My 17 yr old daughter has very low ferritin levels, <10, she is not anemic. she does not have heavy periods, she is extremely tired. any ideas?

Iron: You can be iron deficient and not have anemia. Anemia typically occurs after a period of iron depletion. In young women the depletion is often from menses, and lack of oral iron intake. Additional tests can be performed to suggest if she is really iron deficient, though a low ferritin often indicates this diagnosis. A trial of oral iron would be appropriate, but ask your physician.