I have vitamin deficiencies and so I must to be very careful and considerate , at least to always take the clay on an empty stomach. It still concerns me, not to scare anyone though. One case was reported in a three year old, but the parents had been using it as an enema and there is really no telling how much or for how long
. Still...it is enough to make me think more about it. If you have a reference for it being a condition that occurs only after years of use please link me to it ( I would love to read it to comfort myself on the issue once and for all).