ditto. Not very bio-available. Pretty soon people are going to come to a new understanding: just because something has all the nutrients in it that human beings need doesn't mean human beings are able to access those nutrients. I read something about your average stone you find on the street containing most, if not all, the minerals in it needed to sustain human life. Kind of interesting.
Want a protein shake? Make one with whole food-raw eggs, unheated honey, some berries...etc.