Nutrition Science and Everyday Application - beta v 0.1

512 ALICE CALLAHAN, PHD, HEATHER LEONARD, MED, RDN, AND TAMBERLY POWELL, MS, RDN
excrete it if it’s in excess. However, people should take care not to consume more than the
UL for magnesium from supplements and medications. 3
FLUORIDE
Fluoride is a trace mineral needed in very small amounts in the body. It is known mostly
as the mineral that combats tooth decay, but it also plays a role in assisting with tooth and
bone development and maintenance. Because it isn’t necessary for growth or to sustain
life, fluoride is generally not considered an essential mineral. However, fluoride’s role in
preventing dental caries (i.e., tooth decay), the most prevalent chronic disease in children
and adults, underscores the importance of this mineral in the human diet. 4
Fluoride combats tooth decay via three mechanisms:
• Blocking acid formation by bacteria
• Preventing demineralization of teeth
• Enhancing remineralization of destroyed enamel
As a natural mineral, fluoride is present in the soil and water in varying concentrations
depending on geographical location. In the 1930s, researchers observed that children living
in areas with naturally higher fluoride concentrations in their drinking water had a lower
incidence of cavities, leading to the idea that adding fluoride to municipal water supplies
could benefit public health. Fluoride was first added to drinking water in 1945 in Grand
Rapids, Michigan; now over 60 percent of the U.S. population consumes drinking water that
has been supplemented with fluoride to provide amounts that support dental health. The
Centers for Disease Control and Prevention (CDC) has reported that fluoridation of water
reduces cavities by 25 percent in children and adults and considers water fluoridation one of
the ten great public health achievements in the twentieth century. 5
Fluoride’s benefits to mineralized tissues of the teeth are well substantiated, but fluoride
also plays an important role in the mineralization of bones, increasing their structural
stability. Fluoride is currently being researched as a potential treatment for osteoporosis.
The data are inconsistent on whether consuming fluoridated water reduces the incidence
of osteoporosis and fracture risk. Fluoride does stimulate osteoblast bone building activity,
and fluoride therapy in patients with osteoporosis has been shown to increase bone mineral
density. In general, it appears that at low doses, fluoride treatment increases bone mineral
density in people with osteoporosis and is more effective in increasing bone quality when
the intakes of calcium and vitamin D are adequate. The Food and Drug Administration has
not approved fluoride for the treatment of osteoporosis, mainly because its benefits are not
sufficiently known. It also has several side effects, including frequent stomach upset and
joint pain. The doses of fluoride used to treat osteoporosis are much greater than that in
fluoridated water.
Dietary Sources of Fluoride
Fluoride is not widely found in the food supply. In communities with municipal water
fluoridation, greater than 70 percent of fluoride intake comes from drinking water. In
communities without fluoridated water, intake depends on how much fluoride occurs