Nutritional effects on caries incidence are demonstrated by these observations: (1) With increased Ca intake (as milk) there is decreased tendency to caries. (2) With a given milk intake, administration of graded amounts of vitamin D brings about correspondingly graded reduction in caries. (3) Increased vitamin-D production in the body, by exposure to a suitable source of ultraviolet radiation during the winter, has a comparable effect. (4) A seasonal trend in caries incidence has been established. Low summer values, intermediate fall and early-winter values, and high late-winter values, run parallel to the availability of natural ultraviolet radiation.
The results are interpreted as indicating that increased absorption or retention of calcium favors caries prevention, and that this can be brought about by (a) increased intake of calcium or (b) better retention of calcium induced by vitamin D. It is not claimed either that optimal conditions have as yet been demonstrated or that other factors besides calcium retention can be disregarded. The foregoing findings were obtained in studies of 800 children, during a six-year period in well regulated and supervised home-institutions that assured uniform daily routine. Of the 800 children observed, 200 were controls.
References: J. Den. Res., 1932 ; N. Y. State J. Med., 1933; Am. J. Pub. Health, 1934; N. Y. J. Den., 1937; Independent J. (Columbia Univ.), 1938; J. Nutr., 1938.