You bet it can.
But, ANYTHING taken in too great of quantity can kill you!
Take water for instance.
Water is a necessity for life.
However, you drink too much water too quickly and
you will soon find yourself dead from water toxicity.
People take Tylenol for headaches.
Take 3 bottles of it.
You won't be with us much longer.
People take iron supplements.
Take 3 bottles of that stuff.
See how healthy you feel.
And the list can go on and on and on.
ANYTHING that is taken in the improper quantities can harm you.
Fluoride can absolutely have harmful effects.
That is why it is prescribed by a clinician who is trained
on how to prescribe the drug according to a strict set of
guidelines that take into account the area in which a person lives,
their age, their size, what other drugs they are taking, etc. etc.
"All substances are poisons; there is none which is not a poison.
The right dose differentiates a poison..." Paracelsus (1493- 1541)
I give my children and my patients children fluoride supplements.
I would encourage anyone who is nervous about fluoride to read
up on the subject from CREDIBLE sources and then make
whatever decision they feel comfortable with.