DS (16 months) had a blood test which showed he had low iron last week. He has been given an iron supplement to take, which is a liquid he has 4 times a day. The problem is it is making his teeth go brown and stained. We are brushing his teeth the whole time but it doesn't seem to help - any idea on how I can get his pearly white teeth back and not let it get any worse. I'm mixing it into his food as thought that might help, but it makes no difference they still look stained