<prompt> In calculating RDA for a particular nutrient, 2 SD are not added forIronCalciumEnergyVitamin A  <response>: Recommended Dietary Allowance RDA: Is a level of intake corresponding to Mean 2 Standard Deviation, which covers requirement of 97.5 of populationRDA is safe level of intake which is likely to be inadequate in not more than 2.5 populationRDA safe level approach is NOT USED FOR ENERGY since excess energy intake is undesirable; For energy only mean or average requirement is defined as RDA. 