Who Set the Daily Numbers, and Where the Label Percent Came From

The percent Daily Value on a label traces back to 1968 RDA figures, and men aged 19 to 35 set most of them. This history follows the RDA from its 1941 start through the 1990 labeling law, the 1993 rules and the 1997 DRI report.

Jump to: - [The label's numbers came from men aged 19 to 35](#the-labels-numbers-came-from-men-aged-19-to-35) - [From minimum daily requirements to US RDAs](#from-minimum-daily-requirements-to-us-rdas) - [The 1990 law and the 1993 rules](#the-1990-law-and-the-1993-rules) - [From RDAs to DRIs: the 1997 report](#from-rdas-to-dris-the-1997-report) - [What the percent Daily Value means now](#what-the-percent-daily-value-means-now) The history of the RDA and Daily Value is a chain of handoffs. The recommended dietary allowance was developed in 1941, and the percent Daily Value on a label descends from RDA figures set in 1968. The 1993 rules kept the 1968 figures for vitamins and minerals even though the 1989 RDA edition was already out. ## The label's numbers came from men aged 19 to 35 For most vitamins and minerals, the label values came from the highest figure in the 1968 RDA table, and that figure was the one for men aged 19 to 35. Iron was the exception, and its label value came from the women's figure. According to the Institute of Medicine's (IOM) 2003 history of labeling, the use of the highest values "grew out of concern about nutrient deficiencies in some segments of the population." Calcium and phosphorus followed their own rule, based on approximately 1 gram of calcium and an equimolar basis for phosphorus. The [iron history](/blog/history/history-of-iron-supplements-and-the-ferritin-test) covers iron supplements and the ferritin test. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) ## From minimum daily requirements to US RDAs According to PubMed, a 2024 historical article says the recommended dietary allowance was developed in 1941 and argues that its definition should be redefined. [DOI](https://doi.org/10.1016/j.nut.2024.112519) In 1941, FDA also issued regulations governing the labeling of fortified foods and vitamin and mineral supplements. Where a specific claim was made, the label had to show the percentage of the "minimum daily requirements" for that vitamin or mineral. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) By 1973, FDA's packaged-food labeling used US RDAs, which the IOM says were derived from the highest of the National Research Council's 1968 RDAs for people aged 4 and older, excluding pregnant and lactating women. The National Research Council issued its tenth RDA edition in 1989. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) ## The 1990 law and the 1993 rules President George H.W. Bush signed the Nutrition Labeling and Education Act (NLEA) into law in November 1990. In July 1990, FDA had proposed reference values built on a population-adjusted mean of the RDAs rather than the highest-value approach. In 1991, FDA proposed "Daily Value" as one term for the new reference values. The most frequently expressed concern was that the population-adjusted value was too low for at least half of the population. The Dietary Supplement Act of 1992 (P.L. 102-571) blocked RDA-based labeling rules until November 1993, and it kept NLEA from applying to dietary supplements before December 15, 1993. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) In January 1993, FDA's final rules kept the highest-value approach and the 1968 RDAs as the reference values for vitamins and minerals. The remaining differences were attributed to differences between the 1968 and 1989 RDAs. The macronutrient reference values, called Daily Reference Values, came from a 1988 Surgeon General's report and a 1989 National Research Council report. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) ## From RDAs to DRIs: the 1997 report The 1997 report on calcium, phosphorus, magnesium, vitamin D, and fluoride was the initial report of a major new Food and Nutrition Board activity, the Dietary Reference Intakes (DRIs). [IOM 1997](https://www.nationalacademies.org/read/5776/chapter/1) Calcium shows the change most clearly. Because reducing chronic disease risk was the intended endpoint, and the evidence carried many uncertainties, the committee said an Estimated Average Requirement and an RDA for calcium could not be justified. It set an Adequate Intake instead. The [calcium history](/blog/history/history-of-calcium-supplements-from-chalk-to-bone-trials) covers the mineral's supplement story, and our [magnesium monograph](/ingredients/magnesium) covers another mineral the 1997 report addressed. The NIH Office of Dietary Supplements defines the terms this way. An RDA is the average daily intake sufficient to meet the needs of nearly all (97 to 98 percent) healthy individuals. An AI is the intake assumed to ensure nutritional adequacy when evidence is insufficient to develop an RDA. A UL is the maximum daily intake unlikely to cause adverse health effects. [NIH ODS](https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/) ## What the percent Daily Value means now The FDA developed Daily Values to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet. The DV for vitamin D is 20 mcg (800 IU) for adults and children age 4 and older, and the [vitamin D complete guide](/health/vitamin-d-complete-guide) covers that nutrient. [NIH ODS](https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/) The Supplement Facts box, which FDA's 1997 rules required on all dietary supplements from 1999, must show the amount and % DV of the same nutrients that food labels require, when those nutrients are present in the supplement. [IOM 2003](https://www.nationalacademies.org/read/10872/chapter/2) Myung's 2024 historical article goes further. According to PubMed, it calls the current RDA "an extremely high intake level" that affects only the upper 2.5 percent of the generally healthy population, and it argues the RDA should be redefined using prospective cohort studies that link intake levels to disease or mortality. [DOI](https://doi.org/10.1016/j.nut.2024.112519) ## Bottom line Read the %DV as a per-serving share of a group reference number, not a verdict on your diet. An RDA is set to meet the needs of nearly all healthy people, so an average person often needs less than the figure the label is built on. Use the label to compare servings, and bring dose decisions to a clinician. ## Frequently asked questions ### Why were RDAs created in the 1940s? The sources checked date the RDA to 1941, but none of them gives a reason, so this page does not offer one. ### Who set the first RDA values? The sources checked do not name the committee behind the 1941 values. They do show that the National Research Council issued the 1968 RDA table that the labels used, and that the Food and Nutrition Board later produced the DRI series. ### How did RDAs become DRIs? The 1997 calcium, phosphorus, magnesium, vitamin D, and fluoride report was the initial DRI report. Where the evidence could not support an RDA, as with calcium, the committee set an Adequate Intake instead. ### What is the difference between an RDA, an AI and a UL? An RDA is the daily intake that meets the needs of nearly all (97 to 98 percent) healthy people. An AI is the intake assumed to ensure adequacy when evidence is insufficient for an RDA. A UL is the maximum daily intake unlikely to cause adverse health effects. ### How did the Daily Value on labels come from the RDA? Through the 1968 figures. The 1973 labels used the highest 1968 values, the 1990 proposal shifted to a population-adjusted mean, and the 1993 final rules kept the highest-value approach for vitamins and minerals. ### Why do supplement labels show a percentage of the Daily Value? Because the Supplement Facts box must show the amount and % DV for the same nutrients that food labels require, whenever those nutrients are in the supplement. FDA's 1997 rules made the box mandatory on dietary supplements from 1999. ## Next reads - [Vitamin D complete guide](/health/vitamin-d-complete-guide): the pillar for the vitamin whose label Daily Value is 20 mcg. - [History of calcium supplements, from chalk to bone trials](/blog/history/history-of-calcium-supplements-from-chalk-to-bone-trials): the mineral behind the 1997 report's Adequate Intake decision. ### Related reading - [how RDAs became the percent Daily Value on labels](/blog/history/history-of-the-word-vitamin-from-vitamine-to-the-dropped-e) - [the 1941 fortified-food labeling rules and the percent of the minimum daily requirement](/blog/history/history-of-food-fortification-from-iodized-salt-to-folic-acid-flour) - [the 1990 labeling law and the 1993 rules for supplements](/blog/history/history-of-supplement-law-from-1938-food-act-to-dshea-1994)