During the winter, Deven takes vitamin C supplements because he believes this will keep him from getting sick. Ironically, his doctor thinks Deven might be consuming so much vitamin C that it is causing him to feel sick. What nutritional guideline will be MOST helpful to Deven if he wants to make sure he doesn’t ingest too much vitamin C?

The Tolerable Upper Intake Level (UL) is the highest average daily intake of a nutrient that is unlikely to cause harmful effects for most people. Deven should use the UL to check whether his vitamin C intake is too high. The RDA and AI are guidelines for adequate intake, while the EAR estimates needs for a group; none is specifically the upper safety limit.

AI-written and checked against the verified answer.