Adequate Intake (AI)
Adequate intake is the level of daily intake for a specific nutrient that may ensure nutritional adequacy in most people without health conditions when there is insufficient evidence to develop an estimated average requirement and, therefore, a recommended dietary allowance cannot be calculated.
Last Updated:March 13, 2025
Summary
The Dietary Reference Intake framework, which is used to plan and assess diets in people without health conditions, contains several “reference values”. These include the adequate intake as well as the estimated average requirement, recommended dietary allowance, and tolerable upper intake level.[1][2][3][4]
The adequate intake (AI) for a specific nutrient is the daily intake amount that may ensure nutritional adequacy in most people without health conditions.
An AI value is established when there is insufficient evidence to develop an estimated average requirement and, therefore, a recommended dietary allowance cannot be calculated. AI values are based on observed or experimentally determined estimates of nutrient intake in large groups of people without health conditions. Therefore, a person consuming a nutrient at a level equal to or higher than that nutrient’s AI has a low likelihood of nutritional inadequacy of that nutrient.
AI values for specific nutrients can vary between countries and may change as new evidence emerges. AIs for some nutrients depend on sex, age, and pregnancy,[1][2] but an AI value on food packaging typically refers to the AI for non-pregnant adults ages 19 to 50.[5] For the food-based dietary guidelines across all countries in the United Nations, see here.
In the U.S., reference values to help plan nutritionally adequate diets for individuals — either the recommended dietary allowance (RDA) or AI — have been developed for total energy intake,[6][7] macronutrients (carbohydrates, fats, and protein),[7] fatty acids,[7] cholesterol,[7] amino acids,[7] fiber,[8][7] and several micronutrients (vitamins and minerals).[9][10][11][12][13]