How much Proferrin do you take?
I took two a day for a while along with 65 mg of non-heme iron. (carbonyl at the time) but I'm back to ferrous sulfate for now. It's was just cheaper for me to take the non-heme iron. It doesn't give me much of a problem. A little tummy ache once or twice a month.
I'm not sure ther eis a way to compare the heme and non-heme doses because the absorption is different.
Pete