Merzel,
The amount of elemental iron that is needed by patients, varies according to gender and age. The following are the usual recommended daily requirements.
FERROUS SULFATE CAPSULES
Usual adult and adolescent daily recommened doses
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~
Adolescent and adult males-->10mg
Adolescent and adult females-->10-15mg
Pregnant females-->30mg
Breast-feeding females-->15mg
So, if you are taking 27mg, in addition to what you get in your diet, that should be enough (unless you are pregnant).
Good luck.