In the medical literature there are conflicting reports on whether iron improves symptoms in patients with EPP and XLP. Giving iron to people who are iron deficient is thought to improve EPP symptoms. However, this has never been systematically tested. Therefore, the purpose of this study is to determine the effect of oral iron for EPP and XLP patients.

This is a clinical trial, which means its purpose is to study an intervention or treatment. In this study all patients with EPP or XLP will be given a standard dose of iron pills and monitored for one year. There is currently no effective Food and Drug Administration (FDA) approved treatment for EPP or XLP in the US. Giving iron to patients with low ferritin (a measure of body iron stores) levels may help improve their EPP symptoms by decreasing erythrocyte protoporphyrin levels.

Patients will be asked come to the study site once every three months over the course of a year for a total of five visits. At these visits the study doctors will check in with participants and some blood and urine samples will be taken. Participants will not be charged for any of the lab tests that are being done for part of this study alone. In between these study visits there will be phone call to check in and see how participants are doing. All patients in this study will receive iron pills at no cost to them.

Inclusion Criteria:

• Enrollment in the Longitudinal Study of the Porphyrias
• Male or female age ≥18 years
• History of nonblistering cutaneous photosensitivity
• Biochemical findings - A marked increase in erythrocyte protoporphyrin (total erythrocyte protoporphyrin >400 ug/dL) with a predominance of metal-free protoporphyrin
• Serum ferritin ≤30 ng/mL at baseline
• Able to tolerate oral iron

Exclusion Criteria:

• History of liver or bone marrow transplant or clinically significant liver dysfunction as determined by the investigator
• Known or suspected allergy to oral iron based on patient report
• Clinical evidence of active and ongoing GI bleeding
• Use of any other clinical or experimental therapy in the past 3 months
• Individuals with elevations of porphyrins in plasma or erythrocytes due to other diseases (i.e. secondary porphyrinemia) such as liver and bone marrow diseases
• Patients with any clinically significant comorbid conditions, which in the opinion of the investigator, precludes participation

12 months