Steroid hormone synthesis has an important feature -
These hormones often undergo modifications AFTER they are released into circulation by their parent cell (synthesizing cell).
The peripheral conversion/modification can have one of the following results -
(1) A more active hormone produced. E.g., 25(OH) vitamin D —-> 1,25 (OH) vitamin D in kidney.
(2) A less active hormone. E.g., cortisol —-> cortisone in kidney. [It may again be converted into more active form by another tissue. E.g., cortisone —-> cortisol in abdominal adipose tissue.]
(3) A different class of hormone may be formed. (E.g., testosterone —-> estrogen.]