Understanding the Percent Daily Value (%DV)
To grasp what a "good source" means, one must first understand the Percent Daily Value (%DV) found on a Nutrition Facts label. The %DV is a guide to the nutrients in one serving of a packaged food. For most nutrients, it is based on a 2,000-calorie diet, though individual needs may vary. The %DV provides a snapshot, helping you determine if a serving of food contributes a little or a lot to your daily nutritional needs. Looking at the %DV column is the most reliable way to interpret nutrient claims and make informed decisions.
The Hierarchy of Nutrient Claims
Food manufacturers use specific, regulated terms to describe the level of a nutrient in their products. These terms are all tied to the %DV:
- Low Source (5% DV or less): A serving of food provides a small amount of a particular nutrient. For nutrients you want to limit, like saturated fat, sodium, and added sugars, a low %DV is desirable.
- Good Source (10–19% DV): A product carrying this claim contains a moderate amount of the nutrient. It means you are getting a meaningful contribution toward your daily need from a single serving.
- Excellent or High Source (20% DV or more): This signifies that a single serving provides a substantial amount of the nutrient, making it a highly concentrated source.
For example, if a bowl of cereal lists 15% DV for iron, it's a "good source" of that mineral. If a serving of milk contains 25% DV for calcium, it would be an "excellent source." These standards allow consumers to compare similar products objectively. A low-fat milk labeled "excellent source of calcium" provides a much greater nutritional benefit for that specific nutrient than a breakfast bar labeled "good source" of calcium, especially when considering other factors like sugar content.
Nutrient Density: A Broader Nutritional Concept
While "good source" is a valuable, regulated metric, it doesn't tell the whole story. The concept of nutrient density is often more important for overall dietary health. Nutrient-dense foods are those that provide a high level of vitamins, minerals, and other beneficial compounds relative to their calorie count. For example, a handful of nuts might have more calories per serving than a fortified breakfast cereal, but it provides a wider array of healthy fats, protein, and minerals, making it more nutrient-dense. Conversely, a highly processed food could be fortified to be a "good source" of a certain vitamin but still contain high amounts of added sugar and low-quality fats. A whole food like a spinach salad, which is naturally rich in iron, fiber, and vitamins, is inherently more nutrient-dense than a fortified snack cracker.
Comparing Nutrient and Energy Density
- Nutrient-Dense Foods: These include vegetables, fruits, whole grains, seafood, legumes, nuts, and seeds. They offer a significant nutritional payoff for the calories consumed.
- Energy-Dense Foods (often called "empty calories"): These are high in calories but low in nutritional value. Processed foods stripped of their natural nutrients and filled with added sugars, unhealthy fats, and sodium are examples.
The best dietary choices focus on a balance of both nutrient density and appropriate caloric intake. Choosing foods labeled as a "good source" is a good starting point, but context is key. Always check the other parts of the nutrition label, such as the total sugars, added sugars, and sodium content, to make the healthiest choice possible.
Making Informed Choices with the Nutrition Facts Label
Using the information on the Nutrition Facts label effectively requires more than just looking for "good source" claims. It's about combining multiple pieces of information to build a complete picture of a food's nutritional profile.
- Evaluate the Serving Size: Before anything else, check the serving size and how many servings are in the container. All the information on the label is based on a single serving. If you eat more than one serving, you multiply all the calorie and nutrient values accordingly.
- Check the %DV for Key Nutrients: Pay attention to the nutrients you want to increase (like fiber, vitamin D, calcium, iron, and potassium) and those you want to decrease (like saturated fat, sodium, and added sugars). Aim for higher %DV for beneficial nutrients and lower %DV for those you need to limit.
- Read the Ingredients List: Ingredients are listed in descending order by weight. This is important for spotting added sugars and other less-than-healthy ingredients that might be listed higher up even in a product that is technically a "good source" of a specific nutrient.
By taking these steps, you can avoid being misled by front-of-package claims and truly understand what you are consuming. The most valuable nutritional insights come from a holistic reading of the entire label, not just a single claim.
| Feature | Low Source | Good Source | Excellent/High Source |
|---|---|---|---|
| % Daily Value (%DV) | 5% or less per serving | 10–19% per serving | 20% or more per serving |
| Significance | Provides a small amount of the nutrient. Desirable for nutrients to limit. | Provides a meaningful amount of the nutrient per serving. | Provides a substantial amount of the nutrient per serving. |
| Common Use | A low-sodium product would be an example. | A fortified cereal with 15% DV for iron. | A serving of milk with 25% DV for calcium. |
| Label Term | Not specifically labeled as "low source." Claim would be "low fat" or "low sodium." | "Good source of" / "Contains" / "Provides" | "Excellent source of" / "Rich in" / "High in" |
Conclusion: Interpreting Labels for Better Health
Understanding what "good source" means is a critical step toward becoming a savvy consumer. The term is not a subjective marketing phrase but a specific, regulated claim that indicates a product provides 10-19% of the Daily Value for a nutrient per serving. However, truly smart nutrition goes beyond this single metric. It requires reading the entire Nutrition Facts label, evaluating the %DV for multiple nutrients, and understanding the more comprehensive concept of nutrient density. A food can be a "good source" of a fortified nutrient while still being a less healthy choice than a naturally nutrient-dense whole food. By combining your knowledge of these claims with an overall assessment of a product's ingredients and total nutritional profile, you can make more balanced, healthy decisions that support your long-term wellness. Here's a great resource on how to understand and use the Nutrition Facts Label.
Frequently Asked Questions
What is the difference between a "good source" and a "high source"?
A "good source" provides 10% to 19% of the Daily Value (%DV) for a nutrient, while a "high source" (or "excellent source") contains 20% or more of the %DV per serving.
Is a "good source" of a vitamin always a healthy choice?
No, it is not always a healthy choice. While the product contributes a meaningful amount of a specific vitamin, it could still be high in added sugars, saturated fat, or sodium. A "good source" claim should be evaluated in the context of the entire Nutrition Facts panel.
How do I know if a food is a "low source" of a nutrient?
The FDA considers a food a "low source" of a nutrient if it contains 5% or less of the Daily Value (%DV) per serving. This is particularly useful for limiting intake of nutrients like sodium, saturated fat, and added sugars.
What is the % Daily Value based on?
The % Daily Value is based on a 2,000-calorie diet. Your personal needs may vary based on age, sex, activity level, and weight goals, but the %DV provides a standardized reference point for comparison.
Does a "good source" claim apply to all nutrients?
Nutrient content claims like "good source" are regulated by the FDA and apply to nutrients that have an established Daily Value, including vitamins, minerals, protein, and fiber.
What does "nutrient-dense" mean, and is it the same as a "good source"?
Nutrient-dense describes foods that provide a high level of beneficial nutrients (vitamins, minerals, fiber) relative to their calorie count. It is not the same as a regulated "good source" claim, which is based on a specific %DV threshold.
Are whole, unprocessed foods like vegetables considered "good sources"?
While most whole foods like vegetables are nutrient-dense and excellent sources of many nutrients, they are not typically labeled with "good source" claims, as this labeling is for manufactured products. You would check their nutritional information to see their natural nutrient content.
