I’d think that curcumin is safe enough given its common usage. But...maybe it does serve to delete such as needed iron. I don’t know.
Curcumin, as such, is very potent, but is so strongly metabolized in the liver that much of the harm it could cause is to some degree mitigated. However, caution is advised, as people seem to have an uncanny ability to take otherwise harmless substances and make them dangerous, or even lethal.
(.pdf file, “The Dark Side Of Curcumin”)