In reply to goosebump: Felt sick for the first couple of days of taking the tablets then cleared up. The black poo was an eyeopener.
The main (serious) difference I noticed was I stopped getting out of breath going up stairs and feeling like my heart was going to explode after a run (I am not a completely unfit person), the main (odd) difference was stopping raiding the ice tray every hour to crunch down on ice cubes (this was my pica and my sign that I am becoming anaemic).
Take your tabs with orange juice, it will help absorbtion. Eat lots of spinach and red meat.