Your best natural source for selenium is brazil nuts. 4-6 brazil nuts a day will give you 200 mcg of selenium. It doesn't take much and they taste pretty good to boot.
I'm sure there is selenium in Vital Herbs as well as Superfood, it just isn't measured.
I suspect you could go to Dr. Duke's website and try to piece together the amount of selenium in each ingredient to get a rough estimate of how much selenium there is in Vital Herbs overall.