the serum concentrations of the vitamin d metabolites 25-hydroxyvitamin d2 ( 25ohd2 ) , 25-hydroxyvitamin d3 ( 25ohd3 ) , and 1,25-dihydroxyvitamin d ( calcitriol ) have been measured in normal subjects whose ages varied from 18 months to 35 yr .
C0006657
25-hydroxyvitamin d3
C2713074
25ohd3