Study was not funded.

This is an observational trial, in patients with moderate to severe anemia and control subjects. The main purpose of this study is to understand whether normal brain blood flow, oxygen extraction reserve, white matter volumes, and brain functional connectivity are affected by acquired anemia. The investigators will perform baseline MRI monitoring for all subjects. All eligible subjects will be asked to provide informed consent before participating in the study.

This is an observational trial, in patients with moderate to severe anemia and control subjects. The main purpose of this study is to understand whether normal brain blood flow, oxygen extraction reserve, white matter volumes, and brain functional connectivity are affected by acquired anemia. The investigators will perform baseline MRI monitoring for all subjects. All eligible subjects will be asked to provide informed consent before participating in the study. Comprehensive cerebrovascular MRI, baseline bloodwork, and neurocognitive testing will be collected from all subjects.

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.

Anemic subjects from Blood Donor Centers across Los Angeles will be recruited, the abnormal Menstrual Bleeding Clinic at Children's Hospital Los Angeles, and from the community if anemia can be documented.