Association Between Intestinal Vitamin D Receptor, Calcium Absorption, and Serum 1,25 Dihydroxyvitamin D in Normal Young and Elderly Women

DOI PDF Web Site 2 Citations
  • H. Karimi Kinyamu
    Bone Metabolism Unit, Creighton University School of Medicine, Omaha, Nebraska, U.S.A.
  • J. Christopher Gallagher
    Bone Metabolism Unit, Creighton University School of Medicine, Omaha, Nebraska, U.S.A.
  • Jean M. Prahl
    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, U.S.A.
  • Hector F. Deluca
    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, U.S.A.
  • Kimberly M. Petranick
    Bone Metabolism Unit, Creighton University School of Medicine, Omaha, Nebraska, U.S.A.
  • Stephen J. Lanspa
    Department of Gastroenterology, Division of Digestive Diseases, Creighton University School of Medicine, Omaha, Nebraska, U.S.A.

Search this article

Abstract

<jats:title>Abstract</jats:title> <jats:p>The exact mechanism for the decrease in intestinal calcium absorption with age is not yet understood. A decrease with age in serum 1,25-dihydroxyvitamin D (1,25(OH)2D) or a decrease in the intestinal vitamin D receptor (VDR) protein concentration are possible causes. The objective of this study was to examine the effect of age on these factors. Fifty-nine young women age 25–35 years were compared with 41 elderly women age 65–83 years who underwent measurements of VDR, calcium absorption using a 20 mg and 100 mg calcium carrier, and calciotropic hormones. Calcium absorption by both tests was lower in the elderly women compared with the young women (p &lt; 0.05). Serum 1,25(OH)2D and duodenal VDR protein concentration were not significantly different between the two age groups. Serum 1,25(OH)2D correlated with the 20 mg calcium absorption test in both young (r = 0.35, p &lt; 0.007) and elderly women (r = 0.58, p &lt; 0.0001) and with the 100 mg calcium absorption in the elderly (r = 0.32; p &lt; 0.05). VDR did not correlate with calcium absorption in young women or elderly women, nor did VDR correlate with serum 1,25(OH)2D and serum 25-hydroxyvitamin D. In summary, the decrease in calcium absorption cannot be explained by a decrease in intestinal VDR. The correlation between serum 1,25(OH)2D and both calcium absorption tests only accounts for 12–30% of the variance in the age-related change in the calcium absorption tests. Other factors, not yet understood, are responsible for the decline in calcium absorption with age.</jats:p>

Journal

Citations (2)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top