Understanding Differences in Nutritional Guidelines
The National Research Council's Recommended Dietary Allowances (RDA) is the standard for the daily nutritional needs of healthy people. Broken down by gender and age, it covers 25 vitamins, minerals, and trace elements that are critical for a healthy diet. RDA's are neither the absolute minimum, maximum, or ideal amount of a nutrient you should consume; they merely provide an amount that you can be sure is safe and will promote proper health and development. The RDA’s are set by the Food, and Nutritional Board of the National Academy of Sciences/National Research Council.
The FDA established the U.S. Recommended Daily Allowance (USRDA) in 1973 as a simplified daily nutritional requirement standard for food labeling. Because of confusion between the terms USRDA and RDA, the term USRDA has been renamed RDI.
The FDA established the Reference Daily Intake (RDI) to replace the term USRDA (see above) due to confusion between the terms USRDA and RDA. The RDA also adds six new nutrients, Vitamin K, Selenium, Chloride, Manganese, Chromium, and Molybdenum.
The Daily Recommended Values (DRV) are established for special components of foods not listed by the RDI's, such as Fat, Cholesterol, Carbohydrates, and Protein. Unlike other daily nutritional requirements, the DRV's are derived from how many calories a day you need.