Serum iron, total iron-binding capacity, and percentage saturation in normal subjects.

The serum iron was determined in 60 normal subjects (38 males and 22 females) with a mean age of 32.0 and 36.2 years respectively. The plasma total iron-binding capacity (TIBC) was also determined in 54 of these subjects (32 males and 22 females). Serum iron and TIBC determinations were performed between 8.45 am and 9.15 am. The mean serum iron concentration is 138.3 +/- 4.3 mug/100 ml (SD +/- 32.9 mug/100 ml), and the mean TIBC is 470.1 +/- 6.8 mug/100 ml (SD +/- 50.1 mug/100 ml); the mean plasma siderophilin saturation is 30.0%. The mean values for serum iron, TIBC, and siderophilin saturation are similar in both sexes. They are normally distributed, and there is no significant correlation of serum iron and TIBC with age in either males or females.