The Dietary Supplement Health Education Act (DSHEA) of 1994 defines a dietary supplement as
Dietary supplements are the most commonly used complementary and alternative therapies in the world. They are widely available, relatively inexpensive and can be purchased without the need to visit a healthcare practitioner. Everywhere in the world dietary supplements are regulated differently than drugs. In general, there are quality control and manufacturing regulations, but not regulations ensuring the standardization of active ingredients or their efficacy.
Labelling and Regulation
The standards for dietary supplements and their registration varies widely throughout the world. In the United States the requirements are relatively lax whereby the DSHEA requires that product labels identify the product as a dietary supplement and state that the claims for the supplement have not been evaluated by the Food and Drug Administration (FDA). The FDA is now in the process of creating the Office of Dietary Supplement Programs (ODSP), which should increase the regulation of the dietary supplement market in the US. In Canada, supplements are defined as Natural Health Product and are under the regulation of the Natural and Non-prescription Health Products Directorate (NNHPD). In Canada each manufacturer is required to submit a dossier to the NNHPD for evaluation, unlike in the US, they do evaluate the health claims of each and every health product or dietary supplement that is available for consumers. European legislation is also different, the European Union has laws which predetermine the allowed health claims for each ingredient or combinations of ingredients in dietary supplements. However, nowhere are manufacturers permitted to imply or make claims that their product can be used to treat or diagnose and condition or disease.
Safety and Efficacy
Dietary supplements come from natural sources and are generally supported by centuries of use in various systems of traditional medicine around the world, therefore most people assume that dietary supplements are both safe and efficacious for their intended conditions. Supplements are not required to go through the rigorous clinical trials and research that drugs have to go through. They do have to have a history of safety and use in systems of traditional medicine. This is slowly changing, as the dietary supplement market is maturing, consumers are increasingly critical and educated about what they are taking and consuming and the supplement industry has been responding. Increasingly rigorous clinical research is being conducted into the efficacy of dietary supplements and their components and evidence to the safety and efficacy is rapidly accumulating. This is especially true for serious manufacturers of raw materials and for well-known supplements such as glucosamine, fish oil, etc. Most of this research is readily available for the consumer in various formats. It is highly recommended that any serious producer or consumer of dietary supplements do their research and educate themselves on the what it is they are using.
Purity and Standardization
Unlike drugs, dietary supplements are not regulated to ensure that they are that they contain the active ingredients or the amounts of active ingredients claimed. The quantity of the active ingredients in the supplement may vary or may not be known, especially when herbs or their extracts are used to produce the final product. This problem is being solved with standardization. Standardization requires that each individual dose of the supplement in question contains the same amount of active ingredient, regardless of it being a tablet, capsule, or liquid. Another consideration is that most herbal products are a mixture of several components making it difficult to know exactly what ingredient is the most active and making standardization difficult. However, ongoing research into herbal supplements and plant extracts is reducing this problem and slowly unravelling the main active components in make plants.
There is varied expert advice on how to choose a quality dietary supplement. However, it is always recommended to buy products from a reputable and established manufacturer with a track record of quality products. It may also be better to buy products that are produced in places such as Canada and the European Union which have more stringent regulations regarding the production of dietary supplements.
Dietary supplements, just like prescription and non-prescription drugs, can have serious interactions with each other, as well as with prescription and non-prescription drugs, and even foods. These interactions may amplify or diminish the effects of one or the other substances that one may be taking, leading to potentially serious side effects or make a medicine that one is taking ineffective. Both of these results can have severe consequences for the user. If one is regularly taking medication it is strongly advised to talk to their doctor before starting a supplement regimen.
To illustrate this point, here are a few examples of interactions between dietary supplements and medications. Supplements containing ginseng or ginseng extracts interfere with certain classes of anticoagulant drugs, making them ineffective. If Echinacea is taken with another drug that can damage the liver, it increases the risk of liver damage. These drugs include anabolic steroids, methotrexate, and ketoconazole. Even something as mild as chamomile can have drug interactions. Chamomile can reduce iron absorption, it and increase the risk of bleeding when taken with anticoagulants, and it may increase or prolong the effects of sedatives such as barbituates and benzodiazapines.
From these examples, the need to talk to your healthcare practitioner before starting a supplement regimen should be clear. It is also important to note that it is important to disclose any supplements that one is taking if their doctor is about to prescribe a drugs therapy.