Summary The fluorine content of Japanese foods was determined and the daily intake of fluorine by the individual from the rural diet in the central Japan was estimated with different crop years. In 1958 the fluorine intake of a person was 4.38 mg daily in winter, and in 1965 was 11.13 mg. This increase was due to the yearly increase of the fluorine content of Japanese foods. The contents of fluorine of rice and ''miso", which are the mainstay of the diet in Japan, showed geographical correlat

Summary

The fluorine content of Japanese foods was determined and the daily intake of fluorine by the individual from the rural diet in the central Japan was estimated with different crop years. In 1958 the fluorine intake of a person was 4.38 mg daily in winter, and in 1965 was 11.13 mg. This increase was due to the yearly increase of the fluorine content of Japanese foods. The contents of fluorine of rice and ”miso”, which are the mainstay of the diet in Japan, showed geographical correlations with human mortality with gastric cancer.