Tolerable Upper Intake Level
The highest daily intake of a nutrient considered unlikely to cause harm — the ceiling, not a target.
The Tolerable Upper Intake Level (UL) is the highest daily intake of a nutrient that the reference bodies (the U.S. Institute of Medicine / National Academies and EFSA in Europe) judge unlikely to cause adverse effects in most healthy people. It counts intake from food, water, and supplements combined.
The UL is a ceiling, not a goal — it sits far above the RDA. Not every nutrient has one, and a UL is a general population figure, so it isn't a substitute for advice from a clinician about your own situation.