The recommended dietary allowance (RDA) was developed during World War II by
Lydia J. Roberts,
Hazel Stiebeling, and
Helen S. Mitchell, all part of a committee established by the
United States National Academy of Sciences in order to investigate issues of nutrition that might "affect national defense". The committee was renamed the Food and Nutrition Board in 1941, after which they began to deliberate on a set of recommendations of a standard daily allowance for each type of nutrient. The standards would be used for nutrition recommendations for the armed forces, for civilians, and for overseas population 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, 35). The final set of guidelines, called RDAs for Recommended Dietary Allowances, were 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 the early 1950s,
United States Department of Agriculture nutritionists made a new set of guidelines that also included the number of servings of each food group in order to make it easier for people to receive their RDAs of each nutrient. The DRI was introduced in 1997 in order to broaden the existing system of RDAs. DRIs were published over the period 1998 to 2001. In 2011, revised DRIs were published for calcium and vitamin D. Additionally, revised DRIs were published for potassium and sodium in 2019. The DRI for energy was updated in 2023. None of the other DRIs have been revised since first published 1998 to 2001. ==Current recommendations for United States and Canada==