The recommended dietary allowance / recommended daily allowance is is defined as the average daily dietary intake level that is sufficient to meet the nutrient requirements of approximately 98 percent of healthy individuals.
The RDA for individuals will differ when taking into account the varying requirements of males, females and their relative ages. Most food packing will include the RDA along side its own nutritional content.
It is also evident that even the healthiest of individuals that have a severe surplus or deficit will develop a number of health issues. By keeping the required nutritional intake close to equilibrium, the body can operate at optimum levels.
For those with a deficiency, which is often the result of a poor diet or from the additional nutritional requirements from intense exercise, the use of health supplements (vitamins) and sports supplements in the most efficient means of regaining nutritional balance.