It shouldn't be a problem for most thal minors, as iron absorption isn't typically an issue unless the Hb is chronically low, or there has been long term iron supplementation. The tests for iron are called an iron panel. If there is any uncertainty about the cause of anemia, iron tests should be done before taking iron. Because medical history has to be taken into account, especially any pre-existing skin conditions, it's best to have your allergist decipher the RAST test.