Dietary Supplements

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A well balanced diet often satisfies your body’s needs, yet nutritional deficiencies can still occur in people maintaining a healthy diet.    This discussion is intended as a first look at some tips for consumers seeking reliable information about dietary supplements, whether or not these products have been recommended by a health professional.  Awareness of at least a few key points to remember and recommended resources for those choosing such products are the soundest advice we can offer.

Some definitions and other background information

 The U.S. Food and Drug Administration (FDA) definition of dietary supplements is products intended for ingestion that contain a “dietary ingredient” intended to add further nutritional value to (supplement) the diet.   A “dietary ingredient” may be one, or any combination, of the following substances:

  • a vitamin
  • a mineral
  • an herb or other botanical
  • an amino acid
  • a dietary substance for use by people to supplement the diet by increasing the total dietary intake of that substance
  • a concentrate, metabolite, constituent, or extract

Dietary supplements are sold in many forms such as tablets, capsules, softgels, gelcaps, liquids, or powders.  Some dietary supplements help to ensure an adequate dietary intake of essential nutrients such as vitamins, minerals or amino acids.  Others may help reduce your risk of disease. Supplements are classified as dietary supplements by the U.S. Dietary Supplement Health and Education Act (DSHEA) of 1994. Under this act, supplements, unlike prescription drugs, can be sold over the counter without being tested to prove they are safe and/or effective.   Click here to read more from the FDA about DSHEA and other information for consumers of dietary supplements.

Sometimes a dietary supplement contains just one or a very few specific ingredients; for example, calcium + Vitamin D + trace amounts of other substances needed to formulate the ingredients into a pill that you can swallow and then will dissolve in and be absorbed from your gastrointestinal tract.   That is, at least the label reports the contents as containing those ingredients (read more on labeling later in this topic).  Herbs, botanicals, extracts, and concentrates of plants [and animals]—whether advertised as supplements or more for health or wellness—can contain dozens if not hundreds of different ingredients, many of them having some type of biologically active ingredients.

The National Institutes of Health reports that more than 50% of Americans take one or more dietary supplements daily (https://newsinhealth.nih.gov/issue/aug2013/feature1).  Many viewers will also be interested to learn that a 2010 survey showed that even at that time 73% of Canadians were regularly taking natural health products like vitamins and minerals, herbal products, and homeopathic medicines.   It is not too surprising, therefore, that Canada has taken a very pro-active approach to assessing safety and regulating these types of products [see for example http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php].

All Natural!  But does that necessarily mean All Safe? Key point #1

If someone says it “must be OK” to consume minerals or other supplements derived from natural sources or other natural products because “they do not contain chemicals” this is simply not true.  Everything contains chemicals!  Plants—as well as our bodies—are made of chemicals.  It is the dose of a chemical that makes it poisonous or acceptable to consume.  Many “natural” things are extremely toxic if sufficient quantities are consumed; for example, consumption of certain beautiful appearing mushrooms that contain toxins can result in symptoms that vary from slight gastrointestinal discomfort to  death.  (See ToxTopics “All Natural! All Safe? Everything is a Chemical” and “Basics of Dose and Exposure”)

Regulation and testing of dietary supplements and herbal medicines Key point #2

The US FDA does not regulate dietary supplements as they do therapeutic drugs.  This is not to suggest that the FDA is not concerned about the safety of these consumer products.  The FDA can only take action against a dietary supplement after it reaches the market if a problem is brought to their attention, typically, because the product is adulterated or contaminated in some fashion. If a manufacturer wants to sell a new dietary ingredient, they must notify the FDA prior to putting it on the market. However, it is just a notification and does not mean that the FDA has determined that the use of the new dietary ingredient is either efficacious or safe.  FDA’s regulatory power over dietary supplements falls into two categories: 1) failure to operate under cGMP [current Good Manufacturing Practices] or 2) if a product is shown to be adulterated or contaminated.

Beware of potential for unidentified substances in these products – Key point #3

Adulterated in the broadest sense means to make impure by intentionally adding extraneous, improper, or inferior ingredients.  A product can also contain unintentional contaminants, like trace heavy metals or pesticides, if not manufactured properly.   The issue of potentially harmful impurities present in dietary supplements is one that even reasonably knowledgeable consumers appear to be unaware of.

USP

Some quality products can be identified by the presence of a“USP Verified” seal on the label.  This means the USP  (U.S. Pharmacopeial Convention) has sampled and tested a batch of that product for identity, strength, quality, and purity.    This USP initiative is pertinent to establishing standards for dietary supplements.    For more detail on this important initiative click here.    These standards are used in more than 140 countries, and are enforceable in the United States by the FDA.  On the other hand, dietary supplement companies are not required to follow USP quality standards.

For more on adulteration, viewers are referred to the Society of Toxicology’s “Dietary Supplement Adulteration and Impact on Human Health,” (https://www.toxicology.org/script/admin/toxtopics/120036_PM_Dietary.pdf).

Don’t believe everything you hear!  Be wary of ads promoting use of dietary supplements and consult a professional with knowledge of the subject – Key point #4

Countless provocative, intriguing, sometimes-conflicting and otherwise engaging videos and other websites can be found about both the benefits and the dangers related to dietary supplements. This advice may be obvious, but as with all information on the web and other popular sources, carefully consider the source of information, possible conflicts of interest, and the strength of evidence the claim is based upon.  Ask for evidence!  Are statements backed up by any reliable scientific evidence?  Is there a long history of safe and effective use of that product?  

Regardless of the training and medical philosophy of  the  health professionals you may consult about using these products, you will benefit more if you include all dietary supplements and also herbal remedies in your reporting on “medications” that you are taking.   Also report any changes in your health—whether bad or good–that you think might be related to intake of these products.  Sometimes when a product seems to be helping, a person may be inclined to increase their intake.  However, in many cases consuming even more than a recommended dose can be very harmful.  Always remember the first principle of toxicology:  It is the dose that makes the poison!

Restrict use to products that have been shown to be effective and safe if used appropriately.    It is always advisable to seek objective information offered by scientists and medical professionals working with authoritative entities.  Several of the more helpful government sources of information for consumers are shown below within other recommended resources.  The World Health Organization and the Centers for Disease Control and Prevention websites also address issues related to dietary supplements. (will hot link to main pages of those entities; excellent)

So what is the bottom line here?

 Some physicians and other health professionals say that most dietary supplements [excluding essential vitamins, minerals and amino acids] do not fulfill claims related health, well-being, diseases or death.  Some even suggest use of certain supplements may do more harm than good (http://www.scientificamerican.com/article/multivitamins-are-a-waste-of-money-doctors-say/; http://www.scientificamerican.com/article/fact-or-fiction-vitamin-supplements-improve-health/

 On the other hand, there is also evidence that a dietary supplement may be beneficial if the “right” product is used for the right reasons, taken in proper doses, and monitored by someone with knowledge of the product and possible adverse issues that could arise.  For example, taking proper doses of an appropriate iron supplement could improve a case of iron deficiency anemia.  Or, if a bone density scan clearly reveals that you are at increased risk for developing osteoporosis, then taking a calcium supplement + Vitamin D on the advice of a knowledgeable medical professional makes good sense.  Many would agree that it is best in most cases to try to resolve deficiencies through changes in your regular diet, but sometimes that isn’t possible.

Other recommended resources

Health Canada

Two of Health Canada’s websites are excellent resources:   The Compendium of Monographs website (http://www.hc-sc.gc.ca/dhp-mps/prodnatur/applications/licen-prod/monograph/index-eng.php) makes it easy to search for information about a specific ingredient you may see on a label for a natural or non-prescription health product, and (http://healthycanadians.gc.ca/recall-alert-rappel-avis/index-eng.php?cat=3 ) provides existing safety alerts for all products, including herbal products.

A third resource is a general webpage for the pre-market licensing group for natural health products  http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php

US FDA on dietary supplements

This website is both interesting and informative, offering a Q&A approach to educating consumers about dietary supplements.   http://www.fda.gov/Food/DietarySupplements/UsingDietarySupplements/ucm480069.htm   A few of the questions covered include what producers of these products are obliged to report to the FDA about their product’s safety; tips for searching the web for information about dietary supplements and other ways the consumer can inform themselves better when deciding what to purchase and use.

National Institutes of Health

A wealth of information on herbal supplements, vitamins and minerals can be found at https://sis.nlm.nih.gov/enviro/dietarysupplements.html

 

Related Tox Topics:   All Natural!  All Safe?  Everything is a Chemical, Basics of Dose and Exposure

 

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