200 mcg or 400 mcg selenium per day

I want to take the SeleNext twice instead of once daily .. Is that too much Selenium?

SeleNext (Jarrows) are high bioavailability.

I spent a part of weekend to seek some info about selenium. RDA says something about 200 mg. You know selenium is essential for healthy thyroid. Excellent natural source are brazil nuts (70-90 mcg per nut), broccolli, eggs and others. Selenium toxicity could be developed in high selenium intake (>900 mcg) and the symptoms are hairloss, dermatis and nail deformation anyway.
I would go for 400 mcg.

I have a gut-feeling that selenium (especially high bioavailable ones), are very important for detoxficiation enzymes, and to get rid of toxic evironmental stressors. Fx car-exhaustfumes.