Cytochrome b5 reductase is an enzyme in the blood. It controls the amount of iron in your red blood cells, and helps the cells carry the normal amount of oxygen.
Persons who do not have enough of this enzyme may develop a condition called methemoglobinemia.
Review Date:
2/19/2012
Reviewed By:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.