Reductase activity that acts on Fe(3+)-chelates and uses both NADH and NADPH as electron donors. May play a role in iron uptake. 2 a Fe(II)-siderophore + H(+) + NAD(+) = 2 a Fe(III)-siderophore + NADH Binds 1 FAD per subunit. Homodimer. By Fe(3+) ion deprivation.