A note about dietary supplements
When you go down the pharmacy aisles or see marketing online, can you tell the difference between dietary supplements and drugs? Why is this distinction important? When your doctor asks for a list of your medications, do you know it’s important to include all supplements and over-the-counter products you buy?
Let’s get into some nitty gritty about the laws that surround dietary supplement regulation versus drug regulation! First, let me provide a definition to help us understand the difference between a dietary supplement and a drug (1):
(1) dietary supplement - a product that (1) is intended to supplement the diet; (2) contains one or more of the following dietary ingredients: vitamins, minerals, herbs or other botanicals, amino acids, and other substances or their constituents; (3) is intended to be taken by mouth as a pill, capsule, powder, tablet, or liquid; and (4) is labeled on the front panel as being a dietary supplement.
(2) drug - a product intended to diagnose, mitigate, treat, cure, or prevent a disease or specific class of diseases.
So if we break it down, a dietary supplement should do just that, supplement the diet while a drug is for a specific disease. Below we’ll also learn how the evidence for safety and efficacy of drugs must be demonstrated before they can be marketed to the public, while this is not the case for dietary supplements.
Have you ever seen a product labeled as a dietary supplement that states on the packaging “improves memory” or “builds strong bones”? Why is this not a drug? The key here is that the health claim did not reference a specific disease and is considered a structure/function health claim. Going one step further from our definitions above, this claim should be related to its function in our diet (good opportunity for me to note that I am not a lawyer and I provided references for these statements with intention to represent this information as best I can for information purposes!). As a consumer, we can empower our health decisions by educating ourselves about the levels of evidence required to market a dietary supplement with structure/function claims versus levels of evidence required to market a drug with disease claims.
The Dietary Supplement Health and Education Act of 1994 does not require pre-marketing approval of dietary supplements. In practical terms, this means a manufacturer of dietary supplement registers with the FDA and can produce and distribute their product for sale. There are regulations around the manufacturing processes and inspections of facilities for dietary supplements, as well as safety reporting requirements. However, this lack of premarket approval translates into a “safe until proven otherwise” situation. The burden of demonstrating that a dietary supplement is unsafe is on FDA and action to remove it from the market only occurs after harm occurs.
Has a consumer ever been harmed by taking a dietary supplement according to the labeled instructions? The short answer is: Yes. Liver toxicity has been reported with several dietary supplements (2). Workout supplements have been connected to heart toxicity (3).
Consumers can learn about specific safety concerns related to dietary supplements on the FDA website:
Drugs, as prescribed by a physician after FDA approval, or those purchased in the pharmacy and required to have a Drug Facts Label, must provide evidence of safety and efficacy to the FDA prior to being marketed to the public. Part of the review process includes manufacturing practices and inspection of the facilities the produce the drug.
My takeaways:
The decision to take a dietary supplement requires care and attention. Questions to ask:
What purpose will this supplement serve? In some cases, your doctor may have detected a nutritional deficiency and prescribe the supplement to correct this (example: vitamin B12)
Can I select a dietary supplement that has third party validation for ingredients?
Am I trying to achieve an outcome better served by different lifestyle choices - instead of caffeine can I make sure to practice better sleep hygiene? instead of an “immune booster” can I incorporate more whole foods and exercise? instead of a fiber supplement can I get more fibrous foods in my meals?
References:
(1) Bodie, Agata (2021, September 20). Regulation of Dietary Supplements: Background and Issues for Congress (CRS Report No. R43062)
(2) Navarro VJ, Khan I, Björnsson E, Seeff LB, Serrano J, Hoofnagle JH. Liver injury from herbal and dietary supplements. Hepatology. 2017 Jan;65(1):363-373. doi: 10.1002/hep.28813. Epub 2016 Nov 17. PMID: 27677775; PMCID: PMC5502701.
(3) de Jonge, M.L.L., Kieviet, L.C., Sierts, M. et al. Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine. Cardiovasc Toxicol 23, 1–9 (2023). https://doi.org/10.1007/s12012-022-09777-z