It's a health warning all parents should know about. Fluoride is added to the tap water in most water districts in Tennessee. The American Dental Association says this prevents tooth decay, but this month an advisory was added to their website. It warns parents not to mix fluoridated water with their baby's formula.

Fluoride is added to our water to help strengthen our teeth and prevent cavities, but some are saying it may do more harm than good. Fluoride can be a poisonous substance when it is in the body in certain amounts. Health researcher Dan Stockin worries that severe dental fluorosis is a warning to a deeper danger.

"It's... [Click to view video]