6):G695–G700. doi: 10.1152/ajpgi.1983.244.6.G695. [DOI] [PubMed] [Google Scholar]
  11. Parker T. F., Vergne-Marini P., Hull A. R., Pak C. Y., Fordtran J. S. Jejunal absorption and secretion of calcium in patients with chronic renal disease on hemodialysis. J Clin Invest. 1974 Aug;54(2):358–365. doi: 10.1172/JCI107771. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ramirez J. A., Emmett M., White M. G., Fathi N., Santa Ana C. A., Morawski S. G., Fordtran J. S. The absorption of dietary phosphorus and calcium in hemodialysis patients. Kidney Int. 1986 Nov;30(5):753–759. doi: 10.1038/ki.1986.252. [DOI] [PubMed] [Google Scholar]
  13. Regan P. T., Malagelada J. R., DiMagno E. P. Duodenal calcium outputs in health and pancreatic disease. Gut. 1980 Jul;21(7):614–618. doi: 10.1136/gut.21.7.614. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Reinhardt T. A., Horst R. L., Orf J. W., Hollis B. W. A microassay for 1,25-dihydroxyvitamin D not requiring high performance liquid chromatography: application to clinical studies. J Clin Endocrinol Metab. 1984 Jan;58(1):91–98. doi: 10.1210/jcem-58-1-91. [DOI] [PubMed] [Google Scholar]
  15. SCHACHTER D., ROSEN S. M. Active transport of Ca45 by the small intestine and its dependence on vitamin D. Am J Physiol. 1959 Feb;196(2):357–362. doi: 10.1152/ajplegacy.1959.196.2.357. [DOI] [PubMed] [Google Scholar]
  16. Vergne-Marini P., Parker T. F., Pak C. Y., Hull A. R., DeLuca H. F., Fordtran J. S. Jejunal and ileal absorption in patients with chronic renal disease. Effect of 1alpha-hydroxycholecalciferol. J Clin Invest. 1976 Apr;57(4):861–866. doi: 10.1172/JCI108362. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Wensel R. H., Rich C., Brown A. C., Volwiler W. Absorption of calcium measured by intubation and perfusion of the intact hyman small intestine. J Clin Invest. 1969 Sep;48(9):1768–1775. doi: 10.1172/JCI106143. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES