Strontium is present in bones and teeth and is thought to replace a small fraction of the calcium in the hydroxyapatite crystal during mineralization. Epidemiologic studies have shown that the incidence of caries in areas with optimal fluoridation is related to the level of strontium in the water. The lowest incidence of caries occurred in areas with strontium levels of 5.4 and 8.3 mg/L, with increased incidence at higher and lower levels of water strontium. Strontium supplementation has also reduced the incidence of experimentally induced caries in animals.

Comment: Interest in strontium has been revived recently, after a three-year study demonstrated that large doses of the mineral (680 mg per day) increased bone mineral density and reduced the incidence of fractures in postmenopausal women. However, that dose of strontium is 200 to 300 times the amount normally present in food, and well above the amount that epidemiological studies suggest is optimal for caries prevention. In animal studies, administration of large doses of strontium caused bone mineralization defects and inhibited the synthesis of 1,25-dihydroxyvitamin D (the active form of vitamin D. While no abnormalities of bone mineralization occurred in the three-year human study, one cannot rule out the possibility that longer-term use of pharmacological doses would adversely affect bone or tooth structure.

A typical diet provides about 2 to 3 mg of strontium per day, and epidemiological studies suggest that doubling that amount might help prevent dental caries. Foods high in strontium include fish, whole grains, kale, parsley, lettuce, Brazil nuts, and molasses. More than 95% of the strontium is lost when sugar cane or beets are refined into white sugar. Most of the strontium is lost when whole wheat is refined to white flour.

Anonymous. Strontium and dental caries. Nutr Rev 1983;41:342-344.