February 2018 Issue

Supplements: A Guide to Safe, Effective Use
By Andrea N. Giancoli, MPH, RD
Today's Dietitian
Vol. 20, No. 2, P. 16

There's no question dietary supplement use is popular in the United States. Per government data taken from the National Health and Nutrition Examination Survey 2011–2012, more than one-half of adult Americans use dietary supplements.1 The Council for Responsible Nutrition (CRN) claims the number of Americans using supplements is significantly higher, asserting that 76% of US adults reported taking supplements in its most recent annual survey released October 2017.2

To be sure, the dietary supplement industry is a multibillion dollar business with the most recent reportable data showing sales estimates reaching $41 billion in 2016.3,4 This should come as no surprise considering close to 56,000 products were estimated to be on the market in 2012, with another 5,560 projected new dietary supplements appearing on shelves every year as reported by the FDA, a stark contrast to a mere 4,000 products available for sale back in 1994.5,6

Dietary supplement products, as defined by the 1994 Dietary Supplement Health and Education Act (DSHEA), are "intended to supplement the diet containing one or more dietary ingredients including vitamins, minerals, herbs or other botanicals, amino acids, and other substances or their constituents."6 According to the CRN survey, consumers have a high degree of confidence in the safety, quality, and efficacy of dietary supplements.2

This is an interesting finding considering the scientific literature has primarily yielded minimal health benefits and even some risks from dietary supplement consumption.7 Indeed, reports of harmful effects from such products have been rising in recent years. Adverse events as reported to the FDA steadily increased from less than 700 in 2008 to nearly 2,500 in 2011.8 Furthermore, researchers from the Centers for Disease Control and Prevention estimate that 23,000 emergency department visits annually are attributed to detrimental effects from dietary supplements. Among the findings were that products to enhance energy and induce weight loss were commonly implicated in cardiovascular symptoms such as chest pain, increased heart rate, and palpitations. Sexual enhancement and body-building products also were associated with adverse cardiac symptoms.9 Equally concerning is that liver toxicity from supplements makes up 20% of hepatotoxicity cases in the United States, per a recent study published in the journal Hepatology. The study authors identified anabolic steroids, green tea extract, and supplements with multiple ingredients as the primary culprits.10

It's important to put this in perspective, as millions of Americans use supplements and don't report negative health effects. With this in mind, the majority of supplements likely are safe for consumption in healthy adults, and some may be helpful for a variety of conditions.4 Vitamin and mineral supplements certainly can help fill gaps in a nutrient-deficient diet. For example, DHA and EPA omega-3 fatty acids may help lower triglycerides and can potentially reduce the risk of CVD.11

The challenge is, how can consumers discern which products are effective and safe to use when perusing the supplement aisle? Before considering such a question, we must first understand how dietary supplements are regulated in this country. The FDA is charged with regulating dietary supplements under DSHEA. Unlike pharmaceuticals, DSHEA doesn't require supplement manufacturers to establish product safety, health benefits, efficacy, quality, or ingredient integrity before going to market. Consequently, mislabeled and/or contaminated products that could cause harm may find their way into consumers' hands. Only after a supplement has been available for sale can the FDA initiate warnings to manufacturers or pull products from sale if they've been found to be harmful or contaminated.

Quality Assurance Programs
To address issues of quality and integrity, in 2007 the FDA released Good Manufacturing Practices (GMP) to which supplement makers are expected to adhere. The GMP program is intended to protect the public by ensuring manufacturers meet quality control standards in the production, labeling, packaging, and storage of goods. Manufacturers are allowed to set their own standards and methods of measuring quality to meet GMP. Companies may choose to set higher quality standards than others, thus there can be much variability. Moreover, with the many thousands of supplement products available to the public, the FDA isn't equipped to ensure GMPs are met for every product.

Fortunately for consumers, there are independent organizations that offer quality certification programs to help and encourage dietary supplement makers to meet higher standards of GMP. As part of these programs, dietary supplements are tested for ingredient legitimacy and integrity, product potency, and contamination. Each program issues corresponding marks or seals of certification that can be displayed on participating manufacturers' product labels to alert consumers that the dietary supplement meets the corresponding organization's tests for quality (see table).

Role of Dietitians
RDs need to keep in mind, as well as to relay to clients and patients, that these programs don't evaluate product safety or efficacy. They only offer assurances that a product is accurately labeled, free from contaminants, and is made with the ingredients listed on the packaging. That being said, instructing clients and patients to check product labels for one or more of these quality seals of certification is a first step in evaluating product integrity.

When considering whether to suggest supplements for clients or patients, RDs can take direction from the Academy of Nutrition and Dietetics' (the Academy) Guidelines Regarding the Recommendation and Sale of Dietary Supplements that can be found on the Academy's website EatRight.org. The following is a sampling of key guidelines for dietitians.

Recommendations for dietary supplements should be based on a thorough review of the currently available scientific evidence. Careful consideration should be given to the following:

• level of currently available scientific evidence;
• demographic characteristics (eg, age, gender, ethnicity, and economic status);
• disease states;
• clinical parameters (eg, blood pressure, weight, and biochemistries);
• medications (prescription and over the counter)—some supplements can interfere with pharmaceuticals; and
• risks and/or benefits.

The dietetics professional is responsible for reporting any adverse reactions by using available FDA documentation procedures. Referring health care professionals should be notified of any adverse reactions.

Dietary supplementation should be complementary to diet. Efforts to improve diet to meet nutrient needs should be made before, or in conjunction with, dietary supplementation.

The dietetics professional may make dietary supplements available to patients/clients with respect to the unique nutrition needs of the individual (based on Principle #8 of the Academy's Code of Ethics). The dietetics professional needs to do the following:

• avoid bias to ensure patient/client's choice in selection and use of dietary supplement (ie, allow patients to make selections and decisions to use a dietary supplement without provider bias); and
• provide appropriate educational materials to patients/clients about dietary supplements.

Useful Resources
ConsumerLab.com and the Natural Medicines Comprehensive Database (NMCD) are great resources RDs can use when researching and evaluating dietary supplements for clients, patients, and the general public. ConsumerLab.com has conducted quality testing for more than 4,400 dietary supplements of various brands and published detailed reports on its findings. The NMCD has released about 1,100 evidence-based monographs evaluating natural ingredients found in supplements, such as kava and glucosamine, providing extensive information related to safety, efficacy, drug interactions, and adverse effects. (Access to full reports and monographs requires an annual subscription.)

When advising clients, patients, health care professionals, and the public at large, the bottom line is that RDs should provide education about the implications of dietary supplement regulations and GMP, and instruct clients to, at a minimum, inspect labels for at least one of the quality seals of certification. Dietitians can further empower consumers to educate themselves by contacting manufacturers to request information about the efficacy, safety, and quality of their products.

— Andrea N. Giancoli, MPH, RD, is a freelance nutrition and health writer based in Hermosa Beach, California.


1. Kantor ED, Rehm CD, Du M, White E, Giovannucci EL. Trends in dietary supplement use among US adults from 1999-2012. JAMA. 2016;316(14):1464-1474.

2. Dietary supplement usage increases, says new survey. Council for Responsible Nutrition website. http://www.crnusa.org/newsroom/dietary-supplement-usage-increases-says-new-survey. Published October 19, 2017.

3. Nutrition Business Journal. Condition specific report 2017. http://images.info.newhope.com/Web/NewHopeNaturalMedia/%7Bfea469b1-a84e-4720-b875-5711f98e6718%7D_Condition_Specific_ToC_ExecutiveSummary.pdf

4. Dietary supplements — safe, beneficial and regulated. Council for Responsible Nutrition website. http://www.crnusa.org/resources/dietary-supplements-safe-beneficial-and-regulated

5. US Department of Health and Human Services, Food and Drug Administration, Center for Food Safety and Applied Nutrition. Dietary supplements: new dietary ingredient notifications and related issues: guidance for industry. https://www.fda.gov/downloads/Food/GuidanceRegulation/GuidanceDocumentsRegulatory
. Published August 2016.

6. US Government Publishing Office. Dietary Supplement Health and Education Act of 1994, Public Law 103-417. https://www.gpo.gov/fdsys/pkg/STATUTE-108/pdf/STATUTE-108-Pg4325.pdf. Published October 25, 1994.

7. Cohen PA. The supplement paradox: negligible benefits, robust consumption. JAMA. 2016;316(14):1453-1454.

8. US Government Accountability Office. Dietary supplements: FDA may have opportunities to expand its use of reported health problems to oversee products. https://www.gao.gov/products/GAO-13-244. Published March 18, 2013.

9. Geller AI, Shehab N, Weidle NJ, et al. Emergency department visits for adverse events related to dietary supplements. N Engl J Med. 2015;373(16):1531-1540.

10. Navarro VJ, Khan I, Björnsson E, Seeff LB, Serrano J, Hoofnagle JH. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363-373.

11. Omega-3 fatty acids: fact sheet for health professionals. National Institute of Health, Office of Dietary Supplements website. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/. Updated November 2, 2016.