Of the flouride we ingest a proportion is retained in the body mainly in the bones, and some in organs that calcify like arteries. If intake is significantly lowered some, a limited amount, of the deposited fouride will leave the body. Much as yet is unknown but it appears in general the amount of fluoride in bone increases throughout life.
This paper http://www.google.com/url?sa=t&rct=j...55123115,d.Yms used radioactive fluoride for a pet scan. It is very clear from the PET scan image in the paper where most of the fluoride ends up, the spine, and interestingly some is evidently taken up by the blood vessels.
The effects at flouride intakes in the particular background circumstances that lead to fluorosis of the bone are devastating as clearly evident from this video. http://fluoridealert.org/fan-tv/crippling-waters/
High fluoride in bones is associated with more brittle bones etc. What the effects of a lifetimes accumulation of fouride are in more 'normal' circumstances is much less clear.
It appears that fluoride intake from our youngest moments is in a sense 'for life', and it is probably only in the long term that we will have a better understanding of the effects of our increasing intake from a range of sources including water, and how other factors such as iodine and mineral intake effect fluoride metabolism .
Association of vascular fluoride uptake with vascular
calcification and coronary artery disease
Yuxin Lia, Gholam R. Berenjia, Wisam F. Shabaa, Bashir Taftia, Ella Yevdayeva
and Simin Dadparvarb
Conclusion sodium [18F]fluoride PET/CT might be
useful in the evaluation of the atherosclerotic process in
major arteries, including coronary arteries. An increased
fluoride uptake in coronary arteries may be associated with
an increased cardiovascular risk.