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Passport to Whole Health: Chapter 15

Chapter 15.  Biologically-Based Approaches: Dietary Supplements

An icon of two pill bottles, the larger of which has a leaf on it symbolizing its natural qualities.

The History of Medicine:

2000 BC—Here, eat this root.

1000 BC—That root is heathen; say this prayer.

1850 AD—That prayer is superstition, drink this potion.

1940 AD—That potion is snake oil, swallow this pill.

1985 AD—That pill is ineffective, take this antibiotic.

2000 AD—That antibiotic is artificial.  Here, eat this root.


Dietary supplements are compounds that people take orally in addition to what they eat, including vitamins, minerals, herbals, amino acids, and a variety of other products.[907]  A 2017 survey found that 76% of U.S. adults (170 million people) reported taking at least one dietary supplement in the past year, compared to 64% in 2008.[908]  75% said they were taking multivitamin/mineral supplements (MVMS), 38% take specialty supplements, 29% take herbals, 22% take sports nutrition supplements, and 15% take supplements for weight management.  Earlier surveys from 1999-2012 found that about 52% of U.S. adults used any supplements.[909]  Supplement sales have been a 6.4% overall sales growth each year, and projections are that it could rise form $125 billion in 2018 to over $210 billion by 2026.[910] 

34% of all U.S. adults simultaneously take dietary supplements and prescription medications,[911] but as many as 42% of people who take dietary supplements do not report their use to their health care providers.[912]  Use rates are higher in certain groups, particularly older adults.[913],[914]  Women who are highly educated are the most likely to take supplements.5

A survey of primary care patients in the Philadelphia VA Medical Center found that 75% of patients used supplements, and 18% of those used them as substitutes for medications, largely due to medication costs.[915]  74% of Servicemembers use supplements at least once per month, and 49% use them daily.[916]  In a 2015 survey of 131 VA sites, nine reported offering herbal remedies to Veterans in some fashion, and 44 said they provided “dietary and nutritional supplements” in general.[917]

What Are People Taking and Why?

Multivitamin/Mineral Supplements.  The World Health Organization estimates over 2 billion people worldwide are deficient in essential vitamins and minerals.[918]  Many Americans take MVMS, reporting that they do so primarily to preserve wellness.  However, recent research findings have been mixed.  A number have failed to show that MVMS have significant benefits for all-cause mortality, cancer prevention, or other health concerns.[919],[920],[921],[922]  One 11-year study did note an 8% reduction in total cancer cases for those on MVMS.15  Use among men may be linked to a higher probability of healthy aging.[923]  A recent systematic review noted that while people who followed carbohydrate-restricted diets did not become deficient, their intakes of thiamine, folate magnesium, iodine, calcium, and iron all decreased by 10-70%.[924]  It may be that the people who can most easily afford to take them are the ones that do not need them as much.[925]  Fortunately, reviews do not find safety risks related to long-term MVMS use.[926]  It does not result in excess intake, even if a person is also eating fortified foods.

Herbal Supplements.  Herbal supplement (botanical) sales have risen steadily in recent years.  Total sales increased by 9.4% to over $8.8 billion in 2018, one of the highest yearly increases in 20 years.[927]  Some of the biggest growth has been for Cannabidiol (CBD) oil, mushrooms (mycomedicinals), and immune health products.21

If you are unfamiliar with herbal remedies, it is helpful to first focus your attention on supplements that are most popular.  “Popular” is not necessarily synonymous with “proven effective,” but the best-sellers are more likely to come up during patient visits.  The lists below include popular supplements and some of the main reasons people take them, but this is not to say that all of these uses are supported by research (though some are).  More information on specific supplements can be found using the Resources section at the end of this chapter. 

The following list notes the top-selling herbal supplements in the U.S. for mainstream markets (grocery stores, mass merchandise, Walmart, Costco, etc.) as well as some of the main reasons people take them21:

  1. Horehound—member of the mint family that is the main ingredient of many cough drops and lozenges
  2. Echinacea—prevention and treatment of colds
  3. Turmeric—a popular and safe herbal anti-inflammatory
  4. Elderberry—respiratory infections and sore throats
  5. Green tea—stimulant, cancer preventative
  6. Ginger—anti-inflammatory, anti-emetic
  7. Ivy leaf—chronic inflammatory bronchial conditions
  8. Garlic—blood pressure, infection prevention
  9. Fenugreek—herb popular in India for digestive function, improving lactation
  10. Black cohosh—hot flashes in menopause
  11. Saw palmetto—prostate health 
  12. Flaxseed/Flax oil—seed used as a fiber source and for cholesterol management; oil is a source of small amounts of omega-3 fatty acids
  13. Yohimbe—male sexual function
  14. Pumpkin—prostate health
  15. Garcinia—a fruit used for weight loss and exercise performance
  16. Aloe—skin burns and digestive health, depending on which part of the plant is used
  17. Wheatgrass—used as overall tonics, as well as for digestive support and/or cardiovascular health
  18. Cinnamon—used for blood sugar balance
  19. Valerian—sleep remedy
  20. Milk thistle—liver concerns

Natural products markets, which include supplement retail outlets such as Whole Foods, GNC, and sports nutrition stores, sold the following as the top 20 herbal supplements (note that starred items (*) were also on the preceding list for mainstream markets):

  1. Cannabidiol (CBD)—pain, other inflammation, mood.  This supplement is very popular, but marketing has far outpaced any research showing benefits.[928]
  2. *Turmeric
  3. *Elderberry
  4. Wheatgrass*/Barley—used as overall tonics, as well as for digestive support and/or cardiovascular health
  5. *Flaxseed/Flax oil
  6. *Aloe
  7. Ashwagandha—adaptogen used to boost energy levels, immunity, and overall function.  An Ayurvedic remedy.
  8. *Milk thistle
  9. *Echinacea
  10. Oregano—anti-infective
  11. Psyllium—stool softener
  12. Maca—adaptogen used to support energy levels, immunity, and overall function
  13. Medicinal mushrooms – adaptogen, cancer-prevention, immune support
  14. *Saw palmetto
  15. Cranberry—Urinary tract infections
  16. *Garlic
  17. *Valerian
  18. Echinacea/Goldenseal combo—prevention and treatment of colds
  19. Nigella (black cumin)—immune support, allergies
  20. Horsetail—urinary concerns and edema

The following non-herbal, non-vitamin, and non-mineral supplements have also become more popular in the past 5 years5,7:

  • Omega-3s (fish oil, alpha linolenic acid from flaxseed)—anti-inflammatory, source of essential fatty acids, mood disorders
  • Omega-6 fatty acids—some omega 6s, like gamma linolenic acid (GLA) may have benefits for conditions such as eczema[929] and rheumatoid arthritis,[930] while conjugated linoleic acid seems to modestly reduce body fat mass[931]
  • Omega-9 fatty acids—monounsaturated fatty acids like oleic acid seem to improve insulin sensitivity and decrease inflammation[932]
  • Coenzyme Q10—used to boost energy, as well as to prevent or treat high blood pressure, heart failure, and migraines[933],[934]
  • Probiotics—beneficial microbes that are ingested to influence the microbiome (bacteria and other microorganism population) of the gut.  For more on probiotics, see Chapter 8, “Food & Drink.”)
  • Methylsulfonylmethane (MSM)—anti-inflammatory, used for joint and muscle pain[935]

Use of other supplements, including glucosamine and chondroitin sulfate (used for joint health), fiber, grape seed (antioxidant, used for poor vein function), quercetin (used as an antihistamine, to lower cholesterol, and to help with prostate conditions), and soy (used for menopausal symptoms) remained stable over the past several years.  While not mentioned in the NHANES 2012 data, melatonin, which is now on the VA formulary, is quite popular for sleep-related concerns.

Why People Take Supplements.  According to a 2011 survey of 1579 adults, people most commonly take supplements in order to[936]:

  1. Feel better overall (41%)
  2. Improve energy levels (41%)
  3. Boost immune function (36%)
  4. Improve digestion (28%)
  5. Prevent heart disease (28%)
  6. Relieve pain (26%)
  7. Improve mental functioning (25%)
  8. Help with sleep (24%)
  9. Help with staying awake or getting a quick energy boost (24%)
  10. Lower cholesterol (21%)
  11. Manage weight (20%)
  12. Prevent cancer (19%)
  13. Address menstrual or menopausal conditions (18%)
  14. Manage blood pressure (16%)
  15. Build muscle (14%)
  16. Treat arthritis (13%)
  17. Improve mood (12%)
  18. Improve athletic performance (11%)
  19. Slow aging (11%)
  20. Improve appearance (11%)
  21. Manage blood sugars (9%)
  22. Treat skin problems (5%)
  23. Improve sexual function and drive (5%)
  24. Reduce effects of altitude (1%)

The VA’s Integrative Health Coordinating Center (IHCC) has a nutraceuticals working group that continues to explore which dietary supplements would be appropriate for the VA formulary. 

Choosing Supplements

As with all complementary and integrative health (CIH) approaches, you can choose whether or not to take a given supplement based on the ECHO criteria (Efficacy, Costs, Harms, Opinions) as outlined in Chapter 14.  Here are a few general tips to keep in mind:

  • Know what has specifically been studied.  Search PubMed for trials.  When you review research, make sure it gives appropriate details about specifically what was studied.  For example, does a study of an herbal tell you the Latin name of the plant used, the parts of the plant used, and the solvent those parts were dissolved in?  If alcohol is used (e.g., in a tincture), different substances will be dissolved than if water is the solvent (e.g., in a tea or decoction).
  • Be familiar with different supplement information sources.  Always ask people where they get their supplement information.  Check out those sources yourself, so you have a sense of how reliable they are.  It can help to build up your own resource list of favorites, to guide patients.  (The Resources section at the end of this chapter for some suggestions.)
  • Consider costs and insurance coverage.  Most supplements are not in the VA formulary; this may lead Veterans to choose other CIH approaches over dietary supplements.  Some exceptions that are on the formulary include various vitamins and minerals (e.g., vitamin D3), melatonin, and omega-3s.  There are various wholesale sites online which may be cheaper than local stores and allow for people in rural areas to access supplements.
  • Ask your patients about their experiences.  Why do they take what they do?

Supplement Safety

It is important to be able to discuss supplements’ efficacy, and it is just as important to discuss safety.  In general, supplements seem to be comparable to, if not much better than, medications when it comes to safety profile.  However, safety regulations are much more stringent for medications.  This was the case with the removal of the weight loss supplement ingredient Ephedra in 2004, years after problems had begun to be reported. There can be a lag between the appearance of adverse effects and the removal of a harmful product.

It is important to ensure that people are well-informed about the supplements they are taking; many are not.  A 2020 survey of 2,623 preoperative patients at 6 different U.S. military medical centers found that[937]

  • 18% of them were taking supplements associated with an increased bleeding risk
  • 90% were not aware of any potential side effects
  • 97% were unaware of potential interactions with their medications

There are tens of thousands of different supplements on the market.  They are marketed as capsules, softgels, liquids, and powders; even food bars and drinks might be considered supplements, depending on their ingredient lists.  Part of the challenge of advising patients about them—and studying them—is that there is a great deal of variation in the forms they take.  This is particularly true for herbals.  Plants can be dissolved in water to make infusions, and more woody parts can be gradually soaked and boiled in water over time to create decoctions.  In addition to being dissolved in water, a plant can also be dissolved in alcohol or glycerin to make a tincture.  Tinctures and infusions of the same botanical can contain different chemical compounds.  Essential oils (used in aromatherapy) are processed in an entirely different way as well.  Chemical contents of supplements made from the same plant can end up being very different depending on how they are processed.

Supplements can also end up being quite different from one another for other reasons.  For herbal remedies, there can be differences in biological effects because of the part of the plant used.  For example, some echinacea supplements will use the plant’s roots, while others will use the above-ground parts.  Even more challenging is that more than one species or subspecies of a plant may be referred to by the same name, even though they may be very different in terms of their biochemical effects.  For example, “ginseng” can refer to Chinese ginseng or American ginseng, which are different species in the Panax genus, or it can refer to Siberian ginseng (Eleuthero) or other plants informally called “ginseng” which are not related to one another at all and contain totally different chemical compounds.

Dietary supplements can be harmful because they contain compounds that are unsafe.  For example, butterbur (used for allergies and migraines) and comfrey (used for inflammation) contain pyrrolizidine alkaloids, which can be carcinogenic and hepatotoxic if not removed.  Supplements may also be unsafe because of the way they interact with foods, medications, or other supplements.[938]  For example, St. John’s wort, which is beneficial in the treatment of depression, interacts with the cytochrome P450 system in the liver, altering the potency of many medications.  Similarly, when certain supplements are taken with warfarin or other blood thinners, risk of complications from bleeding can increase.  Some supplements that may rarely contribute to increased bleeding risk—according to case reports or based upon theoretical concerns—include omega-3s, ginkgo, ginseng, ginger, and garlic.  It is typically suggested that they be stopped at least 7-10 days before surgery, just like nonsteroidal anti-inflammatory medications.  Fiber and calcium supplements can decrease absorption of medications and other supplements if taken at the same time.

As a result of the Dietary Supplement Health and Education Act (DSHEA, often pronounced “de shay”), supplements are treated as foods from a legal standpoint, not as pharmaceuticals.[939]  Manufacturers must prove that they meet Good Manufacturing Practices (GMPs), and they cannot make inaccurate claims about what their products can do.  However, they do not need to prove that their supplement is efficacious; the burden of proof of safety is put on consumers and researchers.  It is usually after products appear in the marketplace that they are monitored for safety and false label claims, as compared to pharmaceuticals, for which regulation is much stricter.

Just as providers should ensure that a given supplement has a low likelihood for adverse effects or interactions, they should also ensure the quality of products being used.  Does a product contain the compounds their labeling claims they do?  Third-party certification, or evaluation of supplement content by a group with no financial ties to supplement manufacturers, can be helpful.  These groups use laboratory analyses independent of Dietary Supplement companies to determine the accuracy of label claims, and to assess for the presence of adulterants or contaminants.[940]  Examples include the following[941]:

Tips for Reducing Risks from Supplements
  1. Most importantly, ensure that patients are telling their health care team about what they are taking.  Simply remembering to ask can make a big difference.  Make sure this is documented in their charts.
  2. Learn about supplements yourself, so that you can offer good advice.  Start with those that are most commonly used, which were listed earlier this chapter.  See the Resources section at the end of this chapter as well.
  3. Remember that products vary.  Just because products contain the same compounds, plants, etc., they are not necessarily equivalent in terms of quality or biochemistry.
  4. Use caution with imported supplements, particularly from China or India; risk of contamination has historically been higher with supplements from these areas. 
  5. While it may mean more work from the clinical end, it is not enough just to know specific compounds or plants and their effects.  Safe supplement use also requires a familiarity with manufacturers and specific products.
  6. A good rule of thumb is to use the specific products that were used in research studies.  It is reasonable to support companies that have actually invested in doing supplement research, as this is, unfortunately, somewhat rare.
  7. Keep interactions in mind.  These might be between drugs and supplements or even supplement-supplement interactions.  “Polyherbacy” is a possibility, just like polypharmacy.  Supplements may have hundreds of different chemical components.  Always consider effects on coagulation.  Work with an online interaction checker that is able to check supplement safety as well; examples are listed at the end of this chapter. 
  8. Make sure your patients are getting good information.  The Internet and health food store clerks are not always reliable sources of information.  It is important to know how to read supplement labels and teach patients to do the same.  A 2019 review of 127 studies found that many consumers do not regularly read product labels, and if they do, many do not understand them.[942] 
  9. Pay attention with specific patient populations.  Supplements may or may not be contraindicated in pregnancy or lactation, or in children and people with liver or kidney failure.  Always be cautious when a person is taking medications with an anticoagulant effect. 
  10. Talk to your local colleagues.  Pharmacists can be excellent sources of information, as can clinicians and other colleagues who have received additional Integrative Health training.  Find out if there are any herbalists or naturopaths in your area as well.  What are their perspectives?  What resources do they use?

Throughout the materials on the Whole Health Library website, whenever supplements are mentioned, you will see the following reminder, referring you back to this chapter:

Note: Please refer to the Passport to Whole Health, Chapter 15 on Dietary Supplements for more information about how to determine whether or not a specific supplement is appropriate for a given individual.  Supplements are not regulated with the same degree of oversight as medications, and it is important that clinicians keep this in mind.  Products vary greatly in terms of accuracy of labeling, presence of adulterants, and the legitimacy of claims made by the manufacturer.

For more on dietary supplements, especially as they relate to Whole Health care of specific patients, refer to “Implementing Whole Health in Your Practice, Part III: Complementary and Integrative Health” on the Whole Health Library website.

  Whole Health Tool: Reading Supplement Labels

If someone asks you about a supplement, look at the container or go online to review the label.  If the label isn’t meeting the requirements below, it may be that the supplement itself is not either.  Use the following checklist to evaluate a supplement’s quality:

For all supplements, check for the following:

r  The manufacturer’s name and address are on the label. 

r  There is an expiration date.

r  The product is not expired.

r  The lot number and manufacturer’s contact information are clearly visible. 

r  The font is such that a person with poor eyesight can read it.

r  The label makes an appropriate structure/function claim (and it should not claim to cure, treat, or prevent disease).  Examples include “Promotes immune function” or “Supports digestive health.”

r  It is clear what ingredients are in the product.  Some labels may be in another language, which can be a challenge.  Be cautious when a label simply reads “Proprietary blend” and does not break down the amounts of individual ingredients.

r  The label makes it clear what type of formulation (tincture, infusion, extract, pills, capsules) the product is.

r  The numbers of tabs or capsules, or the volume, is clear.

r  This item does not mislead the buyer by requiring multiple pills to get a full ‘serving.’

r  There is a “Supplement Facts” section that makes it is clear how much of each ingredient is in the product, both in terms of active ingredients and excipients (additives).  These might include corn, soy, and wheat, which some people must avoid. 

r  What is in the supplement is actually the same as what has been studied (both in terms of dose and chemical form).

r  There is a symbol on the package indicating third-party certification from groups like the United States Pharmacopeia that indicates more rigorous quality testing was done.  (This is rare.)

r  The price of this supplement is reasonable. 

For herbal remedies, also check the following criteria:

r  Latin names (Genus, species, and subspecies as appropriate) are given for the plants used.  This is especially important for Chinese and Ayurvedic remedies.

r  It is possible to tell how the ingredients were standardized (e.g., St. John’s wort “standardized to 3-5% hyperforin”).

r  One can tell which part(s) of plants were used (e.g., leaves, roots/rhizomes, flowers).

r  The herbs being used make sense in terms of what the supplement is supposed to do.

r  For tinctures (liquid solutions), labels should contain a ratio of how many kg of herb there are per liter of solvent (or ounce to ounce).  Most are between 1:2 and 1:5.

r  For extracts (solutions where some or all of the solvent is evaporated off) the label should include the marker compound and the percentage standardization.  (e.g., “Gingko biloba, 50:1 standardized extract with 6% terpene lactones.”  50:1 means 50 grams of the original plant material has been concentrated into 1 gram of solid extract.)

Dietary Supplement Resources


Whole Health Library Website

Other Websites

  • An Evidence Based Approach to Phytochemicals and Other Dietary Factors, Jane Higdon (2012)
  • An Evidence Based Approach to Vitamins and Minerals: Health Benefits and Intake Recommendations, Jane Higdon (2011)
  • Clinical Botanical Medicine: Revised & Expanded, Eric Yarnell & Kathy Abascal (2009)
  • Clinical Natural Medicines Handbook, Chris Meletis (2008)
  • Dietary Supplements, 4th edition, Pamela Mason (2011)
  • Herb Contraindications and Drug Interactions, Francis Brinker (2010)
  • Herb, Nutrient, and Drug Interactions: Clinical Implications and Therapeutic Strategies, Mitchell Stargrove, et al. (2008)
  • National Geographic Guide to Medicinal Herbs, Tieraona Low Dog, et al. (2010)
  • Principles and Practice of Phytotherapy: Modern Herbal Medicine, 2nd edition, Kerry Bone & Simon Mills (2013)
  • Rational Phytotherapy, Volker Schulz, et al. (2004)
  • The H.E.R.B.A.L.  Guide: Dietary Supplement Resources for the Clinician, Robert Bonakdar (2010)
  • The Supplement Handbook: A Trusted Expert’s Guide to What Works & What’s Worthless for More than 100 Conditions, Mark Moyad & Janet Lee (2014)
  • Economic Botany
  • HerbalGram
  • Journal of Ethnopharmacology
  • Journal of Herbal Pharmacotherapy
  • Phytomedicine