Nutrient Analysis of Dietary Supplements: White Paper and FAQ

Manufacturers and marketers of dietary supplements often have questions about what testing is required for Supplement Facts labels. This white paper is intended to provide information to help companies make informed choices about the testing and claims made on dietary supplements.

NOTE: Ultimately, the manufacturer (including the packager or labeler) of the dietary supplement is responsible for label compliance. Manufacturers should conduct their own review of regulations and make considerations specific to their product and marketing. This white paper is not intended as legal advice. Manufacturers should seek independent counsel on the legal interpretation of regulations.

Introduction

Dietary supplements are intended to supplement the diet and are different from conventional foods. Dietary supplements are subject to labeling rules that resemble and differ from conventional foods. Specific rules (21 CFR 111 GMPs) assure the identity, purity, strength, and composition of dietary supplements. This white paper is not specifically about those purposely claimed dietary ingredients, but rather about the mandatory nutrients that may also need to be declared.

Key Terms

• Dietary Supplement: Dietary supplements are intended to add to or supplement the diet and are different from conventional food. Supplements are ingested and must contain at least one dietary ingredient. If a product is marketed with a Supplement Facts Panel, it must follow Dietary Supplement rules.
• Dietary Ingredient: Dietary Ingredients include vitamins and minerals; herbs and other botanicals; amino acids; "dietary substances" that are part of the food supply, such as enzymes and live microbials (commonly referred to as "probiotics"); and concentrates, metabolites, constituents, extracts, or combinations of any dietary ingredient from the preceding categories.
• Mandatory Nutrient: Mandatory Nutrients are required to be labeled on a conventional food Nutrition Facts Panel. Nutrients are mandatory because the FDA considers them to be the most important nutrients to either increase (e.g. Vitamin D or Dietary Fiber) or limit (e.g. Sodium or Added Sugars) within one’s diet based on scientific evidence that guides these regulations. See Table 1 for the full list of Mandatory Nutrients. Some Dietary Ingredients are also Mandatory Nutrients (e.g. Vitamin D, Potassium).
• Voluntary Nutrient: Voluntary Nutrients are not required to be declared unless a claim is made about them. Manufacturers can voluntarily choose to declare them within a Nutrition Facts or Dietary Supplement Facts panel. Some Dietary Ingredients are also Voluntary Nutrients, but in the context of a Dietary Supplement, the claimed Dietary Ingredient is no longer voluntary.

Manufacturers need to understand how dietary ingredients and mandatory nutrients in their dietary supplements are included in a supplement facts panel.

Figure 1 provides an example that includes both the claimed dietary ingredients (e.g. Vitamin A, D, Omega-3 fatty acids) as well as mandatory nutrients (e.g. Calories, Total, and Saturated Fat from Cod Liver Oil added to provide the Omega-3 fatty acids) and voluntary nutrients (Poly and Monounsaturated Fat). In this example, the Front label may have a product name like “Omega 3 Fish Oil Plus Vitamins A and D” to describe the claimed dietary ingredients. Vitamins A, D, and Omega 3 are for the purpose of supplementing one’s diet. While the calories and fats are incidental (not purposely supplemented), they are relevant to the overall nutrient intake and, as mandatory nutrients, must also be declared should they meet certain thresholds.

Supplements come in many forms, and many include nutrients that require content declaration beyond the primary claimed dietary ingredients. This is especially true with larger serving dietary supplements such as soft gels, powders, bars, gummies, and liquids.

Figure 1. Supplement Facts example from 21 CFR 101.36 (e)(11)(iv)

Rationale

According to 21 CFR 101.36, Dietary Supplement Facts should include both the claimed dietary ingredients and any mandatory nutrients that are part of the food Nutrition Facts panel, if present at a declarable level. The rules define the amount of which, that if below would be considered 0 (0 g, 0 mg, 0% Daily Value as per the individual nutrient) and not be included on a Supplement Facts, or if equal to or above is required to be labeled (Table 1). Following is the direct excerpt from 21 CFR 101.36 (b)(2) describing this rule:

…dietary ingredients to be declared, that is, total calories, total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrate, dietary fiber, total sugars, added sugars, protein, vitamin D, calcium, iron, and potassium, shall be declared when they are present in a dietary supplement in quantitative amounts by weight that exceed the amount that can be declared as zero in nutrition labeling of foods in accordance with § 101.9(c). Calories from saturated fat, polyunsaturated fat, monounsaturated fat, soluble fiber, insoluble fiber, and sugar alcohol may be declared, but they shall be declared when a claim is made about them. Any (b)(2)-dietary ingredients that are not present, or that are present in amounts that can be declared as zero in § 101.9(c), shall not be declared (e.g., amounts corresponding to less than 2 percent of the RDI for vitamins and minerals)…

So if a serving of a dietary supplement contains the minimal amount for declaration as listed in Table 1, that product must declare that content.  

Table 1 Minimal amount of Mandatory Nutrient for Declaration in a Supplement Facts

Frequently Asked Questions

Do I need to test my product for these nutrients?

There is no specific requirement to test for all nutrients. However, manufacturers are responsible for the accuracy and completeness of their labels. Manufacturers should have data to support their declarations and omissions. The supporting data can be from various sources, but having analytical data from the finished manufactured product is often the most accurate and defendable. Regulatory compliance is evaluated by both chemical analysis and record review.

Do I need to test for every one of these nutrients?

Manufacturers can make their own decisions on the amount of supportive data to support their product labels. If uncertain, testing for all of the above nutrients would be a safe option and would avoid missing any unexpected nutrient that is present. However, knowledge of the included ingredients can allow the manufacturer to choose only those tests relevant to their product and conduct an abbreviated analysis profile.

What are some examples of selectively choosing specific nutrients to test or not test for?

Manufacturers must own responsibility for these choices. For some dietary supplements, simple logic can infer that some or all of these mandatory nutrients are not necessary to test.

Consider, for example, a Calcium tablet containing 500 mg of Calcium (as Calcium Carbonate), with minor amounts of tableting aids (Cellulose Gel, Magnesium Stearate, etc.) If there is less than 0.5 g of all other ingredients, there is no possibility that on a serving basis that the tablet will contain 0.5 g of fat, protein or carbohydrates, etc. And, if there is less than 0.5 g of other ingredients, there cannot be over 5 calories, as the maximum caloric content from pure fat is still less than 5 calories (0.5 g X 9 cal/g = 4.5 calories, still below the 5 calorie threshold). So testing for those nutrients will not provide information that cannot be inferred from formulation records.

As an additional example, if the dietary supplement does not use animal fat sources, it is unlikely to contain cholesterol. By knowing your ingredients well, you could omit cholesterol analysis. Vitamin D is almost exclusively a fortified nutrient, so if that is not a purposely added nutrient in a dietary supplement, it is also unlikely to be present.

How should Fat be tested? Do I need to test for Saturated, Trans, Mono, and Polyunsaturated fats?

Fats are primarily tested in two ways: crude solvent extraction methods and fatty acid profiles. Crude fat analysis is an extraction that includes fats, as well as other lipid-like materials (e.g. waxes, sterols, etc). Fatty acid profiles measure individual fatty acids (e.g. palmitic acid, oleic acid) and can be calculated on a triglyceride basis for a total fat.

The fatty acid profile method is the official method for total fats as well as saturated, trans, mono, and polyunsaturated fats. So, a fatty acid profile is recommended for products with significant fat content. However, to show compliance of an omission, a simple crude fat extraction may be sufficient since crude fats should always equal or overestimate the fat content versus a fatty acid profile. One could test with a crude fat analysis, and assuming a value of <0.5 g/serving, use that for justification that saturated, trans, mono, and polyunsaturated fats all must be <0.5 g/serving. 

Note that mono and polyunsaturated fats are optional nutrients that do not need to be declared even if present unless any claim is made about them. In Figure 1, they are claimed, which is completely optional. In this example, a fatty acid profile is necessary to confirm the saturated fat claim, but the example company also choose to provide the mono and polyunsaturated fat contents, which some consumers may value.

Do I need to calculate the Added Sugars in my Dietary Supplement?

The manufacturer is responsible for declaring added sugars in any product with 0.5 g or more added sugars. Sucrose, glucose (dextrose), lactose and sugar-containing syrups, maltodextrins, etc. are commonly used in formulations for bulking and processing reasons as well as to provide sweetness and textural functions. So added sugars should be high in consideration. There are extensive rules and explanations on what is and is not included in added sugars. However, in many cases, the manufacturer does not need to concern themselves with these rules if the product contains less than 0.5 g of total sugars. So a simple sugar analysis can be pursued first, and if less than 0.5 g, both sugar and added sugars can be omitted. If 0.5 g or more, then decisions on added sugar are necessary.

It may be obvious by formulation records if sucrose is the only source of sugar in a gummy dietary supplement that contains 2 g sugar/serving, so declaring 2 g added sugars is a simple inference. It is less obvious if that dietary supplement contains concentrated fruit juices or milk powder. Eurofins can assist with calculations for Added Sugars. The manufacturer can request test code K1010 and provide formulation records for us to make that determination.

Do I need to declare Calories on my Supplement Facts, and how is that calculated?

The manufacturer is responsible for declaring calories if a serving contains 5 or more calories. There are multiple ways to determine calories, as described in 21 CFR 101.9(c)(1), but the general factors of 4, 4, 9 are typically used based on the grams of protein, carbohydrate, and fat, with carbohydrates calculated by difference (100% - moisture – ash - protein – fat). So at a minimum, tests for ash, moisture, crude protein, and crude fat will provide enough information to calculate total carbohydrates and calories. Depending on the product and ingredients, additional tests and adjustments can be made for soluble and insoluble fibers, sugar alcohols, ethanol, etc.

A full fatty acid profile analysis rather than crude fat may also provide a more accurate total fat content. As described, these are generally standard food analysis methods but note that many dietary supplements differ from traditional foods in ways that complicate calorie and carbohydrate calculations. The manufacturer may need to make additional considerations, supported by sound science in how they claim calories and carbohydrates if they choose not to follow standard test methods.   

Is there a simple way to order the tests I need?

Eurofins has analytical tests for each nutrient and offers services for calculating added sugar and generating a Supplement Facts panel. Clients can request a complete package of typical nutrient analysis (e.g. code PFS06). They can also request added sugar calculations alone or a complete generation of the Supplement Facts Panel. A client’s quotation is set up so that each of the components of the package is available, and one can selectively choose which tests to include or not (e.g. omitting Vitamin D).

Additional tests can also be added for simple inclusion or exclusion by product as PFS06 is only a typical profile but different test methods may be more appropriate for specific products. For example, there are multiple moisture, dietary fiber, and fat methods depending on the product and ingredients. Inquire with your Eurofins contact if other tests are appropriate based on the product’s specific ingredients.

My analysis indicates my product rounds to 0 mg sodium, 0 g sugar, 0 calories, etc. Can I claim those on my label?

Dietary Supplement rules prohibit making claims on absent nutrients. If any of these nutrients are at levels considered to be zero, they should be completely omitted from the label, and NOT declared as zero calories, etc. This dietary supplements rule differs from foods, where there is allowance to claim a product as Low, No, or Free of Sodium, Sugar, Fat, Calories, etc. The purpose of dietary supplements is to exclusively supplement a diet and, therefore, not considered as replacements of foods, where a consumer would choose to limit their intake of sugar, sodium, calories, etc. by comparing and substituting one food for another.

What about confirming the content of the primary dietary ingredients (other vitamins, amino acids, botanicals, etc)?

Eurofins offers hundreds of tests for the identity, purity, strength, and composition of dietary ingredients and dietary supplements. Although outside of the scope of this white paper, inquire with your Eurofins contact about the tests available. Providing a label, ingredient statement, and ingredient specification or data sheets is often helpful in providing the proper test codes for your analysis.

References

U.S. Food & Drug Administration, Center for Food Safety and Applied Nutrition.  A Food Labeling Guide Guidance for Industry. Appendix H: Rounding the Values According to FDA Rounding Rules. January 2013.  https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-food-labeling-guide

U.S. Food & Drug Administration. Nutrition Labeling of Food. Code of Federal Regulations 21 CFR 101.9. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.9

U.S. Food & Drug Administration. Nutrition labeling of dietary supplements. Code of Federal Regulations 21 CFR 101.36. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.36

U.S. Food & Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels. Final Rule. Document FDA-2012-N-1210-0875, Federal Register Number 2016-11867. May 26, 2016. https://www.regulations.gov/document/FDA-2012-N-1210-0875

U.S. Food & Drug Administration.  Office of Dietary Supplement Programs. Questions and Answers on Dietary Supplements. October 26, 2022.  https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements

Meet the Author - Daniel Berg

Daniel Berg is an Analytical Service Manager for Eurofins Food Chemistry Testing, based in Madison, WI, with an emphasis on nutrient analysis of foods, special-use foods, and dietary supplements. With over 10 years at Eurofins and 25 years with R&D and technical service roles at food, ingredient, and dietary supplement companies, Daniel helps direct the nutrient analysis programs at the Madison lab and supports clients in developing and maintaining effective analytical testing programs.

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