Table 1. Free D and I in normal urine (micrograms per gram of creatinine).

Subjects (sex, age)	D	I
1 (M, 78)	0.42 ± 0.01	0.38 ± 0.01
2 (M, 70)	0.75 ± 0.16	0.35 ± 0.19
3 (M, 50)	0.51 ± 0.11	0.64 ± 0.17
4 (F, 53)	2.98 ± 0.33	2.75 ± 0.37
5 (M, 32)	1.55 ± 0.20	1.59 ± 0.26
6 (F, 28)	0.50 ± 0.15	0.43 ± 0.05
7 (M, 28)	3.33 ± 0.40	2.42 ± 0.31

M, male; F, female.