Relation between calcium absorption and serum calcitriol in normal men: evidence for age-related intestinal resistance to calcitriol

Copyright © 2004 Nature Publishing GroupObjectiveTo obtain information on the causes of age-related bone loss in men and the concomitant decline in calcium absorption.DesignCross-sectional study.SettingAdelaide, South Australia, Australia.SubjectsA total of 95 healthy, Caucasian men (age range 27-87 y).ResultsCalcium absorption declined with age (r=-0.46, P-0.21, P0.41, PConclusionsIn healthy Caucasian males (i) calcium absorption falls, but serum calcitriol does not change with age, (ii) the relation between calcium absorption and serum calcitriol changes with age, indicative of an intestinal resistance to calcitriol and (iii) calcium absorption is a significant determinant of 24-h urinary calcium excretion.F Scopacasa, JM Wishart, M Horowitz, HA Morris and AG Nee