How Do You Tell if a Dietary Supplement Will Work?

In my last post I discussed the safety of Dietary Ingredients and Dietary Supplements.  We saw that a company that wants to market a New Dietary Ingredient* must notify FDA 75 days in advance, and in that notification must present information on the safety of the NDI.  The burden is on FDA to prove the NDI is unsafe if it does not deem the information sufficient.

This time I want to tell you about the claims that a Dietary Supplement marketer can make about their product.  Dietary supplement marketers do not need to register their products with FDA or get FDA approval before producing or selling dietary supplements.  They must, however, register their manufacturing facilities with FDA.

In contrast to drug marketers, FDA does not approve the claims that dietary supplement marketers make for their products in advance.  In the cases where the company is making Health Claims, FDA is involved in determining whether the dietary supplement company’s claims have scientific merit.  But this involvement does not mean that it can prevent a product from being marketed unless it can build a convincing case to show substantial harm to the public health and prevail in court.

 In this discussion, it’s helpful to think in terms of two.

There are two types of claims that a dietary supplement marketer can make, Health Claims and Structure / Function claims.  There are two types of health claims that a Dietary Supplement marketer can make:

• Authorized Health Claims
• Qualified Health Claims

Authorized Health Claims must be authorized by an FDA regulation.  They are based on an extensive review of the scientific literature, which are generally the result of the submission of a health claim petition to FDA.  FDA uses the significant scientific agreement standard to determine that the nutrient/disease relationship is well established.  See Guidance for Industry: Evidence-Based Review System for the Scientific Evaluation of Health Claims - Final

If FDA agrees with the petition, it promulgates a regulation which will appear in the Code of Federal Regulations (CFR).  An example would be 21 CFR 101.74 - Health claims: sodium and hypertension.  A dietary supplement marketer can make Authorized Health Claims for their product only if the claim mirrors the CFR.

Qualified Health Claims are also initiated by a petition to FDA.  In this case, however, FDA evaluates the information based on the totality of the scientific evidence.  If FDA agrees with the petition, it issues a letter of “enforcement discretion” to the petitioner.  The qualified claims are available for use on any food or dietary supplement product meeting the enforcement discretion conditions specified in the letter.

The term “qualified” in this context means limited, or less than complete.

If you want to see the status of any petitions that have been made to FDA, you can go to Qualified Health Claims.  There you can see:

• Qualified Health Claims: Letters of Enforcement Discretion
• Qualified Health Claims: Letters of Denial
• Qualified Health Claims: Withdrawn
• Electronic Submission of Health Claim Petitions and Notifications
• Search Qualified Health Claim Petitions Open for Comment

Structure / Function Claims are not considered health claims.  They describe the role of a nutrient or dietary ingredient intended to affect normal structure or function in humans, but not with a specified disease or dysfunction.

Like the bridge shown here, the human body needs constant maintenance.  If there is not enough paint to protect the support structure from corrosion, the life span of the bridge will be shortened.  Paint will not fix a bridge that is already corroded.  The same is true for dietary supplements.

Structure/function claims may describe:

• the role of a nutrient or dietary ingredient intended to affect normal structure or function in humans,
• the means by which a nutrient or dietary ingredient acts to maintain structure / function, for example, “antioxidants maintain cell integrity,”
• general well-being from consumption of a nutrient or dietary ingredient
• a benefit related to a nutrient deficiency disease (like vitamin C and scurvy), as long as the statement also tells how widespread such a disease is in the US

A marketer who wants to make Structure / Function claims must notify FDA not later than 30 days after the first marketing of the dietary supplement.  In the notification the marketer must certify that it has substantiation for the claim, signed by responsible management.

What should you do if you want to evaluate a particular dietary supplement?

1. Look up the individual ingredients on the label and then check in 21 CFR 101 to see if there are any Authorized Health Claims for those ingredients.
2. Look up the dietary supplement and its ingredients in the Qualified Health Claims FDA webpage cited above to see the status of any Qualified Health Claims.
3. If you don’t see anything about the dietary supplement in question, then the marketer is probably making a Structure / Function Claim.  The company should have documented substantiation of their claim, signed by responsible management.  I would contact the company and ask them for a copy of that substantiation.  You can then make your own evaluation.

Make your evaluation based on the quality of the evidence that you find. 

The types of Evidence that may Substantiate a Claim:

• Animal studies are low quality.
• Human Observational studies are of moderate quality.  These are studies of existing or historical human populations that have different usages of a dietary ingredient.  Beware of the assumption that correlation equals causation.
• Human Intervention studies are of the highest quality.  This means that the patients are sorted randomly into different parallel groups.  Neither the patients nor the evaluators know who is in which group.  The groups receive different interventions, usually including a placebo.

Whatever you do, don't rely on anecdotal evidence.  The placebo effect is very real, and it is very strong.  The Placebo Effect.

Buy your dietary supplements from a well reputed manufacturer.  If possible, the manufacturer should be GMP certified by an ANSI accredited organization.

How about you?  Do you have a similar story?  Comment below.

*A Dietary Ingredient is the active ingredient in a Dietary Supplement.  It could be the actual St. John’s Wort in a Dietary Supplement pill, for instance.  The remainder of the material in the pill might be binders, other dietary ingredients, or flow aids that help to make a consistent tablet.  A Dietary Supplement is the actual finished formulation that will be sold to consumers.