Define Requirements and Recommended Dietary Allowances (RDA)?

What do we mean by requirements and RDA? The requirement level is the amount of nutrient needed to be absorbed to maintain adequate nutritional status in an individual. It differs with body size, age, rate of growth and special physiological situations such as pregnancy and lactation and some pathological conditions that accelerate usage, wastage or destruction as in certain acute or chronic diseases (diarrhoea/constipation). RDA, on the other hand, is the amount of a nutrient that will meet the needs of practically all individuals in n defined physiological category. We shall get to know about the requirements and RDA of the fat-soluble vitamins in this section.

• Hypo and Hypervitaminosis: This section shall describe the adverse affects associated with deficient or excessive intake.
• Criteria for assessing vitamin status: The ability to accurately assess vitamin status requires criteria which are "unique to the vitamin and will provide valid results fundamental to clinical and research settings. Such criteria are used to assess the nutriture of fat soluble vitamins, which are discussed here in this section.