What are supplements?
A supplement is a concentrated ingredient that is added to the diet for nutritional or therapeutic benefits. Examples of supplements include vitamins, minerals, amino acids, herbs, botanicals, and enzymes. There is a great deal of confusion around the terminology of food additives, and sometimes terms are used interchangeably. For clarity, the following terminology will be used in this handout.
Dietary supplements or dietary nutrients are substances that are added to a food, usually to make it nutritionally complete and balanced. Therapeutic supplements, also called nutraceuticals or animal health supplements, are foods or food nutrients that are taken orally to provide a health benefit, either for the prevention or the treatment of disease. To have this therapeutic effect, a nutraceutical is usually taken at a larger dose than the daily requirement of that same ingredient when used as a nutrient.
How do I find out what a supplement is used for?
You may learn about supplements from a friend, a retail store employee, the internet, an advertisement in the media, or from a health care provider. Sometimes, this information may be incomplete or biased. Information that comes from the internet or other written sources may or may not be accurate or complete, depending on who has prepared the information.
"The least biased information comes from publications that have some regulatory control."
Some published information about a nutraceutical may be biased, especially if the information source is the manufacturer or product retailer. The least biased information comes from publications that have some regulatory control (e.g., they are regulated by a federal government agency). For example, a database of herbal products is available at https://phytochem.nal.usda.gov/phytochem/search/ that lists general uses and the reference sources for these uses. Another good source of information about supplements and manufacturer quality is www.consumerlab.com.
With respect to vitamins, minerals, amino acids, fatty acids, and other nutrients, some information can be found in standard nutrition textbooks. However, these sources may provide outdated information and may only include well-recognized and well-documented indications for specific nutrients. These sources may also discuss supplements as a nutritional requirement, rather than their role as a nutraceutical.
How do I know if a supplement is effective?
Very few supplements or herbs have been subjected to rigorous scientific trials to determine their efficacy. Some supplements have been thoroughly researched in humans, but not animal species. Indeed, much information about supplements comes from anecdotal or testimonial evidence (someone tells you about their personal experience or about another patient who showed some benefit when taking the product). Although this information may be helpful, it may also be incomplete and may not indicate the effects the supplement could have on your pet.
"It is common for supplements to be given to a patient along with other supplements, or in conjunction with other lifestyle changes."
It is common for supplements to be given to a patient along with other supplements, or in conjunction with other lifestyle changes. In these cases, it can be difficult to sort out exactly what effects can be attributed to the supplement and what can be attributed to other factors, especially if multiple changes were made simultaneously. For example, if a patient starts to take supplement Y, and at the same time changes their diet and starts an exercise program, then the observed changes may be due to any one of the factors, to a combination of all three, or even to a placebo effect.
To further complicate the issue of effectiveness, some supplements are only effective after they have been given for a period of time, and the patient may continue to show some of the positive effects for a few weeks after the supplement has been discontinued. An example of this situation is when glucosamine is used to ease the symptoms of arthritis. It may take approximately 4–8 weeks to show its effects and can take the same amount of time to “wear off” after it has been discontinued.
How do I know if a supplement is safe to use for my pet?
Just because a product is natural does not mean that it is safe. All medicines and medicinal plants are potentially toxic if used inappropriately or given at high doses. Supplements can also have side effects, just like pharmaceuticals. Your veterinarian is the best source of information about the safety of supplements in domestic animals.
Because the use of supplements and nutraceuticals in veterinary medicine is a relatively recent practice, some veterinarians may be unfamiliar with the indications and precautions surrounding the use of various products. Fortunately, reliable information about the clinical application of supplements is becoming increasingly available for veterinarians.
Some privately maintained websites, such as www.ahvma.org, provide brief information and links to other relevant sites. Another way to gather information about the use of a supplement in a certain species or for a certain disease is to consult the manufacturer of the product. If there is reliable information about the product's safety and efficacy in animals, the manufacturer should be able to provide you with it. If the manufacturer is unwilling to provide this information, it is safer for your pet if you err on the side of caution and do not use the product.
What is quality assurance or quality control?
Quality control provides a measure of assurance about what a product contains (medicinal ingredients and purity). Not all distributors share the same concerns about ensuring their products are high quality and free of contaminants, contain consistent levels of active ingredients, and retain their potency after processing. Frequently, herbal supplements may not even contain the same species of plant as listed on the label. For example, a 1991 article in the Canadian Pharmacology Journal estimated that 50% of the Echinacea products sold in the US between 1908 and 1991 contained a plant referred to as Missouri snakeroot.
Are there any regulations for packaging of supplements?
With pharmaceutical products, the manufacturer is governed by strict legislation about contents and labeling. In North America, supplements, nutraceuticals, and herbs are not considered pharmaceuticals and in most cases are not considered to be foods either. The FDA requires that all ingredients in a pharmaceutical or food be listed, and that none of these products be recognized as a potential health threat. The FDA also requires that unsubstantiated claims are not made regarding the ability of a product to treat a disease.
"The consumer must become informed about the integrity and ethics of the manufacturer to obtain any measure of assurance that the product is effective and unadulterated."
Unfortunately, because many natural health products and supplements are not considered pharmaceuticals, they are not regulated and therefore do not have to meet the same strict requirements. However, the FDA does require that non-pharmaceuticals contain a disclaimer saying, “This product is not intended to diagnose, treat, cure or prevent any disease.”
Because of this lack of control, there is no guarantee of the package contents or product strength. The consumer must become informed about the integrity and ethics of the manufacturer to obtain any measure of assurance that the product is effective and unadulterated.
What should I look for on a label or package?
Every package should have the name and contact information of the product’s manufacturer. It should contain information about the product's contents, ideally with a minimum analysis of the active ingredients. It should also contain information about any inert or carrier substances that are present, such as milk, sugar, whey, and vegetable or animal proteins. When the label includes the USP seal in a prominent location, the product contents have been evaluated to ensure the listed ingredients are accurate.
For herbal products, the label should also include the Latin name of the plant, a harvest date or an expiration date, the part of the herb used, and the quantity of active constituents.
Who can give me advice about treating my pet with a supplement?
Your best source of professional nutritional advice is a licensed veterinarian who is knowledgeable about the supplement and about alternative medicine. Veterinarians have been trained about the anatomy and physiology of animals and are expected to be knowledgeable about the treatments they prescribe, including toxicity and predictable side effects.
What should I do if my pet shows an unexpected reaction to a supplement?
Unexpected reactions must always be reported to your veterinarian or the person who recommended the supplement, and to the manufacturer. There are often government agencies that collect and collate this information, and it is strongly recommended that you also inform these agencies of your concerns.
