July 2019 Issue

Ask the Expert: Supplement Savvy
By Toby Amidor, MS, RD, CDN
Today’s Dietitian
Vol. 21, No. 7, P. 8

Q: How can I tell which supplement brands are the best to recommend to my clients and in what forms should they purchase them?

A: Consumers face much confusion as to what forms of supplements they should take and how those supplements should be stored. RDs can help clients make the safest, most healthful, and most efficacious choices from the wide range of supplements on the market.

Third-Party Verification
Supplements aren’t required to undergo testing to ensure they contain substances in the amounts listed on the labels, but third-party certifications can provide some reassurance. Dana Angelo White, MS, RD, ATC, a certified athletic trainer and sports dietitian at Quinnipiac University in Hamden, Connecticut, recommends looking for third-party verifications, such as USP Verified, NSF International, ConsumerLab.com, Informed Choice, and NSF Certified for Sport, on supplement labels. “Independent testing can be helpful in making recommendations to patients [taking] medication [and] with preexisting medical conditions, [as well as] athletes subject to drug and banned substance testing, she says. “While these verification systems don’t ensure safety and effectiveness, they help give some reassurance that what you see listed on the label is in fact what is in the product.”

Refrigerated vs Nonrefrigerated Supplements
Contrary to popular belief, most supplements don’t require refrigeration, and, in fact, shouldn’t be refrigerated, as the humidity can lead to the degradation of shelf-stable supplements’ water-soluble components. Heat also can damage supplements, so most should be stored in a cool, dry place.1 Liquid supplements such as multivitamins, probiotics, and minerals typically must be refrigerated per the instructions on the bottle, as they tend to have a shorter shelf life than their nonliquid counterparts.

For probiotic supplements, some, such as those containing freeze-dried organisms (usually sold in tablet or capsule form), don’t need to be refrigerated, but also shouldn’t be exposed to heat above room temperature.2 With any supplement, following the manufacturer’s directions for storage will ensure quality and efficacy is maintained.

Whole Food Supplements
Whole food supplements claim to provide nutrients in forms as close as possible to how they’re found in nature, but this terminology is unregulated. For example, whole food supplement manufacturer Perfect Supplements argues that “pure, nutrient dense, whole foods are far more effective than synthetic supplements, which is why we aim to create whole food supplements whenever possible.”3 ConsumerLab.com says whole food supplements may include some fiber and phytochemicals not found in conventional supplements that may be beneficial. However, the organization points out that whole food supplements don’t necessarily contain more vitamins and could contain lower levels than conventional supplements. In addition, ConsumerLab.com has found lead contamination in some whole food supplements.4

Organic Supplements
The USDA Organic seal on supplements means that foods or food derivatives in the supplements are grown and processed according to federal organic guidelines. These products don’t include GMOs, antibiotics or growth hormones, synthetic fertilizers, pesticides, irradiation, or sewage sludge, and livestock-derived ingredients come from animals fed 100% organic feed and that were given access to the outdoors. As organic supplements don’t differ nutritionally from their conventional counterparts and tend to be more expensive, RDs should defer to each client’s preferences to determine whether organic supplements are the right option for them.

Methylated Supplements
Methylated supplements are a newer category that targets consumers with a genetic mutation that can inhibit the conversion of dietary nutrients such as folic acid into cofactors in methylation—a body process that affects everything from eye and liver health to DNA and neurotransmitter production. The popularity of these supplements is due in part to the increase in consumers aware of their genetic makeup through at-home genetic testing, but their safety is questionable; it’s easy for consumers to overdo methylate intake, leading to insomnia, rash, anxiety, headache, mood swings, and allergylike symptoms.5 It’s essential for consumers to consult with a physician and/or RD before trying these supplements.

— Toby Amidor, MS, RD, CDN, is the founder of Toby Amidor Nutrition (http://tobyamidornutrition.com) and a Wall Street Journal best-selling author. Her four cookbooks are Smart Meal Prep for Beginners, The Easy 5-Ingredient Healthy Cookbook, The Healthy Meal Prep Cookbook, and The Greek Yogurt Kitchen. She’s the nutrition expert for FoodNetwork.com and a contributor to U.S. News Eat + Run, Muscle&Fitness, and Shape.com.


1. Gillespie C. Do vitamins expire? Healthline website. https://www.healthline.com/health/food-nutrition/do-vitamins-expire. Updated January 22, 2018.

2. ConsumerLab.com answers. ConsumerLab.com website. https://www.consumerlab.com/answers/which-probiotics-require-refrigeration/probiotic_refrigeration/. Updated August 8, 2017.

3. Whole food supplements. Perfect Supplements website. https://www.perfectsupplements.com/Whole-Food-Supplements-s/55.htm

4. ConsumerLab.com answers: is it better to get vitamins from foods or supplements? ConsumerLab.com website. https://www.consumerlab.com/answers/is-it-better-to-get-vitamins-from-foods-or-supplements/natural_vs_synthetic_vitamin/. Updated April 12, 2019.

5. Kresser C. Treating methylation: are we over-supplementing? Kresser Institute website. https://kresserinstitute.com/treating-methylation-supplementing/. Published June 21, 2017.