Dietary intake of fluoride ashed (total fluoride) v. unashed (inorganic fluoride) analysis of individual foods

Fluoride content in ninety-three individual food items from a hospital in a fluoridated area was determined by ashing (total fluoride) v. unashing (inorganic fluoride) analysis. No discrepancy between the two methods was found by food group but two dry cereals and black pepper did show significantly more fluoride after ashing. The reason for the unavailability before ashing was not determined. Daily fluoride intake was estimated at 1.783 mg which is midway between the 1.211 and 2.201 mg reported from studies in which composite diets were analysed. Daily intake from food at 0.4 mg was one-quarter of the daily total intake 1.8 mg; a ratio consistent with those previously reported in serum, urine and bone between residents from a non-fluoridated v. fluoridated community.