Can iron cause nausea?

Im not preg but I do take prescription iron tablets and they do make me feel nausea. But I have spoken with my doctor and he said to cut my dose done by one to see if that makes a difference. Maybe your sister could talk to her doctor and ask if she can half her dose or something. My doctor also prescribed me a anti-nausea drug that I can take with my iron to prevent the nausea or take it if it starts to come on. I know that there are certain meds you cant use thru preg but maybe her and her doctor will be able to wrk something out. Another thing that works is to take the iron pill with orange jucie this helps the iron be absorbed faster into the system which may prevent the nausea....Hope this helps your sister