The Supplement Facts Panel: Serving Size, Amounts and Percent Daily Value Explained

What the panel is

The Supplement Facts panel is the nutrition label on a US dietary supplement. It must list the serving size and servings per container and declare each dietary ingredient. [1] It is not the same as a food's Nutrition Facts panel. This page explains US rules as FDA describes them. Other countries are not covered by the sources we read; see reading supplement labels for general label tips.

Serving size comes first

FDA's labeling guide (April 2005, nonbinding) says one serving equals the maximum amount recommended on the label per eating occasion. [2] So if the directions say 1-3 tablets with breakfast, the serving size is 3 tablets. [2] Every amount on the panel is for that serving, not for one tablet.

Serving size is chosen by the maker. FDA says no laws or regulations limit the serving size of a supplement. [1] It adds that no law or regulation it describes limits the amount of an ingredient in a serving, apart from the maker's duty to meet safety and labeling standards. [1]

A simple cost check, using invented numbers: if a bottle holds 90 capsules and the serving size is 3 capsules, the bottle has 30 servings. Divide the price by 30, not by 90. See comparing supplement labels and cost per serving.

Amount per serving

The panel lists the name and amount of each dietary ingredient by weight, and for vitamins and minerals with Daily Values, and a percent Daily Value for ingredients that have one. [2] Some details from FDA's guide:

• Source or form. A maker may name the source, such as "calcium (as calcium carbonate)." [2] The amount listed is the weight of calcium, not the whole salt. [2]
• Plant part. The part of the plant an ingredient comes from must be shown. [2]
• No zeros. Supplements are not allowed to list "zero" amounts of nutrients. [2]
• Order. Ingredients without Daily Values are listed after those with Daily Values, by common or usual name. [2]
• Hidden amounts. Ingredients inside a proprietary blend do not need individual amounts. [1] See proprietary blends explained.

Percent Daily Value (%DV)

The %DV is the percent of the Daily Value that one serving of the product supplies. [2][3] Daily Values are reference amounts used on US labels, not a personal requirement and not an upper limit. FDA's general rule of thumb is that 5% DV or less per serving is low and 20% DV or more is high. [3]

Three cautions:

• %DV describes a single serving of a single product. [3] It does not add up across your multivitamin, a blend and a fortified drink for you.
• A high %DV is not a safe-to-exceed signal and not a goal. Official upper limits are a different set of numbers; see RDA, AI, DV and UL.
• Different groups can have different Daily Values. FDA's guide says one set applies to children under 4, infants, and pregnant and lactating women. [2] Products for those groups should be chosen with a clinician.

Ingredients with no Daily Value show a symbol in the %DV column instead of a number, meaning "Daily Value not established." [2] That is not a measure of safety or of how much is typical.

Is the amount on the panel the amount in the bottle?

For ingredients a maker specifically adds, FDA's guide says the product must contain 100% of the declared weight, allowing for analytical method differences. Naturally occurring ingredients must be at 80% of the declared value. [2] FDA also says it has limited resources to analyze supplement contents, and does not test products before sale. [1] Tests in published studies have found mismatches in some product types. [4][5] The rule describes what is required, not what every bottle contains. See what third-party testing can and cannot show.

Below the panel: Other Ingredients

Ingredients that are not listed in the panel must appear in an "Other Ingredients" list beneath. [1] See "Other Ingredients": fillers, binders, colors, sweeteners and allergens.