Heating/cooking with fluoridated water CONCENTRATES fluoride, so I hope you're not cooking with that water:
According to ATSDR, "Cooking food in fluoridated water results in increased dietary fluoride levels (p 151)." Approximately 60% of US public drinking water supplies are fluoridated. Unlike chlorine, fluoride does not enter the steam when water is boiled. Thus during cooking the fluoride increases in concentration.