Your new favorite cereal tells you it’s a “good source of fiber.” Your orange juice is an “excellent” source of calcium. The butternut squash discussed in the post below is an “excellent” source of potassium, vitamin A, and vitamin C.
What do these labeling terms really mean?
A food can claim that it is an “excellent” source of a nutrient (usually vitamins or minerals but sometimes other things we need in our diet such as fiber) if it contains 20% or more of your Daily Value (DV). A food can be labeled as a “good” source if it contains 10-19% of your DV.
These estimates are based on an average 2,ooo calorie diet. Individual diets will vary so the exact numbers of each nutrient you need changes based on your age, gender, weight, and physical activity level. Still, the %DVs can help you get a good reference point on how much of a nutrient a food contains compared to others.
Side note: There are some exceptions to this rule. If the food contains too much fat, sodium, or cholesterol per serving for example to be considered a healthy part of your diet by the U.S. Dietary Guidelines, then the packaging can’t make these health claims, even if they do contain a lot of the nutrient. Whole milk, for example is also an excellent source of calcium but contains too much fat per serving to be allowed to list this fact on the food label.