Evidence that there are Two Forms of Fluoride in Human Serum

Abstract

IT has been assumed that there is only one form of fluoride in serum, the inorganic F ion. It would therefore seem that either the value for serum fluoride which I found (1 µM) (refs. 1 and 2) or that found by Singer and Armstrong (7.5 µM) (ref. 3) must be in error. While the diffusion method of Singer and Armstrong has been shown to produce erroneous values, the same cannot be said for their ashing and distillation procedure. The evidence that the serum fluoride is about 1 µM in a fluoridated community does not rule out the possibility that more fluoride could be made available from serum by ashing; it only indicates that the fluoride in serum able to exchange with added radioactive fluoride can be measured and is 1 µM.