Neurovascular Complications and White Matter Damage in Acquired Anemias

Inclusion criteria (observational component): * Age between 16 and 60 years of age. * Any ethnicity. * Either sex. * Anemic group: hemoglobin less than 10.5 g/dl on screening hemoglobin. * Control group: hemoglobin \>13.2 g/dl for females, \>14.6 g/dl for males, comparable age, sex and ethnicity to currently enrolled anemic subjects. Exclusion criteria (observational component): * Diabetes requiring medication. * Hypertension requiring medication. * Sleep disordered breathing requiring intervention. * Body mass index \>35 (morbid obesity) * Contraindications to MRI, including pacemaker, severe claustrophobia, pregnancy. * Known systemic inflammatory disease such as inflammatory bowel disease, systemic lupus erythematosus, or scleroderma. * Known HIV. Inclusion criteria (interventional component): * Criteria for observational component, plus * ron deficiency anemia based upon attending hematologist interpretation of transferrin saturation, ferritin, and other ancillary labs including hs-CRP, MMA. Exclusion criteria (interventional component): * Criteria for observational component, plus * Prior reaction to intravenous iron. * History of multiple drug allergies. * History of severe asthma, eczema, or atopy. * Systemic mastocytosis. * Severe respiratory or cardiac disease.