The Recommended Dietary Allowance (RDA) is a guideline that indicates the daily intake level of essential nutrients needed to meet the nutritional requirements of most healthy individuals. It is established by the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine and varies based on factors such as age, sex, and life stage. The RDA helps individuals understand how much of a specific nutrient, like vitamin C or calcium, they should consume to maintain good health and prevent deficiencies. These recommendations are based on scientific research and aim to promote overall well-being in the population.