VITAMIN-D METABOLITES IN NORMAL SUBJECTS DURING ONE YEAR - A LONGITUDINAL-STUDY

  • 1 January 1983
    • journal article
    • research article
    • Vol. 43 (1), 85-89
Abstract
The serum concentrations of 25-hydroxycholecalciferol (25OHD3), 25-hydroxyergocalciferol (25OHD2), 24,25-dihydroxyvitamin D (24,25(OH)2D), and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured in 10 normal subjects every 2 mo. for 1 yr. Parallel seasonal variations were found in serum 25-hydroxycholecalciferol and 24,25-dihydroxyvitamin D reaching maximum values in June. A highly significant correlation between changes in these 2 metabolites was observed (r = 0.89, P < 0.001). The mean serum 1,25-dihydroxyvitamin D concentration remained constant throughout the year. The data add further evidence to the tight regulatory mechanism of serum 1,25-dihydroxyvitamin D and the lack of regulatory mechanism of serum 24,25-dihydroxyvitamin D.