As a general guideline, if the primary source of water is fluoridated tap or well water, the child will not require fluoride supplementa- tion, even if he or she primarily drinks bottled water, because the teeth are exposed to fluoride through cooking and brushing. The risk of fluorosis is high if fluoride supplements are given to a child consuming fluoridated water.30 Information about the fluoridation levels in many community water systems can be found on the CDC Web site entitled My Water’s Fluoride (http://apps.nccd. cdc.gov/MWF/Index.asp). Not all commu- nities report this information to the CDC; therefore, it may be necessary to con- tact the local water department to de- termine the level of fluoride in the community water. Well water must be tested for fluoride content before pre- scribing supplements; such testing is available in most states through the state or county public health laboratory