The RDI is derived from the RDAs, which were first developed during
World War II by
Lydia J. Roberts,
Hazel Stiebeling and
Helen S. Mitchell, all part of a committee established by the U.S.
National Academy of Sciences to investigate issues of nutrition that might "affect national defense" (Nestle, p 35). The committee was renamed the Food and Nutrition Board in 1941, after which they began to deliberate on a set of recommendations for a standard daily allowance for each type of
nutrient. The standards would be used for nutrition recommendations for the armed forces, civilians, and overseas populations who might need food relief. Roberts, Stiebeling, and Mitchell surveyed all available data, created a tentative set of allowances for "energy and eight nutrients", and submitted them to experts for review (Nestle, p 35). The final set of guidelines, called RDAs for Recommended Dietary Allowances, was accepted in 1941. The allowances were meant to provide superior nutrition for civilians and military personnel, so they included a "margin of safety". Because of food rationing during the war, the food guides created by government agencies to direct citizens' nutritional intake also took food availability into account. The Food and Nutrition Board subsequently revised the RDAs every five to ten years. In 1973, the FDA introduced regulations to specify the format of nutrition labels when present, although the inclusion of such labels was largely voluntary, only being required if nutrition claims were made or if nutritional supplements were added to the food. The nutrition labels were to include percent U.S. RDA based on the 1968 RDAs in effect at the time. The RDAs continued to be updated (in 1974, 1980 and 1989) but the values specified for nutrition labeling remained unchanged. In 1993, the FDA published new regulations mandating the inclusion of a
nutrition facts label on most packaged foods. Originally the FDA had proposed replacing the percent U.S. RDAs with percent daily values based on the 1989 RDAs but the Dietary Supplement Act of 1992 prevented it from doing so. Instead, it introduced the RDI to be the basis of the new daily values. The RDI consisted of the existing U.S. RDA values (still based on the 1968 RDAs as the FDA was not allowed to change them at the time) and new values for additional nutrients not included in the 1968 RDAs. On May 4, 2018, the FDA released a final rule that extended the deadline to January 1, 2020, for large companies and to January 1, 2021, for small companies. During the first six months following the January 1, 2020 compliance date, the FDA worked cooperatively with manufacturers to meet the new Nutrition Facts label requirements and did not focus on enforcement actions regarding these requirements during that time. ==Sodium and potassium==