What to think about
If you suspect you have iron deficiency anemia, do not take iron pills without consulting your doctor. Taking iron pills could delay the diagnosis of a serious problem such as colorectal cancer or a bleeding ulcer.
If the anemia is not due to iron deficiency, taking iron pills will not relieve the anemia and could cause poisoning (iron toxicity). It could also cause an iron overload condition called hemochromatosis, especially in people who have a genetic tendency toward storing too much iron in their bodies.
In some people, iron pills cause stomach discomfort, nausea, diarrhea, constipation, and black stool. Iron is best absorbed if taken on an empty stomach. But if you are having stomach problems, you may need to take the pills with food. Do not take iron pills with milk, caffeinated drinks, or antacids. If the side effects of your iron pills make you feel too sick, talk to your doctor. He or she may know of another type of iron pill you can take.
If you get iron through an IV, there is a risk of an allergic reaction.