At study entry, all participants will receive daily iron supplementation, either as ferrous sulfate or a multivitamin with iron. Participants will be followed for up to 2 years to assess their overall diabetes health and to capture laboratory measures of beta cell and immune system function. Medication history and adverse event assessment will occur at all visits. A physical exam, vital signs measurement, and blood collection will occur at most visits. Medical history and urine collection will occur at selected visits.