Recommended Dietary Allowance(RDA)
Recommended Dietary Allowances (RDAs) are designated by health authorities as the appropriate measure of a nutrient you should consume each day to meet your needs. These values aim to meet the physiologic requirements for the majority of healthy populations (97%-98%), and prevent disease risk and nutrient deficits. In actuality, they tend to exceed the average requirements though they may account for less amounts than are typically consumed. The implementation of this recommendation implies the high likelihood of achieving the intake requirement of a given nutrient.
Unlike the EAR (Estimated Average Requirement) that targets to meet the nutrient requirements of half the healthy population(50%), RDA aims to meet the needs of a greater number of individuals (97%-98% of total population), and as such RDA is more accommodating to the needs of most individuals whilst EAR is mainly applied for population assessments.
RDAs however, still come with shortfalls within its knowledge base as not all nutrients have a set RDA. This is greatly influenced by individual nutrient factors such as the rate of turnover, the length of time over which averaging is attained etc. To illustrate, certain nutrients especially fat-soluble ones such as Vitamin A are stored and broken down slowly over time while others such as Vitamin B1 (Thiamine) have a faster turn-over rate such that a complete lack of their intake implies the manifestation of deficiency symptoms within a short time span i.e. in weeks, and not for months like those degraded slowly. The lack of intake of a nutrient stored in a day can be compensated from the surplus. Moreover, nutrient utilization of the different nutrients varies from one person to another. In turn, RDAs for some nutrients are not well-established and for most, their average intakes are intended for a number of days while others for weeks.
Applications Of RDA
The RDAs can serve as a guide such that a varied diet meeting RDAs will probably be adequate in all other nutrients. RDA values aid in planning of nutritious diets that comprise variety and nutrient adequacy. However, in addition to its mentioned basic application, it serves other major functions in various domains including:
- In determining individual risk of nutrient deficiency.
- In the food industry, it guides the development of novel food products and dietary supplements as well as institute the guidelines for nutrition labelling.
- In the clinical management field, by aiding in the modification of nutrient requirements in the management of diseases.
- For the development of nutrition policies and nutrition intervention projects by health policy- makers.
- Public health nutritionists utilize it in the composition of diets for various institutions including schools, prisons, health facilities etc.
- In the planning and purchase of food provisions for population groups.
- In the design and development of nutrition health programmes.
- In the interpretation of food consumption records of individuals and populations.
- For establishing guidelines for feeding initiatives targeted for vulnerable populations.
In conclusion, RDAs are recommendations of nutrient intake that accommodate the needs of most of the population. They help you achieve the nutrient requirements for most nutrients to prevent deficiencies while reducing the risk of disease.