date:May 24, 2012
PNET rates increased from 1986 to 1993 and decreased thereafter. This change in the trend does not coincide exactly with folic acid fortification, but does coincide nicely with the 1992 recommendation for women of childbearing age to consume 400 micrograms of folic acid daily.
The study used the 1986-2008 data from the National Cancer Institutes Surveillance, Epidemiology, and End Results Program (SEER). This program has collected information on cancer cases in various areas of the US since 197