Question: What is the primary difference between recommended dietary allowances (RDAs) and adequate intake (AI)? Need Assignment Help? There is no difference between RDAs and AI. RDAs can be applied to nearly the entire population, while AI can only be used for half. RDAs do not distinguish the specific nutrient needs of all genders and ages, but AI does. RDAs are established when there is sufficient scientific data on specific nutrients; AI is established when there is not.