The recommended dietary allowance, also known as RDA, is an estimation of the amount of a particular vitamin or nutrient the average person needs on a daily basis. This estimation is provided by the United States Food and Nutrition Board. The estimation provided for each nutrient is the amount scientists believe the body needs for the overall maintenance of good health. Often, people refer to the recommended dietary allowance as the recommended daily allowance instead.
The recommended dietary allowance isn’t intended to provide estimations of nutrient levels needed to treat disease or cure medical conditions. Instead, it is intended to provide a guideline people can use when consuming nutrients for optimal health. For example, a person may consume the recommended dietary allowance of vitamin C in order to protect his overall health.
Some people may consume more of a particular nutrient than the recommended dietary allowance suggests in an effort to treat or prevent particular illnesses. For example, a person may take a high-dose supplement of vitamin C in an effort to develop fewer respiratory illnesses or even to prevent cancer. There have been many research studies that have shown that eating significant amounts of particular nutrients may lower a person's risk of developing a disease or even help to relieve symptoms if a person has been diagnosed with an illness.
The recommended dietary allowance doesn’t take into consideration any health problems or stresses that may increase a person’s requirements for a particular nutrient. For example, an individual with a chronic illness may need more of a particular vitamin. Likewise, an individual who doesn’t get enough sleep or is under emotional strain may need more as well. These and other factors are not a part of the recommended dietary allowance estimation. Instead, the estimation is based on the amounts scientist think most healthy people of a particular age and gender group will need daily.
When an individual notes a recommended dietary allowance of a food or supplement, he should know that the amount listed won’t necessarily meet the needs of every person. A child, for example, may have less need for certain vitamins than an adult or senior citizen does. This is not always the case, however, as children may need more of other nutrients to aid their bodies in growth and development. Likewise, each gender may have a different requirement for the same nutrient. In many cases, pregnant and breastfeeding mothers also have an increased need for certain nutrients.