The kidneys are believed to be the most important organ in the human body in the fight against long-term fluoride exposure. Healthy adult kidneys are able to excrete about 50 percent of ingested fluoride and are responsible for preventing toxic levels of fluoride from accumulating in the body. However, adults who have kidney disease excrete about 10 to 20 percent of ingested fluoride, which increases their body burden of fluoride and increases their likelihood of fluoride poisoning.
According to the Journal of Dental Research (Whitford 1987, 1990), there is enough fluoride in a tube of children's fluoride toothpaste to kill an average-weighing child under the age of 9. Why else would the FDA require the following warning label on fluoride toothpaste? "WARNING: Keep out of reach of children under 6 years of age. If you accidentally swallow more than used for brushing, seek professional help or contact a poison control center immediately." The 1984 Clinical Toxicology of Commercial Products rates lead’s toxicity at 3-4, while fluoride is rated at 4 (3 = moderately toxic; 4 = very toxic).
Gastrointestinal symptoms like nausea, abdominal pain and vomiting are the most common early symptoms of acute fluoride poisoning. For people who are sensitive to fluoride, ingesting 1 mg tablets of fluoride or drinking 1 parts per million of fluoridated water can cause these gastrointestinal symptoms. A 5-to-10 gram dose of fluoride for an adult or 500 mg dose for a child can cause damage to the body’s major organs and even cause death.