Upper Safe Levels of Intake for Adults

Our bodies need vitamins and essential minerals, but if taken in large amounts they can adversely affect our health. Large amounts of many of the vitamins and minerals can be toxic.

Individuals can have deficient, adequate, or toxic intakes of any essential nutrient. A deficiency occurs when the intake of the essential nutrient is too low to meet a person's need for that specific nutrient. Adequacy occurs when a person gets enough but not too much of a nutrient. Nutrient toxicity occurs when a person gets an overdose of a given nutrient.

The National Academy of Sciences, Institute of Medicine, has established Dietary Reference Intakes (DRIs), which can be used in planning and assessing diets of the healthy general population, as well as for other purposes. The Dietary Reference Intakes are a set of nutrient-based reference values: the Estimated Average Requirement (EAR), the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), and the Tolerable Upper Intake Level (UL).