Knowing which supplement to buy can be difficult. Complex vitamin and mineral labels and mixtures confuse consumers. Learn more about supplements, FDA regulation, and how to find quality brands.
What are Dietary Supplements?
Oral food supplements contain concentrated vitamins and minerals (1). Often called micronutrients, these medical food products keep the body healthy (1). A well-rounded diet provides all the nutrients needed to maintain good health (1). But sometimes poor dietary habits or illnesses require supplementation to restore micronutrient levels (1).
Pharmacies and grocery stores sale dietary supplements or vitamins and minerals. Manufacturing companies market oral food supplements as being advantageous to health. Many labels on vitamins and minerals claim to enhance well-being.
Does the FDA Approve Supplements?
The FDA regulates but does not ‘approve’ supplement production (3). The regulation of supplements differs to ‘approval’ of drugs (3). Pharmaceutical drug approval involves strict FDA review for the development, testing, and sale of medication (3). The FDA requires less for supplements because they are classified as food products (3).
The US passed the first regulation on dietary supplements in 1994 (3). Dietary supplements are classified as medical food products (3). Manufacturers do not test supplements for safety or effectiveness before selling. For example, companies may not determine if the supplement works to prevent or improve specific medical conditions.
How Does the FDA Regulate Dietary Supplements?
Any supplements with ingredients introduced before 1994 likely have decades of human and animal testing, clinical trial, and post-market data. The historical data suggest safety and effectiveness for use in the US. Unless otherwise determined, the FDA trusts companies to make and label its products truthfully and honestly.
Any supplement with new dietary ingredients introduced after 1994 require a premarket safety notification. Premarket safety notifications require proof of checks and balances for supplement manufacturing and labeling. Companies must show consistent production, meeting certain FDA chemical quality standards for the supplement:
- Identity
- Purity
- Strength
- Composition
These help provide consumers with quality supplements free from contamination. The FDA may also inspect the manufacturing facility to ensure public safety. Prior to selling the new dietary products, companies submit labeling to the FDA:
- Nutrition information
- Serving size
- Nutrition or supplement facts
Some supplement companies sell products in the US before completing the premarket submission. But the safety notification must be completed within 75 days and align with current good manufacturing practices (cGMP). Additionally, manufacturers must monitor product sales for any adverse medical events or complaints.
If a supplement receives complaints of medical reactions, there could be a risk to public health. The FDA investigates adverse health reports to determine the risk to safety. If required, the FDA removes the supplement from the market to keep the public safe.
Supplement Your Knowledge With the FDA
The FDA launched a ‘Supplement Your Knowledge’ initiative to educate the public about supplements (4). The website provides dietary supplement fact sheets, videos, and risk-benefit information on vitamins and minerals (4). The content ranges from consumer information to in-depth continuing medical education (CME) programs developed in collaboration with the American Medical Association (AMA).
How are Supplements Categorized?
There are many ways to categorize vitamins and minerals. In fact, some people may find the many varieties, brands, and types of supplements overwhelming. These dietary supplements claim to treat, cure, or improve health and well-being (1, 2). The micronutrients sold on the shelves come as tablets, soft gels, powders, liquids, capsules, or gummies (1, 2).
Looking at Chemical Ingredients in Supplements
The FDA classifies supplements by chemical composition (2):
- Vitamins: Micronutrients sold as multivitamins, essential vitamins, or individual non-essential vitamins.
- Minerals: Micronutrients sold as essential and non-essential minerals or trace elements.
- Botanicals or Herbs: Supplements sold as dietary food to enhance or aid health conditions.
- Botanical Compounds: Dietary supplements sold as a compound to treat medical conditions.
- Amino Acids: Dietary supplements sold with one or more amino acids.
- Live Microbials: Also called probiotics, products sold with active or live cultures that claim to benefit the body.
Clinical Classifications for Supplements
The body needs many vitamins and minerals to properly function, but 23 micronutrients are historically considered essential (1). The body can make or store enough of the nonessential micronutrients to function. But essential vitamins and minerals must be replenished from the diet (1) each day.
Dietary supplements fall into two categories (1):
- Essential Supplements: The product contains one or more of the 23 essential micronutrients.
- Nonessential Supplements: The product ingredients are not required for health, or the body readily makes/stores the ingredient (1).
Vitamins as Essential Micronutrients
Micronutrients absorbed from meals or supplements on a regular basis keep the body healthy (1). Micronutrient solubility differs between fat-soluble or water-soluble types (1). The solubility type also reflects how the body absorbs the micronutrient (1). The 13 essential vitamins include (6):
- Vitamin A
- Vitamin C
- Vitamin D
- Vitamin E
- Vitamin K
- Thiamine
- Riboflavin
- Niacin
- Pantothenic acid
- Biotin
- Vitamin B6
- Vitamin B12
- Folate
The water-soluble vitamins include vitamin C and all the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, folate) (1). Water-soluble vitamins are easily absorbed and excreted from our body.
Fat-soluble vitamins enter the body through fat digestion (1). Vitamins A, D, E, and K are fat soluble. People with difficultly absorbing fat because of medication or health-related conditions are at risk of developing fat-soluble vitamin deficiencies (1).
Trace Elements
Ten of the 23 essential micronutrients are trace elements or minerals. These trace elements make up less than 0.01% of our body weight (1). Mineral deficiency is uncommon in countries like the US. But iodine, zinc, and selenium deficiencies may occur in developing countries because of limited food resources (1).
A healthy diet usually provides plenty of essential minerals to maintain body function (1). But certain trace elements vary in the soil and plants depending on geographical location (1). The 10 essential minerals to help the body function include (1, 6):
- Chromium
- Cobalt
- Copper
- Fluoride
- Iodine
- Iron
- Manganese
- Molybdenum
- Selenium
- Zinc
Interestingly, the body still requires many of the ‘nonessential’ minerals to function. Some common examples include sodium, potassium, calcium, and phosphorus (1). Many of the nonessential micronutrients play primary roles in cellular, tissue, and body function (1, 6).
For example, potassium is the most abundant positively charged molecule or cation found inside cells. Normal cell function ceases without potassium. But potassium is not considered an essential micronutrient. Nonessential minerals are often present in large quantities within the body or absorbed readily from the diet (1).
Can You Trust Supplement Brand Quality?
For consumers, purchasing supplements becomes troublesome. Many food supplements now contain a mixture of botanical and herbal products (8). Many of the ingredients come from all over the world (8). And the list of micronutrients continues to grow each year (8).
The Office of Dietary Supplements at the National Institutes of Health (NIH) maintains a factsheet listing for many dietary supplements (6). The listing includes micronutrients, herbs, botanicals, and probiotics (6). NIH also issues safety, quality, and guideline information on food supplements (7).
Each micronutrient has a Recommended Dietary Allowance (RDA) or daily dose that meets the body’s needs to stay healthy (7). The RDA value is useful for up to 98% of healthy individuals (7). These values provide daily requirements based on age, gender, and physiological need.
With various chemicals and ingredients contained in these supplements, the information provided on the label remains confusing (8). Both customers and doctors require the product information to be accurate (8). But sometimes, the chemical composition and label does not match (8).
Challenges of Testing Supplements for Quality
Consistent, high-quality testing methods for vitamins, minerals, and herbs remains a challenge (8). Some testing platforms and methods require long periods of time (8). Other chemical testing processes use expensive resources (8).
To complicate matters, scientists do not always agree on which chemicals will act as the reference standard (8). In the absence of scientific agreement, most supplements lack high-quality materials to compare the vitamin or mineral against (8).
AI Integrates Big Data for Supplements
Globally, large amounts of information exist on supplements. Various databases fill up with clinical studies, scientific articles, and regulatory reports. The monitoring and surveillance requirement for supplements continues to generate massive amounts of untapped scientific and medical data (8).
The information being generated contains real-use experiences on dietary supplement formulations. If organized, this data may be useful for doctors and consumers (8). But access to big data remains a challenge (8). The information is often spread out across different databases or contained in unsearchable formats (8).
Artificial Intelligence (AI) big data mining techniques may hold promise in the future. Some healthcare companies already leverage AI-power to help educate people on vitamins and minerals. Examples include the integrated DIetary Supplement Knowledge base (iDISK) (14) and SUPP.AI (15).
These databases and cloud-based solutions may reveal trends or useful patterns relating to supplements and medical interactions (8, 15).
Where Can You Find Trustworthy Supplement Brands?
The FDA requires all supplement companies to follow GMP (13). Although these manufacturing practices help keep production consistent and reduce the chances of impurity, consumers may want additional quality testing (13).
Third-party organizations test the quality of supplements (9, 10, 11, 12). When a product passes certain quality standards, the supplement displays a seal on the label (13). Looking for one of these seals may improve the chance of the ingredients matching the label:
- USP (12)
- ConsuerLab.com (10)
- NSF International (11)
- BSCG (9)
Keep in mind that the third-party seals do not mean the supplement is safe or effective (13). The seal only indicates that the product passed quality testing for (13):
- Ingredients matching the label
- Products manufactured under GMP
- Supplements not being contaminated
Before taking or discontinuing any medication or supplement, speak with your healthcare provider about your health.
References
- Salwen, M. J., “Vitamins and Trace Elements”, Chapter 26 in McPherson, R. A., Pincus, M. R., eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods, 22nd edition, Elsevier Saunders, Philadelphia, PA, 2011.
- FDA 101: dietary supplements. US Food & Drug Administration. Last reviewed on June 02, 2022. Accessed on March 15, 2024. https://www.fda.gov/consumers/consumer-updates/fda-101-dietary-supplements
- Questions and answers on dietary supplements. US Food & Drug Administration. Last reviewed February 21, 2024. Accessed on March 15, 2024. https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements
- Supplement your knowledge. US Food & Drug Administration. Last Reviewed May 25, 2022. Accessed on March 15, 2024. https://www.fda.gov/food/information-consumers-using-dietary-supplements/supplement-your-knowledge
- Vitamins and minerals for older adults. National Institute on Aging. Last reviewed January 02, 2021. Accessed on March 15, 2024. https://www.nia.nih.gov/health/vitamins-and-supplements/vitamins-and-minerals-older-adults
- Dietary supplement fact sheets. National Institutes of Health. Office of Dietary Supplements. Accessed on March 15, 2024. https://ods.od.nih.gov/factsheets/list-all/
- Nutrient Recommendations and Databases. National Institutes of Health. Office of Dietary Supplements. Accessed on March 15, 2024.https://ods.od.nih.gov/HealthInformation/nutrientrecommendations.aspx
- Durazzo A, Sorkin BC, Lucarini M, Gusev PA, Kuszak AJ, et. al. Analytical challenges and metrological approaches to ensuring dietary supplement quality: international perspectives. Frontiers in Pharmacology. 2022;12(7):714434. doi: 10.3389/phar.2021.714434.
- Banned Substances Control Group (BSCG). Accessed on March 15, 2024. https://www.bscg.org/history-of-bscg
- ConsumerLab.com Accessed on March 15, 2024. https://www.consumerlab.com/about/
- National Sanitation Foundation (NSF). Accessed on March 15, 2024. https://www.nsf.org/about-nsf
- United States pharmacopeia (USP). Accessed on March 15, 2024. https://www.quality-supplements.org/about-us
- Dietary supplements: what you need to know. National Institutes of Health. Office of Dietary Supplements. Last Updated on January 4, 2023. Accessed on March 15, 2024. https://ods.od.nih.gov/factsheets/WYNTK-Consumer/
- SUPP.AI Accessed on March 15, 2024. https://supp.ai
- Rizvi RS, Vasilakes J, Adam TJ, Melton GB, Bishop JR, et. al. iDISK: the integrated DIetary Supplements Knowledge base. J Amer med Info Ass. 2020;27(4):539-548. doi: 10.1093/jamia/ocz216.
